diff --git a/ChangeLog b/ChangeLog
index 839cefd..5739517 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -47,6 +47,14 @@
      in favour a new generic error MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA.
    * Deprecate the Blowfish error MBEDTLS_ERR_BLOWFISH_INVALID_KEY_LENGTH
      in favour of a new generic error MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA.
+   * Add validation checks for input parameters to functions in the CCM module.
+   * Add validation checks for input parameters to functions in the GCM module.
+   * Add validation checks for input parameters to functions in the SHA-1
+     module.
+   * Add validation checks for input parameters to functions in the SHA-256
+     module.
+   * Add validation checks for input parameters to functions in the SHA-512
+     module.
    * Add validation checks for input parameters to functions in the Cipher
      module.
 
diff --git a/include/mbedtls/aes.h b/include/mbedtls/aes.h
index 11edc0f..b42e564 100644
--- a/include/mbedtls/aes.h
+++ b/include/mbedtls/aes.h
@@ -197,8 +197,10 @@
  *                 sets the encryption key.
  *
  * \param ctx      The AES XTS context to which the key should be bound.
+ *                 It must be initialized.
  * \param key      The encryption key. This is comprised of the XTS key1
  *                 concatenated with the XTS key2.
+ *                 This must be a readable buffer of size \p keybits bits.
  * \param keybits  The size of \p key passed in bits. Valid options are:
  *                 <ul><li>256 bits (each of key1 and key2 is a 128-bit key)</li>
  *                 <li>512 bits (each of key1 and key2 is a 256-bit key)</li></ul>
@@ -215,8 +217,10 @@
  *                 sets the decryption key.
  *
  * \param ctx      The AES XTS context to which the key should be bound.
+ *                 It must be initialized.
  * \param key      The decryption key. This is comprised of the XTS key1
  *                 concatenated with the XTS key2.
+ *                 This must be a readable buffer of size \p keybits bits.
  * \param keybits  The size of \p key passed in bits. Valid options are:
  *                 <ul><li>256 bits (each of key1 and key2 is a 128-bit key)</li>
  *                 <li>512 bits (each of key1 and key2 is a 256-bit key)</li></ul>
@@ -242,10 +246,13 @@
  *                 call to this API with the same context.
  *
  * \param ctx      The AES context to use for encryption or decryption.
+ *                 It must be initialized and bound to a key.
  * \param mode     The AES operation: #MBEDTLS_AES_ENCRYPT or
  *                 #MBEDTLS_AES_DECRYPT.
- * \param input    The 16-Byte buffer holding the input data.
- * \param output   The 16-Byte buffer holding the output data.
+ * \param input    The buffer holding the input data.
+ *                 It must be readable and at least \c 16 Bytes long.
+ * \param output   The buffer where the output data will be written.
+ *                 It must be writeable and at least \c 16 Bytes long.
 
  * \return         \c 0 on success.
  */
@@ -268,8 +275,8 @@
  *         mbedtls_aes_setkey_enc() or mbedtls_aes_setkey_dec() must be called
  *         before the first call to this API with the same context.
  *
- * \note   This function operates on aligned blocks, that is, the input size
- *         must be a multiple of the AES block size of 16 Bytes.
+ * \note   This function operates on full blocks, that is, the input size
+ *         must be a multiple of the AES block size of \c 16 Bytes.
  *
  * \note   Upon exit, the content of the IV is updated so that you can
  *         call the same function again on the next
@@ -280,13 +287,17 @@
  *
  *
  * \param ctx      The AES context to use for encryption or decryption.
+ *                 It must be initialized and bound to a key.
  * \param mode     The AES operation: #MBEDTLS_AES_ENCRYPT or
  *                 #MBEDTLS_AES_DECRYPT.
  * \param length   The length of the input data in Bytes. This must be a
- *                 multiple of the block size (16 Bytes).
+ *                 multiple of the block size (\c 16 Bytes).
  * \param iv       Initialization vector (updated after use).
+ *                 It must be a readable and writeable buffer of \c 16 Bytes.
  * \param input    The buffer holding the input data.
+ *                 It must be readable and of size \p length Bytes.
  * \param output   The buffer holding the output data.
+ *                 It must be writeable and of size \p length Bytes.
  *
  * \return         \c 0 on success.
  * \return         #MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH
@@ -314,9 +325,10 @@
  *             returns #MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH.
  *
  * \param ctx          The AES XTS context to use for AES XTS operations.
+ *                     It must be initialized and bound to a key.
  * \param mode         The AES operation: #MBEDTLS_AES_ENCRYPT or
  *                     #MBEDTLS_AES_DECRYPT.
- * \param length       The length of a data unit in bytes. This can be any
+ * \param length       The length of a data unit in Bytes. This can be any
  *                     length between 16 bytes and 2^24 bytes inclusive
  *                     (between 1 and 2^20 block cipher blocks).
  * \param data_unit    The address of the data unit encoded as an array of 16
@@ -324,15 +336,15 @@
  *                     is typically the index of the block device sector that
  *                     contains the data.
  * \param input        The buffer holding the input data (which is an entire
- *                     data unit). This function reads \p length bytes from \p
+ *                     data unit). This function reads \p length Bytes from \p
  *                     input.
  * \param output       The buffer holding the output data (which is an entire
- *                     data unit). This function writes \p length bytes to \p
+ *                     data unit). This function writes \p length Bytes to \p
  *                     output.
  *
  * \return             \c 0 on success.
  * \return             #MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH if \p length is
- *                     smaller than an AES block in size (16 bytes) or if \p
+ *                     smaller than an AES block in size (16 Bytes) or if \p
  *                     length is larger than 2^20 blocks (16 MiB).
  */
 int mbedtls_aes_crypt_xts( mbedtls_aes_xts_context *ctx,
@@ -368,13 +380,18 @@
  *
  *
  * \param ctx      The AES context to use for encryption or decryption.
+ *                 It must be initialized and bound to a key.
  * \param mode     The AES operation: #MBEDTLS_AES_ENCRYPT or
  *                 #MBEDTLS_AES_DECRYPT.
- * \param length   The length of the input data.
+ * \param length   The length of the input data in Bytes.
  * \param iv_off   The offset in IV (updated after use).
+ *                 It must point to a valid \c size_t.
  * \param iv       The initialization vector (updated after use).
+ *                 It must be a readable and writeable buffer of \c 16 Bytes.
  * \param input    The buffer holding the input data.
+ *                 It must be readable and of size \p length Bytes.
  * \param output   The buffer holding the output data.
+ *                 It must be writeable and of size \p length Bytes.
  *
  * \return         \c 0 on success.
  */
@@ -409,12 +426,16 @@
  *
  *
  * \param ctx      The AES context to use for encryption or decryption.
+ *                 It must be initialized and bound to a key.
  * \param mode     The AES operation: #MBEDTLS_AES_ENCRYPT or
  *                 #MBEDTLS_AES_DECRYPT
  * \param length   The length of the input data.
  * \param iv       The initialization vector (updated after use).
+ *                 It must be a readable and writeable buffer of \c 16 Bytes.
  * \param input    The buffer holding the input data.
+ *                 It must be readable and of size \p length Bytes.
  * \param output   The buffer holding the output data.
+ *                 It must be writeable and of size \p length Bytes.
  *
  * \return         \c 0 on success.
  */
@@ -459,11 +480,16 @@
  *              will compromise security.
  *
  * \param ctx      The AES context to use for encryption or decryption.
+ *                 It must be initialized and bound to a key.
  * \param length   The length of the input data.
  * \param iv_off   The offset in IV (updated after use).
+ *                 It must point to a valid \c size_t.
  * \param iv       The initialization vector (updated after use).
+ *                 It must be a readable and writeable buffer of \c 16 Bytes.
  * \param input    The buffer holding the input data.
+ *                 It must be readable and of size \p length Bytes.
  * \param output   The buffer holding the output data.
+ *                 It must be writeable and of size \p length Bytes.
  *
  * \return         \c 0 on success.
  */
@@ -535,15 +561,21 @@
  *             securely discarded as soon as it's no longer needed.
  *
  * \param ctx              The AES context to use for encryption or decryption.
+ *                         It must be initialized and bound to a key.
  * \param length           The length of the input data.
  * \param nc_off           The offset in the current \p stream_block, for
  *                         resuming within the current cipher stream. The
  *                         offset pointer should be 0 at the start of a stream.
+ *                         It must point to a valid \c size_t.
  * \param nonce_counter    The 128-bit nonce and counter.
+ *                         It must be a readable-writeable buffer of \c 16 Bytes.
  * \param stream_block     The saved stream block for resuming. This is
  *                         overwritten by the function.
+ *                         It must be a readable-writeable buffer of \c 16 Bytes.
  * \param input            The buffer holding the input data.
+ *                         It must be readable and of size \p length Bytes.
  * \param output           The buffer holding the output data.
+ *                         It must be writeable and of size \p length Bytes.
  *
  * \return                 \c 0 on success.
  */
@@ -596,7 +628,7 @@
  * \brief           Deprecated internal AES block encryption function
  *                  without return value.
  *
- * \deprecated      Superseded by mbedtls_aes_encrypt_ext() in 2.5.0.
+ * \deprecated      Superseded by mbedtls_internal_aes_encrypt()
  *
  * \param ctx       The AES context to use for encryption.
  * \param input     Plaintext block.
@@ -610,7 +642,7 @@
  * \brief           Deprecated internal AES block decryption function
  *                  without return value.
  *
- * \deprecated      Superseded by mbedtls_aes_decrypt_ext() in 2.5.0.
+ * \deprecated      Superseded by mbedtls_internal_aes_decrypt()
  *
  * \param ctx       The AES context to use for decryption.
  * \param input     Ciphertext block.
diff --git a/include/mbedtls/aesni.h b/include/mbedtls/aesni.h
index 746baa0..0196f49 100644
--- a/include/mbedtls/aesni.h
+++ b/include/mbedtls/aesni.h
@@ -2,6 +2,9 @@
  * \file aesni.h
  *
  * \brief AES-NI for hardware AES acceleration on some Intel processors
+ *
+ * \warning These functions are only for internal use by other library
+ *          functions; you must not call them directly.
  */
 /*
  *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
@@ -42,7 +45,10 @@
 #endif
 
 /**
- * \brief          AES-NI features detection routine
+ * \brief          Internal function to detect the AES-NI feature in CPUs.
+ *
+ * \note           This function is only for internal use by other library
+ *                 functions; you must not call it directly.
  *
  * \param what     The feature to detect
  *                 (MBEDTLS_AESNI_AES or MBEDTLS_AESNI_CLMUL)
@@ -52,7 +58,10 @@
 int mbedtls_aesni_has_support( unsigned int what );
 
 /**
- * \brief          AES-NI AES-ECB block en(de)cryption
+ * \brief          Internal AES-NI AES-ECB block encryption and decryption
+ *
+ * \note           This function is only for internal use by other library
+ *                 functions; you must not call it directly.
  *
  * \param ctx      AES context
  * \param mode     MBEDTLS_AES_ENCRYPT or MBEDTLS_AES_DECRYPT
@@ -62,12 +71,15 @@
  * \return         0 on success (cannot fail)
  */
 int mbedtls_aesni_crypt_ecb( mbedtls_aes_context *ctx,
-                     int mode,
-                     const unsigned char input[16],
-                     unsigned char output[16] );
+                             int mode,
+                             const unsigned char input[16],
+                             unsigned char output[16] );
 
 /**
- * \brief          GCM multiplication: c = a * b in GF(2^128)
+ * \brief          Internal GCM multiplication: c = a * b in GF(2^128)
+ *
+ * \note           This function is only for internal use by other library
+ *                 functions; you must not call it directly.
  *
  * \param c        Result
  * \param a        First operand
@@ -77,21 +89,29 @@
  *                 elements of GF(2^128) as per the GCM spec.
  */
 void mbedtls_aesni_gcm_mult( unsigned char c[16],
-                     const unsigned char a[16],
-                     const unsigned char b[16] );
+                             const unsigned char a[16],
+                             const unsigned char b[16] );
 
 /**
- * \brief           Compute decryption round keys from encryption round keys
+ * \brief           Internal round key inversion. This function computes
+ *                  decryption round keys from the encryption round keys.
+ *
+ * \note            This function is only for internal use by other library
+ *                  functions; you must not call it directly.
  *
  * \param invkey    Round keys for the equivalent inverse cipher
  * \param fwdkey    Original round keys (for encryption)
  * \param nr        Number of rounds (that is, number of round keys minus one)
  */
 void mbedtls_aesni_inverse_key( unsigned char *invkey,
-                        const unsigned char *fwdkey, int nr );
+                                const unsigned char *fwdkey,
+                                int nr );
 
 /**
- * \brief           Perform key expansion (for encryption)
+ * \brief           Internal key expansion for encryption
+ *
+ * \note            This function is only for internal use by other library
+ *                  functions; you must not call it directly.
  *
  * \param rk        Destination buffer where the round keys are written
  * \param key       Encryption key
@@ -100,8 +120,8 @@
  * \return          0 if successful, or MBEDTLS_ERR_AES_INVALID_KEY_LENGTH
  */
 int mbedtls_aesni_setkey_enc( unsigned char *rk,
-                      const unsigned char *key,
-                      size_t bits );
+                              const unsigned char *key,
+                              size_t bits );
 
 #ifdef __cplusplus
 }
diff --git a/include/mbedtls/aria.h b/include/mbedtls/aria.h
index c80c9fd..1e8956e 100644
--- a/include/mbedtls/aria.h
+++ b/include/mbedtls/aria.h
@@ -91,14 +91,16 @@
  *                 It must be the first API called before using
  *                 the context.
  *
- * \param ctx      The ARIA context to initialize.
+ * \param ctx      The ARIA context to initialize. This must not be \c NULL.
  */
 void mbedtls_aria_init( mbedtls_aria_context *ctx );
 
 /**
  * \brief          This function releases and clears the specified ARIA context.
  *
- * \param ctx      The ARIA context to clear.
+ * \param ctx      The ARIA context to clear. This may be \c NULL, in which
+ *                 case this function returns immediately. If it is not \c NULL,
+ *                 it must point to an initialized ARIA context.
  */
 void mbedtls_aria_free( mbedtls_aria_context *ctx );
 
@@ -106,14 +108,16 @@
  * \brief          This function sets the encryption key.
  *
  * \param ctx      The ARIA context to which the key should be bound.
- * \param key      The encryption key.
- * \param keybits  The size of data passed in bits. Valid options are:
+ *                 This must be initialized.
+ * \param key      The encryption key. This must be a readable buffer
+ *                 of size \p keybits Bits.
+ * \param keybits  The size of \p key in Bits. Valid options are:
  *                 <ul><li>128 bits</li>
  *                 <li>192 bits</li>
  *                 <li>256 bits</li></ul>
  *
- * \return         \c 0 on success or #MBEDTLS_ERR_ARIA_BAD_INPUT_DATA
- *                 on failure.
+ * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_aria_setkey_enc( mbedtls_aria_context *ctx,
                              const unsigned char *key,
@@ -123,13 +127,16 @@
  * \brief          This function sets the decryption key.
  *
  * \param ctx      The ARIA context to which the key should be bound.
- * \param key      The decryption key.
+ *                 This must be initialized.
+ * \param key      The decryption key. This must be a readable buffer
+ *                 of size \p keybits Bits.
  * \param keybits  The size of data passed. Valid options are:
  *                 <ul><li>128 bits</li>
  *                 <li>192 bits</li>
  *                 <li>256 bits</li></ul>
  *
- * \return         \c 0 on success, or #MBEDTLS_ERR_ARIA_BAD_INPUT_DATA on failure.
+ * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_aria_setkey_dec( mbedtls_aria_context *ctx,
                              const unsigned char *key,
@@ -148,10 +155,12 @@
  *                 call to this API with the same context.
  *
  * \param ctx      The ARIA context to use for encryption or decryption.
+ *                 This must be initialized and bound to a key.
  * \param input    The 16-Byte buffer holding the input data.
  * \param output   The 16-Byte buffer holding the output data.
 
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_aria_crypt_ecb( mbedtls_aria_context *ctx,
                             const unsigned char input[MBEDTLS_ARIA_BLOCKSIZE],
@@ -183,16 +192,21 @@
  *
  *
  * \param ctx      The ARIA context to use for encryption or decryption.
- * \param mode     The ARIA operation: #MBEDTLS_ARIA_ENCRYPT or
- *                 #MBEDTLS_ARIA_DECRYPT.
+ *                 This must be initialized and bound to a key.
+ * \param mode     The mode of operation. This must be either
+ *                 #MBEDTLS_ARIA_ENCRYPT for encryption, or
+ *                 #MBEDTLS_ARIA_DECRYPT for decryption.
  * \param length   The length of the input data in Bytes. This must be a
  *                 multiple of the block size (16 Bytes).
  * \param iv       Initialization vector (updated after use).
- * \param input    The buffer holding the input data.
- * \param output   The buffer holding the output data.
+ *                 This must be a readable buffer of size 16 Bytes.
+ * \param input    The buffer holding the input data. This must
+ *                 be a readable buffer of length \p length Bytes.
+ * \param output   The buffer holding the output data. This must
+ *                 be a writable buffer of length \p length Bytes.
  *
- * \return         \c 0 on success, or #MBEDTLS_ERR_ARIA_INVALID_INPUT_LENGTH
- *                 on failure.
+ * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_aria_crypt_cbc( mbedtls_aria_context *ctx,
                             int mode,
@@ -227,15 +241,22 @@
  *
  *
  * \param ctx      The ARIA context to use for encryption or decryption.
- * \param mode     The ARIA operation: #MBEDTLS_ARIA_ENCRYPT or
- *                 #MBEDTLS_ARIA_DECRYPT.
- * \param length   The length of the input data.
+ *                 This must be initialized and bound to a key.
+ * \param mode     The mode of operation. This must be either
+ *                 #MBEDTLS_ARIA_ENCRYPT for encryption, or
+ *                 #MBEDTLS_ARIA_DECRYPT for decryption.
+ * \param length   The length of the input data \p input in Bytes.
  * \param iv_off   The offset in IV (updated after use).
+ *                 This must not be larger than 15.
  * \param iv       The initialization vector (updated after use).
- * \param input    The buffer holding the input data.
- * \param output   The buffer holding the output data.
+ *                 This must be a readable buffer of size 16 Bytes.
+ * \param input    The buffer holding the input data. This must
+ *                 be a readable buffer of length \p length Bytes.
+ * \param output   The buffer holding the output data. This must
+ *                 be a writable buffer of length \p length Bytes.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_aria_crypt_cfb128( mbedtls_aria_context *ctx,
                                int mode,
@@ -305,17 +326,24 @@
  *             securely discarded as soon as it's no longer needed.
  *
  * \param ctx              The ARIA context to use for encryption or decryption.
- * \param length           The length of the input data.
- * \param nc_off           The offset in the current \p stream_block, for
- *                         resuming within the current cipher stream. The
- *                         offset pointer should be 0 at the start of a stream.
- * \param nonce_counter    The 128-bit nonce and counter.
- * \param stream_block     The saved stream block for resuming. This is
- *                         overwritten by the function.
- * \param input            The buffer holding the input data.
- * \param output           The buffer holding the output data.
+ *                         This must be initialized and bound to a key.
+ * \param length           The length of the input data \p input in Bytes.
+ * \param nc_off           The offset in Bytes in the current \p stream_block,
+ *                         for resuming within the current cipher stream. The
+ *                         offset pointer should be \c 0 at the start of a
+ *                         stream. This must not be larger than \c 15 Bytes.
+ * \param nonce_counter    The 128-bit nonce and counter. This must point to
+ *                         a read/write buffer of length \c 16 bytes.
+ * \param stream_block     The saved stream block for resuming. This must
+ *                         point to a read/write buffer of length \c 16 bytes.
+ *                         This is overwritten by the function.
+ * \param input            The buffer holding the input data. This must
+ *                         be a readable buffer of length \p length Bytes.
+ * \param output           The buffer holding the output data. This must
+ *                         be a writable buffer of length \p length Bytes.
  *
- * \return     \c 0 on success.
+ * \return                 \c 0 on success.
+ * \return                 A negative error code on failure.
  */
 int mbedtls_aria_crypt_ctr( mbedtls_aria_context *ctx,
                             size_t length,
diff --git a/include/mbedtls/blowfish.h b/include/mbedtls/blowfish.h
index 922d8f8..f01573d 100644
--- a/include/mbedtls/blowfish.h
+++ b/include/mbedtls/blowfish.h
@@ -76,40 +76,53 @@
 #endif /* MBEDTLS_BLOWFISH_ALT */
 
 /**
- * \brief          Initialize Blowfish context
+ * \brief          Initialize a Blowfish context.
  *
- * \param ctx      Blowfish context to be initialized
+ * \param ctx      The Blowfish context to be initialized.
+ *                 This must not be \c NULL.
  */
 void mbedtls_blowfish_init( mbedtls_blowfish_context *ctx );
 
 /**
- * \brief          Clear Blowfish context
+ * \brief          Clear a Blowfish context.
  *
- * \param ctx      Blowfish context to be cleared
+ * \param ctx      The Blowfish context to be cleared.
+ *                 This may be \c NULL, in which case this function
+ *                 returns immediately. If it is not \c NULL, it must
+ *                 point to an initialized Blowfish context.
  */
 void mbedtls_blowfish_free( mbedtls_blowfish_context *ctx );
 
 /**
- * \brief          Blowfish key schedule
+ * \brief          Perform a Blowfish key schedule operation.
  *
- * \param ctx      Blowfish context to be initialized
- * \param key      encryption key
- * \param keybits  must be between 32 and 448 bits
+ * \param ctx      The Blowfish context to perform the key schedule on.
+ * \param key      The encryption key. This must be a readable buffer of
+ *                 length \p keybits Bits.
+ * \param keybits  The length of \p key in Bits. This must be between
+ *                 \c 32 and \c 448 and a multiple of \c 8.
  *
- * \return         0 if successful, or MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA
+ * \return         \c 0 if successful.
+ * \return         A negative error code on failure.
  */
 int mbedtls_blowfish_setkey( mbedtls_blowfish_context *ctx, const unsigned char *key,
                      unsigned int keybits );
 
 /**
- * \brief          Blowfish-ECB block encryption/decryption
+ * \brief          Perform a Blowfish-ECB block encryption/decryption operation.
  *
- * \param ctx      Blowfish context
- * \param mode     MBEDTLS_BLOWFISH_ENCRYPT or MBEDTLS_BLOWFISH_DECRYPT
- * \param input    8-byte input block
- * \param output   8-byte output block
+ * \param ctx      The Blowfish context to use. This must be initialized
+ *                 and bound to a key.
+ * \param mode     The mode of operation. Possible values are
+ *                 #MBEDTLS_BLOWFISH_ENCRYPT for encryption, or
+ *                 #MBEDTLS_BLOWFISH_DECRYPT for decryption.
+ * \param input    The input block. This must be a readable buffer
+ *                 of size \c 8 Bytes.
+ * \param output   The output block. This must be a writable buffer
+ *                 of size \c 8 Bytes.
  *
- * \return         0 if successful
+ * \return         \c 0 if successful.
+ * \return         A negative error code on failure.
  */
 int mbedtls_blowfish_crypt_ecb( mbedtls_blowfish_context *ctx,
                         int mode,
@@ -118,9 +131,7 @@
 
 #if defined(MBEDTLS_CIPHER_MODE_CBC)
 /**
- * \brief          Blowfish-CBC buffer encryption/decryption
- *                 Length should be a multiple of the block
- *                 size (8 bytes)
+ * \brief          Perform a Blowfish-CBC buffer encryption/decryption operation.
  *
  * \note           Upon exit, the content of the IV is updated so that you can
  *                 call the function same function again on the following
@@ -130,15 +141,22 @@
  *                 IV, you should either save it manually or use the cipher
  *                 module instead.
  *
- * \param ctx      Blowfish context
- * \param mode     MBEDTLS_BLOWFISH_ENCRYPT or MBEDTLS_BLOWFISH_DECRYPT
- * \param length   length of the input data
- * \param iv       initialization vector (updated after use)
- * \param input    buffer holding the input data
- * \param output   buffer holding the output data
+ * \param ctx      The Blowfish context to use. This must be initialized
+ *                 and bound to a key.
+ * \param mode     The mode of operation. Possible values are
+ *                 #MBEDTLS_BLOWFISH_ENCRYPT for encryption, or
+ *                 #MBEDTLS_BLOWFISH_DECRYPT for decryption.
+ * \param length   The length of the input data in Bytes. This must be
+ *                 multiple of \c 8.
+ * \param iv       The initialization vector. This must be a read/write buffer
+ *                 of length \c 8 Bytes. It is updated by this function.
+ * \param input    The input data. This must be a readable buffer of length
+ *                 \p length Bytes.
+ * \param output   The output data. This must be a writable buffer of length
+ *                 \p length Bytes.
  *
- * \return         0 if successful, or
- *                 MBEDTLS_ERR_BLOWFISH_INVALID_INPUT_LENGTH
+ * \return         \c 0 if successful.
+ * \return         A negative error code on failure.
  */
 int mbedtls_blowfish_crypt_cbc( mbedtls_blowfish_context *ctx,
                         int mode,
@@ -150,7 +168,7 @@
 
 #if defined(MBEDTLS_CIPHER_MODE_CFB)
 /**
- * \brief          Blowfish CFB buffer encryption/decryption.
+ * \brief          Perform a Blowfish CFB buffer encryption/decryption operation.
  *
  * \note           Upon exit, the content of the IV is updated so that you can
  *                 call the function same function again on the following
@@ -160,15 +178,25 @@
  *                 IV, you should either save it manually or use the cipher
  *                 module instead.
  *
- * \param ctx      Blowfish context
- * \param mode     MBEDTLS_BLOWFISH_ENCRYPT or MBEDTLS_BLOWFISH_DECRYPT
- * \param length   length of the input data
- * \param iv_off   offset in IV (updated after use)
- * \param iv       initialization vector (updated after use)
- * \param input    buffer holding the input data
- * \param output   buffer holding the output data
+ * \param ctx      The Blowfish context to use. This must be initialized
+ *                 and bound to a key.
+ * \param mode     The mode of operation. Possible values are
+ *                 #MBEDTLS_BLOWFISH_ENCRYPT for encryption, or
+ *                 #MBEDTLS_BLOWFISH_DECRYPT for decryption.
+ * \param length   The length of the input data in Bytes.
+ * \param iv_off   The offset in the initialiation vector.
+ *                 The value pointed to must be smaller than \c 8 Bytes.
+ *                 It is updated by this function to support the aforementioned
+ *                 streaming usage.
+ * \param iv       The initialization vector. This must be a read/write buffer
+ *                 of size \c 8 Bytes. It is updated after use.
+ * \param input    The input data. This must be a readable buffer of length
+ *                 \p length Bytes.
+ * \param output   The output data. This must be a writable buffer of length
+ *                 \p length Bytes.
  *
- * \return         0 if successful
+ * \return         \c 0 if successful.
+ * \return         A negative error code on failure.
  */
 int mbedtls_blowfish_crypt_cfb64( mbedtls_blowfish_context *ctx,
                           int mode,
@@ -181,7 +209,7 @@
 
 #if defined(MBEDTLS_CIPHER_MODE_CTR)
 /**
- * \brief               Blowfish-CTR buffer encryption/decryption
+ * \brief      Perform a Blowfish-CTR buffer encryption/decryption operation.
  *
  * \warning    You must never reuse a nonce value with the same key. Doing so
  *             would void the encryption for the two messages encrypted with
@@ -224,18 +252,24 @@
  *             content must not be written to insecure storage and should be
  *             securely discarded as soon as it's no longer needed.
  *
- * \param ctx           Blowfish context
- * \param length        The length of the data
+ * \param ctx           The Blowfish context to use. This must be initialized
+ *                      and bound to a key.
+ * \param length        The length of the input data in Bytes.
  * \param nc_off        The offset in the current stream_block (for resuming
- *                      within current cipher stream). The offset pointer to
- *                      should be 0 at the start of a stream.
- * \param nonce_counter The 64-bit nonce and counter.
- * \param stream_block  The saved stream-block for resuming. Is overwritten
- *                      by the function.
- * \param input         The input data stream
- * \param output        The output data stream
+ *                      within current cipher stream). The offset pointer
+ *                      should be \c 0 at the start of a stream and must be
+ *                      smaller than \c 8. It is updated by this function.
+ * \param nonce_counter The 64-bit nonce and counter. This must point to a
+ *                      read/write buffer of length \c 8 Bytes.
+ * \param stream_block  The saved stream-block for resuming. This must point to
+ *                      a read/write buffer of length \c 8 Bytes.
+ * \param input         The input data. This must be a readable buffer of
+ *                      length \p length Bytes.
+ * \param output        The output data. This must be a writable buffer of
+ *                      length \p length Bytes.
  *
- * \return         0 if successful
+ * \return              \c 0 if successful.
+ * \return              A negative error code on failure.
  */
 int mbedtls_blowfish_crypt_ctr( mbedtls_blowfish_context *ctx,
                         size_t length,
diff --git a/include/mbedtls/camellia.h b/include/mbedtls/camellia.h
index 0a02335..0f7c42c 100644
--- a/include/mbedtls/camellia.h
+++ b/include/mbedtls/camellia.h
@@ -72,52 +72,68 @@
 #endif /* MBEDTLS_CAMELLIA_ALT */
 
 /**
- * \brief          Initialize CAMELLIA context
+ * \brief          Initialize a CAMELLIA context.
  *
- * \param ctx      CAMELLIA context to be initialized
+ * \param ctx      The CAMELLIA context to be initialized.
+ *                 This must not be \c NULL.
  */
 void mbedtls_camellia_init( mbedtls_camellia_context *ctx );
 
 /**
- * \brief          Clear CAMELLIA context
+ * \brief          Clear a CAMELLIA context.
  *
- * \param ctx      CAMELLIA context to be cleared
+ * \param ctx      The CAMELLIA context to be cleared. This may be \c NULL,
+ *                 in which case this function returns immediately. If it is not
+ *                 \c NULL, it must be initialized.
  */
 void mbedtls_camellia_free( mbedtls_camellia_context *ctx );
 
 /**
- * \brief          CAMELLIA key schedule (encryption)
+ * \brief          Perform a CAMELLIA key schedule operation for encryption.
  *
- * \param ctx      CAMELLIA context to be initialized
- * \param key      encryption key
- * \param keybits  must be 128, 192 or 256
+ * \param ctx      The CAMELLIA context to use. This must be initialized.
+ * \param key      The encryption key to use. This must be a readable buffer
+ *                 of size \p keybits Bits.
+ * \param keybits  The length of \p key in Bits. This must be either \c 128,
+ *                 \c 192 or \c 256.
  *
- * \return         0 if successful, or MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA
+ * \return         \c 0 if successful.
+ * \return         A negative error code on failure.
  */
-int mbedtls_camellia_setkey_enc( mbedtls_camellia_context *ctx, const unsigned char *key,
-                         unsigned int keybits );
+int mbedtls_camellia_setkey_enc( mbedtls_camellia_context *ctx,
+                                 const unsigned char *key,
+                                 unsigned int keybits );
 
 /**
- * \brief          CAMELLIA key schedule (decryption)
+ * \brief          Perform a CAMELLIA key schedule operation for decryption.
  *
- * \param ctx      CAMELLIA context to be initialized
- * \param key      decryption key
- * \param keybits  must be 128, 192 or 256
+ * \param ctx      The CAMELLIA context to use. This must be initialized.
+ * \param key      The decryption key. This must be a readable buffer
+ *                 of size \p keybits Bits.
+ * \param keybits  The length of \p key in Bits. This must be either \c 128,
+ *                 \c 192 or \c 256.
  *
- * \return         0 if successful, or MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA
+ * \return         \c 0 if successful.
+ * \return         A negative error code on failure.
  */
-int mbedtls_camellia_setkey_dec( mbedtls_camellia_context *ctx, const unsigned char *key,
-                         unsigned int keybits );
+int mbedtls_camellia_setkey_dec( mbedtls_camellia_context *ctx,
+                                 const unsigned char *key,
+                                 unsigned int keybits );
 
 /**
- * \brief          CAMELLIA-ECB block encryption/decryption
+ * \brief          Perform a CAMELLIA-ECB block encryption/decryption operation.
  *
- * \param ctx      CAMELLIA context
- * \param mode     MBEDTLS_CAMELLIA_ENCRYPT or MBEDTLS_CAMELLIA_DECRYPT
- * \param input    16-byte input block
- * \param output   16-byte output block
+ * \param ctx      The CAMELLIA context to use. This must be initialized
+ *                 and bound to a key.
+ * \param mode     The mode of operation. This must be either
+ *                 #MBEDTLS_CAMELLIA_ENCRYPT or #MBEDTLS_CAMELLIA_DECRYPT.
+ * \param input    The input block. This must be a readable buffer
+ *                 of size \c 16 Bytes.
+ * \param output   The output block. This must be a writable buffer
+ *                 of size \c 16 Bytes.
  *
- * \return         0 if successful
+ * \return         \c 0 if successful.
+ * \return         A negative error code on failure.
  */
 int mbedtls_camellia_crypt_ecb( mbedtls_camellia_context *ctx,
                     int mode,
@@ -126,9 +142,7 @@
 
 #if defined(MBEDTLS_CIPHER_MODE_CBC)
 /**
- * \brief          CAMELLIA-CBC buffer encryption/decryption
- *                 Length should be a multiple of the block
- *                 size (16 bytes)
+ * \brief          Perform a CAMELLIA-CBC buffer encryption/decryption operation.
  *
  * \note           Upon exit, the content of the IV is updated so that you can
  *                 call the function same function again on the following
@@ -138,15 +152,22 @@
  *                 IV, you should either save it manually or use the cipher
  *                 module instead.
  *
- * \param ctx      CAMELLIA context
- * \param mode     MBEDTLS_CAMELLIA_ENCRYPT or MBEDTLS_CAMELLIA_DECRYPT
- * \param length   length of the input data
- * \param iv       initialization vector (updated after use)
- * \param input    buffer holding the input data
- * \param output   buffer holding the output data
+ * \param ctx      The CAMELLIA context to use. This must be initialized
+ *                 and bound to a key.
+ * \param mode     The mode of operation. This must be either
+ *                 #MBEDTLS_CAMELLIA_ENCRYPT or #MBEDTLS_CAMELLIA_DECRYPT.
+ * \param length   The length in Bytes of the input data \p input.
+ *                 This must be a multiple of \c 16 Bytes.
+ * \param iv       The initialization vector. This must be a read/write buffer
+ *                 of length \c 16 Bytes. It is updated to allow streaming
+ *                 use as explained above.
+ * \param input    The buffer holding the input data. This must point to a
+ *                 readable buffer of length \p length Bytes.
+ * \param output   The buffer holding the output data. This must point to a
+ *                 writable buffer of length \p length Bytes.
  *
- * \return         0 if successful, or
- *                 MBEDTLS_ERR_CAMELLIA_INVALID_INPUT_LENGTH
+ * \return         \c 0 if successful.
+ * \return         A negative error code on failure.
  */
 int mbedtls_camellia_crypt_cbc( mbedtls_camellia_context *ctx,
                     int mode,
@@ -158,11 +179,14 @@
 
 #if defined(MBEDTLS_CIPHER_MODE_CFB)
 /**
- * \brief          CAMELLIA-CFB128 buffer encryption/decryption
+ * \brief          Perform a CAMELLIA-CFB128 buffer encryption/decryption
+ *                 operation.
  *
- * Note: Due to the nature of CFB you should use the same key schedule for
- * both encryption and decryption. So a context initialized with
- * mbedtls_camellia_setkey_enc() for both MBEDTLS_CAMELLIA_ENCRYPT and CAMELLIE_DECRYPT.
+ * \note           Due to the nature of CFB mode, you should use the same
+ *                 key for both encryption and decryption. In particular, calls
+ *                 to this function should be preceded by a key-schedule via
+ *                 mbedtls_camellia_setkey_enc() regardless of whether \p mode
+ *                 is #MBEDTLS_CAMELLIA_ENCRYPT or #MBEDTLS_CAMELLIA_DECRYPT.
  *
  * \note           Upon exit, the content of the IV is updated so that you can
  *                 call the function same function again on the following
@@ -172,16 +196,24 @@
  *                 IV, you should either save it manually or use the cipher
  *                 module instead.
  *
- * \param ctx      CAMELLIA context
- * \param mode     MBEDTLS_CAMELLIA_ENCRYPT or MBEDTLS_CAMELLIA_DECRYPT
- * \param length   length of the input data
- * \param iv_off   offset in IV (updated after use)
- * \param iv       initialization vector (updated after use)
- * \param input    buffer holding the input data
- * \param output   buffer holding the output data
+ * \param ctx      The CAMELLIA context to use. This must be initialized
+ *                 and bound to a key.
+ * \param mode     The mode of operation. This must be either
+ *                 #MBEDTLS_CAMELLIA_ENCRYPT or #MBEDTLS_CAMELLIA_DECRYPT.
+ * \param length   The length of the input data \p input. Any value is allowed.
+ * \param iv_off   The current offset in the IV. This must be smaller
+ *                 than \c 16 Bytes. It is updated after this call to allow
+ *                 the aforementioned streaming usage.
+ * \param iv       The initialization vector. This must be a read/write buffer
+ *                 of length \c 16 Bytes. It is updated after this call to
+ *                 allow the aforementioned streaming usage.
+ * \param input    The buffer holding the input data. This must be a readable
+ *                 buffer of size \p length Bytes.
+ * \param output   The buffer to hold the output data. This must be a writable
+ *                 buffer of length \p length Bytes.
  *
- * \return         0 if successful, or
- *                 MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA.
+ * \return         \c 0 if successful.
+ * \return         A negative error code on failure.
  */
 int mbedtls_camellia_crypt_cfb128( mbedtls_camellia_context *ctx,
                        int mode,
@@ -194,11 +226,13 @@
 
 #if defined(MBEDTLS_CIPHER_MODE_CTR)
 /**
- * \brief               CAMELLIA-CTR buffer encryption/decryption
+ * \brief      Perform a CAMELLIA-CTR buffer encryption/decryption operation.
  *
- * Note: Due to the nature of CTR you should use the same key schedule for
- * both encryption and decryption. So a context initialized with
- * mbedtls_camellia_setkey_enc() for both MBEDTLS_CAMELLIA_ENCRYPT and MBEDTLS_CAMELLIA_DECRYPT.
+ * *note       Due to the nature of CTR mode, you should use the same
+ *             key for both encryption and decryption. In particular, calls
+ *             to this function should be preceded by a key-schedule via
+ *             mbedtls_camellia_setkey_enc() regardless of whether \p mode
+ *             is #MBEDTLS_CAMELLIA_ENCRYPT or #MBEDTLS_CAMELLIA_DECRYPT.
  *
  * \warning    You must never reuse a nonce value with the same key. Doing so
  *             would void the encryption for the two messages encrypted with
@@ -221,41 +255,49 @@
  *             per-message nonce, handled by yourself, and the second one
  *             updated by this function internally.
  *
- *             For example, you might reserve the first 12 bytes for the
- *             per-message nonce, and the last 4 bytes for internal use. In that
- *             case, before calling this function on a new message you need to
- *             set the first 12 bytes of \p nonce_counter to your chosen nonce
- *             value, the last 4 to 0, and \p nc_off to 0 (which will cause \p
- *             stream_block to be ignored). That way, you can encrypt at most
- *             2**96 messages of up to 2**32 blocks each with the same key.
+ *             For example, you might reserve the first \c 12 Bytes for the
+ *             per-message nonce, and the last \c 4 Bytes for internal use.
+ *             In that case, before calling this function on a new message you
+ *             need to set the first \c 12 Bytes of \p nonce_counter to your
+ *             chosen nonce value, the last four to \c 0, and \p nc_off to \c 0
+ *             (which will cause \p stream_block to be ignored). That way, you
+ *             can encrypt at most \c 2**96 messages of up to \c 2**32 blocks
+ *             each  with the same key.
  *
  *             The per-message nonce (or information sufficient to reconstruct
- *             it) needs to be communicated with the ciphertext and must be unique.
- *             The recommended way to ensure uniqueness is to use a message
- *             counter. An alternative is to generate random nonces, but this
- *             limits the number of messages that can be securely encrypted:
- *             for example, with 96-bit random nonces, you should not encrypt
- *             more than 2**32 messages with the same key.
+ *             it) needs to be communicated with the ciphertext and must be
+ *             unique. The recommended way to ensure uniqueness is to use a
+ *             message counter. An alternative is to generate random nonces,
+ *             but this limits the number of messages that can be securely
+ *             encrypted: for example, with 96-bit random nonces, you should
+ *             not encrypt more than 2**32 messages with the same key.
  *
  *             Note that for both stategies, sizes are measured in blocks and
- *             that a CAMELLIA block is 16 bytes.
+ *             that a CAMELLIA block is \c 16 Bytes.
  *
  * \warning    Upon return, \p stream_block contains sensitive data. Its
  *             content must not be written to insecure storage and should be
  *             securely discarded as soon as it's no longer needed.
  *
- * \param ctx           CAMELLIA context
- * \param length        The length of the data
- * \param nc_off        The offset in the current stream_block (for resuming
+ * \param ctx           The CAMELLIA context to use. This must be initialized
+ *                      and bound to a key.
+ * \param length        The length of the input data \p input in Bytes.
+ *                      Any value is allowed.
+ * \param nc_off        The offset in the current \p stream_block (for resuming
  *                      within current cipher stream). The offset pointer to
- *                      should be 0 at the start of a stream.
- * \param nonce_counter The 128-bit nonce and counter.
- * \param stream_block  The saved stream-block for resuming. Is overwritten
- *                      by the function.
- * \param input         The input data stream
- * \param output        The output data stream
+ *                      should be \c 0 at the start of a stream. It is updated
+ *                      at the end of this call.
+ * \param nonce_counter The 128-bit nonce and counter. This must be a read/write
+ *                      buffer of length \c 16 Bytes.
+ * \param stream_block  The saved stream-block for resuming. This must be a
+ *                      read/write buffer of length \c 16 Bytes.
+ * \param input         The input data stream. This must be a readable buffer of
+ *                      size \p length Bytes.
+ * \param output        The output data stream. This must be a writable buffer
+ *                      of size \p length Bytes.
  *
- * \return         0 if successful
+ * \return              \c 0 if successful.
+ * \return              A negative error code on failure.
  */
 int mbedtls_camellia_crypt_ctr( mbedtls_camellia_context *ctx,
                        size_t length,
diff --git a/include/mbedtls/ccm.h b/include/mbedtls/ccm.h
index dfb1b5e..3f6b8f6 100644
--- a/include/mbedtls/ccm.h
+++ b/include/mbedtls/ccm.h
@@ -57,7 +57,6 @@
 /* MBEDTLS_ERR_CCM_HW_ACCEL_FAILED is deprecated and should not be used. */
 #define MBEDTLS_ERR_CCM_HW_ACCEL_FAILED -0x0011 /**< CCM hardware accelerator failed. */
 
-
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -85,7 +84,7 @@
  *                  to make references valid, and prepare the context
  *                  for mbedtls_ccm_setkey() or mbedtls_ccm_free().
  *
- * \param ctx       The CCM context to initialize.
+ * \param ctx       The CCM context to initialize. This must not be \c NULL.
  */
 void mbedtls_ccm_init( mbedtls_ccm_context *ctx );
 
@@ -93,9 +92,10 @@
  * \brief           This function initializes the CCM context set in the
  *                  \p ctx parameter and sets the encryption key.
  *
- * \param ctx       The CCM context to initialize.
+ * \param ctx       The CCM context to initialize. This must be an initialized
+ *                  context.
  * \param cipher    The 128-bit block cipher to use.
- * \param key       The encryption key.
+ * \param key       The encryption key. This must not be \c NULL.
  * \param keybits   The key size in bits. This must be acceptable by the cipher.
  *
  * \return          \c 0 on success.
@@ -110,7 +110,8 @@
  * \brief   This function releases and clears the specified CCM context
  *          and underlying cipher sub-context.
  *
- * \param ctx       The CCM context to clear.
+ * \param ctx       The CCM context to clear. If this is \c NULL, the function
+ *                  has no effect. Otherwise, this must be initialized.
  */
 void mbedtls_ccm_free( mbedtls_ccm_context *ctx );
 
@@ -123,19 +124,27 @@
  *                  \p tag = \p output + \p length, and make sure that the
  *                  output buffer is at least \p length + \p tag_len wide.
  *
- * \param ctx       The CCM context to use for encryption.
+ * \param ctx       The CCM context to use for encryption. This must be
+ *                  initialized and bound to a key.
  * \param length    The length of the input data in Bytes.
- * \param iv        Initialization vector (nonce).
+ * \param iv        The initialization vector (nonce). This must be a readable
+ *                  buffer of at least \p iv_len Bytes.
  * \param iv_len    The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12,
  *                  or 13. The length L of the message length field is
  *                  15 - \p iv_len.
- * \param add       The additional data field.
+ * \param add       The additional data field. If \p add_len is greater than
+ *                  zero, \p add must be a readable buffer of at least that
+ *                  length.
  * \param add_len   The length of additional data in Bytes.
- *                  Must be less than 2^16 - 2^8.
- * \param input     The buffer holding the input data.
- * \param output    The buffer holding the output data.
- *                  Must be at least \p length Bytes wide.
- * \param tag       The buffer holding the authentication field.
+ *                  This must be less than `2^16 - 2^8`.
+ * \param input     The buffer holding the input data. If \p length is greater
+ *                  than zero, \p input must be a readable buffer of at least
+ *                  that length.
+ * \param output    The buffer holding the output data. If \p length is greater
+ *                  than zero, \p output must be a writable buffer of at least
+ *                  that length.
+ * \param tag       The buffer holding the authentication field. This must be a
+ *                  readable buffer of at least \p tag_len Bytes.
  * \param tag_len   The length of the authentication field to generate in Bytes:
  *                  4, 6, 8, 10, 12, 14 or 16.
  *
@@ -161,23 +170,30 @@
  *                  the tag length has to be encoded into the \p iv passed to
  *                  this function.
  *
- * \param ctx       The CCM context to use for encryption.
+ * \param ctx       The CCM context to use for encryption. This must be
+ *                  initialized and bound to a key.
  * \param length    The length of the input data in Bytes.
- * \param iv        Initialization vector (nonce).
+ * \param iv        The initialization vector (nonce). This must be a readable
+ *                  buffer of at least \p iv_len Bytes.
  * \param iv_len    The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12,
  *                  or 13. The length L of the message length field is
  *                  15 - \p iv_len.
- * \param add       The additional data field.
+ * \param add       The additional data field. This must be a readable buffer of
+ *                  at least \p add_len Bytes.
  * \param add_len   The length of additional data in Bytes.
- *                  Must be less than 2^16 - 2^8.
- * \param input     The buffer holding the input data.
- * \param output    The buffer holding the output data.
- *                  Must be at least \p length Bytes wide.
- * \param tag       The buffer holding the authentication field.
+ *                  This must be less than 2^16 - 2^8.
+ * \param input     The buffer holding the input data. If \p length is greater
+ *                  than zero, \p input must be a readable buffer of at least
+ *                  that length.
+ * \param output    The buffer holding the output data. If \p length is greater
+ *                  than zero, \p output must be a writable buffer of at least
+ *                  that length.
+ * \param tag       The buffer holding the authentication field. This must be a
+ *                  readable buffer of at least \p tag_len Bytes.
  * \param tag_len   The length of the authentication field to generate in Bytes:
  *                  0, 4, 6, 8, 10, 12, 14 or 16.
  *
- * \warning         Passing 0 as \p tag_len means that the message is no
+ * \warning         Passing \c 0 as \p tag_len means that the message is no
  *                  longer authenticated.
  *
  * \return          \c 0 on success.
@@ -193,20 +209,27 @@
  * \brief           This function performs a CCM authenticated decryption of a
  *                  buffer.
  *
- * \param ctx       The CCM context to use for decryption.
+ * \param ctx       The CCM context to use for decryption. This must be
+ *                  initialized and bound to a key.
  * \param length    The length of the input data in Bytes.
- * \param iv        Initialization vector (nonce).
+ * \param iv        The initialization vector (nonce). This must be a readable
+ *                  buffer of at least \p iv_len Bytes.
  * \param iv_len    The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12,
  *                  or 13. The length L of the message length field is
  *                  15 - \p iv_len.
- * \param add       The additional data field.
+ * \param add       The additional data field. This must be a readable buffer
+ *                  of at least that \p add_len Bytes..
  * \param add_len   The length of additional data in Bytes.
- *                  Must be less than 2^16 - 2^8.
- * \param input     The buffer holding the input data.
- * \param output    The buffer holding the output data.
- *                  Must be at least \p length Bytes wide.
- * \param tag       The buffer holding the authentication field.
- * \param tag_len   The length of the authentication field in Bytes.
+ *                  This must be less than 2^16 - 2^8.
+ * \param input     The buffer holding the input data. If \p length is greater
+ *                  than zero, \p input must be a readable buffer of at least
+ *                  that length.
+ * \param output    The buffer holding the output data. If \p length is greater
+ *                  than zero, \p output must be a writable buffer of at least
+ *                  that length.
+ * \param tag       The buffer holding the authentication field. This must be a
+ *                  readable buffer of at least \p tag_len Bytes.
+ * \param tag_len   The length of the authentication field to generate in Bytes:
  *                  4, 6, 8, 10, 12, 14 or 16.
  *
  * \return          \c 0 on success. This indicates that the message is authentic.
@@ -228,23 +251,30 @@
  *                  this function as \p tag_len. (\p tag needs to be adjusted
  *                  accordingly.)
  *
- * \param ctx       The CCM context to use for decryption.
+ * \param ctx       The CCM context to use for decryption. This must be
+ *                  initialized and bound to a key.
  * \param length    The length of the input data in Bytes.
- * \param iv        Initialization vector (nonce).
+ * \param iv        The initialization vector (nonce). This must be a readable
+ *                  buffer of at least \p iv_len Bytes.
  * \param iv_len    The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12,
  *                  or 13. The length L of the message length field is
  *                  15 - \p iv_len.
- * \param add       The additional data field.
+ * \param add       The additional data field. This must be a readable buffer of
+ *                  at least that \p add_len Bytes.
  * \param add_len   The length of additional data in Bytes.
- *                  Must be less than 2^16 - 2^8.
- * \param input     The buffer holding the input data.
- * \param output    The buffer holding the output data.
- *                  Must be at least \p length Bytes wide.
- * \param tag       The buffer holding the authentication field.
+ *                  This must be less than 2^16 - 2^8.
+ * \param input     The buffer holding the input data. If \p length is greater
+ *                  than zero, \p input must be a readable buffer of at least
+ *                  that length.
+ * \param output    The buffer holding the output data. If \p length is greater
+ *                  than zero, \p output must be a writable buffer of at least
+ *                  that length.
+ * \param tag       The buffer holding the authentication field. This must be a
+ *                  readable buffer of at least \p tag_len Bytes.
  * \param tag_len   The length of the authentication field in Bytes.
  *                  0, 4, 6, 8, 10, 12, 14 or 16.
  *
- * \warning         Passing 0 as \p tag_len means that the message is no
+ * \warning         Passing \c 0 as \p tag_len means that the message is nos
  *                  longer authenticated.
  *
  * \return          \c 0 on success.
diff --git a/include/mbedtls/chacha20.h b/include/mbedtls/chacha20.h
index 529f22d..2ae5e6e 100644
--- a/include/mbedtls/chacha20.h
+++ b/include/mbedtls/chacha20.h
@@ -83,13 +83,18 @@
  *                  \c mbedtls_chacha20_free().
  *
  * \param ctx       The ChaCha20 context to initialize.
+ *                  This must not be \c NULL.
  */
 void mbedtls_chacha20_init( mbedtls_chacha20_context *ctx );
 
 /**
- * \brief           This function releases and clears the specified ChaCha20 context.
+ * \brief           This function releases and clears the specified
+ *                  ChaCha20 context.
  *
- * \param ctx       The ChaCha20 context to clear.
+ * \param ctx       The ChaCha20 context to clear. This may be \c NULL,
+ *                  in which case this function is a no-op. If it is not
+ *                  \c NULL, it must point to an initialized context.
+ *
  */
 void mbedtls_chacha20_free( mbedtls_chacha20_context *ctx );
 
@@ -102,7 +107,9 @@
  *                  \c mbedtls_chacha_update().
  *
  * \param ctx       The ChaCha20 context to which the key should be bound.
- * \param key       The encryption/decryption key. Must be 32 bytes in length.
+ *                  It must be initialized.
+ * \param key       The encryption/decryption key. This must be \c 32 Bytes
+ *                  in length.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA if ctx or key is NULL.
@@ -121,8 +128,9 @@
  *                  messages encrypted with the same nonce and key.
  *
  * \param ctx       The ChaCha20 context to which the nonce should be bound.
- * \param nonce     The nonce. Must be 12 bytes in size.
- * \param counter   The initial counter value. This is usually 0.
+ *                  It must be initialized and bound to a key.
+ * \param nonce     The nonce. This must be \c 12 Bytes in size.
+ * \param counter   The initial counter value. This is usually \c 0.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA if ctx or nonce is
@@ -150,16 +158,16 @@
  *                  key and nonce.
  *
  * \param ctx       The ChaCha20 context to use for encryption or decryption.
- * \param size      The length of the input data in bytes.
+ *                  It must be initialized and bound to a key and nonce.
+ * \param size      The length of the input data in Bytes.
  * \param input     The buffer holding the input data.
- *                  This pointer can be NULL if size == 0.
+ *                  This pointer can be \c NULL if `size == 0`.
  * \param output    The buffer holding the output data.
- *                  Must be able to hold \p size bytes.
- *                  This pointer can be NULL if size == 0.
+ *                  This must be able to hold \p size Bytes.
+ *                  This pointer can be \c NULL if `size == 0`.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA if the ctx, input, or
- *                  output pointers are NULL.
+ * \return          A negative error code on failure.
  */
 int mbedtls_chacha20_update( mbedtls_chacha20_context *ctx,
                              size_t size,
@@ -180,19 +188,19 @@
  * \note            The \p input and \p output pointers must either be equal or
  *                  point to non-overlapping buffers.
  *
- * \param key       The encryption/decryption key. Must be 32 bytes in length.
- * \param nonce     The nonce. Must be 12 bytes in size.
- * \param counter   The initial counter value. This is usually 0.
- * \param size      The length of the input data in bytes.
+ * \param key       The encryption/decryption key.
+ *                  This must be \c 32 Bytes in length.
+ * \param nonce     The nonce. This must be \c 12 Bytes in size.
+ * \param counter   The initial counter value. This is usually \c 0.
+ * \param size      The length of the input data in Bytes.
  * \param input     The buffer holding the input data.
- *                  This pointer can be NULL if size == 0.
+ *                  This pointer can be \c NULL if `size == 0`.
  * \param output    The buffer holding the output data.
- *                  Must be able to hold \p size bytes.
- *                  This pointer can be NULL if size == 0.
+ *                  This must be able to hold \p size Bytes.
+ *                  This pointer can be \c NULL if `size == 0`.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA if key, nonce, input,
- *                  or output is NULL.
+ * \return          A negative error code on failure.
  */
 int mbedtls_chacha20_crypt( const unsigned char key[32],
                             const unsigned char nonce[12],
diff --git a/include/mbedtls/chachapoly.h b/include/mbedtls/chachapoly.h
index 7de6f4e..49e615d 100644
--- a/include/mbedtls/chachapoly.h
+++ b/include/mbedtls/chachapoly.h
@@ -115,27 +115,29 @@
  *                  all previous outputs of \c mbedtls_chachapoly_update(),
  *                  otherwise you can now safely use the plaintext.
  *
- * \param ctx       The ChachaPoly context to initialize.
+ * \param ctx       The ChachaPoly context to initialize. Must not be \c NULL.
  */
 void mbedtls_chachapoly_init( mbedtls_chachapoly_context *ctx );
 
 /**
- * \brief           This function releases and clears the specified ChaCha20-Poly1305 context.
+ * \brief           This function releases and clears the specified
+ *                  ChaCha20-Poly1305 context.
  *
- * \param ctx       The ChachaPoly context to clear.
+ * \param ctx       The ChachaPoly context to clear. This may be \c NULL, in which
+ *                  case this function is a no-op.
  */
 void mbedtls_chachapoly_free( mbedtls_chachapoly_context *ctx );
 
 /**
- * \brief           This function sets the ChaCha20-Poly1305 symmetric encryption key.
+ * \brief           This function sets the ChaCha20-Poly1305
+ *                  symmetric encryption key.
  *
  * \param ctx       The ChaCha20-Poly1305 context to which the key should be
- *                  bound.
- * \param key       The 256-bit (32 bytes) key.
+ *                  bound. This must be initialized.
+ * \param key       The \c 256 Bit (\c 32 Bytes) key.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
- *                  if \p ctx or \p key are NULL.
+ * \return          A negative error code on failure.
  */
 int mbedtls_chachapoly_setkey( mbedtls_chachapoly_context *ctx,
                                const unsigned char key[32] );
@@ -155,14 +157,15 @@
  * \warning         Decryption with the piecewise API is discouraged, see the
  *                  warning on \c mbedtls_chachapoly_init().
  *
- * \param ctx       The ChaCha20-Poly1305 context.
- * \param nonce     The nonce/IV to use for the message. Must be 12 bytes.
+ * \param ctx       The ChaCha20-Poly1305 context. This must be initialized
+ *                  and bound to a key.
+ * \param nonce     The nonce/IV to use for the message.
+ *                  This must be a redable buffer of length \c 12 Bytes.
  * \param mode      The operation to perform: #MBEDTLS_CHACHAPOLY_ENCRYPT or
  *                  #MBEDTLS_CHACHAPOLY_DECRYPT (discouraged, see warning).
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
- *                  if \p ctx or \p mac are NULL.
+ * \return          A negative error code on failure.
  */
 int mbedtls_chachapoly_starts( mbedtls_chachapoly_context *ctx,
                                const unsigned char nonce[12],
@@ -193,11 +196,12 @@
  * \warning         Decryption with the piecewise API is discouraged, see the
  *                  warning on \c mbedtls_chachapoly_init().
  *
- * \param ctx       The ChaCha20-Poly1305 context to use.
- * \param aad_len   The length (in bytes) of the AAD. The length has no
+ * \param ctx       The ChaCha20-Poly1305 context. This must be initialized
+ *                  and bound to a key.
+ * \param aad_len   The length in Bytes of the AAD. The length has no
  *                  restrictions.
  * \param aad       Buffer containing the AAD.
- *                  This pointer can be NULL if aad_len == 0.
+ *                  This pointer can be \c NULL if `aad_len == 0`.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
@@ -227,20 +231,19 @@
  * \warning         Decryption with the piecewise API is discouraged, see the
  *                  warning on \c mbedtls_chachapoly_init().
  *
- * \param ctx       The ChaCha20-Poly1305 context to use.
+ * \param ctx       The ChaCha20-Poly1305 context to use. This must be initialized.
  * \param len       The length (in bytes) of the data to encrypt or decrypt.
  * \param input     The buffer containing the data to encrypt or decrypt.
- *                  This pointer can be NULL if len == 0.
- * \param output    The buffer to where the encrypted or decrypted data is written.
- *                  Must be able to hold \p len bytes.
- *                  This pointer can be NULL if len == 0.
+ *                  This pointer can be \c NULL if `len == 0`.
+ * \param output    The buffer to where the encrypted or decrypted data is
+ *                  written. This must be able to hold \p len bytes.
+ *                  This pointer can be \c NULL if `len == 0`.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
- *                  if \p ctx, \p input, or \p output are NULL.
  * \return          #MBEDTLS_ERR_CHACHAPOLY_BAD_STATE
  *                  if the operation has not been started or has been
  *                  finished.
+ * \return          Another negative error code on other kinds of failure.
  */
 int mbedtls_chachapoly_update( mbedtls_chachapoly_context *ctx,
                                size_t len,
@@ -251,18 +254,17 @@
  * \brief           This function finished the ChaCha20-Poly1305 operation and
  *                  generates the MAC (authentication tag).
  *
- * \param ctx       The ChaCha20-Poly1305 context to use.
+ * \param ctx       The ChaCha20-Poly1305 context to use. This must be initialized.
  * \param mac       The buffer to where the 128-bit (16 bytes) MAC is written.
  *
  * \warning         Decryption with the piecewise API is discouraged, see the
  *                  warning on \c mbedtls_chachapoly_init().
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
- *                  if \p ctx or \p mac are NULL.
  * \return          #MBEDTLS_ERR_CHACHAPOLY_BAD_STATE
  *                  if the operation has not been started or has been
  *                  finished.
+ * \return          Another negative error code on other kinds of failure.
  */
 int mbedtls_chachapoly_finish( mbedtls_chachapoly_context *ctx,
                                unsigned char mac[16] );
@@ -280,20 +282,21 @@
  *                  and key.
  *
  * \param ctx       The ChaCha20-Poly1305 context to use (holds the key).
+ *                  This must be initialized.
  * \param length    The length (in bytes) of the data to encrypt or decrypt.
  * \param nonce     The 96-bit (12 bytes) nonce/IV to use.
- * \param aad       The buffer containing the additional authenticated data (AAD).
- *                  This pointer can be NULL if aad_len == 0.
+ * \param aad       The buffer containing the additional authenticated
+ *                  data (AAD). This pointer can be \c NULL if `aad_len == 0`.
  * \param aad_len   The length (in bytes) of the AAD data to process.
  * \param input     The buffer containing the data to encrypt or decrypt.
- *                  This pointer can be NULL if ilen == 0.
- * \param output    The buffer to where the encrypted or decrypted data is written.
- *                  This pointer can be NULL if ilen == 0.
- * \param tag       The buffer to where the computed 128-bit (16 bytes) MAC is written.
+ *                  This pointer can be \c NULL if `ilen == 0`.
+ * \param output    The buffer to where the encrypted or decrypted data
+ *                  is written. This pointer can be \c NULL if `ilen == 0`.
+ * \param tag       The buffer to where the computed 128-bit (16 bytes) MAC
+ *                  is written. This must not be \c NULL.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
- *                  if one or more of the required parameters are NULL.
+ * \return          A negative error code on failure.
  */
 int mbedtls_chachapoly_encrypt_and_tag( mbedtls_chachapoly_context *ctx,
                                         size_t length,
@@ -312,22 +315,22 @@
  *                  \c mbedtls_chachapoly_setkey().
  *
  * \param ctx       The ChaCha20-Poly1305 context to use (holds the key).
- * \param length    The length (in bytes) of the data to decrypt.
- * \param nonce     The 96-bit (12 bytes) nonce/IV to use.
+ * \param length    The length (in Bytes) of the data to decrypt.
+ * \param nonce     The \c 96 Bit (\c 12 bytes) nonce/IV to use.
  * \param aad       The buffer containing the additional authenticated data (AAD).
- *                  This pointer can be NULL if aad_len == 0.
+ *                  This pointer can be \c NULL if `aad_len == 0`.
  * \param aad_len   The length (in bytes) of the AAD data to process.
  * \param tag       The buffer holding the authentication tag.
+ *                  This must be a readable buffer of length \c 16 Bytes.
  * \param input     The buffer containing the data to decrypt.
- *                  This pointer can be NULL if ilen == 0.
+ *                  This pointer can be \c NULL if `ilen == 0`.
  * \param output    The buffer to where the decrypted data is written.
- *                  This pointer can be NULL if ilen == 0.
+ *                  This pointer can be \c NULL if `ilen == 0`.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
- *                  if one or more of the required parameters are NULL.
  * \return          #MBEDTLS_ERR_CHACHAPOLY_AUTH_FAILED
  *                  if the data was not authentic.
+ * \return          Another negative error code on other kinds of failure.
  */
 int mbedtls_chachapoly_auth_decrypt( mbedtls_chachapoly_context *ctx,
                                      size_t length,
diff --git a/include/mbedtls/dhm.h b/include/mbedtls/dhm.h
index 27e3753..a5452c1 100644
--- a/include/mbedtls/dhm.h
+++ b/include/mbedtls/dhm.h
@@ -127,9 +127,15 @@
 void mbedtls_dhm_init( mbedtls_dhm_context *ctx );
 
 /**
- * \brief          This function parses the ServerKeyExchange parameters.
+ * \brief          This function parses the DHM parameters in a
+ *                 TLS ServerKeyExchange handshake message
+ *                 (DHM modulus, generator, and public key).
  *
- * \param ctx      The DHM context.
+ * \note           In a TLS handshake, this is the how the client
+ *                 sets up its DHM context from the server's public
+ *                 DHM key material.
+ *
+ * \param ctx      The DHM context to use. This must be initialized.
  * \param p        On input, *p must be the start of the input buffer.
  *                 On output, *p is updated to point to the end of the data
  *                 that has been read. On success, this is the first byte
@@ -143,31 +149,37 @@
  * \return         An \c MBEDTLS_ERR_DHM_XXX error code on failure.
  */
 int mbedtls_dhm_read_params( mbedtls_dhm_context *ctx,
-                     unsigned char **p,
-                     const unsigned char *end );
+                             unsigned char **p,
+                             const unsigned char *end );
 
 /**
- * \brief          This function sets up and writes the ServerKeyExchange
- *                 parameters.
+ * \brief          This function generates a DHM key pair and exports its
+ *                 public part together with the DHM parameters in the format
+ *                 used in a TLS ServerKeyExchange handshake message.
  *
- * \note           The destination buffer must be large enough to hold
- *                 the reduced binary presentation of the modulus, the generator
- *                 and the public key, each wrapped with a 2-byte length field.
- *                 It is the responsibility of the caller to ensure that enough
- *                 space is available. Refer to \c mbedtls_mpi_size to computing
- *                 the byte-size of an MPI.
- *
- * \note           This function assumes that \c ctx->P and \c ctx->G
- *                 have already been properly set. For that, use
+ * \note           This function assumes that the DHM parameters \c ctx->P
+ *                 and \c ctx->G have already been properly set. For that, use
  *                 mbedtls_dhm_set_group() below in conjunction with
  *                 mbedtls_mpi_read_binary() and mbedtls_mpi_read_string().
  *
- * \param ctx      The DHM context.
+ * \note           In a TLS handshake, this is the how the server generates
+ *                 and exports its DHM key material.
+ *
+ * \param ctx      The DHM context to use. This must be initialized
+ *                 and have the DHM parameters set. It may or may not
+ *                 already have imported the peer's public key.
  * \param x_size   The private key size in Bytes.
- * \param olen     The number of characters written.
- * \param output   The destination buffer.
- * \param f_rng    The RNG function.
- * \param p_rng    The RNG context.
+ * \param olen     The address at which to store the number of Bytes
+ *                 written on success. This must not be \c NULL.
+ * \param output   The destination buffer. This must be a writable buffer of
+ *                 sufficient size to hold the reduced binary presentation of
+ *                 the modulus, the generator and the public key, each wrapped
+ *                 with a 2-byte length field. It is the responsibility of the
+ *                 caller to ensure that enough space is available. Refer to
+ *                 mbedtls_mpi_size() to computing the byte-size of an MPI.
+ * \param f_rng    The RNG function. Must not be \c NULL.
+ * \param p_rng    The RNG context to be passed to \p f_rng. This may be
+ *                 \c NULL if \p f_rng doesn't need a context parameter.
  *
  * \return         \c 0 on success.
  * \return         An \c MBEDTLS_ERR_DHM_XXX error code on failure.
@@ -180,12 +192,14 @@
 /**
  * \brief          This function sets the prime modulus and generator.
  *
- * \note           This function can be used to set \p P, \p G
+ * \note           This function can be used to set \c ctx->P, \c ctx->G
  *                 in preparation for mbedtls_dhm_make_params().
  *
- * \param ctx      The DHM context.
- * \param P        The MPI holding the DHM prime modulus.
- * \param G        The MPI holding the DHM generator.
+ * \param ctx      The DHM context to configure. This must be initialized.
+ * \param P        The MPI holding the DHM prime modulus. This must be
+ *                 an initialized MPI.
+ * \param G        The MPI holding the DHM generator. This must be an
+ *                 initialized MPI.
  *
  * \return         \c 0 if successful.
  * \return         An \c MBEDTLS_ERR_DHM_XXX error code on failure.
@@ -195,11 +209,17 @@
                            const mbedtls_mpi *G );
 
 /**
- * \brief          This function imports the public value of the peer, G^Y.
+ * \brief          This function imports the raw public value of the peer.
  *
- * \param ctx      The DHM context.
- * \param input    The input buffer containing the G^Y value of the peer.
- * \param ilen     The size of the input buffer.
+ * \note           In a TLS handshake, this is the how the server imports
+ *                 the Client's public DHM key.
+ *
+ * \param ctx      The DHM context to use. This must be initialized and have
+ *                 its DHM parameters set, e.g. via mbedtls_dhm_set_group().
+ *                 It may or may not already have generated its own private key.
+ * \param input    The input buffer containing the \c G^Y value of the peer.
+ *                 This must be a readable buffer of size \p ilen Bytes.
+ * \param ilen     The size of the input buffer \p input in Bytes.
  *
  * \return         \c 0 on success.
  * \return         An \c MBEDTLS_ERR_DHM_XXX error code on failure.
@@ -208,21 +228,25 @@
                      const unsigned char *input, size_t ilen );
 
 /**
- * \brief          This function creates its own private key, \c X, and
- *                 exports \c G^X.
+ * \brief          This function creates a DHM key pair and exports
+ *                 the raw public key in big-endian format.
  *
  * \note           The destination buffer is always fully written
  *                 so as to contain a big-endian representation of G^X mod P.
- *                 If it is larger than ctx->len, it is padded accordingly
+ *                 If it is larger than \c ctx->len, it is padded accordingly
  *                 with zero-bytes at the beginning.
  *
- * \param ctx      The DHM context.
+ * \param ctx      The DHM context to use. This must be initialized and
+ *                 have the DHM parameters set. It may or may not already
+ *                 have imported the peer's public key.
  * \param x_size   The private key size in Bytes.
- * \param output   The destination buffer.
- * \param olen     The length of the destination buffer. Must be at least
- *                  equal to ctx->len (the size of \c P).
- * \param f_rng    The RNG function.
- * \param p_rng    The RNG context.
+ * \param output   The destination buffer. This must be a writable buffer of
+ *                 size \p olen Bytes.
+ * \param olen     The length of the destination buffer. This must be at least
+ *                 equal to `ctx->len` (the size of \c P).
+ * \param f_rng    The RNG function. This must not be \c NULL.
+ * \param p_rng    The RNG context to be passed to \p f_rng. This may be \c NULL
+ *                 if \p f_rng doesn't need a context argument.
  *
  * \return         \c 0 on success.
  * \return         An \c MBEDTLS_ERR_DHM_XXX error code on failure.
@@ -233,22 +257,27 @@
                      void *p_rng );
 
 /**
- * \brief               This function derives and exports the shared secret
- *                      \c (G^Y)^X mod \c P.
+ * \brief          This function derives and exports the shared secret
+ *                 \c (G^Y)^X mod \c P.
  *
- * \note                If \p f_rng is not NULL, it is used to blind the input as
- *                      a countermeasure against timing attacks. Blinding is used
- *                      only if our private key \c X is re-used, and not used
- *                      otherwise. We recommend always passing a non-NULL
- *                      \p f_rng argument.
+ * \note           If \p f_rng is not \c NULL, it is used to blind the input as
+ *                 a countermeasure against timing attacks. Blinding is used
+ *                 only if our private key \c X is re-used, and not used
+ *                 otherwise. We recommend always passing a non-NULL
+ *                 \p f_rng argument.
  *
- * \param ctx           The DHM context.
- * \param output        The destination buffer.
- * \param output_size   The size of the destination buffer. Must be at least
- *                      the size of ctx->len (the size of \c P).
+ * \param ctx           The DHM context to use. This must be initialized
+ *                      and have its own private key generated and the peer's
+ *                      public key imported.
+ * \param output        The buffer to write the generated shared key to. This
+ *                      must be a writable buffer of size \p output_size Bytes.
+ * \param output_size   The size of the destination buffer. This must be at
+ *                      least the size of \c ctx->len (the size of \c P).
  * \param olen          On exit, holds the actual number of Bytes written.
- * \param f_rng         The RNG function, for blinding purposes.
- * \param p_rng         The RNG context.
+ * \param f_rng         The RNG function, for blinding purposes. This may
+ *                      b \c NULL if blinding isn't needed.
+ * \param p_rng         The RNG context. This may be \c NULL if \p f_rng
+ *                      doesn't need a context argument.
  *
  * \return              \c 0 on success.
  * \return              An \c MBEDTLS_ERR_DHM_XXX error code on failure.
@@ -259,9 +288,12 @@
                      void *p_rng );
 
 /**
- * \brief          This function frees and clears the components of a DHM context.
+ * \brief          This function frees and clears the components
+ *                 of a DHM context.
  *
- * \param ctx      The DHM context to free and clear.
+ * \param ctx      The DHM context to free and clear. This may be \c NULL,
+ *                 in which case this function is a no-op. If it is not \c NULL,
+ *                 it must point to an initialized DHM context.
  */
 void mbedtls_dhm_free( mbedtls_dhm_context *ctx );
 
@@ -270,17 +302,19 @@
 /**
  * \brief             This function parses DHM parameters in PEM or DER format.
  *
- * \param dhm         The DHM context to initialize.
- * \param dhmin       The input buffer.
- * \param dhminlen    The size of the buffer, including the terminating null
- *                    Byte for PEM data.
+ * \param dhm         The DHM context to import the DHM parameters into.
+ *                    This must be initialized.
+ * \param dhmin       The input buffer. This must be a readable buffer of
+ *                    length \p dhminlen Bytes.
+ * \param dhminlen    The size of the input buffer \p dhmin, including the
+ *                    terminating \c NULL Byte for PEM data.
  *
  * \return            \c 0 on success.
- * \return            An \c MBEDTLS_ERR_DHM_XXX or \c MBEDTLS_ERR_PEM_XXX error code
- *                    error code on failure.
+ * \return            An \c MBEDTLS_ERR_DHM_XXX or \c MBEDTLS_ERR_PEM_XXX error
+ *                    code on failure.
  */
 int mbedtls_dhm_parse_dhm( mbedtls_dhm_context *dhm, const unsigned char *dhmin,
-                   size_t dhminlen );
+                           size_t dhminlen );
 
 #if defined(MBEDTLS_FS_IO)
 /** \ingroup x509_module */
@@ -288,11 +322,13 @@
  * \brief          This function loads and parses DHM parameters from a file.
  *
  * \param dhm      The DHM context to load the parameters to.
+ *                 This must be initialized.
  * \param path     The filename to read the DHM parameters from.
+ *                 This must not be \c NULL.
  *
  * \return         \c 0 on success.
- * \return            An \c MBEDTLS_ERR_DHM_XXX or \c MBEDTLS_ERR_PEM_XXX error code
- *                    error code on failure.
+ * \return         An \c MBEDTLS_ERR_DHM_XXX or \c MBEDTLS_ERR_PEM_XXX
+ *                 error code on failure.
  */
 int mbedtls_dhm_parse_dhmfile( mbedtls_dhm_context *dhm, const char *path );
 #endif /* MBEDTLS_FS_IO */
diff --git a/include/mbedtls/ecdh.h b/include/mbedtls/ecdh.h
index cbd4841..05b2b03 100644
--- a/include/mbedtls/ecdh.h
+++ b/include/mbedtls/ecdh.h
@@ -149,11 +149,16 @@
  *
  * \see             ecp.h
  *
- * \param grp       The ECP group.
+ * \param grp       The ECP group to use. This must be initialized and have
+ *                  domain parameters loaded, for example through
+ *                  mbedtls_ecp_load() or mbedtls_ecp_tls_read_group().
  * \param d         The destination MPI (private key).
+ *                  This must be initialized.
  * \param Q         The destination point (public key).
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG context.
+ *                  This must be initialized.
+ * \param f_rng     The RNG function to use. This must not be \c NULL.
+ * \param p_rng     The RNG context to be passed to \p f_rng. This may be
+ *                  \c NULL in case \p f_rng doesn't need a context argument.
  *
  * \return          \c 0 on success.
  * \return          Another \c MBEDTLS_ERR_ECP_XXX or
@@ -176,12 +181,22 @@
  *                  countermeasures against side-channel attacks.
  *                  For more information, see mbedtls_ecp_mul().
  *
- * \param grp       The ECP group.
+ * \param grp       The ECP group to use. This must be initialized and have
+ *                  domain parameters loaded, for example through
+ *                  mbedtls_ecp_load() or mbedtls_ecp_tls_read_group().
  * \param z         The destination MPI (shared secret).
+ *                  This must be initialized.
  * \param Q         The public key from another party.
+ *                  This must be initialized.
  * \param d         Our secret exponent (private key).
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG context.
+ *                  This must be initialized.
+ * \param f_rng     The RNG function. This may be \c NULL if randomization
+ *                  of intermediate results during the ECP computations is
+ *                  not needed (discouraged). See the documentation of
+ *                  mbedtls_ecp_mul() for more.
+ * \param p_rng     The RNG context to be passed to \p f_rng. This may be
+ *                  \c NULL if \p f_rng is \c NULL or doesn't need a
+ *                  context argument.
  *
  * \return          \c 0 on success.
  * \return          Another \c MBEDTLS_ERR_ECP_XXX or
@@ -195,7 +210,7 @@
 /**
  * \brief           This function initializes an ECDH context.
  *
- * \param ctx       The ECDH context to initialize.
+ * \param ctx       The ECDH context to initialize. This must not be \c NULL.
  */
 void mbedtls_ecdh_init( mbedtls_ecdh_context *ctx );
 
@@ -210,39 +225,42 @@
  *                  This is the first function used by a TLS server for ECDHE
  *                  ciphersuites.
  *
- * \param ctx       The ECDH context to set up.
+ * \param ctx       The ECDH context to set up. This must be initialized.
  * \param grp_id    The group id of the group to set up the context for.
  *
  * \return          \c 0 on success.
  */
-int mbedtls_ecdh_setup( mbedtls_ecdh_context *ctx, mbedtls_ecp_group_id grp_id );
+int mbedtls_ecdh_setup( mbedtls_ecdh_context *ctx,
+                        mbedtls_ecp_group_id grp_id );
 
 /**
  * \brief           This function frees a context.
  *
- * \param ctx       The context to free.
+ * \param ctx       The context to free. This may be \c NULL, in which
+ *                  case this function does nothing. If it is not \c NULL,
+ *                  it must point to an initialized ECDH context.
  */
 void mbedtls_ecdh_free( mbedtls_ecdh_context *ctx );
 
 /**
- * \brief           This function generates a public key and a TLS
- *                  ServerKeyExchange payload.
+ * \brief           This function generates an EC key pair and exports its
+ *                  in the format used in a TLS ServerKeyExchange handshake
+ *                  message.
  *
  *                  This is the second function used by a TLS server for ECDHE
  *                  ciphersuites. (It is called after mbedtls_ecdh_setup().)
  *
- * \note            This function assumes that the ECP group (grp) of the
- *                  \p ctx context has already been properly set,
- *                  for example, using mbedtls_ecp_group_load().
- *
  * \see             ecp.h
  *
- * \param ctx       The ECDH context.
- * \param olen      The number of characters written.
- * \param buf       The destination buffer.
- * \param blen      The length of the destination buffer.
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG context.
+ * \param ctx       The ECDH context to use. This must be initialized
+ *                  and bound to a group, for example via mbedtls_ecdh_setup().
+ * \param olen      The address at which to store the number of Bytes written.
+ * \param buf       The destination buffer. This must be a writable buffer of
+ *                  length \p blen Bytes.
+ * \param blen      The length of the destination buffer \p buf in Bytes.
+ * \param f_rng     The RNG function to use. This must not be \c NULL.
+ * \param p_rng     The RNG context to be passed to \p f_rng. This may be
+ *                  \c NULL in case \p f_rng doesn't need a context argument.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of
@@ -255,24 +273,32 @@
                       void *p_rng );
 
 /**
- * \brief           This function parses and processes a TLS ServerKeyExhange
- *                  payload.
+ * \brief           This function parses the ECDHE parameters in a
+ *                  TLS ServerKeyExchange handshake message.
  *
- *                  This is the first function used by a TLS client for ECDHE
- *                  ciphersuites.
+ * \note            In a TLS handshake, this is the how the client
+ *                  sets up its ECDHE context from the server's public
+ *                  ECDHE key material.
  *
  * \see             ecp.h
  *
- * \param ctx       The ECDH context.
- * \param buf       The pointer to the start of the input buffer.
- * \param end       The address for one Byte past the end of the buffer.
+ * \param ctx       The ECDHE context to use. This must be initialized.
+ * \param buf       On input, \c *buf must be the start of the input buffer.
+ *                  On output, \c *buf is updated to point to the end of the
+ *                  data that has been read. On success, this is the first byte
+ *                  past the end of the ServerKeyExchange parameters.
+ *                  On error, this is the point at which an error has been
+ *                  detected, which is usually not useful except to debug
+ *                  failures.
+ * \param end       The end of the input buffer.
  *
  * \return          \c 0 on success.
  * \return          An \c MBEDTLS_ERR_ECP_XXX error code on failure.
  *
  */
 int mbedtls_ecdh_read_params( mbedtls_ecdh_context *ctx,
-                      const unsigned char **buf, const unsigned char *end );
+                              const unsigned char **buf,
+                              const unsigned char *end );
 
 /**
  * \brief           This function sets up an ECDH context from an EC key.
@@ -283,33 +309,40 @@
  *
  * \see             ecp.h
  *
- * \param ctx       The ECDH context to set up.
- * \param key       The EC key to use.
- * \param side      Defines the source of the key: 1: Our key, or
- *                  0: The key of the peer.
+ * \param ctx       The ECDH context to set up. This must be initialized.
+ * \param key       The EC key to use. This must be initialized.
+ * \param side      Defines the source of the key. Possible values are:
+ *                  - #MBEDTLS_ECDH_OURS: The key is ours.
+ *                  - #MBEDTLS_ECDH_THEIRS: The key is that of the peer.
  *
  * \return          \c 0 on success.
  * \return          Another \c MBEDTLS_ERR_ECP_XXX error code on failure.
  *
  */
-int mbedtls_ecdh_get_params( mbedtls_ecdh_context *ctx, const mbedtls_ecp_keypair *key,
-                     mbedtls_ecdh_side side );
+int mbedtls_ecdh_get_params( mbedtls_ecdh_context *ctx,
+                             const mbedtls_ecp_keypair *key,
+                             mbedtls_ecdh_side side );
 
 /**
- * \brief           This function generates a public key and a TLS
- *                  ClientKeyExchange payload.
+ * \brief           This function generates a public key and exports it
+ *                  as a TLS ClientKeyExchange payload.
  *
  *                  This is the second function used by a TLS client for ECDH(E)
  *                  ciphersuites.
  *
  * \see             ecp.h
  *
- * \param ctx       The ECDH context.
- * \param olen      The number of Bytes written.
- * \param buf       The destination buffer.
- * \param blen      The size of the destination buffer.
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG context.
+ * \param ctx       The ECDH context to use. This must be initialized
+ *                  and bound to a group, the latter usually by
+ *                  mbedtls_ecdh_read_params().
+ * \param olen      The address at which to store the number of Bytes written.
+ *                  This must not be \c NULL.
+ * \param buf       The destination buffer. This must be a writable buffer
+ *                  of length \p blen Bytes.
+ * \param blen      The size of the destination buffer \p buf in Bytes.
+ * \param f_rng     The RNG function to use. This must not be \c NULL.
+ * \param p_rng     The RNG context to be passed to \p f_rng. This may be
+ *                  \c NULL in case \p f_rng doesn't need a context argument.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of
@@ -322,8 +355,8 @@
                       void *p_rng );
 
 /**
- * \brief       This function parses and processes a TLS ClientKeyExchange
- *              payload.
+ * \brief       This function parses and processes the ECDHE payload of a
+ *              TLS ClientKeyExchange message.
  *
  *              This is the third function used by a TLS server for ECDH(E)
  *              ciphersuites. (It is called after mbedtls_ecdh_setup() and
@@ -331,15 +364,17 @@
  *
  * \see         ecp.h
  *
- * \param ctx   The ECDH context.
- * \param buf   The start of the input buffer.
- * \param blen  The length of the input buffer.
+ * \param ctx   The ECDH context to use. This must be initialized
+ *              and bound to a group, for example via mbedtls_ecdh_setup().
+ * \param buf   The pointer to the ClientKeyExchange payload. This must
+ *              be a readable buffer of length \p blen Bytes.
+ * \param blen  The length of the input buffer \p buf in Bytes.
  *
  * \return      \c 0 on success.
  * \return      An \c MBEDTLS_ERR_ECP_XXX error code on failure.
  */
 int mbedtls_ecdh_read_public( mbedtls_ecdh_context *ctx,
-                      const unsigned char *buf, size_t blen );
+                              const unsigned char *buf, size_t blen );
 
 /**
  * \brief           This function derives and exports the shared secret.
@@ -352,13 +387,19 @@
  *                  For more information, see mbedtls_ecp_mul().
  *
  * \see             ecp.h
- *
- * \param ctx       The ECDH context.
- * \param olen      The number of Bytes written.
- * \param buf       The destination buffer.
- * \param blen      The length of the destination buffer.
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG context.
+
+ * \param ctx       The ECDH context to use. This must be initialized
+ *                  and have its own private key generated and the peer's
+ *                  public key imported.
+ * \param olen      The address at which to store the total number of
+ *                  Bytes written on success. This must not be \c NULL.
+ * \param buf       The buffer to write the generated shared key to. This
+ *                  must be a writable buffer of size \p blen Bytes.
+ * \param blen      The length of the destination buffer \p buf in Bytes.
+ * \param f_rng     The RNG function, for blinding purposes. This may
+ *                  b \c NULL if blinding isn't needed.
+ * \param p_rng     The RNG context. This may be \c NULL if \p f_rng
+ *                  doesn't need a context argument.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of
@@ -381,7 +422,7 @@
  *                  computations once enabled, except by free-ing the context,
  *                  which cancels possible in-progress operations.
  *
- * \param ctx       The ECDH context.
+ * \param ctx       The ECDH context to use. This must be initialized.
  */
 void mbedtls_ecdh_enable_restart( mbedtls_ecdh_context *ctx );
 #endif /* MBEDTLS_ECP_RESTARTABLE */
diff --git a/include/mbedtls/ecdsa.h b/include/mbedtls/ecdsa.h
index 4057828..40fdab3 100644
--- a/include/mbedtls/ecdsa.h
+++ b/include/mbedtls/ecdsa.h
@@ -118,7 +118,8 @@
  * \brief           This function computes the ECDSA signature of a
  *                  previously-hashed message.
  *
- * \note            The deterministic version is usually preferred.
+ * \note            The deterministic version implemented in
+ *                  mbedtls_ecdsa_sign_det() is usually preferred.
  *
  * \note            If the bitlength of the message hash is larger than the
  *                  bitlength of the group order, then the hash is truncated
@@ -128,14 +129,22 @@
  *
  * \see             ecp.h
  *
- * \param grp       The ECP group.
- * \param r         The first output integer.
- * \param s         The second output integer.
- * \param d         The private signing key.
- * \param buf       The message hash.
- * \param blen      The length of \p buf.
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG context.
+ * \param grp       The context for the elliptic curve to use.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param r         The MPI context in which to store the first part
+ *                  the signature. This must be initialized.
+ * \param s         The MPI context in which to store the second part
+ *                  the signature. This must be initialized.
+ * \param d         The private signing key. This must be initialized.
+ * \param buf       The content to be signed. This is usually the hash of
+ *                  the original data to be signed. This must be a readable
+ *                  buffer of length \p blen Bytes. It may be \c NULL if
+ *                  \p blen is zero.
+ * \param blen      The length of \p buf in Bytes.
+ * \param f_rng     The RNG function. This must not be \c NULL.
+ * \param p_rng     The RNG context to be passed to \p f_rng. This may be
+ *                  \c NULL if \p f_rng doesn't need a context parameter.
  *
  * \return          \c 0 on success.
  * \return          An \c MBEDTLS_ERR_ECP_XXX
@@ -162,21 +171,29 @@
  *
  * \see             ecp.h
  *
- * \param grp       The ECP group.
- * \param r         The first output integer.
- * \param s         The second output integer.
- * \param d         The private signing key.
- * \param buf       The message hash.
- * \param blen      The length of \p buf.
- * \param md_alg    The MD algorithm used to hash the message.
+ * \param grp       The context for the elliptic curve to use.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param r         The MPI context in which to store the first part
+ *                  the signature. This must be initialized.
+ * \param s         The MPI context in which to store the second part
+ *                  the signature. This must be initialized.
+ * \param d         The private signing key. This must be initialized
+ *                  and setup, for example through mbedtls_ecp_gen_privkey().
+ * \param buf       The hashed content to be signed. This must be a readable
+ *                  buffer of length \p blen Bytes. It may be \c NULL if
+ *                  \p blen is zero.
+ * \param blen      The length of \p buf in Bytes.
+ * \param md_alg    The hash algorithm used to hash the original data.
  *
  * \return          \c 0 on success.
  * \return          An \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_MPI_XXX
  *                  error code on failure.
  */
-int mbedtls_ecdsa_sign_det( mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi *s,
-                    const mbedtls_mpi *d, const unsigned char *buf, size_t blen,
-                    mbedtls_md_type_t md_alg );
+int mbedtls_ecdsa_sign_det( mbedtls_ecp_group *grp, mbedtls_mpi *r,
+                            mbedtls_mpi *s, const mbedtls_mpi *d,
+                            const unsigned char *buf, size_t blen,
+                            mbedtls_md_type_t md_alg );
 #endif /* MBEDTLS_ECDSA_DETERMINISTIC */
 
 /**
@@ -191,12 +208,19 @@
  *
  * \see             ecp.h
  *
- * \param grp       The ECP group.
- * \param buf       The message hash.
- * \param blen      The length of \p buf.
- * \param Q         The public key to use for verification.
+ * \param grp       The ECP group to use.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param buf       The hashed content that was signed. This must be a readable
+ *                  buffer of length \p blen Bytes. It may be \c NULL if
+ *                  \p blen is zero.
+ * \param blen      The length of \p buf in Bytes.
+ * \param Q         The public key to use for verification. This must be
+ *                  initialized and setup.
  * \param r         The first integer of the signature.
+ *                  This must be initialized.
  * \param s         The second integer of the signature.
+ *                  This must be initialized.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if the signature
@@ -205,8 +229,9 @@
  *                  error code on failure for any other reason.
  */
 int mbedtls_ecdsa_verify( mbedtls_ecp_group *grp,
-                  const unsigned char *buf, size_t blen,
-                  const mbedtls_ecp_point *Q, const mbedtls_mpi *r, const mbedtls_mpi *s);
+                          const unsigned char *buf, size_t blen,
+                          const mbedtls_ecp_point *Q, const mbedtls_mpi *r,
+                          const mbedtls_mpi *s);
 
 /**
  * \brief           This function computes the ECDSA signature and writes it
@@ -223,11 +248,6 @@
  *                  of the Digital Signature Algorithm (DSA) and Elliptic
  *                  Curve Digital Signature Algorithm (ECDSA)</em>.
  *
- * \note            The \p sig buffer must be at least twice as large as the
- *                  size of the curve used, plus 9. For example, 73 Bytes if
- *                  a 256-bit curve is used. A buffer length of
- *                  #MBEDTLS_ECDSA_MAX_LEN is always safe.
- *
  * \note            If the bitlength of the message hash is larger than the
  *                  bitlength of the group order, then the hash is truncated as
  *                  defined in <em>Standards for Efficient Cryptography Group
@@ -236,20 +256,32 @@
  *
  * \see             ecp.h
  *
- * \param ctx       The ECDSA context.
+ * \param ctx       The ECDSA context to use. This must be initialized
+ *                  and have a group and private key bound to it, for example
+ *                  via mbedtls_ecdsa_genkey() or mbedtls_ecdsa_from_keypair().
  * \param md_alg    The message digest that was used to hash the message.
- * \param hash      The message hash.
- * \param hlen      The length of the hash.
- * \param sig       The buffer that holds the signature.
- * \param slen      The length of the signature written.
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG context.
+ * \param hash      The message hash to be signed. This must be a readable
+ *                  buffer of length \p blen Bytes.
+ * \param hlen      The length of the hash \p hash in Bytes.
+ * \param sig       The buffer to which to write the signature. This must be a
+ *                  writable buffer of length at least twice as large as the
+ *                  size of the curve used, plus 9. For example, 73 Bytes if
+ *                  a 256-bit curve is used. A buffer length of
+ *                  #MBEDTLS_ECDSA_MAX_LEN is always safe.
+ * \param slen      The address at which to store the actual length of
+ *                  the signature written. Must not be \c NULL.
+ * \param f_rng     The RNG function. This must not be \c NULL if
+ *                  #MBEDTLS_ECDSA_DETERMINISTIC is unset. Otherwise,
+ *                  it is unused and may be set to \c NULL.
+ * \param p_rng     The RNG context to be passed to \p f_rng. This may be
+ *                  \c NULL if \p f_rng is \c NULL or doesn't use a context.
  *
  * \return          \c 0 on success.
  * \return          An \c MBEDTLS_ERR_ECP_XXX, \c MBEDTLS_ERR_MPI_XXX or
  *                  \c MBEDTLS_ERR_ASN1_XXX error code on failure.
  */
-int mbedtls_ecdsa_write_signature( mbedtls_ecdsa_context *ctx, mbedtls_md_type_t md_alg,
+int mbedtls_ecdsa_write_signature( mbedtls_ecdsa_context *ctx,
+                                   mbedtls_md_type_t md_alg,
                            const unsigned char *hash, size_t hlen,
                            unsigned char *sig, size_t *slen,
                            int (*f_rng)(void *, unsigned char *, size_t),
@@ -265,15 +297,28 @@
  *                  but it can return early and restart according to the limit
  *                  set with \c mbedtls_ecp_set_max_ops() to reduce blocking.
  *
- * \param ctx       The ECDSA context.
+ * \param ctx       The ECDSA context to use. This must be initialized
+ *                  and have a group and private key bound to it, for example
+ *                  via mbedtls_ecdsa_genkey() or mbedtls_ecdsa_from_keypair().
  * \param md_alg    The message digest that was used to hash the message.
- * \param hash      The message hash.
- * \param hlen      The length of the hash.
- * \param sig       The buffer that holds the signature.
- * \param slen      The length of the signature written.
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG context.
- * \param rs_ctx    The restart context (NULL disables restart).
+ * \param hash      The message hash to be signed. This must be a readable
+ *                  buffer of length \p blen Bytes.
+ * \param hlen      The length of the hash \p hash in Bytes.
+ * \param sig       The buffer to which to write the signature. This must be a
+ *                  writable buffer of length at least twice as large as the
+ *                  size of the curve used, plus 9. For example, 73 Bytes if
+ *                  a 256-bit curve is used. A buffer length of
+ *                  #MBEDTLS_ECDSA_MAX_LEN is always safe.
+ * \param slen      The address at which to store the actual length of
+ *                  the signature written. Must not be \c NULL.
+ * \param f_rng     The RNG function. This must not be \c NULL if
+ *                  #MBEDTLS_ECDSA_DETERMINISTIC is unset. Otherwise,
+ *                  it is unused and may be set to \c NULL.
+ * \param p_rng     The RNG context to be passed to \p f_rng. This may be
+ *                  \c NULL if \p f_rng is \c NULL or doesn't use a context.
+ * \param rs_ctx    The restart context to use. This may be \c NULL to disable
+ *                  restarting. If it is not \c NULL, it must point to an
+ *                  initialized restart context.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of
@@ -309,11 +354,6 @@
  * \warning         It is not thread-safe to use the same context in
  *                  multiple threads.
  *
- * \note            The \p sig buffer must be at least twice as large as the
- *                  size of the curve used, plus 9. For example, 73 Bytes if a
- *                  256-bit curve is used. A buffer length of
- *                  #MBEDTLS_ECDSA_MAX_LEN is always safe.
- *
  * \note            If the bitlength of the message hash is larger than the
  *                  bitlength of the group order, then the hash is truncated as
  *                  defined in <em>Standards for Efficient Cryptography Group
@@ -325,12 +365,20 @@
  * \deprecated      Superseded by mbedtls_ecdsa_write_signature() in
  *                  Mbed TLS version 2.0 and later.
  *
- * \param ctx       The ECDSA context.
- * \param hash      The message hash.
- * \param hlen      The length of the hash.
- * \param sig       The buffer that holds the signature.
- * \param slen      The length of the signature written.
- * \param md_alg    The MD algorithm used to hash the message.
+ * \param ctx       The ECDSA context to use. This must be initialized
+ *                  and have a group and private key bound to it, for example
+ *                  via mbedtls_ecdsa_genkey() or mbedtls_ecdsa_from_keypair().
+ * \param hash      The message hash to be signed. This must be a readable
+ *                  buffer of length \p blen Bytes.
+ * \param hlen      The length of the hash \p hash in Bytes.
+ * \param sig       The buffer to which to write the signature. This must be a
+ *                  writable buffer of length at least twice as large as the
+ *                  size of the curve used, plus 9. For example, 73 Bytes if
+ *                  a 256-bit curve is used. A buffer length of
+ *                  #MBEDTLS_ECDSA_MAX_LEN is always safe.
+ * \param slen      The address at which to store the actual length of
+ *                  the signature written. Must not be \c NULL.
+ * \param md_alg    The message digest that was used to hash the message.
  *
  * \return          \c 0 on success.
  * \return          An \c MBEDTLS_ERR_ECP_XXX, \c MBEDTLS_ERR_MPI_XXX or
@@ -355,11 +403,14 @@
  *
  * \see             ecp.h
  *
- * \param ctx       The ECDSA context.
- * \param hash      The message hash.
- * \param hlen      The size of the hash.
- * \param sig       The signature to read and verify.
- * \param slen      The size of \p sig.
+ * \param ctx       The ECDSA context to use. This must be initialized
+ *                  and have a group and public key bound to it.
+ * \param hash      The message hash that was signed. This must be a readable
+ *                  buffer of length \p size Bytes.
+ * \param hlen      The size of the hash \p hash.
+ * \param sig       The signature to read and verify. This must be a readable
+ *                  buffer of length \p slen Bytes.
+ * \param slen      The size of \p sig in Bytes.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if signature is invalid.
@@ -382,12 +433,17 @@
  *                  but it can return early and restart according to the limit
  *                  set with \c mbedtls_ecp_set_max_ops() to reduce blocking.
  *
- * \param ctx       The ECDSA context.
- * \param hash      The message hash.
- * \param hlen      The size of the hash.
- * \param sig       The signature to read and verify.
- * \param slen      The size of \p sig.
- * \param rs_ctx    The restart context (NULL disables restart).
+ * \param ctx       The ECDSA context to use. This must be initialized
+ *                  and have a group and public key bound to it.
+ * \param hash      The message hash that was signed. This must be a readable
+ *                  buffer of length \p size Bytes.
+ * \param hlen      The size of the hash \p hash.
+ * \param sig       The signature to read and verify. This must be a readable
+ *                  buffer of length \p slen Bytes.
+ * \param slen      The size of \p sig in Bytes.
+ * \param rs_ctx    The restart context to use. This may be \c NULL to disable
+ *                  restarting. If it is not \c NULL, it must point to an
+ *                  initialized restart context.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if signature is invalid.
@@ -409,10 +465,12 @@
  * \see            ecp.h
  *
  * \param ctx      The ECDSA context to store the keypair in.
+ *                 This must be initialized.
  * \param gid      The elliptic curve to use. One of the various
  *                 \c MBEDTLS_ECP_DP_XXX macros depending on configuration.
- * \param f_rng    The RNG function.
- * \param p_rng    The RNG context.
+ * \param f_rng    The RNG function to use. This must not be \c NULL.
+ * \param p_rng    The RNG context to be passed to \p f_rng. This may be
+ *                 \c NULL if \p f_rng doesn't need a context argument.
  *
  * \return         \c 0 on success.
  * \return         An \c MBEDTLS_ERR_ECP_XXX code on failure.
@@ -421,40 +479,55 @@
                   int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
 
 /**
- * \brief           This function sets an ECDSA context from an EC key pair.
+ * \brief           This function sets up an ECDSA context from an EC key pair.
  *
  * \see             ecp.h
  *
- * \param ctx       The ECDSA context to set.
- * \param key       The EC key to use.
+ * \param ctx       The ECDSA context to setup. This must be initialized.
+ * \param key       The EC key to use. This must be initialized and hold
+ *                  a private-public key pair or a public key. In the former
+ *                  case, the ECDSA context may be used for signature creation
+ *                  and verification after this call. In the latter case, it
+ *                  may be used for signature verification.
  *
  * \return          \c 0 on success.
  * \return          An \c MBEDTLS_ERR_ECP_XXX code on failure.
  */
-int mbedtls_ecdsa_from_keypair( mbedtls_ecdsa_context *ctx, const mbedtls_ecp_keypair *key );
+int mbedtls_ecdsa_from_keypair( mbedtls_ecdsa_context *ctx,
+                                const mbedtls_ecp_keypair *key );
 
 /**
  * \brief           This function initializes an ECDSA context.
  *
  * \param ctx       The ECDSA context to initialize.
+ *                  This must not be \c NULL.
  */
 void mbedtls_ecdsa_init( mbedtls_ecdsa_context *ctx );
 
 /**
  * \brief           This function frees an ECDSA context.
  *
- * \param ctx       The ECDSA context to free.
+ * \param ctx       The ECDSA context to free. This may be \c NULL,
+ *                  in which case this function does nothing. If it
+ *                  is not \c NULL, it must be initialized.
  */
 void mbedtls_ecdsa_free( mbedtls_ecdsa_context *ctx );
 
 #if defined(MBEDTLS_ECP_RESTARTABLE)
 /**
- * \brief           Initialize a restart context
+ * \brief           Initialize a restart context.
+ *
+ * \param ctx       The restart context to initialize.
+ *                  This must not be \c NULL.
  */
 void mbedtls_ecdsa_restart_init( mbedtls_ecdsa_restart_ctx *ctx );
 
 /**
- * \brief           Free the components of a restart context
+ * \brief           Free the components of a restart context.
+ *
+ * \param ctx       The restart context to free. This may be \c NULL,
+ *                  in which case this function does nothing. If it
+ *                  is not \c NULL, it must be initialized.
  */
 void mbedtls_ecdsa_restart_free( mbedtls_ecdsa_restart_ctx *ctx );
 #endif /* MBEDTLS_ECP_RESTARTABLE */
diff --git a/include/mbedtls/ecjpake.h b/include/mbedtls/ecjpake.h
index 59d12f0..b967af8 100644
--- a/include/mbedtls/ecjpake.h
+++ b/include/mbedtls/ecjpake.h
@@ -92,28 +92,33 @@
 #endif /* MBEDTLS_ECJPAKE_ALT */
 
 /**
- * \brief           Initialize a context
- *                  (just makes it ready for setup() or free()).
+ * \brief           Initialize an ECJPAKE context.
  *
- * \param ctx       context to initialize
+ * \param ctx       The ECJPAKE context to initialize.
+ *                  This must not be \c NULL.
  */
 void mbedtls_ecjpake_init( mbedtls_ecjpake_context *ctx );
 
 /**
- * \brief           Set up a context for use
+ * \brief           Set up an ECJPAKE context for use.
  *
  * \note            Currently the only values for hash/curve allowed by the
- *                  standard are MBEDTLS_MD_SHA256/MBEDTLS_ECP_DP_SECP256R1.
+ *                  standard are #MBEDTLS_MD_SHA256/#MBEDTLS_ECP_DP_SECP256R1.
  *
- * \param ctx       context to set up
- * \param role      Our role: client or server
- * \param hash      hash function to use (MBEDTLS_MD_XXX)
- * \param curve     elliptic curve identifier (MBEDTLS_ECP_DP_XXX)
- * \param secret    pre-shared secret (passphrase)
- * \param len       length of the shared secret
+ * \param ctx       The ECJPAKE context to set up. This must be initialized.
+ * \param role      The role of the caller. This must be either
+ *                  #MBEDTLS_ECJPAKE_CLIENT or #MBEDTLS_ECJPAKE_SERVER.
+ * \param hash      The identifier of the hash function to use,
+ *                  for example #MBEDTLS_MD_SHA256.
+ * \param curve     The identifier of the elliptic curve to use,
+ *                  for example #MBEDTLS_ECP_DP_SECP256R1.
+ * \param secret    The pre-shared secret (passphrase). This must be
+ *                  a readable buffer of length \p len Bytes. It need
+ *                  only be valid for the duration of this call.
+ * \param len       The length of the pre-shared secret \p secret.
  *
- * \return          0 if successfull,
- *                  a negative error code otherwise
+ * \return          \c 0 if successful.
+ * \return          A negative error code on failure.
  */
 int mbedtls_ecjpake_setup( mbedtls_ecjpake_context *ctx,
                            mbedtls_ecjpake_role role,
@@ -123,29 +128,34 @@
                            size_t len );
 
 /**
- * \brief           Check if a context is ready for use
+ * \brief           Check if an ECJPAKE context is ready for use.
  *
- * \param ctx       Context to check
+ * \param ctx       The ECJPAKE context to check. This must be
+ *                  initialized.
  *
- * \return          0 if the context is ready for use,
- *                  MBEDTLS_ERR_ECP_BAD_INPUT_DATA otherwise
+ * \return          \c 0 if the context is ready for use.
+ * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA otherwise.
  */
 int mbedtls_ecjpake_check( const mbedtls_ecjpake_context *ctx );
 
 /**
  * \brief           Generate and write the first round message
  *                  (TLS: contents of the Client/ServerHello extension,
- *                  excluding extension type and length bytes)
+ *                  excluding extension type and length bytes).
  *
- * \param ctx       Context to use
- * \param buf       Buffer to write the contents to
- * \param len       Buffer size
- * \param olen      Will be updated with the number of bytes written
- * \param f_rng     RNG function
- * \param p_rng     RNG parameter
+ * \param ctx       The ECJPAKE context to use. This must be
+ *                  initialized and set up.
+ * \param buf       The buffer to write the contents to. This must be a
+ *                  writable buffer of length \p len Bytes.
+ * \param len       The length of \p buf in Bytes.
+ * \param olen      The address at which to store the total number
+ *                  of Bytes written to \p buf. This must not be \c NULL.
+ * \param f_rng     The RNG function to use. This must not be \c NULL.
+ * \param p_rng     The RNG parameter to be passed to \p f_rng. This
+ *                  may be \c NULL if \p f_rng doesn't use a context.
  *
- * \return          0 if successfull,
- *                  a negative error code otherwise
+ * \return          \c 0 if successful.
+ * \return          A negative error code on failure.
  */
 int mbedtls_ecjpake_write_round_one( mbedtls_ecjpake_context *ctx,
                             unsigned char *buf, size_t len, size_t *olen,
@@ -155,14 +165,16 @@
 /**
  * \brief           Read and process the first round message
  *                  (TLS: contents of the Client/ServerHello extension,
- *                  excluding extension type and length bytes)
+ *                  excluding extension type and length bytes).
  *
- * \param ctx       Context to use
- * \param buf       Pointer to extension contents
- * \param len       Extension length
+ * \param ctx       The ECJPAKE context to use. This must be initialized
+ *                  and set up.
+ * \param buf       The buffer holding the first round message. This must
+ *                  be a readable buffer of length \p len Bytes.
+ * \param len       The length in Bytes of \p buf.
  *
- * \return          0 if successfull,
- *                  a negative error code otherwise
+ * \return          \c 0 if successful.
+ * \return          A negative error code on failure.
  */
 int mbedtls_ecjpake_read_round_one( mbedtls_ecjpake_context *ctx,
                                     const unsigned char *buf,
@@ -170,17 +182,21 @@
 
 /**
  * \brief           Generate and write the second round message
- *                  (TLS: contents of the Client/ServerKeyExchange)
+ *                  (TLS: contents of the Client/ServerKeyExchange).
  *
- * \param ctx       Context to use
- * \param buf       Buffer to write the contents to
- * \param len       Buffer size
- * \param olen      Will be updated with the number of bytes written
- * \param f_rng     RNG function
- * \param p_rng     RNG parameter
+ * \param ctx       The ECJPAKE context to use. This must be initialized,
+ *                  set up, and already have performed round one.
+ * \param buf       The buffer to write the round two contents to.
+ *                  This must be a writable buffer of length \p len Bytes.
+ * \param len       The size of \p buf in Bytes.
+ * \param olen      The address at which to store the total number of Bytes
+ *                  written to \p buf. This must not be \c NULL.
+ * \param f_rng     The RNG function to use. This must not be \c NULL.
+ * \param p_rng     The RNG parameter to be passed to \p f_rng. This
+ *                  may be \c NULL if \p f_rng doesn't use a context.
  *
- * \return          0 if successfull,
- *                  a negative error code otherwise
+ * \return          \c 0 if successful.
+ * \return          A negative error code on failure.
  */
 int mbedtls_ecjpake_write_round_two( mbedtls_ecjpake_context *ctx,
                             unsigned char *buf, size_t len, size_t *olen,
@@ -189,14 +205,16 @@
 
 /**
  * \brief           Read and process the second round message
- *                  (TLS: contents of the Client/ServerKeyExchange)
+ *                  (TLS: contents of the Client/ServerKeyExchange).
  *
- * \param ctx       Context to use
- * \param buf       Pointer to the message
- * \param len       Message length
+ * \param ctx       The ECJPAKE context to use. This must be initialized
+ *                  and set up and already have performed round one.
+ * \param buf       The buffer holding the second round message. This must
+ *                  be a readable buffer of length \p len Bytes.
+ * \param len       The length in Bytes of \p buf.
  *
- * \return          0 if successfull,
- *                  a negative error code otherwise
+ * \return          \c 0 if successful.
+ * \return          A negative error code on failure.
  */
 int mbedtls_ecjpake_read_round_two( mbedtls_ecjpake_context *ctx,
                                     const unsigned char *buf,
@@ -204,17 +222,21 @@
 
 /**
  * \brief           Derive the shared secret
- *                  (TLS: Pre-Master Secret)
+ *                  (TLS: Pre-Master Secret).
  *
- * \param ctx       Context to use
- * \param buf       Buffer to write the contents to
- * \param len       Buffer size
- * \param olen      Will be updated with the number of bytes written
- * \param f_rng     RNG function
- * \param p_rng     RNG parameter
+ * \param ctx       The ECJPAKE context to use. This must be initialized,
+ *                  set up and have performed both round one and two.
+ * \param buf       The buffer to write the derived secret to. This must
+ *                  be a writable buffer of length \p len Bytes.
+ * \param len       The length of \p buf in Bytes.
+ * \param olen      The address at which to store the total number of Bytes
+ *                  written to \p buf. This must not be \c NULL.
+ * \param f_rng     The RNG function to use. This must not be \c NULL.
+ * \param p_rng     The RNG parameter to be passed to \p f_rng. This
+ *                  may be \c NULL if \p f_rng doesn't use a context.
  *
- * \return          0 if successfull,
- *                  a negative error code otherwise
+ * \return          \c 0 if successful.
+ * \return          A negative error code on failure.
  */
 int mbedtls_ecjpake_derive_secret( mbedtls_ecjpake_context *ctx,
                             unsigned char *buf, size_t len, size_t *olen,
@@ -222,14 +244,15 @@
                             void *p_rng );
 
 /**
- * \brief           Free a context's content
+ * \brief           This clears an ECJPAKE context and frees any
+ *                  embedded data structure.
  *
- * \param ctx       context to free
+ * \param ctx       The ECJPAKE context to free. This may be \c NULL,
+ *                  in which case this function does nothing. If it is not
+ *                  \c NULL, it must point to an initialized ECJPAKE context.
  */
 void mbedtls_ecjpake_free( mbedtls_ecjpake_context *ctx );
 
-
-
 #if defined(MBEDTLS_SELF_TEST)
 
 /**
diff --git a/include/mbedtls/ecp.h b/include/mbedtls/ecp.h
index 1c37298..de3a343 100644
--- a/include/mbedtls/ecp.h
+++ b/include/mbedtls/ecp.h
@@ -497,24 +497,37 @@
 
 /**
  * \brief           This function frees the components of an ECP group.
- * \param grp       The group to free.
+ *
+ * \param grp       The group to free. This may be \c NULL, in which
+ *                  case this function returns immediately. If it is not
+ *                  \c NULL, it must point to an initialized ECP group.
  */
 void mbedtls_ecp_group_free( mbedtls_ecp_group *grp );
 
 /**
  * \brief           This function frees the components of a key pair.
- * \param key       The key pair to free.
+ *
+ * \param key       The key pair to free. This may be \c NULL, in which
+ *                  case this function returns immediately. If it is not
+ *                  \c NULL, it must point to an initialized ECP key pair.
  */
 void mbedtls_ecp_keypair_free( mbedtls_ecp_keypair *key );
 
 #if defined(MBEDTLS_ECP_RESTARTABLE)
 /**
- * \brief           Initialize a restart context
+ * \brief           Initialize a restart context.
+ *
+ * \param ctx       The restart context to initialize. This must
+ *                  not be \c NULL.
  */
 void mbedtls_ecp_restart_init( mbedtls_ecp_restart_ctx *ctx );
 
 /**
- * \brief           Free the components of a restart context
+ * \brief           Free the components of a restart context.
+ *
+ * \param ctx       The restart context to free. This may be \c NULL, in which
+ *                  case this function returns immediately. If it is not
+ *                  \c NULL, it must point to an initialized restart context.
  */
 void mbedtls_ecp_restart_free( mbedtls_ecp_restart_ctx *ctx );
 #endif /* MBEDTLS_ECP_RESTARTABLE */
@@ -523,11 +536,12 @@
  * \brief           This function copies the contents of point \p Q into
  *                  point \p P.
  *
- * \param P         The destination point.
- * \param Q         The source point.
+ * \param P         The destination point. This must be initialized.
+ * \param Q         The source point. This must be initialized.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure.
+ * \return          Another negative error code for other kinds of failure.
  */
 int mbedtls_ecp_copy( mbedtls_ecp_point *P, const mbedtls_ecp_point *Q );
 
@@ -535,31 +549,35 @@
  * \brief           This function copies the contents of group \p src into
  *                  group \p dst.
  *
- * \param dst       The destination group.
- * \param src       The source group.
+ * \param dst       The destination group. This must be initialized.
+ * \param src       The source group. This must be initialized.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure.
+ * \return          Another negative error code on other kinds of failure.
  */
-int mbedtls_ecp_group_copy( mbedtls_ecp_group *dst, const mbedtls_ecp_group *src );
+int mbedtls_ecp_group_copy( mbedtls_ecp_group *dst,
+                            const mbedtls_ecp_group *src );
 
 /**
- * \brief           This function sets a point to zero.
+ * \brief           This function sets a point to the point at infinity.
  *
- * \param pt        The point to set.
+ * \param pt        The point to set. This must be initialized.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure.
+ * \return          Another negative error code on other kinds of failure.
  */
 int mbedtls_ecp_set_zero( mbedtls_ecp_point *pt );
 
 /**
- * \brief           This function checks if a point is zero.
+ * \brief           This function checks if a point is the point at infinity.
  *
- * \param pt        The point to test.
+ * \param pt        The point to test. This must be initialized.
  *
  * \return          \c 1 if the point is zero.
  * \return          \c 0 if the point is non-zero.
+ * \return          A negative error code on failure.
  */
 int mbedtls_ecp_is_zero( mbedtls_ecp_point *pt );
 
@@ -569,8 +587,8 @@
  * \note            This assumes that the points are normalized. Otherwise,
  *                  they may compare as "not equal" even if they are.
  *
- * \param P         The first point to compare.
- * \param Q         The second point to compare.
+ * \param P         The first point to compare. This must be initialized.
+ * \param Q         The second point to compare. This must be initialized.
  *
  * \return          \c 0 if the points are equal.
  * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if the points are not equal.
@@ -582,7 +600,7 @@
  * \brief           This function imports a non-zero point from two ASCII
  *                  strings.
  *
- * \param P         The destination point.
+ * \param P         The destination point. This must be initialized.
  * \param radix     The numeric base of the input.
  * \param x         The first affine coordinate, as a null-terminated string.
  * \param y         The second affine coordinate, as a null-terminated string.
@@ -597,15 +615,21 @@
  * \brief           This function exports a point into unsigned binary data.
  *
  * \param grp       The group to which the point should belong.
- * \param P         The point to export.
- * \param format    The point format. Should be an \c MBEDTLS_ECP_PF_XXX macro.
- * \param olen      The length of the output.
- * \param buf       The output buffer.
- * \param buflen    The length of the output buffer.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param P         The point to export. This must be initialized.
+ * \param format    The point format. This must be either
+ *                  #MBEDTLS_ECP_PF_COMPRESSED or #MBEDTLS_ECP_PF_UNCOMPRESSED.
+ * \param olen      The address at which to store the length of
+ *                  the output in Bytes. This must not be \c NULL.
+ * \param buf       The output buffer. This must be a writable buffer
+ *                  of length \p buflen Bytes.
+ * \param buflen    The length of the output buffer \p buf in Bytes.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA
- *                  or #MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL on failure.
+ * \return          #MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL if the output buffer
+ *                  is too small to hold the point.
+ * \return          Another negative error code on other kinds of failure.
  */
 int mbedtls_ecp_point_write_binary( const mbedtls_ecp_group *grp, const mbedtls_ecp_point *P,
                             int format, size_t *olen,
@@ -619,19 +643,23 @@
  *                  for that.
  *
  * \param grp       The group to which the point should belong.
- * \param P         The point to import.
- * \param buf       The input buffer.
- * \param ilen      The length of the input.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param P         The destination context to import the point to.
+ *                  This must be initialized.
+ * \param buf       The input buffer. This must be a readable buffer
+ *                  of length \p ilen Bytes.
+ * \param ilen      The length of the input buffer \p buf in Bytes.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if input is invalid.
+ * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if the input is invalid.
  * \return          #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure.
  * \return          #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if the point format
  *                  is not implemented.
- *
  */
-int mbedtls_ecp_point_read_binary( const mbedtls_ecp_group *grp, mbedtls_ecp_point *P,
-                           const unsigned char *buf, size_t ilen );
+int mbedtls_ecp_point_read_binary( const mbedtls_ecp_group *grp,
+                                   mbedtls_ecp_point *P,
+                                   const unsigned char *buf, size_t ilen );
 
 /**
  * \brief           This function imports a point from a TLS ECPoint record.
@@ -639,7 +667,9 @@
  * \note            On function return, \p *buf is updated to point immediately
  *                  after the ECPoint record.
  *
- * \param grp       The ECP group used.
+ * \param grp       The ECP group to use.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
  * \param pt        The destination point.
  * \param buf       The address of the pointer to the start of the input buffer.
  * \param len       The length of the buffer.
@@ -649,99 +679,122 @@
  *                  failure.
  * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if input is invalid.
  */
-int mbedtls_ecp_tls_read_point( const mbedtls_ecp_group *grp, mbedtls_ecp_point *pt,
-                        const unsigned char **buf, size_t len );
+int mbedtls_ecp_tls_read_point( const mbedtls_ecp_group *grp,
+                                mbedtls_ecp_point *pt,
+                                const unsigned char **buf, size_t len );
 
 /**
- * \brief           This function exports a point as a TLS ECPoint record.
+ * \brief           This function exports a point as a TLS ECPoint record
+ *                  defined in RFC 4492, Section 5.4.
  *
- * \param grp       The ECP group used.
- * \param pt        The point format to export to. The point format is an
- *                  \c MBEDTLS_ECP_PF_XXX constant.
- * \param format    The export format.
- * \param olen      The length of the data written.
- * \param buf       The buffer to write to.
- * \param blen      The length of the buffer.
+ * \param grp       The ECP group to use.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param pt        The point to be exported. This must be initialized.
+ * \param format    The point format to use. This must be either
+ *                  #MBEDTLS_ECP_PF_COMPRESSED or #MBEDTLS_ECP_PF_UNCOMPRESSED.
+ * \param olen      The address at which to store the length in Bytes
+ *                  of the data written.
+ * \param buf       The target buffer. This must be a writable buffer of
+ *                  length \p blen Bytes.
+ * \param blen      The length of the target buffer \p buf in Bytes.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA or
- *                  #MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL on failure.
+ * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if the input is invalid.
+ * \return          #MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL if the target buffer
+ *                  is too small to hold the exported point.
+ * \return          Another negative error code on other kinds of failure.
  */
-int mbedtls_ecp_tls_write_point( const mbedtls_ecp_group *grp, const mbedtls_ecp_point *pt,
-                         int format, size_t *olen,
-                         unsigned char *buf, size_t blen );
+int mbedtls_ecp_tls_write_point( const mbedtls_ecp_group *grp,
+                                 const mbedtls_ecp_point *pt,
+                                 int format, size_t *olen,
+                                 unsigned char *buf, size_t blen );
 
 /**
- * \brief           This function sets a group using standardized domain parameters.
+ * \brief           This function sets up an ECP group context
+ *                  from a standardized set of domain parameters.
  *
  * \note            The index should be a value of the NamedCurve enum,
  *                  as defined in <em>RFC-4492: Elliptic Curve Cryptography
  *                  (ECC) Cipher Suites for Transport Layer Security (TLS)</em>,
  *                  usually in the form of an \c MBEDTLS_ECP_DP_XXX macro.
  *
- * \param grp       The destination group.
+ * \param grp       The group context to setup. This must be initialized.
  * \param id        The identifier of the domain parameter set to load.
  *
- * \return          \c 0 on success,
- * \return          An \c MBEDTLS_ERR_MPI_XXX error code on initialization failure.
- * \return          #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE for unkownn groups.
-
+ * \return          \c 0 on success.
+ * \return          #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if \p id doesn't
+ *                  correspond to a known group.
+ * \return          Another negative error code on other kinds of failure.
  */
 int mbedtls_ecp_group_load( mbedtls_ecp_group *grp, mbedtls_ecp_group_id id );
 
 /**
- * \brief           This function sets a group from a TLS ECParameters record.
+ * \brief           This function sets up an ECP group context from a TLS
+ *                  ECParameters record as defined in RFC 4492, Section 5.4.
  *
- * \note            \p buf is updated to point right after the ECParameters
- *                  record on exit.
+ * \note            The read pointer \p buf is updated to point right after
+ *                  the ECParameters record on exit.
  *
- * \param grp       The destination group.
+ * \param grp       The group context to setup. This must be initialized.
  * \param buf       The address of the pointer to the start of the input buffer.
- * \param len       The length of the buffer.
+ * \param len       The length of the input buffer \c *buf in Bytes.
  *
  * \return          \c 0 on success.
- * \return          An \c MBEDTLS_ERR_MPI_XXX error code on initialization
- *                  failure.
  * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if input is invalid.
  * \return          #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if the group is not
- *                  recognised.
+ *                  recognized.
+ * \return          Another negative error code on other kinds of failure.
  */
-int mbedtls_ecp_tls_read_group( mbedtls_ecp_group *grp, const unsigned char **buf, size_t len );
+int mbedtls_ecp_tls_read_group( mbedtls_ecp_group *grp,
+                                const unsigned char **buf, size_t len );
 
 /**
- * \brief           This function reads a group from a TLS ECParameters record.
+ * \brief           This function extracts an elliptic curve group ID from a
+ *                  TLS ECParameters record as defined in RFC 4492, Section 5.4.
  *
- * \note            \p buf is updated to point right after the ECParameters
- *                  record on exit.
+ * \note            The read pointer \p buf is updated to point right after
+ *                  the ECParameters record on exit.
  *
- * \param grp       Output parameter to hold the group id.
+ * \param grp       The address at which to store the group id.
+ *                  This must not be \c NULL.
  * \param buf       The address of the pointer to the start of the input buffer.
- * \param len       The length of the buffer.
+ * \param len       The length of the input buffer \c *buf in Bytes.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if input is invalid.
  * \return          #MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE if the group is not
- *                  recognised.
+ *                  recognized.
+ * \return          Another negative error code on other kinds of failure.
  */
 int mbedtls_ecp_tls_read_group_id( mbedtls_ecp_group_id *grp,
-                                   const unsigned char **buf, size_t len );
+                                   const unsigned char **buf,
+                                   size_t len );
 /**
- * \brief           This function writes the TLS ECParameters record for a group.
+ * \brief           This function exports an elliptic curve as a TLS
+ *                  ECParameters record as defined in RFC 4492, Section 5.4.
  *
- * \param grp       The ECP group used.
- * \param olen      The number of Bytes written.
- * \param buf       The buffer to write to.
- * \param blen      The length of the buffer.
+ * \param grp       The ECP group to be exported.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param olen      The address at which to store the number of Bytes written.
+ *                  This must not be \c NULL.
+ * \param buf       The buffer to write to. This must be a writable buffer
+ *                  of length \p blen Bytes.
+ * \param blen      The length of the output buffer \p buf in Bytes.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL on failure.
+ * \return          #MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL if the output
+ *                  buffer is too small to hold the exported group.
+ * \return          Another negative error code on other kinds of failure.
  */
-int mbedtls_ecp_tls_write_group( const mbedtls_ecp_group *grp, size_t *olen,
-                         unsigned char *buf, size_t blen );
+int mbedtls_ecp_tls_write_group( const mbedtls_ecp_group *grp,
+                                 size_t *olen,
+                                 unsigned char *buf, size_t blen );
 
 /**
- * \brief           This function performs multiplication of a point by
- *                  an integer: \p R = \p m * \p P.
+ * \brief           This function performs a scalar multiplication of a point
+ *                  by an integer: \p R = \p m * \p P.
  *
  *                  It is not thread-safe to use same group in multiple threads.
  *
@@ -755,17 +808,22 @@
  *                  targeting these results. We recommend always providing
  *                  a non-NULL \p f_rng. The overhead is negligible.
  *
- * \param grp       The ECP group.
- * \param R         The destination point.
- * \param m         The integer by which to multiply.
- * \param P         The point to multiply.
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG context.
+ * \param grp       The ECP group to use.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param R         The point in which to store the result of the calculation.
+ *                  This must be initialized.
+ * \param m         The integer by which to multiply. This must be initialized.
+ * \param P         The point to multiply. This must be initialized.
+ * \param f_rng     The RNG function. This may be \c NULL if randomization
+ *                  of intermediate results isn't desired (discouraged).
+ * \param p_rng     The RNG context to be passed to \p p_rng.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_ECP_INVALID_KEY if \p m is not a valid private
  *                  key, or \p P is not a valid public key.
  * \return          #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure.
+ * \return          Another negative error code on other kinds of failure.
  */
 int mbedtls_ecp_mul( mbedtls_ecp_group *grp, mbedtls_ecp_point *R,
              const mbedtls_mpi *m, const mbedtls_ecp_point *P,
@@ -781,12 +839,16 @@
  *                  it can return early and restart according to the limit set
  *                  with \c mbedtls_ecp_set_max_ops() to reduce blocking.
  *
- * \param grp       The ECP group.
- * \param R         The destination point.
- * \param m         The integer by which to multiply.
- * \param P         The point to multiply.
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG context.
+ * \param grp       The ECP group to use.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param R         The point in which to store the result of the calculation.
+ *                  This must be initialized.
+ * \param m         The integer by which to multiply. This must be initialized.
+ * \param P         The point to multiply. This must be initialized.
+ * \param f_rng     The RNG function. This may be \c NULL if randomization
+ *                  of intermediate results isn't desired (discouraged).
+ * \param p_rng     The RNG context to be passed to \p p_rng.
  * \param rs_ctx    The restart context (NULL disables restart).
  *
  * \return          \c 0 on success.
@@ -795,6 +857,7 @@
  * \return          #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure.
  * \return          #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of
  *                  operations was reached: see \c mbedtls_ecp_set_max_ops().
+ * \return          Another negative error code on other kinds of failure.
  */
 int mbedtls_ecp_mul_restartable( mbedtls_ecp_group *grp, mbedtls_ecp_point *R,
              const mbedtls_mpi *m, const mbedtls_ecp_point *P,
@@ -810,18 +873,25 @@
  * \note            In contrast to mbedtls_ecp_mul(), this function does not
  *                  guarantee a constant execution flow and timing.
  *
- * \param grp       The ECP group.
- * \param R         The destination point.
+ * \param grp       The ECP group to use.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param R         The point in which to store the result of the calculation.
+ *                  This must be initialized.
  * \param m         The integer by which to multiply \p P.
- * \param P         The point to multiply by \p m.
+ *                  This must be initialized.
+ * \param P         The point to multiply by \p m. This must be initialized.
  * \param n         The integer by which to multiply \p Q.
+ *                  This must be initialized.
  * \param Q         The point to be multiplied by \p n.
+ *                  This must be initialized.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_ECP_INVALID_KEY if \p m or \p n are not
  *                  valid private keys, or \p P or \p Q are not valid public
  *                  keys.
  * \return          #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure.
+ * \return          Another negative error code on other kinds of failure.
  */
 int mbedtls_ecp_muladd( mbedtls_ecp_group *grp, mbedtls_ecp_point *R,
              const mbedtls_mpi *m, const mbedtls_ecp_point *P,
@@ -838,12 +908,18 @@
  *                  but it can return early and restart according to the limit
  *                  set with \c mbedtls_ecp_set_max_ops() to reduce blocking.
  *
- * \param grp       The ECP group.
- * \param R         The destination point.
+ * \param grp       The ECP group to use.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param R         The point in which to store the result of the calculation.
+ *                  This must be initialized.
  * \param m         The integer by which to multiply \p P.
- * \param P         The point to multiply by \p m.
+ *                  This must be initialized.
+ * \param P         The point to multiply by \p m. This must be initialized.
  * \param n         The integer by which to multiply \p Q.
+ *                  This must be initialized.
  * \param Q         The point to be multiplied by \p n.
+ *                  This must be initialized.
  * \param rs_ctx    The restart context (NULL disables restart).
  *
  * \return          \c 0 on success.
@@ -853,6 +929,7 @@
  * \return          #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory-allocation failure.
  * \return          #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of
  *                  operations was reached: see \c mbedtls_ecp_set_max_ops().
+ * \return          Another negative error code on other kinds of failure.
  */
 int mbedtls_ecp_muladd_restartable(
              mbedtls_ecp_group *grp, mbedtls_ecp_point *R,
@@ -877,38 +954,51 @@
  *                  structures, such as ::mbedtls_ecdh_context or
  *                  ::mbedtls_ecdsa_context.
  *
- * \param grp       The curve the point should lie on.
- * \param pt        The point to check.
+ * \param grp       The ECP group the point should belong to.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param pt        The point to check. This must be initialized.
  *
  * \return          \c 0 if the point is a valid public key.
- * \return          #MBEDTLS_ERR_ECP_INVALID_KEY on failure.
+ * \return          #MBEDTLS_ERR_ECP_INVALID_KEY if the point is not
+ *                  a valid public key for the given curve.
+ * \return          Another negative error code on other kinds of failure.
  */
-int mbedtls_ecp_check_pubkey( const mbedtls_ecp_group *grp, const mbedtls_ecp_point *pt );
+int mbedtls_ecp_check_pubkey( const mbedtls_ecp_group *grp,
+                              const mbedtls_ecp_point *pt );
 
 /**
- * \brief           This function checks that an \p mbedtls_mpi is a valid private
- *                  key for this curve.
+ * \brief           This function checks that an \p mbedtls_mpi is a
+ *                  valid private key for this curve.
  *
  * \note            This function uses bare components rather than an
  *                  ::mbedtls_ecp_keypair structure to ease use with other
  *                  structures, such as ::mbedtls_ecdh_context or
  *                  ::mbedtls_ecdsa_context.
  *
- * \param grp       The group used.
- * \param d         The integer to check.
+ * \param grp       The ECP group the private key should belong to.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param d         The integer to check. This must be initialized.
  *
  * \return          \c 0 if the point is a valid private key.
- * \return          #MBEDTLS_ERR_ECP_INVALID_KEY on failure.
+ * \return          #MBEDTLS_ERR_ECP_INVALID_KEY if the point is not a valid
+ *                  private key for the given curve.
+ * \return          Another negative error code on other kinds of failure.
  */
-int mbedtls_ecp_check_privkey( const mbedtls_ecp_group *grp, const mbedtls_mpi *d );
+int mbedtls_ecp_check_privkey( const mbedtls_ecp_group *grp,
+                               const mbedtls_mpi *d );
 
 /**
  * \brief           This function generates a private key.
  *
- * \param grp       The ECP group.
- * \param d         The destination MPI (secret part).
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG parameter.
+ * \param grp       The ECP group to generate a private key for.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param d         The destination MPI (secret part). This must be initialized.
+ * \param f_rng     The RNG function. This must not be \c NULL.
+ * \param p_rng     The RNG parameter to be passed to \p f_rng. This may be
+ *                  \c NULL if \p f_rng doesn't need a context argument.
  *
  * \return          \c 0 on success.
  * \return          An \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_MPI_XXX error code
@@ -928,22 +1018,29 @@
  *                  structures, such as ::mbedtls_ecdh_context or
  *                  ::mbedtls_ecdsa_context.
  *
- * \param grp       The ECP group.
- * \param G         The chosen base point.
+ * \param grp       The ECP group to generate a key pair for.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
+ * \param G         The base point to use. This must be initialized
+ *                  and belong to \p grp. It replaces the default base
+ *                  point \c grp->G used by mbedtls_ecp_gen_keypair().
  * \param d         The destination MPI (secret part).
+ *                  This must be initialized.
  * \param Q         The destination point (public part).
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG context.
+ *                  This must be initialized.
+ * \param f_rng     The RNG function. This must not be \c NULL.
+ * \param p_rng     The RNG context to be passed to \p f_rng. This may
+ *                  be \c NULL if \p f_rng doesn't need a context argument.
  *
  * \return          \c 0 on success.
  * \return          An \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_MPI_XXX error code
  *                  on failure.
  */
 int mbedtls_ecp_gen_keypair_base( mbedtls_ecp_group *grp,
-                     const mbedtls_ecp_point *G,
-                     mbedtls_mpi *d, mbedtls_ecp_point *Q,
-                     int (*f_rng)(void *, unsigned char *, size_t),
-                     void *p_rng );
+                                  const mbedtls_ecp_point *G,
+                                  mbedtls_mpi *d, mbedtls_ecp_point *Q,
+                                  int (*f_rng)(void *, unsigned char *, size_t),
+                                  void *p_rng );
 
 /**
  * \brief           This function generates an ECP keypair.
@@ -953,34 +1050,42 @@
  *                  structures, such as ::mbedtls_ecdh_context or
  *                  ::mbedtls_ecdsa_context.
  *
- * \param grp       The ECP group.
+ * \param grp       The ECP group to generate a key pair for.
+ *                  This must be initialized and have group parameters
+ *                  set, for example through mbedtls_ecp_group_load().
  * \param d         The destination MPI (secret part).
+ *                  This must be initialized.
  * \param Q         The destination point (public part).
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG context.
+ *                  This must be initialized.
+ * \param f_rng     The RNG function. This must not be \c NULL.
+ * \param p_rng     The RNG context to be passed to \p f_rng. This may
+ *                  be \c NULL if \p f_rng doesn't need a context argument.
  *
  * \return          \c 0 on success.
  * \return          An \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_MPI_XXX error code
  *                  on failure.
  */
-int mbedtls_ecp_gen_keypair( mbedtls_ecp_group *grp, mbedtls_mpi *d, mbedtls_ecp_point *Q,
-                     int (*f_rng)(void *, unsigned char *, size_t),
-                     void *p_rng );
+int mbedtls_ecp_gen_keypair( mbedtls_ecp_group *grp, mbedtls_mpi *d,
+                             mbedtls_ecp_point *Q,
+                             int (*f_rng)(void *, unsigned char *, size_t),
+                             void *p_rng );
 
 /**
  * \brief           This function generates an ECP key.
  *
  * \param grp_id    The ECP group identifier.
- * \param key       The destination key.
- * \param f_rng     The RNG function.
- * \param p_rng     The RNG context.
+ * \param key       The destination key. This must be initialized.
+ * \param f_rng     The RNG function to use. This must not be \c NULL.
+ * \param p_rng     The RNG context to be passed to \p f_rng. This may
+ *                  be \c NULL if \p f_rng doesn't need a context argument.
  *
  * \return          \c 0 on success.
  * \return          An \c MBEDTLS_ERR_ECP_XXX or \c MBEDTLS_MPI_XXX error code
  *                  on failure.
  */
 int mbedtls_ecp_gen_key( mbedtls_ecp_group_id grp_id, mbedtls_ecp_keypair *key,
-                int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
+                         int (*f_rng)(void *, unsigned char *, size_t),
+                         void *p_rng );
 
 /**
  * \brief           This function checks that the keypair objects
@@ -988,16 +1093,19 @@
  *                  same public point, and that the private key in
  *                  \p prv is consistent with the public key.
  *
- * \param pub       The keypair structure holding the public key.
- *                  If it contains a private key, that part is ignored.
+ * \param pub       The keypair structure holding the public key. This
+ *                  must be initialized. If it contains a private key, that
+ *                  part is ignored.
  * \param prv       The keypair structure holding the full keypair.
+ *                  This must be initialized.
  *
  * \return          \c 0 on success, meaning that the keys are valid and match.
  * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if the keys are invalid or do not match.
  * \return          An \c MBEDTLS_ERR_ECP_XXX or an \c MBEDTLS_ERR_MPI_XXX
  *                  error code on calculation failure.
  */
-int mbedtls_ecp_check_pub_priv( const mbedtls_ecp_keypair *pub, const mbedtls_ecp_keypair *prv );
+int mbedtls_ecp_check_pub_priv( const mbedtls_ecp_keypair *pub,
+                                const mbedtls_ecp_keypair *prv );
 
 #if defined(MBEDTLS_SELF_TEST)
 
diff --git a/include/mbedtls/error.h b/include/mbedtls/error.h
index 0c38889..647a11a 100644
--- a/include/mbedtls/error.h
+++ b/include/mbedtls/error.h
@@ -74,9 +74,9 @@
  * MD4       1                  0x002D-0x002D
  * MD5       1                  0x002F-0x002F
  * RIPEMD160 1                  0x0031-0x0031
- * SHA1      1                  0x0035-0x0035
- * SHA256    1                  0x0037-0x0037
- * SHA512    1                  0x0039-0x0039
+ * SHA1      1                  0x0035-0x0035 0x0073-0x0073
+ * SHA256    1                  0x0037-0x0037 0x0074-0x0074
+ * SHA512    1                  0x0039-0x0039 0x0075-0x0075
  * CHACHA20  3                  0x0051-0x0055
  * POLY1305  3                  0x0057-0x005B
  * CHACHAPOLY 2 0x0054-0x0056
diff --git a/include/mbedtls/gcm.h b/include/mbedtls/gcm.h
index 93d15ee..fccabb0 100644
--- a/include/mbedtls/gcm.h
+++ b/include/mbedtls/gcm.h
@@ -85,7 +85,7 @@
  *                  cipher, nor set the key. For this purpose, use
  *                  mbedtls_gcm_setkey().
  *
- * \param ctx       The GCM context to initialize.
+ * \param ctx       The GCM context to initialize. This must not be \c NULL.
  */
 void mbedtls_gcm_init( mbedtls_gcm_context *ctx );
 
@@ -93,9 +93,10 @@
  * \brief           This function associates a GCM context with a
  *                  cipher algorithm and a key.
  *
- * \param ctx       The GCM context to initialize.
+ * \param ctx       The GCM context. This must be initialized.
  * \param cipher    The 128-bit block cipher to use.
- * \param key       The encryption key.
+ * \param key       The encryption key. This must be a readable buffer of at
+ *                  least \p keybits bits.
  * \param keybits   The key size in bits. Valid options are:
  *                  <ul><li>128 bits</li>
  *                  <li>192 bits</li>
@@ -122,7 +123,8 @@
  *                  authentic. You should use this function to perform encryption
  *                  only. For decryption, use mbedtls_gcm_auth_decrypt() instead.
  *
- * \param ctx       The GCM context to use for encryption or decryption.
+ * \param ctx       The GCM context to use for encryption or decryption. This
+ *                  must be initialized.
  * \param mode      The operation to perform:
  *                  - #MBEDTLS_GCM_ENCRYPT to perform authenticated encryption.
  *                    The ciphertext is written to \p output and the
@@ -136,21 +138,27 @@
  *                    calling this function in decryption mode.
  * \param length    The length of the input data, which is equal to the length
  *                  of the output data.
- * \param iv        The initialization vector.
+ * \param iv        The initialization vector. This must be a readable buffer of
+ *                  at least \p iv_len Bytes.
  * \param iv_len    The length of the IV.
- * \param add       The buffer holding the additional data.
+ * \param add       The buffer holding the additional data. This must be of at
+ *                  least that size in Bytes.
  * \param add_len   The length of the additional data.
- * \param input     The buffer holding the input data. Its size is \b length.
- * \param output    The buffer for holding the output data. It must have room
- *                  for \b length bytes.
+ * \param input     The buffer holding the input data. If \p length is greater
+ *                  than zero, this must be a readable buffer of at least that
+ *                  size in Bytes.
+ * \param output    The buffer for holding the output data. If \p length is greater
+ *                  than zero, this must be a writable buffer of at least that
+ *                  size in Bytes.
  * \param tag_len   The length of the tag to generate.
- * \param tag       The buffer for holding the tag.
+ * \param tag       The buffer for holding the tag. This must be a readable
+ *                  buffer of at least \p tag_len Bytes.
  *
  * \return          \c 0 if the encryption or decryption was performed
  *                  successfully. Note that in #MBEDTLS_GCM_DECRYPT mode,
  *                  this does not indicate that the data is authentic.
- * \return          #MBEDTLS_ERR_GCM_BAD_INPUT if the lengths are not valid or
- *                  a cipher-specific error code if the encryption
+ * \return          #MBEDTLS_ERR_GCM_BAD_INPUT if the lengths or pointers are
+ *                  not valid or a cipher-specific error code if the encryption
  *                  or decryption failed.
  */
 int mbedtls_gcm_crypt_and_tag( mbedtls_gcm_context *ctx,
@@ -173,23 +181,30 @@
  *                  input buffer. If the buffers overlap, the output buffer
  *                  must trail at least 8 Bytes behind the input buffer.
  *
- * \param ctx       The GCM context.
+ * \param ctx       The GCM context. This must be initialized.
  * \param length    The length of the ciphertext to decrypt, which is also
  *                  the length of the decrypted plaintext.
- * \param iv        The initialization vector.
+ * \param iv        The initialization vector. This must be a readable buffer
+ *                  of at least \p iv_len Bytes.
  * \param iv_len    The length of the IV.
- * \param add       The buffer holding the additional data.
+ * \param add       The buffer holding the additional data. This must be of at
+ *                  least that size in Bytes.
  * \param add_len   The length of the additional data.
- * \param tag       The buffer holding the tag to verify.
+ * \param tag       The buffer holding the tag to verify. This must be a
+ *                  readable buffer of at least \p tag_len Bytes.
  * \param tag_len   The length of the tag to verify.
- * \param input     The buffer holding the ciphertext. Its size is \b length.
- * \param output    The buffer for holding the decrypted plaintext. It must
- *                  have room for \b length bytes.
+ * \param input     The buffer holding the ciphertext. If \p length is greater
+ *                  than zero, this must be a readable buffer of at least that
+ *                  size.
+ * \param output    The buffer for holding the decrypted plaintext. If \p length
+ *                  is greater than zero, this must be a writable buffer of at
+ *                  least that size.
  *
  * \return          \c 0 if successful and authenticated.
  * \return          #MBEDTLS_ERR_GCM_AUTH_FAILED if the tag does not match.
- * \return          #MBEDTLS_ERR_GCM_BAD_INPUT if the lengths are not valid or
- *                  a cipher-specific error code if the decryption failed.
+ * \return          #MBEDTLS_ERR_GCM_BAD_INPUT if the lengths or pointers are
+ *                  not valid or a cipher-specific error code if the decryption
+ *                  failed.
  */
 int mbedtls_gcm_auth_decrypt( mbedtls_gcm_context *ctx,
                       size_t length,
@@ -206,15 +221,16 @@
  * \brief           This function starts a GCM encryption or decryption
  *                  operation.
  *
- * \param ctx       The GCM context.
+ * \param ctx       The GCM context. This must be initialized.
  * \param mode      The operation to perform: #MBEDTLS_GCM_ENCRYPT or
  *                  #MBEDTLS_GCM_DECRYPT.
- * \param iv        The initialization vector.
+ * \param iv        The initialization vector. This must be a readable buffer of
+ *                  at least \p iv_len Bytes.
  * \param iv_len    The length of the IV.
- * \param add       The buffer holding the additional data, or NULL
- *                  if \p add_len is 0.
- * \param add_len   The length of the additional data. If 0,
- *                  \p add is NULL.
+ * \param add       The buffer holding the additional data, or \c NULL
+ *                  if \p add_len is \c 0.
+ * \param add_len   The length of the additional data. If \c 0,
+ *                  \p add may be \c NULL.
  *
  * \return          \c 0 on success.
  */
@@ -237,11 +253,15 @@
  *                  input buffer. If the buffers overlap, the output buffer
  *                  must trail at least 8 Bytes behind the input buffer.
  *
- * \param ctx       The GCM context.
+ * \param ctx       The GCM context. This must be initialized.
  * \param length    The length of the input data. This must be a multiple of
  *                  16 except in the last call before mbedtls_gcm_finish().
- * \param input     The buffer holding the input data.
- * \param output    The buffer for holding the output data.
+ * \param input     The buffer holding the input data. If \p length is greater
+ *                  than zero, this must be a readable buffer of at least that
+ *                  size in Bytes.
+ * \param output    The buffer for holding the output data. If \p length is
+ *                  greater than zero, this must be a writable buffer of at
+ *                  least that size in Bytes.
  *
  * \return         \c 0 on success.
  * \return         #MBEDTLS_ERR_GCM_BAD_INPUT on failure.
@@ -258,9 +278,11 @@
  *                  It wraps up the GCM stream, and generates the
  *                  tag. The tag can have a maximum length of 16 Bytes.
  *
- * \param ctx       The GCM context.
- * \param tag       The buffer for holding the tag.
- * \param tag_len   The length of the tag to generate. Must be at least four.
+ * \param ctx       The GCM context. This must be initialized.
+ * \param tag       The buffer for holding the tag. This must be a readable
+ *                  buffer of at least \p tag_len Bytes.
+ * \param tag_len   The length of the tag to generate. This must be at least
+ *                  four.
  *
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_GCM_BAD_INPUT on failure.
@@ -273,7 +295,8 @@
  * \brief           This function clears a GCM context and the underlying
  *                  cipher sub-context.
  *
- * \param ctx       The GCM context to clear.
+ * \param ctx       The GCM context to clear. If this is \c NULL, the call has
+ *                  no effect. Otherwise, this must be initialized.
  */
 void mbedtls_gcm_free( mbedtls_gcm_context *ctx );
 
diff --git a/include/mbedtls/padlock.h b/include/mbedtls/padlock.h
index 677936e..7a5d083 100644
--- a/include/mbedtls/padlock.h
+++ b/include/mbedtls/padlock.h
@@ -3,6 +3,9 @@
  *
  * \brief VIA PadLock ACE for HW encryption/decryption supported by some
  *        processors
+ *
+ * \warning These functions are only for internal use by other library
+ *          functions; you must not call them directly.
  */
 /*
  *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
@@ -57,7 +60,10 @@
 #endif
 
 /**
- * \brief          PadLock detection routine
+ * \brief          Internal PadLock detection routine
+ *
+ * \note           This function is only for internal use by other library
+ *                 functions; you must not call it directly.
  *
  * \param feature  The feature to detect
  *
@@ -66,7 +72,10 @@
 int mbedtls_padlock_has_support( int feature );
 
 /**
- * \brief          PadLock AES-ECB block en(de)cryption
+ * \brief          Internal PadLock AES-ECB block en(de)cryption
+ *
+ * \note           This function is only for internal use by other library
+ *                 functions; you must not call it directly.
  *
  * \param ctx      AES context
  * \param mode     MBEDTLS_AES_ENCRYPT or MBEDTLS_AES_DECRYPT
@@ -76,12 +85,15 @@
  * \return         0 if success, 1 if operation failed
  */
 int mbedtls_padlock_xcryptecb( mbedtls_aes_context *ctx,
-                       int mode,
-                       const unsigned char input[16],
-                       unsigned char output[16] );
+                               int mode,
+                               const unsigned char input[16],
+                               unsigned char output[16] );
 
 /**
- * \brief          PadLock AES-CBC buffer en(de)cryption
+ * \brief          Internal PadLock AES-CBC buffer en(de)cryption
+ *
+ * \note           This function is only for internal use by other library
+ *                 functions; you must not call it directly.
  *
  * \param ctx      AES context
  * \param mode     MBEDTLS_AES_ENCRYPT or MBEDTLS_AES_DECRYPT
@@ -93,11 +105,11 @@
  * \return         0 if success, 1 if operation failed
  */
 int mbedtls_padlock_xcryptcbc( mbedtls_aes_context *ctx,
-                       int mode,
-                       size_t length,
-                       unsigned char iv[16],
-                       const unsigned char *input,
-                       unsigned char *output );
+                               int mode,
+                               size_t length,
+                               unsigned char iv[16],
+                               const unsigned char *input,
+                               unsigned char *output );
 
 #ifdef __cplusplus
 }
diff --git a/include/mbedtls/poly1305.h b/include/mbedtls/poly1305.h
index b02f968..05866a2 100644
--- a/include/mbedtls/poly1305.h
+++ b/include/mbedtls/poly1305.h
@@ -84,14 +84,18 @@
  *                  \c mbedtls_poly1305_finish(), then finally
  *                  \c mbedtls_poly1305_free().
  *
- * \param ctx       The Poly1305 context to initialize.
+ * \param ctx       The Poly1305 context to initialize. This must
+ *                  not be \c NULL.
  */
 void mbedtls_poly1305_init( mbedtls_poly1305_context *ctx );
 
 /**
- * \brief           This function releases and clears the specified Poly1305 context.
+ * \brief           This function releases and clears the specified
+ *                  Poly1305 context.
  *
- * \param ctx       The Poly1305 context to clear.
+ * \param ctx       The Poly1305 context to clear. This may be \c NULL, in which
+ *                  case this function is a no-op. If it is not \c NULL, it must
+ *                  point to an initialized Poly1305 context.
  */
 void mbedtls_poly1305_free( mbedtls_poly1305_context *ctx );
 
@@ -102,11 +106,11 @@
  *                  invocation of Poly1305.
  *
  * \param ctx       The Poly1305 context to which the key should be bound.
- * \param key       The buffer containing the 256-bit key.
+ *                  This must be initialized.
+ * \param key       The buffer containing the \c 32 Byte (\c 256 Bit) key.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
- *                  if ctx or key are NULL.
+ * \return          A negative error code on failure.
  */
 int mbedtls_poly1305_starts( mbedtls_poly1305_context *ctx,
                              const unsigned char key[32] );
@@ -120,13 +124,14 @@
  *                  It can be called repeatedly to process a stream of data.
  *
  * \param ctx       The Poly1305 context to use for the Poly1305 operation.
- * \param ilen      The length of the input data (in bytes). Any value is accepted.
+ *                  This must be initialized and bound to a key.
+ * \param ilen      The length of the input data in Bytes.
+ *                  Any value is accepted.
  * \param input     The buffer holding the input data.
- *                  This pointer can be NULL if ilen == 0.
+ *                  This pointer can be \c NULL if `ilen == 0`.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
- *                  if ctx or input are NULL.
+ * \return          A negative error code on failure.
  */
 int mbedtls_poly1305_update( mbedtls_poly1305_context *ctx,
                              const unsigned char *input,
@@ -137,12 +142,12 @@
  *                  Authentication Code (MAC).
  *
  * \param ctx       The Poly1305 context to use for the Poly1305 operation.
- * \param mac       The buffer to where the MAC is written. Must be big enough
- *                  to hold the 16-byte MAC.
+ *                  This must be initialized and bound to a key.
+ * \param mac       The buffer to where the MAC is written. This must
+ *                  be a writable buffer of length \c 16 Bytes.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
- *                  if ctx or mac are NULL.
+ * \return          A negative error code on failure.
  */
 int mbedtls_poly1305_finish( mbedtls_poly1305_context *ctx,
                              unsigned char mac[16] );
@@ -154,16 +159,16 @@
  * \warning         The key must be unique and unpredictable for each
  *                  invocation of Poly1305.
  *
- * \param key       The buffer containing the 256-bit key.
- * \param ilen      The length of the input data (in bytes). Any value is accepted.
+ * \param key       The buffer containing the \c 32 Byte (\c 256 Bit) key.
+ * \param ilen      The length of the input data in Bytes.
+ *                  Any value is accepted.
  * \param input     The buffer holding the input data.
- *                  This pointer can be NULL if ilen == 0.
- * \param mac       The buffer to where the MAC is written. Must be big enough
- *                  to hold the 16-byte MAC.
+ *                  This pointer can be \c NULL if `ilen == 0`.
+ * \param mac       The buffer to where the MAC is written. This must be
+ *                  a writable buffer of length \c 16 Bytes.
  *
  * \return          \c 0 on success.
- * \return          #MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA
- *                  if key, input, or mac are NULL.
+ * \return          A negative error code on failure.
  */
 int mbedtls_poly1305_mac( const unsigned char key[32],
                           const unsigned char *input,
diff --git a/include/mbedtls/sha1.h b/include/mbedtls/sha1.h
index bcaeab5..38ea10b 100644
--- a/include/mbedtls/sha1.h
+++ b/include/mbedtls/sha1.h
@@ -42,6 +42,7 @@
 
 /* MBEDTLS_ERR_SHA1_HW_ACCEL_FAILED is deprecated and should not be used. */
 #define MBEDTLS_ERR_SHA1_HW_ACCEL_FAILED                  -0x0035  /**< SHA-1 hardware accelerator failed */
+#define MBEDTLS_ERR_SHA1_BAD_INPUT_DATA                   -0x0073  /**< SHA-1 input data was malformed. */
 
 #ifdef __cplusplus
 extern "C" {
@@ -79,6 +80,7 @@
  *                 stronger message digests instead.
  *
  * \param ctx      The SHA-1 context to initialize.
+ *                 This must not be \c NULL.
  *
  */
 void mbedtls_sha1_init( mbedtls_sha1_context *ctx );
@@ -90,7 +92,10 @@
  *                 constitutes a security risk. We recommend considering
  *                 stronger message digests instead.
  *
- * \param ctx      The SHA-1 context to clear.
+ * \param ctx      The SHA-1 context to clear. This may be \c NULL,
+ *                 in which case this function does nothing. If it is
+ *                 not \c NULL, it must point to an initialized
+ *                 SHA-1 context.
  *
  */
 void mbedtls_sha1_free( mbedtls_sha1_context *ctx );
@@ -102,8 +107,8 @@
  *                 constitutes a security risk. We recommend considering
  *                 stronger message digests instead.
  *
- * \param dst      The SHA-1 context to clone to.
- * \param src      The SHA-1 context to clone from.
+ * \param dst      The SHA-1 context to clone to. This must be initialized.
+ * \param src      The SHA-1 context to clone from. This must be initialized.
  *
  */
 void mbedtls_sha1_clone( mbedtls_sha1_context *dst,
@@ -116,9 +121,10 @@
  *                 constitutes a security risk. We recommend considering
  *                 stronger message digests instead.
  *
- * \param ctx      The SHA-1 context to initialize.
+ * \param ctx      The SHA-1 context to initialize. This must be initialized.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  *
  */
 int mbedtls_sha1_starts_ret( mbedtls_sha1_context *ctx );
@@ -131,11 +137,14 @@
  *                 constitutes a security risk. We recommend considering
  *                 stronger message digests instead.
  *
- * \param ctx      The SHA-1 context.
+ * \param ctx      The SHA-1 context. This must be initialized
+ *                 and have a hash operation started.
  * \param input    The buffer holding the input data.
- * \param ilen     The length of the input data.
+ *                 This must be a readable buffer of length \p ilen Bytes.
+ * \param ilen     The length of the input data \p input in Bytes.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_sha1_update_ret( mbedtls_sha1_context *ctx,
                              const unsigned char *input,
@@ -149,10 +158,13 @@
  *                 constitutes a security risk. We recommend considering
  *                 stronger message digests instead.
  *
- * \param ctx      The SHA-1 context.
- * \param output   The SHA-1 checksum result.
+ * \param ctx      The SHA-1 context to use. This must be initialized and
+ *                 have a hash operation started.
+ * \param output   The SHA-1 checksum result. This must be a writable
+ *                 buffer of length \c 20 Bytes.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_sha1_finish_ret( mbedtls_sha1_context *ctx,
                              unsigned char output[20] );
@@ -164,10 +176,12 @@
  *                 constitutes a security risk. We recommend considering
  *                 stronger message digests instead.
  *
- * \param ctx      The SHA-1 context.
- * \param data     The data block being processed.
+ * \param ctx      The SHA-1 context to use. This must be initialized.
+ * \param data     The data block being processed. This must be a
+ *                 readable buffer of length \c 64 Bytes.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  *
  */
 int mbedtls_internal_sha1_process( mbedtls_sha1_context *ctx,
@@ -188,7 +202,7 @@
  *
  * \deprecated     Superseded by mbedtls_sha1_starts_ret() in 2.7.0.
  *
- * \param ctx      The SHA-1 context to initialize.
+ * \param ctx      The SHA-1 context to initialize. This must be initialized.
  *
  */
 MBEDTLS_DEPRECATED void mbedtls_sha1_starts( mbedtls_sha1_context *ctx );
@@ -203,9 +217,11 @@
  *
  * \deprecated     Superseded by mbedtls_sha1_update_ret() in 2.7.0.
  *
- * \param ctx      The SHA-1 context.
+ * \param ctx      The SHA-1 context. This must be initialized and
+ *                 have a hash operation started.
  * \param input    The buffer holding the input data.
- * \param ilen     The length of the input data.
+ *                 This must be a readable buffer of length \p ilen Bytes.
+ * \param ilen     The length of the input data \p input in Bytes.
  *
  */
 MBEDTLS_DEPRECATED void mbedtls_sha1_update( mbedtls_sha1_context *ctx,
@@ -222,9 +238,10 @@
  *
  * \deprecated     Superseded by mbedtls_sha1_finish_ret() in 2.7.0.
  *
- * \param ctx      The SHA-1 context.
+ * \param ctx      The SHA-1 context. This must be initialized and
+ *                 have a hash operation started.
  * \param output   The SHA-1 checksum result.
- *
+ *                 This must be a writable buffer of length \c 20 Bytes.
  */
 MBEDTLS_DEPRECATED void mbedtls_sha1_finish( mbedtls_sha1_context *ctx,
                                              unsigned char output[20] );
@@ -238,8 +255,9 @@
  *
  * \deprecated     Superseded by mbedtls_internal_sha1_process() in 2.7.0.
  *
- * \param ctx      The SHA-1 context.
+ * \param ctx      The SHA-1 context. This must be initialized.
  * \param data     The data block being processed.
+ *                 This must be a readable buffer of length \c 64 bytes.
  *
  */
 MBEDTLS_DEPRECATED void mbedtls_sha1_process( mbedtls_sha1_context *ctx,
@@ -262,10 +280,13 @@
  *                 stronger message digests instead.
  *
  * \param input    The buffer holding the input data.
- * \param ilen     The length of the input data.
+ *                 This must be a readable buffer of length \p ilen Bytes.
+ * \param ilen     The length of the input data \p input in Bytes.
  * \param output   The SHA-1 checksum result.
+ *                 This must be a writable buffer of length \c 20 Bytes.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  *
  */
 int mbedtls_sha1_ret( const unsigned char *input,
@@ -294,8 +315,10 @@
  * \deprecated     Superseded by mbedtls_sha1_ret() in 2.7.0
  *
  * \param input    The buffer holding the input data.
- * \param ilen     The length of the input data.
- * \param output   The SHA-1 checksum result.
+ *                 This must be a readable buffer of length \p ilen Bytes.
+ * \param ilen     The length of the input data \p input in Bytes.
+ * \param output   The SHA-1 checksum result. This must be a writable
+ *                 buffer of size \c 20 Bytes.
  *
  */
 MBEDTLS_DEPRECATED void mbedtls_sha1( const unsigned char *input,
diff --git a/include/mbedtls/sha256.h b/include/mbedtls/sha256.h
index 47a31e8..0e42f0a 100644
--- a/include/mbedtls/sha256.h
+++ b/include/mbedtls/sha256.h
@@ -38,6 +38,7 @@
 
 /* MBEDTLS_ERR_SHA256_HW_ACCEL_FAILED is deprecated and should not be used. */
 #define MBEDTLS_ERR_SHA256_HW_ACCEL_FAILED                -0x0037  /**< SHA-256 hardware accelerator failed */
+#define MBEDTLS_ERR_SHA256_BAD_INPUT_DATA                 -0x0074  /**< SHA-256 input data was malformed. */
 
 #ifdef __cplusplus
 extern "C" {
@@ -71,22 +72,24 @@
 /**
  * \brief          This function initializes a SHA-256 context.
  *
- * \param ctx      The SHA-256 context to initialize.
+ * \param ctx      The SHA-256 context to initialize. This must not be \c NULL.
  */
 void mbedtls_sha256_init( mbedtls_sha256_context *ctx );
 
 /**
  * \brief          This function clears a SHA-256 context.
  *
- * \param ctx      The SHA-256 context to clear.
+ * \param ctx      The SHA-256 context to clear. This may be \c NULL, in which
+ *                 case this function returns immediately. If it is not \c NULL,
+ *                 it must point to an initialized SHA-256 context.
  */
 void mbedtls_sha256_free( mbedtls_sha256_context *ctx );
 
 /**
  * \brief          This function clones the state of a SHA-256 context.
  *
- * \param dst      The destination context.
- * \param src      The context to clone.
+ * \param dst      The destination context. This must be initialized.
+ * \param src      The context to clone. This must be initialized.
  */
 void mbedtls_sha256_clone( mbedtls_sha256_context *dst,
                            const mbedtls_sha256_context *src );
@@ -95,11 +98,12 @@
  * \brief          This function starts a SHA-224 or SHA-256 checksum
  *                 calculation.
  *
- * \param ctx      The context to initialize.
- * \param is224    Determines which function to use:
- *                 0: Use SHA-256, or 1: Use SHA-224.
+ * \param ctx      The context to use. This must be initialized.
+ * \param is224    This determines which function to use. This must be
+ *                 either \c 0 for SHA-256, or \c 1 for SHA-224.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_sha256_starts_ret( mbedtls_sha256_context *ctx, int is224 );
 
@@ -107,11 +111,14 @@
  * \brief          This function feeds an input buffer into an ongoing
  *                 SHA-256 checksum calculation.
  *
- * \param ctx      The SHA-256 context.
- * \param input    The buffer holding the data.
- * \param ilen     The length of the input data.
+ * \param ctx      The SHA-256 context. This must be initialized
+ *                 and have a hash operation started.
+ * \param input    The buffer holding the data. This must be a readable
+ *                 buffer of length \p ilen Bytes.
+ * \param ilen     The length of the input data in Bytes.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_sha256_update_ret( mbedtls_sha256_context *ctx,
                                const unsigned char *input,
@@ -121,10 +128,13 @@
  * \brief          This function finishes the SHA-256 operation, and writes
  *                 the result to the output buffer.
  *
- * \param ctx      The SHA-256 context.
+ * \param ctx      The SHA-256 context. This must be initialized
+ *                 and have a hash operation started.
  * \param output   The SHA-224 or SHA-256 checksum result.
+ *                 This must be a writable buffer of length \c 32 Bytes.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_sha256_finish_ret( mbedtls_sha256_context *ctx,
                                unsigned char output[32] );
@@ -134,10 +144,12 @@
  *                 the ongoing SHA-256 computation. This function is for
  *                 internal use only.
  *
- * \param ctx      The SHA-256 context.
- * \param data     The buffer holding one block of data.
+ * \param ctx      The SHA-256 context. This must be initialized.
+ * \param data     The buffer holding one block of data. This must
+ *                 be a readable buffer of length \c 64 Bytes.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_internal_sha256_process( mbedtls_sha256_context *ctx,
                                      const unsigned char data[64] );
@@ -152,12 +164,11 @@
  * \brief          This function starts a SHA-224 or SHA-256 checksum
  *                 calculation.
  *
- *
  * \deprecated     Superseded by mbedtls_sha256_starts_ret() in 2.7.0.
  *
- * \param ctx      The context to initialize.
- * \param is224    Determines which function to use:
- *                 0: Use SHA-256, or 1: Use SHA-224.
+ * \param ctx      The context to use. This must be initialized.
+ * \param is224    Determines which function to use. This must be
+ *                 either \c 0 for SHA-256, or \c 1 for SHA-224.
  */
 MBEDTLS_DEPRECATED void mbedtls_sha256_starts( mbedtls_sha256_context *ctx,
                                                int is224 );
@@ -168,9 +179,11 @@
  *
  * \deprecated     Superseded by mbedtls_sha256_update_ret() in 2.7.0.
  *
- * \param ctx      The SHA-256 context to initialize.
- * \param input    The buffer holding the data.
- * \param ilen     The length of the input data.
+ * \param ctx      The SHA-256 context to use. This must be
+ *                 initialized and have a hash operation started.
+ * \param input    The buffer holding the data. This must be a readable
+ *                 buffer of length \p ilen Bytes.
+ * \param ilen     The length of the input data in Bytes.
  */
 MBEDTLS_DEPRECATED void mbedtls_sha256_update( mbedtls_sha256_context *ctx,
                                                const unsigned char *input,
@@ -182,8 +195,10 @@
  *
  * \deprecated     Superseded by mbedtls_sha256_finish_ret() in 2.7.0.
  *
- * \param ctx      The SHA-256 context.
- * \param output   The SHA-224 or SHA-256 checksum result.
+ * \param ctx      The SHA-256 context. This must be initialized and
+ *                 have a hash operation started.
+ * \param output   The SHA-224 or SHA-256 checksum result. This must be
+ *                 a writable buffer of length \c 32 Bytes.
  */
 MBEDTLS_DEPRECATED void mbedtls_sha256_finish( mbedtls_sha256_context *ctx,
                                                unsigned char output[32] );
@@ -195,8 +210,9 @@
  *
  * \deprecated     Superseded by mbedtls_internal_sha256_process() in 2.7.0.
  *
- * \param ctx      The SHA-256 context.
- * \param data     The buffer holding one block of data.
+ * \param ctx      The SHA-256 context. This must be initialized.
+ * \param data     The buffer holding one block of data. This must be
+ *                 a readable buffer of size \c 64 Bytes.
  */
 MBEDTLS_DEPRECATED void mbedtls_sha256_process( mbedtls_sha256_context *ctx,
                                                 const unsigned char data[64] );
@@ -214,11 +230,13 @@
  *                 The SHA-256 result is calculated as
  *                 output = SHA-256(input buffer).
  *
- * \param input    The buffer holding the input data.
- * \param ilen     The length of the input data.
- * \param output   The SHA-224 or SHA-256 checksum result.
- * \param is224    Determines which function to use:
- *                 0: Use SHA-256, or 1: Use SHA-224.
+ * \param input    The buffer holding the data. This must be a readable
+ *                 buffer of length \p ilen Bytes.
+ * \param ilen     The length of the input data in Bytes.
+ * \param output   The SHA-224 or SHA-256 checksum result. This must
+ *                 be a writable buffer of length \c 32 Bytes.
+ * \param is224    Determines which function to use. This must be
+ *                 either \c 0 for SHA-256, or \c 1 for SHA-224.
  */
 int mbedtls_sha256_ret( const unsigned char *input,
                         size_t ilen,
@@ -244,11 +262,13 @@
  *
  * \deprecated     Superseded by mbedtls_sha256_ret() in 2.7.0.
  *
- * \param input    The buffer holding the data.
- * \param ilen     The length of the input data.
- * \param output   The SHA-224 or SHA-256 checksum result.
- * \param is224    Determines which function to use:
- *                 0: Use SHA-256, or 1: Use SHA-224.
+ * \param input    The buffer holding the data. This must be a readable
+ *                 buffer of length \p ilen Bytes.
+ * \param ilen     The length of the input data in Bytes.
+ * \param output   The SHA-224 or SHA-256 checksum result. This must be
+ *                 a writable buffer of length \c 32 Bytes.
+ * \param is224    Determines which function to use. This must be either
+ *                 \c 0 for SHA-256, or \c 1 for SHA-224.
  */
 MBEDTLS_DEPRECATED void mbedtls_sha256( const unsigned char *input,
                                         size_t ilen,
diff --git a/include/mbedtls/sha512.h b/include/mbedtls/sha512.h
index 020f95d..7b26cf5 100644
--- a/include/mbedtls/sha512.h
+++ b/include/mbedtls/sha512.h
@@ -37,6 +37,7 @@
 
 /* MBEDTLS_ERR_SHA512_HW_ACCEL_FAILED is deprecated and should not be used. */
 #define MBEDTLS_ERR_SHA512_HW_ACCEL_FAILED                -0x0039  /**< SHA-512 hardware accelerator failed */
+#define MBEDTLS_ERR_SHA512_BAD_INPUT_DATA                 -0x0075  /**< SHA-512 input data was malformed. */
 
 #ifdef __cplusplus
 extern "C" {
@@ -70,22 +71,26 @@
 /**
  * \brief          This function initializes a SHA-512 context.
  *
- * \param ctx      The SHA-512 context to initialize.
+ * \param ctx      The SHA-512 context to initialize. This must
+ *                 not be \c NULL.
  */
 void mbedtls_sha512_init( mbedtls_sha512_context *ctx );
 
 /**
  * \brief          This function clears a SHA-512 context.
  *
- * \param ctx      The SHA-512 context to clear.
+ * \param ctx      The SHA-512 context to clear. This may be \c NULL,
+ *                 in which case this function does nothing. If it
+ *                 is not \c NULL, it must point to an initialized
+ *                 SHA-512 context.
  */
 void mbedtls_sha512_free( mbedtls_sha512_context *ctx );
 
 /**
  * \brief          This function clones the state of a SHA-512 context.
  *
- * \param dst      The destination context.
- * \param src      The context to clone.
+ * \param dst      The destination context. This must be initialized.
+ * \param src      The context to clone. This must be initialized.
  */
 void mbedtls_sha512_clone( mbedtls_sha512_context *dst,
                            const mbedtls_sha512_context *src );
@@ -94,11 +99,12 @@
  * \brief          This function starts a SHA-384 or SHA-512 checksum
  *                 calculation.
  *
- * \param ctx      The SHA-512 context to initialize.
- * \param is384    Determines which function to use:
- *                 0: Use SHA-512, or 1: Use SHA-384.
+ * \param ctx      The SHA-512 context to use. This must be initialized.
+ * \param is384    Determines which function to use. This must be
+ *                 either \c for SHA-512, or \c 1 for SHA-384.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_sha512_starts_ret( mbedtls_sha512_context *ctx, int is384 );
 
@@ -106,11 +112,14 @@
  * \brief          This function feeds an input buffer into an ongoing
  *                 SHA-512 checksum calculation.
  *
- * \param ctx      The SHA-512 context.
- * \param input    The buffer holding the input data.
- * \param ilen     The length of the input data.
+ * \param ctx      The SHA-512 context. This must be initialized
+ *                 and have a hash operation started.
+ * \param input    The buffer holding the input data. This must
+ *                 be a readable buffer of length \p ilen Bytes.
+ * \param ilen     The length of the input data in Bytes.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_sha512_update_ret( mbedtls_sha512_context *ctx,
                     const unsigned char *input,
@@ -121,10 +130,13 @@
  *                 the result to the output buffer. This function is for
  *                 internal use only.
  *
- * \param ctx      The SHA-512 context.
+ * \param ctx      The SHA-512 context. This must be initialized
+ *                 and have a hash operation started.
  * \param output   The SHA-384 or SHA-512 checksum result.
+ *                 This must be a writable buffer of length \c 64 Bytes.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_sha512_finish_ret( mbedtls_sha512_context *ctx,
                                unsigned char output[64] );
@@ -133,10 +145,12 @@
  * \brief          This function processes a single data block within
  *                 the ongoing SHA-512 computation.
  *
- * \param ctx      The SHA-512 context.
- * \param data     The buffer holding one block of data.
+ * \param ctx      The SHA-512 context. This must be initialized.
+ * \param data     The buffer holding one block of data. This
+ *                 must be a readable buffer of length \c 128 Bytes.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_internal_sha512_process( mbedtls_sha512_context *ctx,
                                      const unsigned char data[128] );
@@ -152,9 +166,9 @@
  *
  * \deprecated     Superseded by mbedtls_sha512_starts_ret() in 2.7.0
  *
- * \param ctx      The SHA-512 context to initialize.
- * \param is384    Determines which function to use:
- *                 0: Use SHA-512, or 1: Use SHA-384.
+ * \param ctx      The SHA-512 context to use. This must be initialized.
+ * \param is384    Determines which function to use. This must be either
+ *                 \c 0 for SHA-512 or \c 1 for SHA-384.
  */
 MBEDTLS_DEPRECATED void mbedtls_sha512_starts( mbedtls_sha512_context *ctx,
                                                int is384 );
@@ -165,9 +179,11 @@
  *
  * \deprecated     Superseded by mbedtls_sha512_update_ret() in 2.7.0.
  *
- * \param ctx      The SHA-512 context.
- * \param input    The buffer holding the data.
- * \param ilen     The length of the input data.
+ * \param ctx      The SHA-512 context. This must be initialized
+ *                 and have a hash operation started.
+ * \param input    The buffer holding the data. This must be a readable
+ *                 buffer of length \p ilen Bytes.
+ * \param ilen     The length of the input data in Bytes.
  */
 MBEDTLS_DEPRECATED void mbedtls_sha512_update( mbedtls_sha512_context *ctx,
                                                const unsigned char *input,
@@ -179,8 +195,10 @@
  *
  * \deprecated     Superseded by mbedtls_sha512_finish_ret() in 2.7.0.
  *
- * \param ctx      The SHA-512 context.
- * \param output   The SHA-384 or SHA-512 checksum result.
+ * \param ctx      The SHA-512 context. This must be initialized
+ *                 and have a hash operation started.
+ * \param output   The SHA-384 or SHA-512 checksum result. This must
+ *                 be a writable buffer of size \c 64 Bytes.
  */
 MBEDTLS_DEPRECATED void mbedtls_sha512_finish( mbedtls_sha512_context *ctx,
                                                unsigned char output[64] );
@@ -192,8 +210,9 @@
  *
  * \deprecated     Superseded by mbedtls_internal_sha512_process() in 2.7.0.
  *
- * \param ctx      The SHA-512 context.
- * \param data     The buffer holding one block of data.
+ * \param ctx      The SHA-512 context. This must be initialized.
+ * \param data     The buffer holding one block of data. This must be
+ *                 a readable buffer of length \c 128 Bytes.
  */
 MBEDTLS_DEPRECATED void mbedtls_sha512_process(
                                             mbedtls_sha512_context *ctx,
@@ -212,13 +231,16 @@
  *                 The SHA-512 result is calculated as
  *                 output = SHA-512(input buffer).
  *
- * \param input    The buffer holding the input data.
- * \param ilen     The length of the input data.
+ * \param input    The buffer holding the input data. This must be
+ *                 a readable buffer of length \p ilen Bytes.
+ * \param ilen     The length of the input data in Bytes.
  * \param output   The SHA-384 or SHA-512 checksum result.
- * \param is384    Determines which function to use:
- *                 0: Use SHA-512, or 1: Use SHA-384.
+ *                 This must be a writable buffer of length \c 64 Bytes.
+ * \param is384    Determines which function to use. This must be either
+ *                 \c 0 for SHA-512, or \c 1 for SHA-384.
  *
  * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 int mbedtls_sha512_ret( const unsigned char *input,
                         size_t ilen,
@@ -243,11 +265,13 @@
  *
  * \deprecated     Superseded by mbedtls_sha512_ret() in 2.7.0
  *
- * \param input    The buffer holding the data.
- * \param ilen     The length of the input data.
- * \param output   The SHA-384 or SHA-512 checksum result.
- * \param is384    Determines which function to use:
- *                 0: Use SHA-512, or 1: Use SHA-384.
+ * \param input    The buffer holding the data. This must be a
+ *                 readable buffer of length \p ilen Bytes.
+ * \param ilen     The length of the input data in Bytes.
+ * \param output   The SHA-384 or SHA-512 checksum result. This must
+ *                 be a writable buffer of length \c 64 Bytes.
+ * \param is384    Determines which function to use. This must be either
+ *                 \c 0 for SHA-512, or \c 1 for SHA-384.
  */
 MBEDTLS_DEPRECATED void mbedtls_sha512( const unsigned char *input,
                                         size_t ilen,
diff --git a/library/aes.c b/library/aes.c
index cc1e5ce..0543cd7 100644
--- a/library/aes.c
+++ b/library/aes.c
@@ -575,7 +575,6 @@
     {
         aes_gen_tables();
         aes_init_done = 1;
-
     }
 #endif
 
@@ -771,6 +770,9 @@
     const unsigned char *key1, *key2;
     unsigned int key1bits, key2bits;
 
+    AES_VALIDATE_RET( ctx != NULL );
+    AES_VALIDATE_RET( key != NULL );
+
     ret = mbedtls_aes_xts_decode_keys( key, keybits, &key1, &key1bits,
                                        &key2, &key2bits );
     if( ret != 0 )
@@ -793,6 +795,9 @@
     const unsigned char *key1, *key2;
     unsigned int key1bits, key2bits;
 
+    AES_VALIDATE_RET( ctx != NULL );
+    AES_VALIDATE_RET( key != NULL );
+
     ret = mbedtls_aes_xts_decode_keys( key, keybits, &key1, &key1bits,
                                        &key2, &key2bits );
     if( ret != 0 )
@@ -996,10 +1001,16 @@
  * AES-ECB block encryption/decryption
  */
 int mbedtls_aes_crypt_ecb( mbedtls_aes_context *ctx,
-                    int mode,
-                    const unsigned char input[16],
-                    unsigned char output[16] )
+                           int mode,
+                           const unsigned char input[16],
+                           unsigned char output[16] )
 {
+    AES_VALIDATE_RET( ctx != NULL );
+    AES_VALIDATE_RET( input != NULL );
+    AES_VALIDATE_RET( output != NULL );
+    AES_VALIDATE_RET( mode == MBEDTLS_AES_ENCRYPT ||
+                      mode == MBEDTLS_AES_DECRYPT );
+
 #if defined(MBEDTLS_AESNI_C) && defined(MBEDTLS_HAVE_X86_64)
     if( mbedtls_aesni_has_support( MBEDTLS_AESNI_AES ) )
         return( mbedtls_aesni_crypt_ecb( ctx, mode, input, output ) );
@@ -1037,6 +1048,13 @@
     int i;
     unsigned char temp[16];
 
+    AES_VALIDATE_RET( ctx != NULL );
+    AES_VALIDATE_RET( mode == MBEDTLS_AES_ENCRYPT ||
+                      mode == MBEDTLS_AES_DECRYPT );
+    AES_VALIDATE_RET( iv != NULL );
+    AES_VALIDATE_RET( input != NULL );
+    AES_VALIDATE_RET( output != NULL );
+
     if( length % 16 )
         return( MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH );
 
@@ -1162,6 +1180,13 @@
     unsigned char prev_tweak[16];
     unsigned char tmp[16];
 
+    AES_VALIDATE_RET( ctx != NULL );
+    AES_VALIDATE_RET( mode == MBEDTLS_AES_ENCRYPT ||
+                      mode == MBEDTLS_AES_DECRYPT );
+    AES_VALIDATE_RET( data_unit != NULL );
+    AES_VALIDATE_RET( input != NULL );
+    AES_VALIDATE_RET( output != NULL );
+
     /* Data units must be at least 16 bytes long. */
     if( length < 16 )
         return MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH;
@@ -1261,7 +1286,20 @@
                        unsigned char *output )
 {
     int c;
-    size_t n = *iv_off;
+    size_t n;
+
+    AES_VALIDATE_RET( ctx != NULL );
+    AES_VALIDATE_RET( mode == MBEDTLS_AES_ENCRYPT ||
+                      mode == MBEDTLS_AES_DECRYPT );
+    AES_VALIDATE_RET( iv_off != NULL );
+    AES_VALIDATE_RET( iv != NULL );
+    AES_VALIDATE_RET( input != NULL );
+    AES_VALIDATE_RET( output != NULL );
+
+    n = *iv_off;
+
+    if( n > 15 )
+        return( MBEDTLS_ERR_AES_BAD_INPUT_DATA );
 
     if( mode == MBEDTLS_AES_DECRYPT )
     {
@@ -1299,15 +1337,21 @@
  * AES-CFB8 buffer encryption/decryption
  */
 int mbedtls_aes_crypt_cfb8( mbedtls_aes_context *ctx,
-                       int mode,
-                       size_t length,
-                       unsigned char iv[16],
-                       const unsigned char *input,
-                       unsigned char *output )
+                            int mode,
+                            size_t length,
+                            unsigned char iv[16],
+                            const unsigned char *input,
+                            unsigned char *output )
 {
     unsigned char c;
     unsigned char ov[17];
 
+    AES_VALIDATE_RET( ctx != NULL );
+    AES_VALIDATE_RET( mode == MBEDTLS_AES_ENCRYPT ||
+                      mode == MBEDTLS_AES_DECRYPT );
+    AES_VALIDATE_RET( iv != NULL );
+    AES_VALIDATE_RET( input != NULL );
+    AES_VALIDATE_RET( output != NULL );
     while( length-- )
     {
         memcpy( ov, iv, 16 );
@@ -1340,7 +1384,18 @@
                            unsigned char *output )
 {
     int ret = 0;
-    size_t n = *iv_off;
+    size_t n;
+
+    AES_VALIDATE_RET( ctx != NULL );
+    AES_VALIDATE_RET( iv_off != NULL );
+    AES_VALIDATE_RET( iv != NULL );
+    AES_VALIDATE_RET( input != NULL );
+    AES_VALIDATE_RET( output != NULL );
+
+    n = *iv_off;
+
+    if( n > 15 )
+        return( MBEDTLS_ERR_AES_BAD_INPUT_DATA );
 
     while( length-- )
     {
@@ -1375,7 +1430,16 @@
                        unsigned char *output )
 {
     int c, i;
-    size_t n = *nc_off;
+    size_t n;
+
+    AES_VALIDATE_RET( ctx != NULL );
+    AES_VALIDATE_RET( nc_off != NULL );
+    AES_VALIDATE_RET( nonce_counter != NULL );
+    AES_VALIDATE_RET( stream_block != NULL );
+    AES_VALIDATE_RET( input != NULL );
+    AES_VALIDATE_RET( output != NULL );
+
+    n = *nc_off;
 
     if ( n > 0x0F )
         return( MBEDTLS_ERR_AES_BAD_INPUT_DATA );
diff --git a/library/aria.c b/library/aria.c
index 6d87941..aff66d6 100644
--- a/library/aria.c
+++ b/library/aria.c
@@ -55,6 +55,12 @@
 #define inline __inline
 #endif
 
+/* Parameter validation macros */
+#define ARIA_VALIDATE_RET( cond )                                       \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_ARIA_BAD_INPUT_DATA )
+#define ARIA_VALIDATE( cond )                                           \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 /*
  * 32-bit integer manipulation macros (little endian)
  */
@@ -449,6 +455,8 @@
 
     int i;
     uint32_t w[4][4], *w2;
+    ARIA_VALIDATE_RET( ctx != NULL );
+    ARIA_VALIDATE_RET( key != NULL );
 
     if( keybits != 128 && keybits != 192 && keybits != 256 )
         return( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA );
@@ -503,6 +511,8 @@
                              const unsigned char *key, unsigned int keybits )
 {
     int i, j, k, ret;
+    ARIA_VALIDATE_RET( ctx != NULL );
+    ARIA_VALIDATE_RET( key != NULL );
 
     ret = mbedtls_aria_setkey_enc( ctx, key, keybits );
     if( ret != 0 )
@@ -539,6 +549,9 @@
     int i;
 
     uint32_t a, b, c, d;
+    ARIA_VALIDATE_RET( ctx != NULL );
+    ARIA_VALIDATE_RET( input != NULL );
+    ARIA_VALIDATE_RET( output != NULL );
 
     GET_UINT32_LE( a, input,  0 );
     GET_UINT32_LE( b, input,  4 );
@@ -586,6 +599,7 @@
 /* Initialize context */
 void mbedtls_aria_init( mbedtls_aria_context *ctx )
 {
+    ARIA_VALIDATE( ctx != NULL );
     memset( ctx, 0, sizeof( mbedtls_aria_context ) );
 }
 
@@ -612,6 +626,13 @@
     int i;
     unsigned char temp[MBEDTLS_ARIA_BLOCKSIZE];
 
+    ARIA_VALIDATE_RET( ctx != NULL );
+    ARIA_VALIDATE_RET( mode == MBEDTLS_ARIA_ENCRYPT ||
+                       mode == MBEDTLS_ARIA_DECRYPT );
+    ARIA_VALIDATE_RET( length == 0 || input  != NULL );
+    ARIA_VALIDATE_RET( length == 0 || output != NULL );
+    ARIA_VALIDATE_RET( iv != NULL );
+
     if( length % MBEDTLS_ARIA_BLOCKSIZE )
         return( MBEDTLS_ERR_ARIA_INVALID_INPUT_LENGTH );
 
@@ -665,7 +686,23 @@
                                unsigned char *output )
 {
     unsigned char c;
-    size_t n = *iv_off;
+    size_t n;
+
+    ARIA_VALIDATE_RET( ctx != NULL );
+    ARIA_VALIDATE_RET( mode == MBEDTLS_ARIA_ENCRYPT ||
+                       mode == MBEDTLS_ARIA_DECRYPT );
+    ARIA_VALIDATE_RET( length == 0 || input  != NULL );
+    ARIA_VALIDATE_RET( length == 0 || output != NULL );
+    ARIA_VALIDATE_RET( iv != NULL );
+    ARIA_VALIDATE_RET( iv_off != NULL );
+
+    n = *iv_off;
+
+    /* An overly large value of n can lead to an unlimited
+     * buffer overflow. Therefore, guard against this
+     * outside of parameter validation. */
+    if( n >= MBEDTLS_ARIA_BLOCKSIZE )
+        return( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA );
 
     if( mode == MBEDTLS_ARIA_DECRYPT )
     {
@@ -713,7 +750,21 @@
                             unsigned char *output )
 {
     int c, i;
-    size_t n = *nc_off;
+    size_t n;
+
+    ARIA_VALIDATE_RET( ctx != NULL );
+    ARIA_VALIDATE_RET( length == 0 || input  != NULL );
+    ARIA_VALIDATE_RET( length == 0 || output != NULL );
+    ARIA_VALIDATE_RET( nonce_counter != NULL );
+    ARIA_VALIDATE_RET( stream_block  != NULL );
+    ARIA_VALIDATE_RET( nc_off != NULL );
+
+    n = *nc_off;
+    /* An overly large value of n can lead to an unlimited
+     * buffer overflow. Therefore, guard against this
+     * outside of parameter validation. */
+    if( n >= MBEDTLS_ARIA_BLOCKSIZE )
+        return( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA );
 
     while( length-- )
     {
diff --git a/library/blowfish.c b/library/blowfish.c
index b3448c2..cbf9238 100644
--- a/library/blowfish.c
+++ b/library/blowfish.c
@@ -40,6 +40,12 @@
 
 #if !defined(MBEDTLS_BLOWFISH_ALT)
 
+/* Parameter validation macros */
+#define BLOWFISH_VALIDATE_RET( cond )                                       \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA )
+#define BLOWFISH_VALIDATE( cond )                                           \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 /*
  * 32-bit integer manipulation macros (big endian)
  */
@@ -153,6 +159,7 @@
 
 void mbedtls_blowfish_init( mbedtls_blowfish_context *ctx )
 {
+    BLOWFISH_VALIDATE( ctx != NULL );
     memset( ctx, 0, sizeof( mbedtls_blowfish_context ) );
 }
 
@@ -167,14 +174,18 @@
 /*
  * Blowfish key schedule
  */
-int mbedtls_blowfish_setkey( mbedtls_blowfish_context *ctx, const unsigned char *key,
-                     unsigned int keybits )
+int mbedtls_blowfish_setkey( mbedtls_blowfish_context *ctx,
+                             const unsigned char *key,
+                             unsigned int keybits )
 {
     unsigned int i, j, k;
     uint32_t data, datal, datar;
+    BLOWFISH_VALIDATE_RET( ctx != NULL );
+    BLOWFISH_VALIDATE_RET( key != NULL );
 
-    if( keybits < MBEDTLS_BLOWFISH_MIN_KEY_BITS || keybits > MBEDTLS_BLOWFISH_MAX_KEY_BITS ||
-        ( keybits % 8 ) )
+    if( keybits < MBEDTLS_BLOWFISH_MIN_KEY_BITS    ||
+        keybits > MBEDTLS_BLOWFISH_MAX_KEY_BITS    ||
+        keybits % 8 != 0 )
     {
         return( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA );
     }
@@ -231,6 +242,11 @@
                     unsigned char output[MBEDTLS_BLOWFISH_BLOCKSIZE] )
 {
     uint32_t X0, X1;
+    BLOWFISH_VALIDATE_RET( ctx != NULL );
+    BLOWFISH_VALIDATE_RET( mode == MBEDTLS_BLOWFISH_ENCRYPT ||
+                           mode == MBEDTLS_BLOWFISH_DECRYPT );
+    BLOWFISH_VALIDATE_RET( input  != NULL );
+    BLOWFISH_VALIDATE_RET( output != NULL );
 
     GET_UINT32_BE( X0, input,  0 );
     GET_UINT32_BE( X1, input,  4 );
@@ -263,6 +279,12 @@
 {
     int i;
     unsigned char temp[MBEDTLS_BLOWFISH_BLOCKSIZE];
+    BLOWFISH_VALIDATE_RET( ctx != NULL );
+    BLOWFISH_VALIDATE_RET( mode == MBEDTLS_BLOWFISH_ENCRYPT ||
+                           mode == MBEDTLS_BLOWFISH_DECRYPT );
+    BLOWFISH_VALIDATE_RET( iv != NULL );
+    BLOWFISH_VALIDATE_RET( length == 0 || input  != NULL );
+    BLOWFISH_VALIDATE_RET( length == 0 || output != NULL );
 
     if( length % MBEDTLS_BLOWFISH_BLOCKSIZE )
         return( MBEDTLS_ERR_BLOWFISH_INVALID_INPUT_LENGTH );
@@ -317,7 +339,19 @@
                        unsigned char *output )
 {
     int c;
-    size_t n = *iv_off;
+    size_t n;
+
+    BLOWFISH_VALIDATE_RET( ctx != NULL );
+    BLOWFISH_VALIDATE_RET( mode == MBEDTLS_BLOWFISH_ENCRYPT ||
+                           mode == MBEDTLS_BLOWFISH_DECRYPT );
+    BLOWFISH_VALIDATE_RET( iv     != NULL );
+    BLOWFISH_VALIDATE_RET( iv_off != NULL );
+    BLOWFISH_VALIDATE_RET( length == 0 || input  != NULL );
+    BLOWFISH_VALIDATE_RET( length == 0 || output != NULL );
+
+    n = *iv_off;
+    if( n >= 8 )
+        return( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA );
 
     if( mode == MBEDTLS_BLOWFISH_DECRYPT )
     {
@@ -365,7 +399,17 @@
                        unsigned char *output )
 {
     int c, i;
-    size_t n = *nc_off;
+    size_t n;
+    BLOWFISH_VALIDATE_RET( ctx != NULL );
+    BLOWFISH_VALIDATE_RET( nonce_counter != NULL );
+    BLOWFISH_VALIDATE_RET( stream_block  != NULL );
+    BLOWFISH_VALIDATE_RET( nc_off != NULL );
+    BLOWFISH_VALIDATE_RET( length == 0 || input  != NULL );
+    BLOWFISH_VALIDATE_RET( length == 0 || output != NULL );
+
+    n = *nc_off;
+    if( n >= 8 )
+        return( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA );
 
     while( length-- )
     {
diff --git a/library/camellia.c b/library/camellia.c
index 97c9f20..22262b8 100644
--- a/library/camellia.c
+++ b/library/camellia.c
@@ -49,6 +49,12 @@
 
 #if !defined(MBEDTLS_CAMELLIA_ALT)
 
+/* Parameter validation macros */
+#define CAMELLIA_VALIDATE_RET( cond )                                       \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA )
+#define CAMELLIA_VALIDATE( cond )                                           \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 /*
  * 32-bit integer manipulation macros (big endian)
  */
@@ -321,6 +327,7 @@
 
 void mbedtls_camellia_init( mbedtls_camellia_context *ctx )
 {
+    CAMELLIA_VALIDATE( ctx != NULL );
     memset( ctx, 0, sizeof( mbedtls_camellia_context ) );
 }
 
@@ -335,8 +342,9 @@
 /*
  * Camellia key schedule (encryption)
  */
-int mbedtls_camellia_setkey_enc( mbedtls_camellia_context *ctx, const unsigned char *key,
-                         unsigned int keybits )
+int mbedtls_camellia_setkey_enc( mbedtls_camellia_context *ctx,
+                                 const unsigned char *key,
+                                 unsigned int keybits )
 {
     int idx;
     size_t i;
@@ -346,6 +354,9 @@
     uint32_t KC[16];
     uint32_t TK[20];
 
+    CAMELLIA_VALIDATE_RET( ctx != NULL );
+    CAMELLIA_VALIDATE_RET( key != NULL );
+
     RK = ctx->rk;
 
     memset( t, 0, 64 );
@@ -440,14 +451,17 @@
 /*
  * Camellia key schedule (decryption)
  */
-int mbedtls_camellia_setkey_dec( mbedtls_camellia_context *ctx, const unsigned char *key,
-                         unsigned int keybits )
+int mbedtls_camellia_setkey_dec( mbedtls_camellia_context *ctx,
+                                 const unsigned char *key,
+                                 unsigned int keybits )
 {
     int idx, ret;
     size_t i;
     mbedtls_camellia_context cty;
     uint32_t *RK;
     uint32_t *SK;
+    CAMELLIA_VALIDATE_RET( ctx != NULL );
+    CAMELLIA_VALIDATE_RET( key != NULL );
 
     mbedtls_camellia_init( &cty );
 
@@ -495,6 +509,11 @@
 {
     int NR;
     uint32_t *RK, X[4];
+    CAMELLIA_VALIDATE_RET( ctx != NULL );
+    CAMELLIA_VALIDATE_RET( mode == MBEDTLS_CAMELLIA_ENCRYPT ||
+                           mode == MBEDTLS_CAMELLIA_DECRYPT );
+    CAMELLIA_VALIDATE_RET( input  != NULL );
+    CAMELLIA_VALIDATE_RET( output != NULL );
 
     ( (void) mode );
 
@@ -552,14 +571,20 @@
  * Camellia-CBC buffer encryption/decryption
  */
 int mbedtls_camellia_crypt_cbc( mbedtls_camellia_context *ctx,
-                    int mode,
-                    size_t length,
-                    unsigned char iv[16],
-                    const unsigned char *input,
-                    unsigned char *output )
+                                int mode,
+                                size_t length,
+                                unsigned char iv[16],
+                                const unsigned char *input,
+                                unsigned char *output )
 {
     int i;
     unsigned char temp[16];
+    CAMELLIA_VALIDATE_RET( ctx != NULL );
+    CAMELLIA_VALIDATE_RET( mode == MBEDTLS_CAMELLIA_ENCRYPT ||
+                           mode == MBEDTLS_CAMELLIA_DECRYPT );
+    CAMELLIA_VALIDATE_RET( iv != NULL );
+    CAMELLIA_VALIDATE_RET( length == 0 || input  != NULL );
+    CAMELLIA_VALIDATE_RET( length == 0 || output != NULL );
 
     if( length % 16 )
         return( MBEDTLS_ERR_CAMELLIA_INVALID_INPUT_LENGTH );
@@ -614,7 +639,18 @@
                        unsigned char *output )
 {
     int c;
-    size_t n = *iv_off;
+    size_t n;
+    CAMELLIA_VALIDATE_RET( ctx != NULL );
+    CAMELLIA_VALIDATE_RET( mode == MBEDTLS_CAMELLIA_ENCRYPT ||
+                           mode == MBEDTLS_CAMELLIA_DECRYPT );
+    CAMELLIA_VALIDATE_RET( iv     != NULL );
+    CAMELLIA_VALIDATE_RET( iv_off != NULL );
+    CAMELLIA_VALIDATE_RET( length == 0 || input  != NULL );
+    CAMELLIA_VALIDATE_RET( length == 0 || output != NULL );
+
+    n = *iv_off;
+    if( n >= 16 )
+        return( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA );
 
     if( mode == MBEDTLS_CAMELLIA_DECRYPT )
     {
@@ -662,7 +698,17 @@
                        unsigned char *output )
 {
     int c, i;
-    size_t n = *nc_off;
+    size_t n;
+    CAMELLIA_VALIDATE_RET( ctx != NULL );
+    CAMELLIA_VALIDATE_RET( nonce_counter != NULL );
+    CAMELLIA_VALIDATE_RET( stream_block  != NULL );
+    CAMELLIA_VALIDATE_RET( nc_off != NULL );
+    CAMELLIA_VALIDATE_RET( length == 0 || input  != NULL );
+    CAMELLIA_VALIDATE_RET( length == 0 || output != NULL );
+
+    n = *nc_off;
+    if( n >= 16 )
+        return( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA );
 
     while( length-- )
     {
diff --git a/library/ccm.c b/library/ccm.c
index 90cab8e..01e58b0 100644
--- a/library/ccm.c
+++ b/library/ccm.c
@@ -52,6 +52,11 @@
 
 #if !defined(MBEDTLS_CCM_ALT)
 
+#define CCM_VALIDATE_RET( cond ) \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_CCM_BAD_INPUT )
+#define CCM_VALIDATE( cond ) \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #define CCM_ENCRYPT 0
 #define CCM_DECRYPT 1
 
@@ -60,6 +65,7 @@
  */
 void mbedtls_ccm_init( mbedtls_ccm_context *ctx )
 {
+    CCM_VALIDATE( ctx != NULL );
     memset( ctx, 0, sizeof( mbedtls_ccm_context ) );
 }
 
@@ -71,6 +77,9 @@
     int ret;
     const mbedtls_cipher_info_t *cipher_info;
 
+    CCM_VALIDATE_RET( ctx != NULL );
+    CCM_VALIDATE_RET( key != NULL );
+
     cipher_info = mbedtls_cipher_info_from_values( cipher, keybits, MBEDTLS_MODE_ECB );
     if( cipher_info == NULL )
         return( MBEDTLS_ERR_CCM_BAD_INPUT );
@@ -97,6 +106,8 @@
  */
 void mbedtls_ccm_free( mbedtls_ccm_context *ctx )
 {
+    if( ctx == NULL )
+        return;
     mbedtls_cipher_free( &ctx->cipher_ctx );
     mbedtls_platform_zeroize( ctx, sizeof( mbedtls_ccm_context ) );
 }
@@ -310,6 +321,12 @@
                          const unsigned char *input, unsigned char *output,
                          unsigned char *tag, size_t tag_len )
 {
+    CCM_VALIDATE_RET( ctx != NULL );
+    CCM_VALIDATE_RET( iv != NULL );
+    CCM_VALIDATE_RET( add_len == 0 || add != NULL );
+    CCM_VALIDATE_RET( length == 0 || input != NULL );
+    CCM_VALIDATE_RET( length == 0 || output != NULL );
+    CCM_VALIDATE_RET( tag_len == 0 || tag != NULL );
     return( ccm_auth_crypt( ctx, CCM_ENCRYPT, length, iv, iv_len,
                             add, add_len, input, output, tag, tag_len ) );
 }
@@ -320,6 +337,12 @@
                          const unsigned char *input, unsigned char *output,
                          unsigned char *tag, size_t tag_len )
 {
+    CCM_VALIDATE_RET( ctx != NULL );
+    CCM_VALIDATE_RET( iv != NULL );
+    CCM_VALIDATE_RET( add_len == 0 || add != NULL );
+    CCM_VALIDATE_RET( length == 0 || input != NULL );
+    CCM_VALIDATE_RET( length == 0 || output != NULL );
+    CCM_VALIDATE_RET( tag_len == 0 || tag != NULL );
     if( tag_len == 0 )
         return( MBEDTLS_ERR_CCM_BAD_INPUT );
 
@@ -341,6 +364,13 @@
     unsigned char i;
     int diff;
 
+    CCM_VALIDATE_RET( ctx != NULL );
+    CCM_VALIDATE_RET( iv != NULL );
+    CCM_VALIDATE_RET( add_len == 0 || add != NULL );
+    CCM_VALIDATE_RET( length == 0 || input != NULL );
+    CCM_VALIDATE_RET( length == 0 || output != NULL );
+    CCM_VALIDATE_RET( tag_len == 0 || tag != NULL );
+
     if( ( ret = ccm_auth_crypt( ctx, CCM_DECRYPT, length,
                                 iv, iv_len, add, add_len,
                                 input, output, check_tag, tag_len ) ) != 0 )
@@ -367,6 +397,13 @@
                       const unsigned char *input, unsigned char *output,
                       const unsigned char *tag, size_t tag_len )
 {
+    CCM_VALIDATE_RET( ctx != NULL );
+    CCM_VALIDATE_RET( iv != NULL );
+    CCM_VALIDATE_RET( add_len == 0 || add != NULL );
+    CCM_VALIDATE_RET( length == 0 || input != NULL );
+    CCM_VALIDATE_RET( length == 0 || output != NULL );
+    CCM_VALIDATE_RET( tag_len == 0 || tag != NULL );
+
     if( tag_len == 0 )
         return( MBEDTLS_ERR_CCM_BAD_INPUT );
 
diff --git a/library/chacha20.c b/library/chacha20.c
index d14a51e..0757163 100644
--- a/library/chacha20.c
+++ b/library/chacha20.c
@@ -53,6 +53,12 @@
 #define inline __inline
 #endif
 
+/* Parameter validation macros */
+#define CHACHA20_VALIDATE_RET( cond )                                       \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA )
+#define CHACHA20_VALIDATE( cond )                                           \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #define BYTES_TO_U32_LE( data, offset )                           \
     ( (uint32_t) data[offset]                                     \
           | (uint32_t) ( (uint32_t) data[( offset ) + 1] << 8 )   \
@@ -181,14 +187,13 @@
 
 void mbedtls_chacha20_init( mbedtls_chacha20_context *ctx )
 {
-    if( ctx != NULL )
-    {
-        mbedtls_platform_zeroize( ctx->state, sizeof( ctx->state ) );
-        mbedtls_platform_zeroize( ctx->keystream8, sizeof( ctx->keystream8 ) );
+    CHACHA20_VALIDATE( ctx != NULL );
 
-        /* Initially, there's no keystream bytes available */
-        ctx->keystream_bytes_used = CHACHA20_BLOCK_SIZE_BYTES;
-    }
+    mbedtls_platform_zeroize( ctx->state, sizeof( ctx->state ) );
+    mbedtls_platform_zeroize( ctx->keystream8, sizeof( ctx->keystream8 ) );
+
+    /* Initially, there's no keystream bytes available */
+    ctx->keystream_bytes_used = CHACHA20_BLOCK_SIZE_BYTES;
 }
 
 void mbedtls_chacha20_free( mbedtls_chacha20_context *ctx )
@@ -202,10 +207,8 @@
 int mbedtls_chacha20_setkey( mbedtls_chacha20_context *ctx,
                             const unsigned char key[32] )
 {
-    if( ( ctx == NULL ) || ( key == NULL ) )
-    {
-        return( MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA );
-    }
+    CHACHA20_VALIDATE_RET( ctx != NULL );
+    CHACHA20_VALIDATE_RET( key != NULL );
 
     /* ChaCha20 constants - the string "expand 32-byte k" */
     ctx->state[0] = 0x61707865;
@@ -230,10 +233,8 @@
                              const unsigned char nonce[12],
                              uint32_t counter )
 {
-    if( ( ctx == NULL ) || ( nonce == NULL ) )
-    {
-        return( MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA );
-    }
+    CHACHA20_VALIDATE_RET( ctx != NULL );
+    CHACHA20_VALIDATE_RET( nonce != NULL );
 
     /* Counter */
     ctx->state[12] = counter;
@@ -259,15 +260,9 @@
     size_t offset = 0U;
     size_t i;
 
-    if( ctx == NULL )
-    {
-        return( MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA );
-    }
-    else if( ( size > 0U ) && ( ( input == NULL ) || ( output == NULL ) ) )
-    {
-        /* input and output pointers are allowed to be NULL only if size == 0 */
-        return( MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA );
-    }
+    CHACHA20_VALIDATE_RET( ctx != NULL );
+    CHACHA20_VALIDATE_RET( size == 0 || input  != NULL );
+    CHACHA20_VALIDATE_RET( size == 0 || output != NULL );
 
     /* Use leftover keystream bytes, if available */
     while( size > 0U && ctx->keystream_bytes_used < CHACHA20_BLOCK_SIZE_BYTES )
@@ -332,6 +327,11 @@
     mbedtls_chacha20_context ctx;
     int ret;
 
+    CHACHA20_VALIDATE_RET( key != NULL );
+    CHACHA20_VALIDATE_RET( nonce != NULL );
+    CHACHA20_VALIDATE_RET( data_len == 0 || input  != NULL );
+    CHACHA20_VALIDATE_RET( data_len == 0 || output != NULL );
+
     mbedtls_chacha20_init( &ctx );
 
     ret = mbedtls_chacha20_setkey( &ctx, key );
diff --git a/library/chachapoly.c b/library/chachapoly.c
index 860f877..dc643dd 100644
--- a/library/chachapoly.c
+++ b/library/chachapoly.c
@@ -44,6 +44,12 @@
 
 #if !defined(MBEDTLS_CHACHAPOLY_ALT)
 
+/* Parameter validation macros */
+#define CHACHAPOLY_VALIDATE_RET( cond )                                       \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA )
+#define CHACHAPOLY_VALIDATE( cond )                                           \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #define CHACHAPOLY_STATE_INIT       ( 0 )
 #define CHACHAPOLY_STATE_AAD        ( 1 )
 #define CHACHAPOLY_STATE_CIPHERTEXT ( 2 ) /* Encrypting or decrypting */
@@ -90,39 +96,35 @@
 
 void mbedtls_chachapoly_init( mbedtls_chachapoly_context *ctx )
 {
-    if( ctx != NULL )
-    {
-        mbedtls_chacha20_init( &ctx->chacha20_ctx );
-        mbedtls_poly1305_init( &ctx->poly1305_ctx );
-        ctx->aad_len        = 0U;
-        ctx->ciphertext_len = 0U;
-        ctx->state          = CHACHAPOLY_STATE_INIT;
-        ctx->mode           = MBEDTLS_CHACHAPOLY_ENCRYPT;
-    }
+    CHACHAPOLY_VALIDATE( ctx != NULL );
+
+    mbedtls_chacha20_init( &ctx->chacha20_ctx );
+    mbedtls_poly1305_init( &ctx->poly1305_ctx );
+    ctx->aad_len        = 0U;
+    ctx->ciphertext_len = 0U;
+    ctx->state          = CHACHAPOLY_STATE_INIT;
+    ctx->mode           = MBEDTLS_CHACHAPOLY_ENCRYPT;
 }
 
 void mbedtls_chachapoly_free( mbedtls_chachapoly_context *ctx )
 {
-    if( ctx != NULL )
-    {
-        mbedtls_chacha20_free( &ctx->chacha20_ctx );
-        mbedtls_poly1305_free( &ctx->poly1305_ctx );
-        ctx->aad_len        = 0U;
-        ctx->ciphertext_len = 0U;
-        ctx->state          = CHACHAPOLY_STATE_INIT;
-        ctx->mode           = MBEDTLS_CHACHAPOLY_ENCRYPT;
-    }
+    if( ctx == NULL )
+        return;
+
+    mbedtls_chacha20_free( &ctx->chacha20_ctx );
+    mbedtls_poly1305_free( &ctx->poly1305_ctx );
+    ctx->aad_len        = 0U;
+    ctx->ciphertext_len = 0U;
+    ctx->state          = CHACHAPOLY_STATE_INIT;
+    ctx->mode           = MBEDTLS_CHACHAPOLY_ENCRYPT;
 }
 
 int mbedtls_chachapoly_setkey( mbedtls_chachapoly_context *ctx,
                                const unsigned char key[32] )
 {
     int ret;
-
-    if( ( ctx == NULL ) || ( key == NULL ) )
-    {
-        return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    }
+    CHACHAPOLY_VALIDATE_RET( ctx != NULL );
+    CHACHAPOLY_VALIDATE_RET( key != NULL );
 
     ret = mbedtls_chacha20_setkey( &ctx->chacha20_ctx, key );
 
@@ -135,11 +137,8 @@
 {
     int ret;
     unsigned char poly1305_key[64];
-
-    if( ( ctx == NULL ) || ( nonce == NULL ) )
-    {
-        return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    }
+    CHACHAPOLY_VALIDATE_RET( ctx != NULL );
+    CHACHAPOLY_VALIDATE_RET( nonce != NULL );
 
     /* Set counter = 0, will be update to 1 when generating Poly1305 key */
     ret = mbedtls_chacha20_starts( &ctx->chacha20_ctx, nonce, 0U );
@@ -176,19 +175,11 @@
                                    const unsigned char *aad,
                                    size_t aad_len )
 {
-    if( ctx == NULL )
-    {
-        return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    }
-    else if( ( aad_len > 0U ) && ( aad == NULL ) )
-    {
-        /* aad pointer is allowed to be NULL if aad_len == 0 */
-        return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    }
-    else if( ctx->state != CHACHAPOLY_STATE_AAD )
-    {
+    CHACHAPOLY_VALIDATE_RET( ctx != NULL );
+    CHACHAPOLY_VALIDATE_RET( aad_len == 0 || aad != NULL );
+
+    if( ctx->state != CHACHAPOLY_STATE_AAD )
         return( MBEDTLS_ERR_CHACHAPOLY_BAD_STATE );
-    }
 
     ctx->aad_len += aad_len;
 
@@ -201,18 +192,12 @@
                                unsigned char *output )
 {
     int ret;
+    CHACHAPOLY_VALIDATE_RET( ctx != NULL );
+    CHACHAPOLY_VALIDATE_RET( len == 0 || input != NULL );
+    CHACHAPOLY_VALIDATE_RET( len == 0 || output != NULL );
 
-    if( ctx == NULL )
-    {
-        return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    }
-    else if( ( len > 0U ) && ( ( input == NULL ) || ( output == NULL ) ) )
-    {
-        /* input and output pointers are allowed to be NULL if len == 0 */
-        return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    }
-    else if( ( ctx->state != CHACHAPOLY_STATE_AAD ) &&
-              ( ctx->state != CHACHAPOLY_STATE_CIPHERTEXT ) )
+    if( ( ctx->state != CHACHAPOLY_STATE_AAD ) &&
+        ( ctx->state != CHACHAPOLY_STATE_CIPHERTEXT ) )
     {
         return( MBEDTLS_ERR_CHACHAPOLY_BAD_STATE );
     }
@@ -257,12 +242,10 @@
 {
     int ret;
     unsigned char len_block[16];
+    CHACHAPOLY_VALIDATE_RET( ctx != NULL );
+    CHACHAPOLY_VALIDATE_RET( mac != NULL );
 
-    if( ( ctx == NULL ) || ( mac == NULL ) )
-    {
-        return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    }
-    else if( ctx->state == CHACHAPOLY_STATE_INIT )
+    if( ctx->state == CHACHAPOLY_STATE_INIT )
     {
         return( MBEDTLS_ERR_CHACHAPOLY_BAD_STATE );
     }
@@ -350,6 +333,13 @@
                                         unsigned char *output,
                                         unsigned char tag[16] )
 {
+    CHACHAPOLY_VALIDATE_RET( ctx   != NULL );
+    CHACHAPOLY_VALIDATE_RET( nonce != NULL );
+    CHACHAPOLY_VALIDATE_RET( tag   != NULL );
+    CHACHAPOLY_VALIDATE_RET( aad_len == 0 || aad    != NULL );
+    CHACHAPOLY_VALIDATE_RET( length  == 0 || input  != NULL );
+    CHACHAPOLY_VALIDATE_RET( length  == 0 || output != NULL );
+
     return( chachapoly_crypt_and_tag( ctx, MBEDTLS_CHACHAPOLY_ENCRYPT,
                                       length, nonce, aad, aad_len,
                                       input, output, tag ) );
@@ -368,9 +358,12 @@
     unsigned char check_tag[16];
     size_t i;
     int diff;
-
-    if( tag == NULL )
-        return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
+    CHACHAPOLY_VALIDATE_RET( ctx   != NULL );
+    CHACHAPOLY_VALIDATE_RET( nonce != NULL );
+    CHACHAPOLY_VALIDATE_RET( tag   != NULL );
+    CHACHAPOLY_VALIDATE_RET( aad_len == 0 || aad    != NULL );
+    CHACHAPOLY_VALIDATE_RET( length  == 0 || input  != NULL );
+    CHACHAPOLY_VALIDATE_RET( length  == 0 || output != NULL );
 
     if( ( ret = chachapoly_crypt_and_tag( ctx,
                         MBEDTLS_CHACHAPOLY_DECRYPT, length, nonce,
diff --git a/library/dhm.c b/library/dhm.c
index 82cbb0c..ee28572 100644
--- a/library/dhm.c
+++ b/library/dhm.c
@@ -60,6 +60,11 @@
 
 #if !defined(MBEDTLS_DHM_ALT)
 
+#define DHM_VALIDATE_RET( cond )    \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_DHM_BAD_INPUT_DATA )
+#define DHM_VALIDATE( cond )        \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 /*
  * helper to validate the mbedtls_mpi size and import it
  */
@@ -121,6 +126,7 @@
 
 void mbedtls_dhm_init( mbedtls_dhm_context *ctx )
 {
+    DHM_VALIDATE( ctx != NULL );
     memset( ctx, 0, sizeof( mbedtls_dhm_context ) );
 }
 
@@ -132,6 +138,9 @@
                      const unsigned char *end )
 {
     int ret;
+    DHM_VALIDATE_RET( ctx != NULL );
+    DHM_VALIDATE_RET( p != NULL && *p != NULL );
+    DHM_VALIDATE_RET( end != NULL );
 
     if( ( ret = dhm_read_bignum( &ctx->P,  p, end ) ) != 0 ||
         ( ret = dhm_read_bignum( &ctx->G,  p, end ) ) != 0 ||
@@ -157,6 +166,10 @@
     int ret, count = 0;
     size_t n1, n2, n3;
     unsigned char *p;
+    DHM_VALIDATE_RET( ctx != NULL );
+    DHM_VALIDATE_RET( output != NULL );
+    DHM_VALIDATE_RET( olen != NULL );
+    DHM_VALIDATE_RET( f_rng != NULL );
 
     if( mbedtls_mpi_cmp_int( &ctx->P, 0 ) == 0 )
         return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
@@ -227,9 +240,9 @@
                            const mbedtls_mpi *G )
 {
     int ret;
-
-    if( ctx == NULL || P == NULL || G == NULL )
-        return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
+    DHM_VALIDATE_RET( ctx != NULL );
+    DHM_VALIDATE_RET( P != NULL );
+    DHM_VALIDATE_RET( G != NULL );
 
     if( ( ret = mbedtls_mpi_copy( &ctx->P, P ) ) != 0 ||
         ( ret = mbedtls_mpi_copy( &ctx->G, G ) ) != 0 )
@@ -248,8 +261,10 @@
                      const unsigned char *input, size_t ilen )
 {
     int ret;
+    DHM_VALIDATE_RET( ctx != NULL );
+    DHM_VALIDATE_RET( input != NULL );
 
-    if( ctx == NULL || ilen < 1 || ilen > ctx->len )
+    if( ilen < 1 || ilen > ctx->len )
         return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
 
     if( ( ret = mbedtls_mpi_read_binary( &ctx->GY, input, ilen ) ) != 0 )
@@ -267,8 +282,11 @@
                      void *p_rng )
 {
     int ret, count = 0;
+    DHM_VALIDATE_RET( ctx != NULL );
+    DHM_VALIDATE_RET( output != NULL );
+    DHM_VALIDATE_RET( f_rng != NULL );
 
-    if( ctx == NULL || olen < 1 || olen > ctx->len )
+    if( olen < 1 || olen > ctx->len )
         return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
 
     if( mbedtls_mpi_cmp_int( &ctx->P, 0 ) == 0 )
@@ -380,8 +398,11 @@
 {
     int ret;
     mbedtls_mpi GYb;
+    DHM_VALIDATE_RET( ctx != NULL );
+    DHM_VALIDATE_RET( output != NULL );
+    DHM_VALIDATE_RET( olen != NULL );
 
-    if( ctx == NULL || output_size < ctx->len )
+    if( output_size < ctx->len )
         return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
 
     if( ( ret = dhm_check_range( &ctx->GY, &ctx->P ) ) != 0 )
@@ -428,6 +449,9 @@
  */
 void mbedtls_dhm_free( mbedtls_dhm_context *ctx )
 {
+    if( ctx == NULL )
+        return;
+
     mbedtls_mpi_free( &ctx->pX ); mbedtls_mpi_free( &ctx->Vf );
     mbedtls_mpi_free( &ctx->Vi ); mbedtls_mpi_free( &ctx->RP );
     mbedtls_mpi_free( &ctx->K  ); mbedtls_mpi_free( &ctx->GY );
@@ -449,7 +473,12 @@
     unsigned char *p, *end;
 #if defined(MBEDTLS_PEM_PARSE_C)
     mbedtls_pem_context pem;
+#endif /* MBEDTLS_PEM_PARSE_C */
 
+    DHM_VALIDATE_RET( dhm != NULL );
+    DHM_VALIDATE_RET( dhmin != NULL );
+
+#if defined(MBEDTLS_PEM_PARSE_C)
     mbedtls_pem_init( &pem );
 
     /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
@@ -596,6 +625,8 @@
     int ret;
     size_t n;
     unsigned char *buf;
+    DHM_VALIDATE_RET( dhm != NULL );
+    DHM_VALIDATE_RET( path != NULL );
 
     if( ( ret = load_file( path, &buf, &n ) ) != 0 )
         return( ret );
diff --git a/library/ecdh.c b/library/ecdh.c
index d68db8a..da95c60 100644
--- a/library/ecdh.c
+++ b/library/ecdh.c
@@ -35,9 +35,16 @@
 #if defined(MBEDTLS_ECDH_C)
 
 #include "mbedtls/ecdh.h"
+#include "mbedtls/platform_util.h"
 
 #include <string.h>
 
+/* Parameter validation macros based on platform_util.h */
+#define ECDH_VALIDATE_RET( cond )    \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_ECP_BAD_INPUT_DATA )
+#define ECDH_VALIDATE( cond )        \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
 typedef mbedtls_ecdh_context mbedtls_ecdh_context_mbed;
 #endif
@@ -78,6 +85,10 @@
                      int (*f_rng)(void *, unsigned char *, size_t),
                      void *p_rng )
 {
+    ECDH_VALIDATE_RET( grp != NULL );
+    ECDH_VALIDATE_RET( d != NULL );
+    ECDH_VALIDATE_RET( Q != NULL );
+    ECDH_VALIDATE_RET( f_rng != NULL );
     return( ecdh_gen_public_restartable( grp, d, Q, f_rng, p_rng, NULL ) );
 }
 #endif /* !MBEDTLS_ECDH_GEN_PUBLIC_ALT */
@@ -123,6 +134,10 @@
                          int (*f_rng)(void *, unsigned char *, size_t),
                          void *p_rng )
 {
+    ECDH_VALIDATE_RET( grp != NULL );
+    ECDH_VALIDATE_RET( Q != NULL );
+    ECDH_VALIDATE_RET( d != NULL );
+    ECDH_VALIDATE_RET( z != NULL );
     return( ecdh_compute_shared_restartable( grp, z, Q, d,
                                              f_rng, p_rng, NULL ) );
 }
@@ -146,6 +161,8 @@
  */
 void mbedtls_ecdh_init( mbedtls_ecdh_context *ctx )
 {
+    ECDH_VALIDATE( ctx != NULL );
+
 #if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
     ecdh_init_internal( ctx );
     mbedtls_ecp_point_init( &ctx->Vi  );
@@ -181,8 +198,7 @@
  */
 int mbedtls_ecdh_setup( mbedtls_ecdh_context *ctx, mbedtls_ecp_group_id grp_id )
 {
-    if( ctx == NULL )
-        return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
+    ECDH_VALIDATE_RET( ctx != NULL );
 
 #if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
     return( ecdh_setup_internal( ctx, grp_id ) );
@@ -218,8 +234,7 @@
  */
 void mbedtls_ecdh_enable_restart( mbedtls_ecdh_context *ctx )
 {
-    if( ctx == NULL )
-        return;
+    ECDH_VALIDATE( ctx != NULL );
 
     ctx->restart_enabled = 1;
 }
@@ -318,9 +333,10 @@
                               void *p_rng )
 {
     int restart_enabled = 0;
-
-    if( ctx == NULL )
-        return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
+    ECDH_VALIDATE_RET( ctx != NULL );
+    ECDH_VALIDATE_RET( olen != NULL );
+    ECDH_VALIDATE_RET( buf != NULL );
+    ECDH_VALIDATE_RET( f_rng != NULL );
 
 #if defined(MBEDTLS_ECP_RESTARTABLE)
     restart_enabled = ctx->restart_enabled;
@@ -366,9 +382,10 @@
 {
     int ret;
     mbedtls_ecp_group_id grp_id;
-
-    if( ctx == NULL )
-        return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
+    ECDH_VALIDATE_RET( ctx != NULL );
+    ECDH_VALIDATE_RET( buf != NULL );
+    ECDH_VALIDATE_RET( *buf != NULL );
+    ECDH_VALIDATE_RET( end != NULL );
 
     if( ( ret = mbedtls_ecp_tls_read_group_id( &grp_id, buf, end - *buf ) )
             != 0 )
@@ -420,9 +437,10 @@
                              mbedtls_ecdh_side side )
 {
     int ret;
-
-    if( ctx == NULL )
-        return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
+    ECDH_VALIDATE_RET( ctx != NULL );
+    ECDH_VALIDATE_RET( key != NULL );
+    ECDH_VALIDATE_RET( side == MBEDTLS_ECDH_OURS ||
+                       side == MBEDTLS_ECDH_THEIRS );
 
     if( ( ret = mbedtls_ecdh_setup( ctx, key->grp.id ) ) != 0 )
         return( ret );
@@ -488,9 +506,10 @@
                               void *p_rng )
 {
     int restart_enabled = 0;
-
-    if( ctx == NULL )
-        return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
+    ECDH_VALIDATE_RET( ctx != NULL );
+    ECDH_VALIDATE_RET( olen != NULL );
+    ECDH_VALIDATE_RET( buf != NULL );
+    ECDH_VALIDATE_RET( f_rng != NULL );
 
 #if defined(MBEDTLS_ECP_RESTARTABLE)
     restart_enabled = ctx->restart_enabled;
@@ -535,8 +554,8 @@
 int mbedtls_ecdh_read_public( mbedtls_ecdh_context *ctx,
                               const unsigned char *buf, size_t blen )
 {
-    if( ctx == NULL )
-        return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
+    ECDH_VALIDATE_RET( ctx != NULL );
+    ECDH_VALIDATE_RET( buf != NULL );
 
 #if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
     return( ecdh_read_public_internal( ctx, buf, blen ) );
@@ -607,9 +626,9 @@
                               void *p_rng )
 {
     int restart_enabled = 0;
-
-    if( ctx == NULL )
-        return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
+    ECDH_VALIDATE_RET( ctx != NULL );
+    ECDH_VALIDATE_RET( olen != NULL );
+    ECDH_VALIDATE_RET( buf != NULL );
 
 #if defined(MBEDTLS_ECP_RESTARTABLE)
     restart_enabled = ctx->restart_enabled;
diff --git a/library/ecdsa.c b/library/ecdsa.c
index a62c14c..1204ef9 100644
--- a/library/ecdsa.c
+++ b/library/ecdsa.c
@@ -50,6 +50,14 @@
 #define mbedtls_free       free
 #endif
 
+#include "mbedtls/platform_util.h"
+
+/* Parameter validation macros based on platform_util.h */
+#define ECDSA_VALIDATE_RET( cond )    \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_ECP_BAD_INPUT_DATA )
+#define ECDSA_VALIDATE( cond )        \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #if defined(MBEDTLS_ECP_RESTARTABLE)
 
 /*
@@ -377,6 +385,13 @@
                 const mbedtls_mpi *d, const unsigned char *buf, size_t blen,
                 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
 {
+    ECDSA_VALIDATE_RET( grp   != NULL );
+    ECDSA_VALIDATE_RET( r     != NULL );
+    ECDSA_VALIDATE_RET( s     != NULL );
+    ECDSA_VALIDATE_RET( d     != NULL );
+    ECDSA_VALIDATE_RET( f_rng != NULL );
+    ECDSA_VALIDATE_RET( buf   != NULL || blen == 0 );
+
     return( ecdsa_sign_restartable( grp, r, s, d, buf, blen,
                                     f_rng, p_rng, NULL ) );
 }
@@ -456,6 +471,12 @@
                     const mbedtls_mpi *d, const unsigned char *buf, size_t blen,
                     mbedtls_md_type_t md_alg )
 {
+    ECDSA_VALIDATE_RET( grp   != NULL );
+    ECDSA_VALIDATE_RET( r     != NULL );
+    ECDSA_VALIDATE_RET( s     != NULL );
+    ECDSA_VALIDATE_RET( d     != NULL );
+    ECDSA_VALIDATE_RET( buf   != NULL || blen == 0 );
+
     return( ecdsa_sign_det_restartable( grp, r, s, d, buf, blen, md_alg, NULL ) );
 }
 #endif /* MBEDTLS_ECDSA_DETERMINISTIC */
@@ -574,9 +595,17 @@
  * Verify ECDSA signature of hashed message
  */
 int mbedtls_ecdsa_verify( mbedtls_ecp_group *grp,
-                  const unsigned char *buf, size_t blen,
-                  const mbedtls_ecp_point *Q, const mbedtls_mpi *r, const mbedtls_mpi *s)
+                          const unsigned char *buf, size_t blen,
+                          const mbedtls_ecp_point *Q,
+                          const mbedtls_mpi *r,
+                          const mbedtls_mpi *s)
 {
+    ECDSA_VALIDATE_RET( grp != NULL );
+    ECDSA_VALIDATE_RET( Q   != NULL );
+    ECDSA_VALIDATE_RET( r   != NULL );
+    ECDSA_VALIDATE_RET( s   != NULL );
+    ECDSA_VALIDATE_RET( buf != NULL || blen == 0 );
+
     return( ecdsa_verify_restartable( grp, buf, blen, Q, r, s, NULL ) );
 }
 #endif /* !MBEDTLS_ECDSA_VERIFY_ALT */
@@ -618,6 +647,10 @@
 {
     int ret;
     mbedtls_mpi r, s;
+    ECDSA_VALIDATE_RET( ctx  != NULL );
+    ECDSA_VALIDATE_RET( hash != NULL );
+    ECDSA_VALIDATE_RET( sig  != NULL );
+    ECDSA_VALIDATE_RET( slen != NULL );
 
     mbedtls_mpi_init( &r );
     mbedtls_mpi_init( &s );
@@ -652,12 +685,17 @@
 /*
  * Compute and write signature
  */
-int mbedtls_ecdsa_write_signature( mbedtls_ecdsa_context *ctx, mbedtls_md_type_t md_alg,
-                           const unsigned char *hash, size_t hlen,
-                           unsigned char *sig, size_t *slen,
-                           int (*f_rng)(void *, unsigned char *, size_t),
-                           void *p_rng )
+int mbedtls_ecdsa_write_signature( mbedtls_ecdsa_context *ctx,
+                                 mbedtls_md_type_t md_alg,
+                                 const unsigned char *hash, size_t hlen,
+                                 unsigned char *sig, size_t *slen,
+                                 int (*f_rng)(void *, unsigned char *, size_t),
+                                 void *p_rng )
 {
+    ECDSA_VALIDATE_RET( ctx  != NULL );
+    ECDSA_VALIDATE_RET( hash != NULL );
+    ECDSA_VALIDATE_RET( sig  != NULL );
+    ECDSA_VALIDATE_RET( slen != NULL );
     return( mbedtls_ecdsa_write_signature_restartable(
                 ctx, md_alg, hash, hlen, sig, slen, f_rng, p_rng, NULL ) );
 }
@@ -669,6 +707,10 @@
                                unsigned char *sig, size_t *slen,
                                mbedtls_md_type_t md_alg )
 {
+    ECDSA_VALIDATE_RET( ctx  != NULL );
+    ECDSA_VALIDATE_RET( hash != NULL );
+    ECDSA_VALIDATE_RET( sig  != NULL );
+    ECDSA_VALIDATE_RET( slen != NULL );
     return( mbedtls_ecdsa_write_signature( ctx, md_alg, hash, hlen, sig, slen,
                                    NULL, NULL ) );
 }
@@ -681,6 +723,9 @@
                           const unsigned char *hash, size_t hlen,
                           const unsigned char *sig, size_t slen )
 {
+    ECDSA_VALIDATE_RET( ctx  != NULL );
+    ECDSA_VALIDATE_RET( hash != NULL );
+    ECDSA_VALIDATE_RET( sig  != NULL );
     return( mbedtls_ecdsa_read_signature_restartable(
                 ctx, hash, hlen, sig, slen, NULL ) );
 }
@@ -698,6 +743,9 @@
     const unsigned char *end = sig + slen;
     size_t len;
     mbedtls_mpi r, s;
+    ECDSA_VALIDATE_RET( ctx  != NULL );
+    ECDSA_VALIDATE_RET( hash != NULL );
+    ECDSA_VALIDATE_RET( sig  != NULL );
 
     mbedtls_mpi_init( &r );
     mbedtls_mpi_init( &s );
@@ -752,6 +800,9 @@
 int mbedtls_ecdsa_genkey( mbedtls_ecdsa_context *ctx, mbedtls_ecp_group_id gid,
                   int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
 {
+    ECDSA_VALIDATE_RET( ctx   != NULL );
+    ECDSA_VALIDATE_RET( f_rng != NULL );
+
     return( mbedtls_ecp_group_load( &ctx->grp, gid ) ||
             mbedtls_ecp_gen_keypair( &ctx->grp, &ctx->d, &ctx->Q, f_rng, p_rng ) );
 }
@@ -763,6 +814,8 @@
 int mbedtls_ecdsa_from_keypair( mbedtls_ecdsa_context *ctx, const mbedtls_ecp_keypair *key )
 {
     int ret;
+    ECDSA_VALIDATE_RET( ctx != NULL );
+    ECDSA_VALIDATE_RET( key != NULL );
 
     if( ( ret = mbedtls_ecp_group_copy( &ctx->grp, &key->grp ) ) != 0 ||
         ( ret = mbedtls_mpi_copy( &ctx->d, &key->d ) ) != 0 ||
@@ -779,6 +832,8 @@
  */
 void mbedtls_ecdsa_init( mbedtls_ecdsa_context *ctx )
 {
+    ECDSA_VALIDATE( ctx != NULL );
+
     mbedtls_ecp_keypair_init( ctx );
 }
 
@@ -787,6 +842,9 @@
  */
 void mbedtls_ecdsa_free( mbedtls_ecdsa_context *ctx )
 {
+    if( ctx == NULL )
+        return;
+
     mbedtls_ecp_keypair_free( ctx );
 }
 
@@ -796,6 +854,8 @@
  */
 void mbedtls_ecdsa_restart_init( mbedtls_ecdsa_restart_ctx *ctx )
 {
+    ECDSA_VALIDATE( ctx != NULL );
+
     mbedtls_ecp_restart_init( &ctx->ecp );
 
     ctx->ver = NULL;
@@ -810,6 +870,9 @@
  */
 void mbedtls_ecdsa_restart_free( mbedtls_ecdsa_restart_ctx *ctx )
 {
+    if( ctx == NULL )
+        return;
+
     mbedtls_ecp_restart_free( &ctx->ecp );
 
     ecdsa_restart_ver_free( ctx->ver );
diff --git a/library/ecjpake.c b/library/ecjpake.c
index ec5a400..be941b1 100644
--- a/library/ecjpake.c
+++ b/library/ecjpake.c
@@ -33,11 +33,18 @@
 #if defined(MBEDTLS_ECJPAKE_C)
 
 #include "mbedtls/ecjpake.h"
+#include "mbedtls/platform_util.h"
 
 #include <string.h>
 
 #if !defined(MBEDTLS_ECJPAKE_ALT)
 
+/* Parameter validation macros based on platform_util.h */
+#define ECJPAKE_VALIDATE_RET( cond )    \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_ECP_BAD_INPUT_DATA )
+#define ECJPAKE_VALIDATE( cond )        \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 /*
  * Convert a mbedtls_ecjpake_role to identifier string
  */
@@ -54,8 +61,7 @@
  */
 void mbedtls_ecjpake_init( mbedtls_ecjpake_context *ctx )
 {
-    if( ctx == NULL )
-        return;
+    ECJPAKE_VALIDATE( ctx != NULL );
 
     ctx->md_info = NULL;
     mbedtls_ecp_group_init( &ctx->grp );
@@ -106,6 +112,11 @@
 {
     int ret;
 
+    ECJPAKE_VALIDATE_RET( ctx != NULL );
+    ECJPAKE_VALIDATE_RET( role == MBEDTLS_ECJPAKE_CLIENT ||
+                          role == MBEDTLS_ECJPAKE_SERVER );
+    ECJPAKE_VALIDATE_RET( secret != NULL || len == 0 );
+
     ctx->role = role;
 
     if( ( ctx->md_info = mbedtls_md_info_from_type( hash ) ) == NULL )
@@ -127,6 +138,8 @@
  */
 int mbedtls_ecjpake_check( const mbedtls_ecjpake_context *ctx )
 {
+    ECJPAKE_VALIDATE_RET( ctx != NULL );
+
     if( ctx->md_info == NULL ||
         ctx->grp.id == MBEDTLS_ECP_DP_NONE ||
         ctx->s.p == NULL )
@@ -504,6 +517,9 @@
                                     const unsigned char *buf,
                                     size_t len )
 {
+    ECJPAKE_VALIDATE_RET( ctx != NULL );
+    ECJPAKE_VALIDATE_RET( buf != NULL );
+
     return( ecjpake_kkpp_read( ctx->md_info, &ctx->grp, ctx->point_format,
                                &ctx->grp.G,
                                &ctx->Xp1, &ctx->Xp2, ID_PEER,
@@ -518,6 +534,11 @@
                             int (*f_rng)(void *, unsigned char *, size_t),
                             void *p_rng )
 {
+    ECJPAKE_VALIDATE_RET( ctx   != NULL );
+    ECJPAKE_VALIDATE_RET( buf   != NULL );
+    ECJPAKE_VALIDATE_RET( olen  != NULL );
+    ECJPAKE_VALIDATE_RET( f_rng != NULL );
+
     return( ecjpake_kkpp_write( ctx->md_info, &ctx->grp, ctx->point_format,
                                 &ctx->grp.G,
                                 &ctx->xm1, &ctx->Xm1, &ctx->xm2, &ctx->Xm2,
@@ -560,6 +581,9 @@
     mbedtls_ecp_group grp;
     mbedtls_ecp_point G;    /* C: GB, S: GA */
 
+    ECJPAKE_VALIDATE_RET( ctx != NULL );
+    ECJPAKE_VALIDATE_RET( buf != NULL );
+
     mbedtls_ecp_group_init( &grp );
     mbedtls_ecp_point_init( &G );
 
@@ -652,6 +676,11 @@
     const unsigned char *end = buf + len;
     size_t ec_len;
 
+    ECJPAKE_VALIDATE_RET( ctx   != NULL );
+    ECJPAKE_VALIDATE_RET( buf   != NULL );
+    ECJPAKE_VALIDATE_RET( olen  != NULL );
+    ECJPAKE_VALIDATE_RET( f_rng != NULL );
+
     mbedtls_ecp_point_init( &G );
     mbedtls_ecp_point_init( &Xm );
     mbedtls_mpi_init( &xm );
@@ -727,6 +756,11 @@
     unsigned char kx[MBEDTLS_ECP_MAX_BYTES];
     size_t x_bytes;
 
+    ECJPAKE_VALIDATE_RET( ctx   != NULL );
+    ECJPAKE_VALIDATE_RET( buf   != NULL );
+    ECJPAKE_VALIDATE_RET( olen  != NULL );
+    ECJPAKE_VALIDATE_RET( f_rng != NULL );
+
     *olen = mbedtls_md_get_size( ctx->md_info );
     if( len < *olen )
         return( MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL );
diff --git a/library/ecp.c b/library/ecp.c
index 7fefb4c..ecea591 100644
--- a/library/ecp.c
+++ b/library/ecp.c
@@ -86,6 +86,12 @@
 
 #if !defined(MBEDTLS_ECP_ALT)
 
+/* Parameter validation macros based on platform_util.h */
+#define ECP_VALIDATE_RET( cond )    \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_ECP_BAD_INPUT_DATA )
+#define ECP_VALIDATE( cond )        \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #if defined(MBEDTLS_PLATFORM_C)
 #include "mbedtls/platform.h"
 #else
@@ -238,6 +244,7 @@
  */
 void mbedtls_ecp_restart_init( mbedtls_ecp_restart_ctx *ctx )
 {
+    ECP_VALIDATE( ctx != NULL );
     ctx->ops_done = 0;
     ctx->depth = 0;
     ctx->rsm = NULL;
@@ -268,6 +275,8 @@
                               mbedtls_ecp_restart_ctx *rs_ctx,
                               unsigned ops )
 {
+    ECP_VALIDATE_RET( grp != NULL );
+
     if( rs_ctx != NULL && ecp_max_ops != 0 )
     {
         /* scale depending on curve size: the chosen reference is 256-bit,
@@ -496,6 +505,9 @@
 {
     const mbedtls_ecp_curve_info *curve_info;
 
+    if( name == NULL )
+        return( NULL );
+
     for( curve_info = mbedtls_ecp_curve_list();
          curve_info->grp_id != MBEDTLS_ECP_DP_NONE;
          curve_info++ )
@@ -526,8 +538,7 @@
  */
 void mbedtls_ecp_point_init( mbedtls_ecp_point *pt )
 {
-    if( pt == NULL )
-        return;
+    ECP_VALIDATE( pt != NULL );
 
     mbedtls_mpi_init( &pt->X );
     mbedtls_mpi_init( &pt->Y );
@@ -539,8 +550,7 @@
  */
 void mbedtls_ecp_group_init( mbedtls_ecp_group *grp )
 {
-    if( grp == NULL )
-        return;
+    ECP_VALIDATE( grp != NULL );
 
     grp->id = MBEDTLS_ECP_DP_NONE;
     mbedtls_mpi_init( &grp->P );
@@ -564,8 +574,7 @@
  */
 void mbedtls_ecp_keypair_init( mbedtls_ecp_keypair *key )
 {
-    if( key == NULL )
-        return;
+    ECP_VALIDATE( key != NULL );
 
     mbedtls_ecp_group_init( &key->grp );
     mbedtls_mpi_init( &key->d );
@@ -633,6 +642,8 @@
 int mbedtls_ecp_copy( mbedtls_ecp_point *P, const mbedtls_ecp_point *Q )
 {
     int ret;
+    ECP_VALIDATE_RET( P != NULL );
+    ECP_VALIDATE_RET( Q != NULL );
 
     MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &P->X, &Q->X ) );
     MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &P->Y, &Q->Y ) );
@@ -647,7 +658,10 @@
  */
 int mbedtls_ecp_group_copy( mbedtls_ecp_group *dst, const mbedtls_ecp_group *src )
 {
-    return mbedtls_ecp_group_load( dst, src->id );
+    ECP_VALIDATE_RET( dst != NULL );
+    ECP_VALIDATE_RET( src != NULL );
+
+    return( mbedtls_ecp_group_load( dst, src->id ) );
 }
 
 /*
@@ -656,6 +670,7 @@
 int mbedtls_ecp_set_zero( mbedtls_ecp_point *pt )
 {
     int ret;
+    ECP_VALIDATE_RET( pt != NULL );
 
     MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &pt->X , 1 ) );
     MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &pt->Y , 1 ) );
@@ -670,6 +685,8 @@
  */
 int mbedtls_ecp_is_zero( mbedtls_ecp_point *pt )
 {
+    ECP_VALIDATE_RET( pt != NULL );
+
     return( mbedtls_mpi_cmp_int( &pt->Z, 0 ) == 0 );
 }
 
@@ -679,6 +696,9 @@
 int mbedtls_ecp_point_cmp( const mbedtls_ecp_point *P,
                            const mbedtls_ecp_point *Q )
 {
+    ECP_VALIDATE_RET( P != NULL );
+    ECP_VALIDATE_RET( Q != NULL );
+
     if( mbedtls_mpi_cmp_mpi( &P->X, &Q->X ) == 0 &&
         mbedtls_mpi_cmp_mpi( &P->Y, &Q->Y ) == 0 &&
         mbedtls_mpi_cmp_mpi( &P->Z, &Q->Z ) == 0 )
@@ -696,6 +716,9 @@
                            const char *x, const char *y )
 {
     int ret;
+    ECP_VALIDATE_RET( P != NULL );
+    ECP_VALIDATE_RET( x != NULL );
+    ECP_VALIDATE_RET( y != NULL );
 
     MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &P->X, radix, x ) );
     MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &P->Y, radix, y ) );
@@ -708,16 +731,19 @@
 /*
  * Export a point into unsigned binary data (SEC1 2.3.3)
  */
-int mbedtls_ecp_point_write_binary( const mbedtls_ecp_group *grp, const mbedtls_ecp_point *P,
-                            int format, size_t *olen,
-                            unsigned char *buf, size_t buflen )
+int mbedtls_ecp_point_write_binary( const mbedtls_ecp_group *grp,
+                                    const mbedtls_ecp_point *P,
+                                    int format, size_t *olen,
+                                    unsigned char *buf, size_t buflen )
 {
     int ret = 0;
     size_t plen;
-
-    if( format != MBEDTLS_ECP_PF_UNCOMPRESSED &&
-        format != MBEDTLS_ECP_PF_COMPRESSED )
-        return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
+    ECP_VALIDATE_RET( grp  != NULL );
+    ECP_VALIDATE_RET( P    != NULL );
+    ECP_VALIDATE_RET( olen != NULL );
+    ECP_VALIDATE_RET( buf  != NULL );
+    ECP_VALIDATE_RET( format == MBEDTLS_ECP_PF_UNCOMPRESSED ||
+                      format == MBEDTLS_ECP_PF_COMPRESSED );
 
     /*
      * Common case: P == 0
@@ -764,11 +790,15 @@
 /*
  * Import a point from unsigned binary data (SEC1 2.3.4)
  */
-int mbedtls_ecp_point_read_binary( const mbedtls_ecp_group *grp, mbedtls_ecp_point *pt,
-                           const unsigned char *buf, size_t ilen )
+int mbedtls_ecp_point_read_binary( const mbedtls_ecp_group *grp,
+                                   mbedtls_ecp_point *pt,
+                                   const unsigned char *buf, size_t ilen )
 {
     int ret;
     size_t plen;
+    ECP_VALIDATE_RET( grp != NULL );
+    ECP_VALIDATE_RET( pt  != NULL );
+    ECP_VALIDATE_RET( buf != NULL );
 
     if( ilen < 1 )
         return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
@@ -803,11 +833,16 @@
  *          opaque point <1..2^8-1>;
  *      } ECPoint;
  */
-int mbedtls_ecp_tls_read_point( const mbedtls_ecp_group *grp, mbedtls_ecp_point *pt,
-                        const unsigned char **buf, size_t buf_len )
+int mbedtls_ecp_tls_read_point( const mbedtls_ecp_group *grp,
+                                mbedtls_ecp_point *pt,
+                                const unsigned char **buf, size_t buf_len )
 {
     unsigned char data_len;
     const unsigned char *buf_start;
+    ECP_VALIDATE_RET( grp != NULL );
+    ECP_VALIDATE_RET( pt  != NULL );
+    ECP_VALIDATE_RET( buf != NULL );
+    ECP_VALIDATE_RET( *buf != NULL );
 
     /*
      * We must have at least two bytes (1 for length, at least one for data)
@@ -825,7 +860,7 @@
     buf_start = *buf;
     *buf += data_len;
 
-    return mbedtls_ecp_point_read_binary( grp, pt, buf_start, data_len );
+    return( mbedtls_ecp_point_read_binary( grp, pt, buf_start, data_len ) );
 }
 
 /*
@@ -839,6 +874,12 @@
                          unsigned char *buf, size_t blen )
 {
     int ret;
+    ECP_VALIDATE_RET( grp  != NULL );
+    ECP_VALIDATE_RET( pt   != NULL );
+    ECP_VALIDATE_RET( olen != NULL );
+    ECP_VALIDATE_RET( buf  != NULL );
+    ECP_VALIDATE_RET( format == MBEDTLS_ECP_PF_UNCOMPRESSED ||
+                      format == MBEDTLS_ECP_PF_COMPRESSED );
 
     /*
      * buffer length must be at least one, for our length byte
@@ -867,11 +908,14 @@
 {
     int ret;
     mbedtls_ecp_group_id grp_id;
+    ECP_VALIDATE_RET( grp  != NULL );
+    ECP_VALIDATE_RET( buf  != NULL );
+    ECP_VALIDATE_RET( *buf != NULL );
 
     if( ( ret = mbedtls_ecp_tls_read_group_id( &grp_id, buf, len ) ) != 0 )
         return( ret );
 
-    return mbedtls_ecp_group_load( grp, grp_id );
+    return( mbedtls_ecp_group_load( grp, grp_id ) );
 }
 
 /*
@@ -883,6 +927,9 @@
 {
     uint16_t tls_id;
     const mbedtls_ecp_curve_info *curve_info;
+    ECP_VALIDATE_RET( grp  != NULL );
+    ECP_VALIDATE_RET( buf  != NULL );
+    ECP_VALIDATE_RET( *buf != NULL );
 
     /*
      * We expect at least three bytes (see below)
@@ -918,6 +965,9 @@
                          unsigned char *buf, size_t blen )
 {
     const mbedtls_ecp_curve_info *curve_info;
+    ECP_VALIDATE_RET( grp  != NULL );
+    ECP_VALIDATE_RET( buf  != NULL );
+    ECP_VALIDATE_RET( olen != NULL );
 
     if( ( curve_info = mbedtls_ecp_curve_info_from_grp_id( grp->id ) ) == NULL )
         return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
@@ -2276,6 +2326,10 @@
 #if defined(MBEDTLS_ECP_INTERNAL_ALT)
     char is_grp_capable = 0;
 #endif
+    ECP_VALIDATE_RET( grp != NULL );
+    ECP_VALIDATE_RET( R   != NULL );
+    ECP_VALIDATE_RET( m   != NULL );
+    ECP_VALIDATE_RET( P   != NULL );
 
 #if defined(MBEDTLS_ECP_RESTARTABLE)
     /* reset ops count for this call if top-level */
@@ -2333,6 +2387,10 @@
              const mbedtls_mpi *m, const mbedtls_ecp_point *P,
              int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
 {
+    ECP_VALIDATE_RET( grp != NULL );
+    ECP_VALIDATE_RET( R   != NULL );
+    ECP_VALIDATE_RET( m   != NULL );
+    ECP_VALIDATE_RET( P   != NULL );
     return( mbedtls_ecp_mul_restartable( grp, R, m, P, f_rng, p_rng, NULL ) );
 }
 
@@ -2435,6 +2493,12 @@
 #if defined(MBEDTLS_ECP_INTERNAL_ALT)
     char is_grp_capable = 0;
 #endif
+    ECP_VALIDATE_RET( grp != NULL );
+    ECP_VALIDATE_RET( R   != NULL );
+    ECP_VALIDATE_RET( m   != NULL );
+    ECP_VALIDATE_RET( P   != NULL );
+    ECP_VALIDATE_RET( n   != NULL );
+    ECP_VALIDATE_RET( Q   != NULL );
 
     if( ecp_get_type( grp ) != ECP_TYPE_SHORT_WEIERSTRASS )
         return( MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE );
@@ -2517,6 +2581,12 @@
              const mbedtls_mpi *m, const mbedtls_ecp_point *P,
              const mbedtls_mpi *n, const mbedtls_ecp_point *Q )
 {
+    ECP_VALIDATE_RET( grp != NULL );
+    ECP_VALIDATE_RET( R   != NULL );
+    ECP_VALIDATE_RET( m   != NULL );
+    ECP_VALIDATE_RET( P   != NULL );
+    ECP_VALIDATE_RET( n   != NULL );
+    ECP_VALIDATE_RET( Q   != NULL );
     return( mbedtls_ecp_muladd_restartable( grp, R, m, P, n, Q, NULL ) );
 }
 
@@ -2539,8 +2609,12 @@
 /*
  * Check that a point is valid as a public key
  */
-int mbedtls_ecp_check_pubkey( const mbedtls_ecp_group *grp, const mbedtls_ecp_point *pt )
+int mbedtls_ecp_check_pubkey( const mbedtls_ecp_group *grp,
+                              const mbedtls_ecp_point *pt )
 {
+    ECP_VALIDATE_RET( grp != NULL );
+    ECP_VALIDATE_RET( pt  != NULL );
+
     /* Must use affine coordinates */
     if( mbedtls_mpi_cmp_int( &pt->Z, 1 ) != 0 )
         return( MBEDTLS_ERR_ECP_INVALID_KEY );
@@ -2559,8 +2633,12 @@
 /*
  * Check that an mbedtls_mpi is valid as a private key
  */
-int mbedtls_ecp_check_privkey( const mbedtls_ecp_group *grp, const mbedtls_mpi *d )
+int mbedtls_ecp_check_privkey( const mbedtls_ecp_group *grp,
+                               const mbedtls_mpi *d )
 {
+    ECP_VALIDATE_RET( grp != NULL );
+    ECP_VALIDATE_RET( d   != NULL );
+
 #if defined(ECP_MONTGOMERY)
     if( ecp_get_type( grp ) == ECP_TYPE_MONTGOMERY )
     {
@@ -2601,7 +2679,13 @@
                      void *p_rng )
 {
     int ret = MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
-    size_t n_size = ( grp->nbits + 7 ) / 8;
+    size_t n_size;
+
+    ECP_VALIDATE_RET( grp   != NULL );
+    ECP_VALIDATE_RET( d     != NULL );
+    ECP_VALIDATE_RET( f_rng != NULL );
+
+    n_size = ( grp->nbits + 7 ) / 8;
 
 #if defined(ECP_MONTGOMERY)
     if( ecp_get_type( grp ) == ECP_TYPE_MONTGOMERY )
@@ -2680,6 +2764,11 @@
                      void *p_rng )
 {
     int ret;
+    ECP_VALIDATE_RET( grp   != NULL );
+    ECP_VALIDATE_RET( d     != NULL );
+    ECP_VALIDATE_RET( G     != NULL );
+    ECP_VALIDATE_RET( Q     != NULL );
+    ECP_VALIDATE_RET( f_rng != NULL );
 
     MBEDTLS_MPI_CHK( mbedtls_ecp_gen_privkey( grp, d, f_rng, p_rng ) );
     MBEDTLS_MPI_CHK( mbedtls_ecp_mul( grp, Q, d, G, f_rng, p_rng ) );
@@ -2696,6 +2785,11 @@
                              int (*f_rng)(void *, unsigned char *, size_t),
                              void *p_rng )
 {
+    ECP_VALIDATE_RET( grp   != NULL );
+    ECP_VALIDATE_RET( d     != NULL );
+    ECP_VALIDATE_RET( Q     != NULL );
+    ECP_VALIDATE_RET( f_rng != NULL );
+
     return( mbedtls_ecp_gen_keypair_base( grp, &grp->G, d, Q, f_rng, p_rng ) );
 }
 
@@ -2706,6 +2800,8 @@
                 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
 {
     int ret;
+    ECP_VALIDATE_RET( key   != NULL );
+    ECP_VALIDATE_RET( f_rng != NULL );
 
     if( ( ret = mbedtls_ecp_group_load( &key->grp, grp_id ) ) != 0 )
         return( ret );
@@ -2721,6 +2817,8 @@
     int ret;
     mbedtls_ecp_point Q;
     mbedtls_ecp_group grp;
+    ECP_VALIDATE_RET( pub != NULL );
+    ECP_VALIDATE_RET( prv != NULL );
 
     if( pub->grp.id == MBEDTLS_ECP_DP_NONE ||
         pub->grp.id != prv->grp.id ||
diff --git a/library/ecp_curves.c b/library/ecp_curves.c
index 68e2441..731621d 100644
--- a/library/ecp_curves.c
+++ b/library/ecp_curves.c
@@ -28,11 +28,18 @@
 #if defined(MBEDTLS_ECP_C)
 
 #include "mbedtls/ecp.h"
+#include "mbedtls/platform_util.h"
 
 #include <string.h>
 
 #if !defined(MBEDTLS_ECP_ALT)
 
+/* Parameter validation macros based on platform_util.h */
+#define ECP_VALIDATE_RET( cond )    \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_ECP_BAD_INPUT_DATA )
+#define ECP_VALIDATE( cond )        \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
     !defined(inline) && !defined(__cplusplus)
 #define inline __inline
@@ -746,6 +753,7 @@
  */
 int mbedtls_ecp_group_load( mbedtls_ecp_group *grp, mbedtls_ecp_group_id id )
 {
+    ECP_VALIDATE_RET( grp != NULL );
     mbedtls_ecp_group_free( grp );
 
     grp->id = id;
diff --git a/library/error.c b/library/error.c
index 3be4175..12312a0 100644
--- a/library/error.c
+++ b/library/error.c
@@ -855,16 +855,22 @@
 #if defined(MBEDTLS_SHA1_C)
     if( use_ret == -(MBEDTLS_ERR_SHA1_HW_ACCEL_FAILED) )
         mbedtls_snprintf( buf, buflen, "SHA1 - SHA-1 hardware accelerator failed" );
+    if( use_ret == -(MBEDTLS_ERR_SHA1_BAD_INPUT_DATA) )
+        mbedtls_snprintf( buf, buflen, "SHA1 - SHA-1 input data was malformed" );
 #endif /* MBEDTLS_SHA1_C */
 
 #if defined(MBEDTLS_SHA256_C)
     if( use_ret == -(MBEDTLS_ERR_SHA256_HW_ACCEL_FAILED) )
         mbedtls_snprintf( buf, buflen, "SHA256 - SHA-256 hardware accelerator failed" );
+    if( use_ret == -(MBEDTLS_ERR_SHA256_BAD_INPUT_DATA) )
+        mbedtls_snprintf( buf, buflen, "SHA256 - SHA-256 input data was malformed" );
 #endif /* MBEDTLS_SHA256_C */
 
 #if defined(MBEDTLS_SHA512_C)
     if( use_ret == -(MBEDTLS_ERR_SHA512_HW_ACCEL_FAILED) )
         mbedtls_snprintf( buf, buflen, "SHA512 - SHA-512 hardware accelerator failed" );
+    if( use_ret == -(MBEDTLS_ERR_SHA512_BAD_INPUT_DATA) )
+        mbedtls_snprintf( buf, buflen, "SHA512 - SHA-512 input data was malformed" );
 #endif /* MBEDTLS_SHA512_C */
 
 #if defined(MBEDTLS_THREADING_C)
diff --git a/library/gcm.c b/library/gcm.c
index c486ef7..675926a 100644
--- a/library/gcm.c
+++ b/library/gcm.c
@@ -57,6 +57,12 @@
 
 #if !defined(MBEDTLS_GCM_ALT)
 
+/* Parameter validation macros */
+#define GCM_VALIDATE_RET( cond ) \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_GCM_BAD_INPUT )
+#define GCM_VALIDATE( cond ) \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 /*
  * 32-bit integer manipulation macros (big endian)
  */
@@ -85,6 +91,7 @@
  */
 void mbedtls_gcm_init( mbedtls_gcm_context *ctx )
 {
+    GCM_VALIDATE( ctx != NULL );
     memset( ctx, 0, sizeof( mbedtls_gcm_context ) );
 }
 
@@ -164,6 +171,10 @@
     int ret;
     const mbedtls_cipher_info_t *cipher_info;
 
+    GCM_VALIDATE_RET( ctx != NULL );
+    GCM_VALIDATE_RET( key != NULL );
+    GCM_VALIDATE_RET( keybits == 128 || keybits == 192 || keybits == 256 );
+
     cipher_info = mbedtls_cipher_info_from_values( cipher, keybits, MBEDTLS_MODE_ECB );
     if( cipher_info == NULL )
         return( MBEDTLS_ERR_GCM_BAD_INPUT );
@@ -274,6 +285,10 @@
     const unsigned char *p;
     size_t use_len, olen = 0;
 
+    GCM_VALIDATE_RET( ctx != NULL );
+    GCM_VALIDATE_RET( iv != NULL );
+    GCM_VALIDATE_RET( add_len == 0 || add != NULL );
+
     /* IV and AD are limited to 2^64 bits, so 2^61 bytes */
     /* IV is not allowed to be zero length */
     if( iv_len == 0 ||
@@ -356,6 +371,10 @@
     unsigned char *out_p = output;
     size_t use_len, olen = 0;
 
+    GCM_VALIDATE_RET( ctx != NULL );
+    GCM_VALIDATE_RET( length == 0 || input != NULL );
+    GCM_VALIDATE_RET( length == 0 || output != NULL );
+
     if( output > input && (size_t) ( output - input ) < length )
         return( MBEDTLS_ERR_GCM_BAD_INPUT );
 
@@ -409,8 +428,14 @@
 {
     unsigned char work_buf[16];
     size_t i;
-    uint64_t orig_len = ctx->len * 8;
-    uint64_t orig_add_len = ctx->add_len * 8;
+    uint64_t orig_len;
+    uint64_t orig_add_len;
+
+    GCM_VALIDATE_RET( ctx != NULL );
+    GCM_VALIDATE_RET( tag != NULL );
+
+    orig_len = ctx->len * 8;
+    orig_add_len = ctx->add_len * 8;
 
     if( tag_len > 16 || tag_len < 4 )
         return( MBEDTLS_ERR_GCM_BAD_INPUT );
@@ -452,6 +477,13 @@
 {
     int ret;
 
+    GCM_VALIDATE_RET( ctx != NULL );
+    GCM_VALIDATE_RET( iv != NULL );
+    GCM_VALIDATE_RET( add_len == 0 || add != NULL );
+    GCM_VALIDATE_RET( length == 0 || input != NULL );
+    GCM_VALIDATE_RET( length == 0 || output != NULL );
+    GCM_VALIDATE_RET( tag != NULL );
+
     if( ( ret = mbedtls_gcm_starts( ctx, mode, iv, iv_len, add, add_len ) ) != 0 )
         return( ret );
 
@@ -480,6 +512,13 @@
     size_t i;
     int diff;
 
+    GCM_VALIDATE_RET( ctx != NULL );
+    GCM_VALIDATE_RET( iv != NULL );
+    GCM_VALIDATE_RET( add_len == 0 || add != NULL );
+    GCM_VALIDATE_RET( tag != NULL );
+    GCM_VALIDATE_RET( length == 0 || input != NULL );
+    GCM_VALIDATE_RET( length == 0 || output != NULL );
+
     if( ( ret = mbedtls_gcm_crypt_and_tag( ctx, MBEDTLS_GCM_DECRYPT, length,
                                    iv, iv_len, add, add_len,
                                    input, output, tag_len, check_tag ) ) != 0 )
@@ -502,6 +541,8 @@
 
 void mbedtls_gcm_free( mbedtls_gcm_context *ctx )
 {
+    if( ctx == NULL )
+        return;
     mbedtls_cipher_free( &ctx->cipher_ctx );
     mbedtls_platform_zeroize( ctx, sizeof( mbedtls_gcm_context ) );
 }
diff --git a/library/poly1305.c b/library/poly1305.c
index e22d3af..b274119 100644
--- a/library/poly1305.c
+++ b/library/poly1305.c
@@ -49,6 +49,12 @@
 #define inline __inline
 #endif
 
+/* Parameter validation macros */
+#define POLY1305_VALIDATE_RET( cond )                                       \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA )
+#define POLY1305_VALIDATE( cond )                                           \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #define POLY1305_BLOCK_SIZE_BYTES ( 16U )
 
 #define BYTES_TO_U32_LE( data, offset )                           \
@@ -276,27 +282,24 @@
 
 void mbedtls_poly1305_init( mbedtls_poly1305_context *ctx )
 {
-    if( ctx != NULL )
-    {
-        mbedtls_platform_zeroize( ctx, sizeof( mbedtls_poly1305_context ) );
-    }
+    POLY1305_VALIDATE( ctx != NULL );
+
+    mbedtls_platform_zeroize( ctx, sizeof( mbedtls_poly1305_context ) );
 }
 
 void mbedtls_poly1305_free( mbedtls_poly1305_context *ctx )
 {
-    if( ctx != NULL )
-    {
-        mbedtls_platform_zeroize( ctx, sizeof( mbedtls_poly1305_context ) );
-    }
+    if( ctx == NULL )
+        return;
+
+    mbedtls_platform_zeroize( ctx, sizeof( mbedtls_poly1305_context ) );
 }
 
 int mbedtls_poly1305_starts( mbedtls_poly1305_context *ctx,
                              const unsigned char key[32] )
 {
-    if( ctx == NULL || key == NULL )
-    {
-        return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    }
+    POLY1305_VALIDATE_RET( ctx != NULL );
+    POLY1305_VALIDATE_RET( key != NULL );
 
     /* r &= 0x0ffffffc0ffffffc0ffffffc0fffffff */
     ctx->r[0] = BYTES_TO_U32_LE( key, 0 )  & 0x0FFFFFFFU;
@@ -331,16 +334,8 @@
     size_t remaining = ilen;
     size_t queue_free_len;
     size_t nblocks;
-
-    if( ctx == NULL )
-    {
-        return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    }
-    else if( ( ilen > 0U ) && ( input == NULL ) )
-    {
-        /* input pointer is allowed to be NULL only if ilen == 0 */
-        return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    }
+    POLY1305_VALIDATE_RET( ctx != NULL );
+    POLY1305_VALIDATE_RET( ilen == 0 || input != NULL );
 
     if( ( remaining > 0U ) && ( ctx->queue_len > 0U ) )
     {
@@ -398,10 +393,8 @@
 int mbedtls_poly1305_finish( mbedtls_poly1305_context *ctx,
                              unsigned char mac[16] )
 {
-    if( ( ctx == NULL ) || ( mac == NULL ) )
-    {
-        return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    }
+    POLY1305_VALIDATE_RET( ctx != NULL );
+    POLY1305_VALIDATE_RET( mac != NULL );
 
     /* Process any leftover data */
     if( ctx->queue_len > 0U )
@@ -431,6 +424,9 @@
 {
     mbedtls_poly1305_context ctx;
     int ret;
+    POLY1305_VALIDATE_RET( key != NULL );
+    POLY1305_VALIDATE_RET( mac != NULL );
+    POLY1305_VALIDATE_RET( ilen == 0 || input != NULL );
 
     mbedtls_poly1305_init( &ctx );
 
diff --git a/library/sha1.c b/library/sha1.c
index bab6087..e8d4096 100644
--- a/library/sha1.c
+++ b/library/sha1.c
@@ -46,6 +46,11 @@
 #endif /* MBEDTLS_PLATFORM_C */
 #endif /* MBEDTLS_SELF_TEST */
 
+#define SHA1_VALIDATE_RET(cond)                             \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_SHA1_BAD_INPUT_DATA )
+
+#define SHA1_VALIDATE(cond)  MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #if !defined(MBEDTLS_SHA1_ALT)
 
 /*
@@ -73,6 +78,8 @@
 
 void mbedtls_sha1_init( mbedtls_sha1_context *ctx )
 {
+    SHA1_VALIDATE( ctx != NULL );
+
     memset( ctx, 0, sizeof( mbedtls_sha1_context ) );
 }
 
@@ -87,6 +94,9 @@
 void mbedtls_sha1_clone( mbedtls_sha1_context *dst,
                          const mbedtls_sha1_context *src )
 {
+    SHA1_VALIDATE( dst != NULL );
+    SHA1_VALIDATE( src != NULL );
+
     *dst = *src;
 }
 
@@ -95,6 +105,8 @@
  */
 int mbedtls_sha1_starts_ret( mbedtls_sha1_context *ctx )
 {
+    SHA1_VALIDATE_RET( ctx != NULL );
+
     ctx->total[0] = 0;
     ctx->total[1] = 0;
 
@@ -120,6 +132,9 @@
 {
     uint32_t temp, W[16], A, B, C, D, E;
 
+    SHA1_VALIDATE_RET( ctx != NULL );
+    SHA1_VALIDATE_RET( (const unsigned char *)data != NULL );
+
     GET_UINT32_BE( W[ 0], data,  0 );
     GET_UINT32_BE( W[ 1], data,  4 );
     GET_UINT32_BE( W[ 2], data,  8 );
@@ -294,6 +309,9 @@
     size_t fill;
     uint32_t left;
 
+    SHA1_VALIDATE_RET( ctx != NULL );
+    SHA1_VALIDATE_RET( ilen == 0 || input != NULL );
+
     if( ilen == 0 )
         return( 0 );
 
@@ -352,6 +370,9 @@
     uint32_t used;
     uint32_t high, low;
 
+    SHA1_VALIDATE_RET( ctx != NULL );
+    SHA1_VALIDATE_RET( (unsigned char *)output != NULL );
+
     /*
      * Add padding: 0x80 then 0x00 until 8 bytes remain for the length
      */
@@ -420,6 +441,9 @@
     int ret;
     mbedtls_sha1_context ctx;
 
+    SHA1_VALIDATE_RET( ilen == 0 || input != NULL );
+    SHA1_VALIDATE_RET( (unsigned char *)output != NULL );
+
     mbedtls_sha1_init( &ctx );
 
     if( ( ret = mbedtls_sha1_starts_ret( &ctx ) ) != 0 )
diff --git a/library/sha256.c b/library/sha256.c
index dbb4a89..8a540ad 100644
--- a/library/sha256.c
+++ b/library/sha256.c
@@ -49,6 +49,10 @@
 #endif /* MBEDTLS_PLATFORM_C */
 #endif /* MBEDTLS_SELF_TEST */
 
+#define SHA256_VALIDATE_RET(cond)                           \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_SHA256_BAD_INPUT_DATA )
+#define SHA256_VALIDATE(cond)  MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #if !defined(MBEDTLS_SHA256_ALT)
 
 /*
@@ -76,6 +80,8 @@
 
 void mbedtls_sha256_init( mbedtls_sha256_context *ctx )
 {
+    SHA256_VALIDATE( ctx != NULL );
+
     memset( ctx, 0, sizeof( mbedtls_sha256_context ) );
 }
 
@@ -90,6 +96,9 @@
 void mbedtls_sha256_clone( mbedtls_sha256_context *dst,
                            const mbedtls_sha256_context *src )
 {
+    SHA256_VALIDATE( dst != NULL );
+    SHA256_VALIDATE( src != NULL );
+
     *dst = *src;
 }
 
@@ -98,6 +107,9 @@
  */
 int mbedtls_sha256_starts_ret( mbedtls_sha256_context *ctx, int is224 )
 {
+    SHA256_VALIDATE_RET( ctx != NULL );
+    SHA256_VALIDATE_RET( is224 == 0 || is224 == 1 );
+
     ctx->total[0] = 0;
     ctx->total[1] = 0;
 
@@ -192,6 +204,9 @@
     uint32_t A[8];
     unsigned int i;
 
+    SHA256_VALIDATE_RET( ctx != NULL );
+    SHA256_VALIDATE_RET( (const unsigned char *)data != NULL );
+
     for( i = 0; i < 8; i++ )
         A[i] = ctx->state[i];
 
@@ -263,6 +278,9 @@
     size_t fill;
     uint32_t left;
 
+    SHA256_VALIDATE_RET( ctx != NULL );
+    SHA256_VALIDATE_RET( ilen == 0 || input != NULL );
+
     if( ilen == 0 )
         return( 0 );
 
@@ -321,6 +339,9 @@
     uint32_t used;
     uint32_t high, low;
 
+    SHA256_VALIDATE_RET( ctx != NULL );
+    SHA256_VALIDATE_RET( (unsigned char *)output != NULL );
+
     /*
      * Add padding: 0x80 then 0x00 until 8 bytes remain for the length
      */
@@ -395,6 +416,10 @@
     int ret;
     mbedtls_sha256_context ctx;
 
+    SHA256_VALIDATE_RET( is224 == 0 || is224 == 1 );
+    SHA256_VALIDATE_RET( ilen == 0 || input != NULL );
+    SHA256_VALIDATE_RET( (unsigned char *)output != NULL );
+
     mbedtls_sha256_init( &ctx );
 
     if( ( ret = mbedtls_sha256_starts_ret( &ctx, is224 ) ) != 0 )
diff --git a/library/sha512.c b/library/sha512.c
index a9440e8..941ecda 100644
--- a/library/sha512.c
+++ b/library/sha512.c
@@ -55,6 +55,10 @@
 #endif /* MBEDTLS_PLATFORM_C */
 #endif /* MBEDTLS_SELF_TEST */
 
+#define SHA512_VALIDATE_RET(cond)                           \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_SHA512_BAD_INPUT_DATA )
+#define SHA512_VALIDATE(cond)  MBEDTLS_INTERNAL_VALIDATE( cond )
+
 #if !defined(MBEDTLS_SHA512_ALT)
 
 /*
@@ -90,6 +94,8 @@
 
 void mbedtls_sha512_init( mbedtls_sha512_context *ctx )
 {
+    SHA512_VALIDATE( ctx != NULL );
+
     memset( ctx, 0, sizeof( mbedtls_sha512_context ) );
 }
 
@@ -104,6 +110,9 @@
 void mbedtls_sha512_clone( mbedtls_sha512_context *dst,
                            const mbedtls_sha512_context *src )
 {
+    SHA512_VALIDATE( dst != NULL );
+    SHA512_VALIDATE( src != NULL );
+
     *dst = *src;
 }
 
@@ -112,6 +121,9 @@
  */
 int mbedtls_sha512_starts_ret( mbedtls_sha512_context *ctx, int is384 )
 {
+    SHA512_VALIDATE_RET( ctx != NULL );
+    SHA512_VALIDATE_RET( is384 == 0 || is384 == 1 );
+
     ctx->total[0] = 0;
     ctx->total[1] = 0;
 
@@ -209,6 +221,9 @@
     uint64_t temp1, temp2, W[80];
     uint64_t A, B, C, D, E, F, G, H;
 
+    SHA512_VALIDATE_RET( ctx != NULL );
+    SHA512_VALIDATE_RET( (const unsigned char *)data != NULL );
+
 #define  SHR(x,n) (x >> n)
 #define ROTR(x,n) (SHR(x,n) | (x << (64 - n)))
 
@@ -294,6 +309,9 @@
     size_t fill;
     unsigned int left;
 
+    SHA512_VALIDATE_RET( ctx != NULL );
+    SHA512_VALIDATE_RET( ilen == 0 || input != NULL );
+
     if( ilen == 0 )
         return( 0 );
 
@@ -351,6 +369,9 @@
     unsigned used;
     uint64_t high, low;
 
+    SHA512_VALIDATE_RET( ctx != NULL );
+    SHA512_VALIDATE_RET( (unsigned char *)output != NULL );
+
     /*
      * Add padding: 0x80 then 0x00 until 16 bytes remain for the length
      */
@@ -427,6 +448,10 @@
     int ret;
     mbedtls_sha512_context ctx;
 
+    SHA512_VALIDATE_RET( is384 == 0 || is384 == 1 );
+    SHA512_VALIDATE_RET( ilen == 0 || input != NULL );
+    SHA512_VALIDATE_RET( (unsigned char *)output != NULL );
+
     mbedtls_sha512_init( &ctx );
 
     if( ( ret = mbedtls_sha512_starts_ret( &ctx, is384 ) ) != 0 )
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index d7a1442..eae1f57 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -93,6 +93,7 @@
 add_test_suite(gcm gcm.aes192_de)
 add_test_suite(gcm gcm.aes256_de)
 add_test_suite(gcm gcm.camellia)
+add_test_suite(gcm gcm.misc)
 add_test_suite(hkdf)
 add_test_suite(hmac_drbg hmac_drbg.misc)
 add_test_suite(hmac_drbg hmac_drbg.no_reseed)
diff --git a/tests/suites/helpers.function b/tests/suites/helpers.function
index 3aa5cd6..2e227f0 100644
--- a/tests/suites/helpers.function
+++ b/tests/suites/helpers.function
@@ -632,4 +632,3 @@
     }
     return ret;
 }
-
diff --git a/tests/suites/test_suite_aes.function b/tests/suites/test_suite_aes.function
index 1315650..da8c1e9 100644
--- a/tests/suites/test_suite_aes.function
+++ b/tests/suites/test_suite_aes.function
@@ -194,8 +194,8 @@
 void aes_crypt_xts_size( int size, int retval )
 {
     mbedtls_aes_xts_context ctx;
-    const unsigned char *src = NULL;
-    unsigned char *output = NULL;
+    const unsigned char src[16] = { 0 };
+    unsigned char output[16];
     unsigned char data_unit[16];
     size_t length = size;
 
@@ -203,10 +203,8 @@
     memset( data_unit, 0x00, sizeof( data_unit ) );
 
 
-    /* Note that this function will most likely crash on failure, as NULL
-     * parameters will be used. In the passing case, the length check in
-     * mbedtls_aes_crypt_xts() will prevent any accesses to parameters by
-     * exiting the function early. */
+    /* Valid pointers are passed for builds with MBEDTLS_CHECK_PARAMS, as
+     * otherwise we wouldn't get to the size check we're interested in. */
     TEST_ASSERT( mbedtls_aes_crypt_xts( &ctx, MBEDTLS_AES_ENCRYPT, length, data_unit, src, output ) == retval );
 }
 /* END_CASE */
@@ -215,7 +213,7 @@
 void aes_crypt_xts_keysize( int size, int retval )
 {
     mbedtls_aes_xts_context ctx;
-    const unsigned char *key = NULL;
+    const unsigned char key[] = { 0x01, 0x02, 0x03, 0x04, 0x05, 0x06 };
     size_t key_len = size;
 
     mbedtls_aes_xts_init( &ctx );
@@ -372,39 +370,255 @@
 /* END_CASE */
 
 /* BEGIN_CASE depends_on:MBEDTLS_CHECK_PARAMS:!MBEDTLS_PARAM_FAILED_ALT */
-void aes_invalid_param( )
+void aes_check_params( )
 {
-    mbedtls_aes_context dummy_ctx;
+    mbedtls_aes_context aes_ctx;
+#if defined(MBEDTLS_CIPHER_MODE_XTS)
+    mbedtls_aes_xts_context xts_ctx;
+#endif
     const unsigned char key[] = { 0x01, 0x02, 0x03, 0x04, 0x05, 0x06 };
+    const unsigned char in[16] = { 0 };
+    unsigned char out[16];
+    size_t size;
+    const int valid_mode = MBEDTLS_AES_ENCRYPT;
+    const int invalid_mode = 42;
 
     TEST_INVALID_PARAM( mbedtls_aes_init( NULL ) );
-
+#if defined(MBEDTLS_CIPHER_MODE_XTS)
     TEST_INVALID_PARAM( mbedtls_aes_xts_init( NULL ) );
+#endif
 
-    /* mbedtls_aes_setkey_enc() */
     TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
                             mbedtls_aes_setkey_enc( NULL, key, 128 ) );
-
     TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
-                            mbedtls_aes_setkey_enc( &dummy_ctx, NULL, 128 ) );
+                            mbedtls_aes_setkey_enc( &aes_ctx, NULL, 128 ) );
 
-    /* mbedtls_aes_setkey_dec() */
     TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
                             mbedtls_aes_setkey_dec( NULL, key, 128 ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_setkey_dec( &aes_ctx, NULL, 128 ) );
+
+#if defined(MBEDTLS_CIPHER_MODE_XTS)
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_xts_setkey_enc( NULL, key, 128 ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_xts_setkey_enc( &xts_ctx, NULL, 128 ) );
 
     TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
-                            mbedtls_aes_setkey_dec( &dummy_ctx, NULL, 128 ) );
+                            mbedtls_aes_xts_setkey_dec( NULL, key, 128 ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_xts_setkey_dec( &xts_ctx, NULL, 128 ) );
+#endif
+
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_ecb( NULL,
+                                                   valid_mode, in, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_ecb( &aes_ctx,
+                                                   invalid_mode, in, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_ecb( &aes_ctx,
+                                                   valid_mode, NULL, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_ecb( &aes_ctx,
+                                                   valid_mode, in, NULL ) );
+
+#if defined(MBEDTLS_CIPHER_MODE_CBC)
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_cbc( NULL,
+                                                   valid_mode, 16,
+                                                   out, in, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_cbc( &aes_ctx,
+                                                   invalid_mode, 16,
+                                                   out, in, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_cbc( &aes_ctx,
+                                                   valid_mode, 16,
+                                                   NULL, in, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_cbc( &aes_ctx,
+                                                   valid_mode, 16,
+                                                   out, NULL, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_cbc( &aes_ctx,
+                                                   valid_mode, 16,
+                                                   out, in, NULL ) );
+#endif /* MBEDTLS_CIPHER_MODE_CBC */
+
+#if defined(MBEDTLS_CIPHER_MODE_XTS)
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_xts( NULL,
+                                                   valid_mode, 16,
+                                                   in, in, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_xts( &xts_ctx,
+                                                   invalid_mode, 16,
+                                                   in, in, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_xts( &xts_ctx,
+                                                   valid_mode, 16,
+                                                   NULL, in, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_xts( &xts_ctx,
+                                                   valid_mode, 16,
+                                                   in, NULL, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_xts( &xts_ctx,
+                                                   valid_mode, 16,
+                                                   in, in, NULL ) );
+#endif /* MBEDTLS_CIPHER_MODE_XTS */
+
+#if defined(MBEDTLS_CIPHER_MODE_CFB)
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_cfb128( NULL,
+                                                      valid_mode, 16,
+                                                      &size, out, in, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_cfb128( &aes_ctx,
+                                                      invalid_mode, 16,
+                                                      &size, out, in, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_cfb128( &aes_ctx,
+                                                      valid_mode, 16,
+                                                      NULL, out, in, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_cfb128( &aes_ctx,
+                                                      valid_mode, 16,
+                                                      &size, NULL, in, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_cfb128( &aes_ctx,
+                                                      valid_mode, 16,
+                                                      &size, out, NULL, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_cfb128( &aes_ctx,
+                                                      valid_mode, 16,
+                                                      &size, out, in, NULL ) );
+
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_cfb8( NULL,
+                                                    valid_mode, 16,
+                                                    out, in, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_cfb8( &aes_ctx,
+                                                    invalid_mode, 16,
+                                                    out, in, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_cfb8( &aes_ctx,
+                                                    valid_mode, 16,
+                                                    NULL, in, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_cfb8( &aes_ctx,
+                                                    valid_mode, 16,
+                                                    out, NULL, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_cfb8( &aes_ctx,
+                                                    valid_mode, 16,
+                                                    out, in, NULL ) );
+#endif /* MBEDTLS_CIPHER_MODE_CFB */
+
+#if defined(MBEDTLS_CIPHER_MODE_OFB)
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_ofb( NULL, 16,
+                                                   &size, out, in, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_ofb( &aes_ctx, 16,
+                                                   NULL, out, in, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_ofb( &aes_ctx, 16,
+                                                   &size, NULL, in, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_ofb( &aes_ctx, 16,
+                                                   &size, out, NULL, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_ofb( &aes_ctx, 16,
+                                                   &size, out, in, NULL ) );
+#endif /* MBEDTLS_CIPHER_MODE_OFB */
+
+#if defined(MBEDTLS_CIPHER_MODE_CTR)
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_ctr( NULL, 16, &size, out,
+                                                   out, in, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_ctr( &aes_ctx, 16, NULL, out,
+                                                   out, in, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_ctr( &aes_ctx, 16, &size, NULL,
+                                                   out, in, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_ctr( &aes_ctx, 16, &size, out,
+                                                   NULL, in, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_ctr( &aes_ctx, 16, &size, out,
+                                                   out, NULL, out ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_AES_BAD_INPUT_DATA,
+                            mbedtls_aes_crypt_ctr( &aes_ctx, 16, &size, out,
+                                                   out, in, NULL ) );
+#endif /* MBEDTLS_CIPHER_MODE_CTR */
 }
 /* END_CASE */
 
 /* BEGIN_CASE */
-void aes_valid_param( )
+void aes_misc_params( )
 {
+#if defined(MBEDTLS_CIPHER_MODE_CBC) || \
+    defined(MBEDTLS_CIPHER_MODE_XTS) || \
+    defined(MBEDTLS_CIPHER_MODE_CFB) || \
+    defined(MBEDTLS_CIPHER_MODE_OFB)
+    mbedtls_aes_context aes_ctx;
+    const unsigned char in[16] = { 0 };
+    unsigned char out[16];
+#endif
+#if defined(MBEDTLS_CIPHER_MODE_XTS)
+    mbedtls_aes_xts_context xts_ctx;
+#endif
+#if defined(MBEDTLS_CIPHER_MODE_CFB) || \
+    defined(MBEDTLS_CIPHER_MODE_OFB)
+    size_t size;
+#endif
+
     /* These calls accept NULL */
     TEST_VALID_PARAM( mbedtls_aes_free( NULL ) );
 #if defined(MBEDTLS_CIPHER_MODE_XTS)
     TEST_VALID_PARAM( mbedtls_aes_xts_free( NULL ) );
 #endif
+
+#if defined(MBEDTLS_CIPHER_MODE_CBC)
+    TEST_ASSERT( mbedtls_aes_crypt_cbc( &aes_ctx, MBEDTLS_AES_ENCRYPT,
+                                        15,
+                                        out, in, out )
+                 == MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH );
+    TEST_ASSERT( mbedtls_aes_crypt_cbc( &aes_ctx, MBEDTLS_AES_ENCRYPT,
+                                        17,
+                                        out, in, out )
+                 == MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH );
+#endif
+
+#if defined(MBEDTLS_CIPHER_MODE_XTS)
+    TEST_ASSERT( mbedtls_aes_crypt_xts( &xts_ctx, MBEDTLS_AES_ENCRYPT,
+                                        15,
+                                        in, in, out )
+                 == MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH );
+    TEST_ASSERT( mbedtls_aes_crypt_xts( &xts_ctx, MBEDTLS_AES_ENCRYPT,
+                                        (1 << 24) + 1,
+                                        in, in, out )
+                 == MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH );
+#endif
+
+#if defined(MBEDTLS_CIPHER_MODE_CFB)
+    size = 16;
+    TEST_ASSERT( mbedtls_aes_crypt_cfb128( &aes_ctx, MBEDTLS_AES_ENCRYPT, 16,
+                                           &size, out, in, out )
+                 == MBEDTLS_ERR_AES_BAD_INPUT_DATA );
+#endif
+
+#if defined(MBEDTLS_CIPHER_MODE_OFB)
+    size = 16;
+    TEST_ASSERT( mbedtls_aes_crypt_ofb( &aes_ctx, 16, &size, out, in, out )
+                 == MBEDTLS_ERR_AES_BAD_INPUT_DATA );
+#endif
 }
 /* END_CASE */
 
diff --git a/tests/suites/test_suite_aes.rest.data b/tests/suites/test_suite_aes.rest.data
index a5d843d..6a76b43 100644
--- a/tests/suites/test_suite_aes.rest.data
+++ b/tests/suites/test_suite_aes.rest.data
@@ -10,11 +10,11 @@
 AES-256-CBC Decrypt (Invalid input length)
 aes_decrypt_cbc:"0000000000000000000000000000000000000000000000000000000000000000":"00000000000000000000000000000000":"623a52fcea5d443e48d9181ab32c74":"":MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH
 
-AES - Invalid parameters
-aes_invalid_param:
+AES - Optional Parameter Validation (MBEDTLS_CHECK_PARAMS)
+aes_check_params:
 
-AES - Valid parameters
-aes_valid_param:
+AES - Mandatory Parameter Validation and Valid Parameters
+aes_misc_params:
 
 AES Selftest
 depends_on:MBEDTLS_SELF_TEST
diff --git a/tests/suites/test_suite_aria.data b/tests/suites/test_suite_aria.data
index 8cb2d2a..2da0b30 100644
--- a/tests/suites/test_suite_aria.data
+++ b/tests/suites/test_suite_aria.data
@@ -1,3 +1,9 @@
+ARIA - Valid parameters
+aria_valid_param:
+
+ARIA - Invalid parameters
+aria_invalid_param:
+
 ARIA-128-ECB Encrypt - RFC 5794
 aria_encrypt_ecb:"000102030405060708090a0b0c0d0e0f":"00112233445566778899aabbccddeeff":"d718fbd6ab644c739da95f3be6451778":0
 
diff --git a/tests/suites/test_suite_aria.function b/tests/suites/test_suite_aria.function
index 4e39078..7e35f15 100644
--- a/tests/suites/test_suite_aria.function
+++ b/tests/suites/test_suite_aria.function
@@ -17,6 +17,195 @@
  */
 
 /* BEGIN_CASE */
+void aria_valid_param( )
+{
+    TEST_VALID_PARAM( mbedtls_aria_free( NULL ) );
+}
+/* END_CASE */
+
+/* BEGIN_CASE depends_on:MBEDTLS_CHECK_PARAMS:!MBEDTLS_PARAM_FAILED_ALT */
+void aria_invalid_param( )
+{
+    mbedtls_aria_context ctx;
+    unsigned char key[128 / 8] = { 0 };
+    unsigned char input[MBEDTLS_ARIA_BLOCKSIZE] = { 0 };
+    unsigned char output[MBEDTLS_ARIA_BLOCKSIZE] = { 0 };
+    unsigned char iv[MBEDTLS_ARIA_BLOCKSIZE] = { 0 };
+    size_t iv_off = 0;
+
+    ((void) iv_off);
+    ((void) iv);
+
+    TEST_INVALID_PARAM( mbedtls_aria_init( NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA,
+                            mbedtls_aria_setkey_enc( NULL, key,
+                                                     sizeof( key ) ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA,
+                            mbedtls_aria_setkey_enc( &ctx, NULL,
+                                                     sizeof( key ) ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA,
+                            mbedtls_aria_setkey_dec( NULL, key,
+                                                     sizeof( key ) ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA,
+                            mbedtls_aria_setkey_dec( &ctx, NULL,
+                                                     sizeof( key ) ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA,
+                            mbedtls_aria_crypt_ecb( NULL, input, output ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA,
+                            mbedtls_aria_crypt_ecb( &ctx, NULL, output ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA,
+                            mbedtls_aria_crypt_ecb( &ctx, input, NULL ) );
+
+#if defined(MBEDTLS_CIPHER_MODE_CBC)
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA,
+                            mbedtls_aria_crypt_cbc( NULL,
+                                                    MBEDTLS_ARIA_ENCRYPT,
+                                                    sizeof( input ),
+                                                    iv,
+                                                    input,
+                                                    output ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA,
+                            mbedtls_aria_crypt_cbc( &ctx,
+                                                    42 /* invalid mode */,
+                                                    sizeof( input ),
+                                                    iv,
+                                                    input,
+                                                    output ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA,
+                            mbedtls_aria_crypt_cbc( &ctx,
+                                                    MBEDTLS_ARIA_ENCRYPT,
+                                                    sizeof( input ),
+                                                    NULL,
+                                                    input,
+                                                    output ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA,
+                            mbedtls_aria_crypt_cbc( &ctx,
+                                                    MBEDTLS_ARIA_ENCRYPT,
+                                                    sizeof( input ),
+                                                    iv,
+                                                    NULL,
+                                                    output ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA,
+                            mbedtls_aria_crypt_cbc( &ctx,
+                                                    MBEDTLS_ARIA_ENCRYPT,
+                                                    sizeof( input ),
+                                                    iv,
+                                                    input,
+                                                    NULL ) );
+#endif /* MBEDTLS_CIPHER_MODE_CBC */
+
+#if defined(MBEDTLS_CIPHER_MODE_CFB)
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA,
+                            mbedtls_aria_crypt_cfb128( NULL,
+                                                    MBEDTLS_ARIA_ENCRYPT,
+                                                    sizeof( input ),
+                                                    &iv_off,
+                                                    iv,
+                                                    input,
+                                                    output ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA,
+                            mbedtls_aria_crypt_cfb128( &ctx,
+                                                    42, /* invalid mode */
+                                                    sizeof( input ),
+                                                    &iv_off,
+                                                    iv,
+                                                    input,
+                                                    output ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA,
+                            mbedtls_aria_crypt_cfb128( &ctx,
+                                                    MBEDTLS_ARIA_ENCRYPT,
+                                                    sizeof( input ),
+                                                    NULL,
+                                                    iv,
+                                                    input,
+                                                    output ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA,
+                            mbedtls_aria_crypt_cfb128( &ctx,
+                                                    MBEDTLS_ARIA_ENCRYPT,
+                                                    sizeof( input ),
+                                                    &iv_off,
+                                                    NULL,
+                                                    input,
+                                                    output ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA,
+                            mbedtls_aria_crypt_cfb128( &ctx,
+                                                    MBEDTLS_ARIA_ENCRYPT,
+                                                    sizeof( input ),
+                                                    &iv_off,
+                                                    iv,
+                                                    NULL,
+                                                    output ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA,
+                            mbedtls_aria_crypt_cfb128( &ctx,
+                                                    MBEDTLS_ARIA_ENCRYPT,
+                                                    sizeof( input ),
+                                                    &iv_off,
+                                                    iv,
+                                                    input,
+                                                    NULL ) );
+#endif /* MBEDTLS_CIPHER_MODE_CFB */
+
+#if defined(MBEDTLS_CIPHER_MODE_CTR)
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA,
+                            mbedtls_aria_crypt_ctr( NULL,
+                                                    sizeof( input ),
+                                                    &iv_off,
+                                                    iv,
+                                                    iv,
+                                                    input,
+                                                    output ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA,
+                            mbedtls_aria_crypt_ctr( &ctx,
+                                                    sizeof( input ),
+                                                    NULL,
+                                                    iv,
+                                                    iv,
+                                                    input,
+                                                    output ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA,
+                            mbedtls_aria_crypt_ctr( &ctx,
+                                                    sizeof( input ),
+                                                    &iv_off,
+                                                    NULL,
+                                                    iv,
+                                                    input,
+                                                    output ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA,
+                            mbedtls_aria_crypt_ctr( &ctx,
+                                                    sizeof( input ),
+                                                    &iv_off,
+                                                    iv,
+                                                    NULL,
+                                                    input,
+                                                    output ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA,
+                            mbedtls_aria_crypt_ctr( &ctx,
+                                                    sizeof( input ),
+                                                    &iv_off,
+                                                    iv,
+                                                    iv,
+                                                    NULL,
+                                                    output ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ARIA_BAD_INPUT_DATA,
+                            mbedtls_aria_crypt_ctr( &ctx,
+                                                    sizeof( input ),
+                                                    &iv_off,
+                                                    iv,
+                                                    iv,
+                                                    input,
+                                                    NULL ) );
+#endif /* MBEDTLS_CIPHER_MODE_CTR */
+
+exit:
+    return;
+
+}
+/* END_CASE */
+
+/* BEGIN_CASE */
 void aria_encrypt_ecb( char *hex_key_string, char *hex_src_string,
                        char *hex_dst_string, int setkey_result )
 {
diff --git a/tests/suites/test_suite_blowfish.data b/tests/suites/test_suite_blowfish.data
index d4e8791..fd172d3 100644
--- a/tests/suites/test_suite_blowfish.data
+++ b/tests/suites/test_suite_blowfish.data
@@ -1,3 +1,9 @@
+BLOWFISH - Valid parameters
+blowfish_valid_param:
+
+BLOWFISH - Invalid parameters
+blowfish_invalid_param:
+
 BLOWFISH-ECB Encrypt SSLeay reference #1
 blowfish_encrypt_ecb:"0000000000000000":"0000000000000000":"4ef997456198dd78":0
 
diff --git a/tests/suites/test_suite_blowfish.function b/tests/suites/test_suite_blowfish.function
index 189e23d..7a93cd1 100644
--- a/tests/suites/test_suite_blowfish.function
+++ b/tests/suites/test_suite_blowfish.function
@@ -8,6 +8,164 @@
  */
 
 /* BEGIN_CASE */
+void blowfish_valid_param( )
+{
+    TEST_VALID_PARAM( mbedtls_blowfish_free( NULL ) );
+}
+/* END_CASE */
+
+/* BEGIN_CASE depends_on:MBEDTLS_CHECK_PARAMS:!MBEDTLS_PARAM_FAILED_ALT */
+void blowfish_invalid_param( )
+{
+    mbedtls_blowfish_context ctx;
+    unsigned char buf[16] = { 0 };
+    size_t const valid_keylength = sizeof( buf ) * 8;
+    size_t valid_mode = MBEDTLS_BLOWFISH_ENCRYPT;
+    size_t invalid_mode = 42;
+    size_t off;
+    ((void) off);
+
+    TEST_INVALID_PARAM( mbedtls_blowfish_init( NULL ) );
+    TEST_VALID_PARAM( mbedtls_blowfish_free( NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA,
+                            mbedtls_blowfish_setkey( NULL,
+                                                     buf,
+                                                     valid_keylength ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA,
+                            mbedtls_blowfish_setkey( &ctx,
+                                                     NULL,
+                                                     valid_keylength ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA,
+                            mbedtls_blowfish_crypt_ecb( NULL,
+                                                     valid_mode,
+                                                     buf, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA,
+                            mbedtls_blowfish_crypt_ecb( &ctx,
+                                                        invalid_mode,
+                                                        buf, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA,
+                            mbedtls_blowfish_crypt_ecb( &ctx,
+                                                        valid_mode,
+                                                        NULL, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA,
+                            mbedtls_blowfish_crypt_ecb( &ctx,
+                                                        valid_mode,
+                                                        buf, NULL ) );
+
+#if defined(MBEDTLS_CIPHER_MODE_CBC)
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA,
+                            mbedtls_blowfish_crypt_cbc( NULL,
+                                                        valid_mode,
+                                                        sizeof( buf ),
+                                                        buf, buf, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA,
+                            mbedtls_blowfish_crypt_cbc( &ctx,
+                                                        invalid_mode,
+                                                        sizeof( buf ),
+                                                        buf, buf, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA,
+                            mbedtls_blowfish_crypt_cbc( &ctx,
+                                                        valid_mode,
+                                                        sizeof( buf ),
+                                                        NULL, buf, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA,
+                            mbedtls_blowfish_crypt_cbc( &ctx,
+                                                        valid_mode,
+                                                        sizeof( buf ),
+                                                        buf, NULL, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA,
+                            mbedtls_blowfish_crypt_cbc( &ctx,
+                                                        valid_mode,
+                                                        sizeof( buf ),
+                                                        buf, buf, NULL ) );
+#endif /* MBEDTLS_CIPHER_MODE_CBC */
+
+#if defined(MBEDTLS_CIPHER_MODE_CFB)
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA,
+                            mbedtls_blowfish_crypt_cfb64( NULL,
+                                                          valid_mode,
+                                                          sizeof( buf ),
+                                                          &off, buf,
+                                                          buf, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA,
+                            mbedtls_blowfish_crypt_cfb64( &ctx,
+                                                          invalid_mode,
+                                                          sizeof( buf ),
+                                                          &off, buf,
+                                                          buf, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA,
+                            mbedtls_blowfish_crypt_cfb64( &ctx,
+                                                          valid_mode,
+                                                          sizeof( buf ),
+                                                          NULL, buf,
+                                                          buf, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA,
+                            mbedtls_blowfish_crypt_cfb64( &ctx,
+                                                          valid_mode,
+                                                          sizeof( buf ),
+                                                          &off, NULL,
+                                                          buf, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA,
+                            mbedtls_blowfish_crypt_cfb64( &ctx,
+                                                          valid_mode,
+                                                          sizeof( buf ),
+                                                          &off, buf,
+                                                          NULL, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA,
+                            mbedtls_blowfish_crypt_cfb64( &ctx,
+                                                          valid_mode,
+                                                          sizeof( buf ),
+                                                          &off, buf,
+                                                          buf, NULL ) );
+#endif /* MBEDTLS_CIPHER_MODE_CFB */
+
+#if defined(MBEDTLS_CIPHER_MODE_CTR)
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA,
+                            mbedtls_blowfish_crypt_ctr( NULL,
+                                                        sizeof( buf ),
+                                                        &off,
+                                                        buf, buf,
+                                                        buf, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA,
+                            mbedtls_blowfish_crypt_ctr( &ctx,
+                                                        sizeof( buf ),
+                                                        NULL,
+                                                        buf, buf,
+                                                        buf, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA,
+                            mbedtls_blowfish_crypt_ctr( &ctx,
+                                                        sizeof( buf ),
+                                                        &off,
+                                                        NULL, buf,
+                                                        buf, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA,
+                            mbedtls_blowfish_crypt_ctr( &ctx,
+                                                        sizeof( buf ),
+                                                        &off,
+                                                        buf, NULL,
+                                                        buf, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA,
+                            mbedtls_blowfish_crypt_ctr( &ctx,
+                                                        sizeof( buf ),
+                                                        &off,
+                                                        buf, buf,
+                                                        NULL, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA,
+                            mbedtls_blowfish_crypt_ctr( &ctx,
+                                                        sizeof( buf ),
+                                                        &off,
+                                                        buf, buf,
+                                                        buf, NULL ) );
+#endif /* MBEDTLS_CIPHER_MODE_CTR */
+
+exit:
+    return;
+}
+/* END_CASE */
+
+/* BEGIN_CASE */
 void blowfish_encrypt_ecb( data_t * key_str, data_t * src_str,
                            data_t * hex_dst_string, int setkey_result )
 {
diff --git a/tests/suites/test_suite_camellia.data b/tests/suites/test_suite_camellia.data
index 190632e..671d570 100644
--- a/tests/suites/test_suite_camellia.data
+++ b/tests/suites/test_suite_camellia.data
@@ -1,3 +1,9 @@
+Camellia - Valid parameters
+camellia_valid_param:
+
+Camellia - Invalid parameters
+camellia_invalid_param:
+
 Camellia-128-ECB Encrypt RFC3713 #1
 camellia_encrypt_ecb:"0123456789abcdeffedcba9876543210":"0123456789abcdeffedcba9876543210":"67673138549669730857065648eabe43":0
 
diff --git a/tests/suites/test_suite_camellia.function b/tests/suites/test_suite_camellia.function
index d09a610..9408348 100644
--- a/tests/suites/test_suite_camellia.function
+++ b/tests/suites/test_suite_camellia.function
@@ -8,6 +8,172 @@
  */
 
 /* BEGIN_CASE */
+void camellia_valid_param( )
+{
+    TEST_VALID_PARAM( mbedtls_camellia_free( NULL ) );
+}
+/* END_CASE */
+
+/* BEGIN_CASE depends_on:MBEDTLS_CHECK_PARAMS:!MBEDTLS_PARAM_FAILED_ALT */
+void camellia_invalid_param( )
+{
+    mbedtls_camellia_context ctx;
+    unsigned char buf[16] = { 0 };
+    const size_t valid_keybits   = 128;
+    const int invalid_mode = 42;
+    const int valid_mode = MBEDTLS_CAMELLIA_ENCRYPT;
+    size_t off;
+    ((void) off);
+
+    TEST_INVALID_PARAM( mbedtls_camellia_init( NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA,
+                            mbedtls_camellia_setkey_enc( NULL,
+                                                         buf,
+                                                         valid_keybits ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA,
+                            mbedtls_camellia_setkey_enc( &ctx,
+                                                         NULL,
+                                                         valid_keybits ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA,
+                            mbedtls_camellia_setkey_dec( NULL,
+                                                         buf,
+                                                         valid_keybits ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA,
+                            mbedtls_camellia_setkey_dec( &ctx,
+                                                         NULL,
+                                                         valid_keybits ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA,
+                            mbedtls_camellia_crypt_ecb( NULL,
+                                                        valid_mode,
+                                                        buf, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA,
+                            mbedtls_camellia_crypt_ecb( &ctx,
+                                                        invalid_mode,
+                                                        buf, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA,
+                            mbedtls_camellia_crypt_ecb( &ctx,
+                                                        valid_mode,
+                                                        NULL, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA,
+                            mbedtls_camellia_crypt_ecb( &ctx,
+                                                        valid_mode,
+                                                        buf, NULL ) );
+
+#if defined(MBEDTLS_CIPHER_MODE_CBC)
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA,
+                            mbedtls_camellia_crypt_cbc( NULL,
+                                                        valid_mode,
+                                                        sizeof( buf ),
+                                                        buf, buf, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA,
+                            mbedtls_camellia_crypt_cbc( &ctx,
+                                                        invalid_mode,
+                                                        sizeof( buf ),
+                                                        buf, buf, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA,
+                            mbedtls_camellia_crypt_cbc( &ctx,
+                                                        valid_mode,
+                                                        sizeof( buf ),
+                                                        NULL, buf, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA,
+                            mbedtls_camellia_crypt_cbc( &ctx,
+                                                        valid_mode,
+                                                        sizeof( buf ),
+                                                        buf, NULL, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA,
+                            mbedtls_camellia_crypt_cbc( &ctx,
+                                                        valid_mode,
+                                                        sizeof( buf ),
+                                                        buf, buf, NULL ) );
+#endif /* MBEDTLS_CIPHER_MODE_CBC */
+
+#if defined(MBEDTLS_CIPHER_MODE_CFB)
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA,
+                            mbedtls_camellia_crypt_cfb128( NULL,
+                                                           valid_mode,
+                                                           sizeof( buf ),
+                                                           &off, buf,
+                                                           buf, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA,
+                            mbedtls_camellia_crypt_cfb128( &ctx,
+                                                           invalid_mode,
+                                                           sizeof( buf ),
+                                                           &off, buf,
+                                                           buf, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA,
+                            mbedtls_camellia_crypt_cfb128( &ctx,
+                                                           valid_mode,
+                                                           sizeof( buf ),
+                                                           NULL, buf,
+                                                           buf, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA,
+                            mbedtls_camellia_crypt_cfb128( &ctx,
+                                                           valid_mode,
+                                                           sizeof( buf ),
+                                                           &off, NULL,
+                                                           buf, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA,
+                            mbedtls_camellia_crypt_cfb128( &ctx,
+                                                           valid_mode,
+                                                           sizeof( buf ),
+                                                           &off, buf,
+                                                           NULL, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA,
+                            mbedtls_camellia_crypt_cfb128( &ctx,
+                                                           valid_mode,
+                                                           sizeof( buf ),
+                                                           &off, buf,
+                                                           buf, NULL ) );
+#endif /* MBEDTLS_CIPHER_MODE_CFB */
+
+#if defined(MBEDTLS_CIPHER_MODE_CTR)
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA,
+                            mbedtls_camellia_crypt_ctr( NULL,
+                                                        sizeof( buf ),
+                                                        &off,
+                                                        buf, buf,
+                                                        buf, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA,
+                            mbedtls_camellia_crypt_ctr( &ctx,
+                                                        sizeof( buf ),
+                                                        NULL,
+                                                        buf, buf,
+                                                        buf, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA,
+                            mbedtls_camellia_crypt_ctr( &ctx,
+                                                        sizeof( buf ),
+                                                        &off,
+                                                        NULL, buf,
+                                                        buf, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA,
+                            mbedtls_camellia_crypt_ctr( &ctx,
+                                                        sizeof( buf ),
+                                                        &off,
+                                                        buf, NULL,
+                                                        buf, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA,
+                            mbedtls_camellia_crypt_ctr( &ctx,
+                                                        sizeof( buf ),
+                                                        &off,
+                                                        buf, buf,
+                                                        NULL, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA,
+                            mbedtls_camellia_crypt_ctr( &ctx,
+                                                        sizeof( buf ),
+                                                        &off,
+                                                        buf, buf,
+                                                        buf, NULL ) );
+#endif /* MBEDTLS_CIPHER_MODE_CTR */
+
+exit:
+    return;
+}
+/* END_CASE */
+
+/* BEGIN_CASE */
 void camellia_encrypt_ecb( data_t * key_str, data_t * src_str,
                            data_t * hex_dst_string, int setkey_result )
 {
diff --git a/tests/suites/test_suite_ccm.data b/tests/suites/test_suite_ccm.data
index a2d8778..819b3b7 100644
--- a/tests/suites/test_suite_ccm.data
+++ b/tests/suites/test_suite_ccm.data
@@ -1,6 +1,12 @@
 CCM self test
 mbedtls_ccm_self_test:
 
+CCM - Invalid parameters
+ccm_invalid_param:
+
+CCM - Valid parameters
+ccm_valid_param:
+
 CCM init #1 AES-128: OK
 depends_on:MBEDTLS_AES_C
 mbedtls_ccm_setkey:MBEDTLS_CIPHER_ID_AES:128:0
diff --git a/tests/suites/test_suite_ccm.function b/tests/suites/test_suite_ccm.function
index 9951ca1..16f9f8e 100644
--- a/tests/suites/test_suite_ccm.function
+++ b/tests/suites/test_suite_ccm.function
@@ -326,3 +326,216 @@
     mbedtls_ccm_free( &ctx );
 }
 /* END_CASE */
+
+/* BEGIN_CASE depends_on:MBEDTLS_CHECK_PARAMS:!MBEDTLS_PARAM_FAILED_ALT */
+void ccm_invalid_param( )
+{
+    struct mbedtls_ccm_context ctx;
+    unsigned char valid_buffer[] = { 0x01, 0x02, 0x03, 0x04, 0x05, 0x06 };
+    mbedtls_cipher_id_t valid_cipher = MBEDTLS_CIPHER_ID_AES;
+    int valid_len = sizeof(valid_buffer);
+    int valid_bitlen = valid_len * 8;
+
+    mbedtls_ccm_init( &ctx );
+
+    /* mbedtls_ccm_init() */
+    TEST_INVALID_PARAM( mbedtls_ccm_init( NULL ) );
+
+    /* mbedtls_ccm_setkey() */
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_CCM_BAD_INPUT,
+        mbedtls_ccm_setkey( NULL, valid_cipher, valid_buffer, valid_bitlen ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_CCM_BAD_INPUT,
+        mbedtls_ccm_setkey( &ctx, valid_cipher, NULL, valid_bitlen ) );
+
+    /* mbedtls_ccm_encrypt_and_tag() */
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_CCM_BAD_INPUT,
+        mbedtls_ccm_encrypt_and_tag( NULL, valid_len,
+                                     valid_buffer, valid_len,
+                                     valid_buffer, valid_len,
+                                     valid_buffer, valid_buffer,
+                                     valid_buffer, valid_len ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_CCM_BAD_INPUT,
+        mbedtls_ccm_encrypt_and_tag( &ctx, valid_len,
+                                     NULL, valid_len,
+                                     valid_buffer, valid_len,
+                                     valid_buffer, valid_buffer,
+                                     valid_buffer, valid_len ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_CCM_BAD_INPUT,
+        mbedtls_ccm_encrypt_and_tag( &ctx, valid_len,
+                                     valid_buffer, valid_len,
+                                     NULL, valid_len,
+                                     valid_buffer, valid_buffer,
+                                     valid_buffer, valid_len ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_CCM_BAD_INPUT,
+        mbedtls_ccm_encrypt_and_tag( &ctx, valid_len,
+                                     valid_buffer, valid_len,
+                                     valid_buffer, valid_len,
+                                     NULL, valid_buffer,
+                                     valid_buffer, valid_len ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_CCM_BAD_INPUT,
+        mbedtls_ccm_encrypt_and_tag( &ctx, valid_len,
+                                     valid_buffer, valid_len,
+                                     valid_buffer, valid_len,
+                                     valid_buffer, NULL,
+                                     valid_buffer, valid_len ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_CCM_BAD_INPUT,
+        mbedtls_ccm_encrypt_and_tag( &ctx, valid_len,
+                                     valid_buffer, valid_len,
+                                     valid_buffer, valid_len,
+                                     valid_buffer, valid_buffer,
+                                     NULL, valid_len ) );
+
+    /* mbedtls_ccm_star_encrypt_and_tag() */
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_CCM_BAD_INPUT,
+        mbedtls_ccm_star_encrypt_and_tag( NULL, valid_len,
+                                          valid_buffer, valid_len,
+                                          valid_buffer, valid_len,
+                                          valid_buffer, valid_buffer,
+                                          valid_buffer, valid_len) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_CCM_BAD_INPUT,
+        mbedtls_ccm_star_encrypt_and_tag( &ctx, valid_len,
+                                          NULL, valid_len,
+                                          valid_buffer, valid_len,
+                                          valid_buffer, valid_buffer,
+                                          valid_buffer, valid_len ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_CCM_BAD_INPUT,
+        mbedtls_ccm_star_encrypt_and_tag( &ctx, valid_len,
+                                          valid_buffer, valid_len,
+                                          NULL, valid_len,
+                                          valid_buffer, valid_buffer,
+                                          valid_buffer, valid_len ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_CCM_BAD_INPUT,
+        mbedtls_ccm_star_encrypt_and_tag( &ctx, valid_len,
+                                          valid_buffer, valid_len,
+                                          valid_buffer, valid_len,
+                                          NULL, valid_buffer,
+                                          valid_buffer, valid_len ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_CCM_BAD_INPUT,
+        mbedtls_ccm_star_encrypt_and_tag( &ctx, valid_len,
+                                          valid_buffer, valid_len,
+                                          valid_buffer, valid_len,
+                                          valid_buffer, NULL,
+                                          valid_buffer, valid_len ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_CCM_BAD_INPUT,
+        mbedtls_ccm_star_encrypt_and_tag( &ctx, valid_len,
+                                          valid_buffer, valid_len,
+                                          valid_buffer, valid_len,
+                                          valid_buffer, valid_buffer,
+                                          NULL, valid_len ) );
+
+    /* mbedtls_ccm_auth_decrypt() */
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_CCM_BAD_INPUT,
+        mbedtls_ccm_auth_decrypt( NULL, valid_len,
+                                  valid_buffer, valid_len,
+                                  valid_buffer, valid_len,
+                                  valid_buffer, valid_buffer,
+                                  valid_buffer, valid_len ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_CCM_BAD_INPUT,
+        mbedtls_ccm_auth_decrypt( &ctx, valid_len,
+                                  NULL, valid_len,
+                                  valid_buffer, valid_len,
+                                  valid_buffer, valid_buffer,
+                                  valid_buffer, valid_len ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_CCM_BAD_INPUT,
+        mbedtls_ccm_auth_decrypt( &ctx, valid_len,
+                                  valid_buffer, valid_len,
+                                  NULL, valid_len,
+                                  valid_buffer, valid_buffer,
+                                  valid_buffer, valid_len ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_CCM_BAD_INPUT,
+        mbedtls_ccm_auth_decrypt( &ctx, valid_len,
+                                  valid_buffer, valid_len,
+                                  valid_buffer, valid_len,
+                                  NULL, valid_buffer,
+                                  valid_buffer, valid_len ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_CCM_BAD_INPUT,
+        mbedtls_ccm_auth_decrypt( &ctx, valid_len,
+                                  valid_buffer, valid_len,
+                                  valid_buffer, valid_len,
+                                  valid_buffer, NULL,
+                                  valid_buffer, valid_len ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_CCM_BAD_INPUT,
+        mbedtls_ccm_auth_decrypt( &ctx, valid_len,
+                                  valid_buffer, valid_len,
+                                  valid_buffer, valid_len,
+                                  valid_buffer, valid_buffer,
+                                  NULL, valid_len ) );
+
+    /* mbedtls_ccm_star_auth_decrypt() */
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_CCM_BAD_INPUT,
+        mbedtls_ccm_star_auth_decrypt( NULL, valid_len,
+                                       valid_buffer, valid_len,
+                                       valid_buffer, valid_len,
+                                       valid_buffer, valid_buffer,
+                                       valid_buffer, valid_len ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_CCM_BAD_INPUT,
+        mbedtls_ccm_star_auth_decrypt( &ctx, valid_len,
+                                       NULL, valid_len,
+                                       valid_buffer, valid_len,
+                                       valid_buffer, valid_buffer,
+                                       valid_buffer, valid_len ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_CCM_BAD_INPUT,
+        mbedtls_ccm_star_auth_decrypt( &ctx, valid_len,
+                                       valid_buffer, valid_len,
+                                       NULL, valid_len,
+                                       valid_buffer, valid_buffer,
+                                       valid_buffer, valid_len ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_CCM_BAD_INPUT,
+        mbedtls_ccm_star_auth_decrypt( &ctx, valid_len,
+                                       valid_buffer, valid_len,
+                                       valid_buffer, valid_len,
+                                       NULL, valid_buffer,
+                                       valid_buffer, valid_len ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_CCM_BAD_INPUT,
+        mbedtls_ccm_star_auth_decrypt( &ctx, valid_len,
+                                       valid_buffer, valid_len,
+                                       valid_buffer, valid_len,
+                                       valid_buffer, NULL,
+                                       valid_buffer, valid_len ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_CCM_BAD_INPUT,
+        mbedtls_ccm_star_auth_decrypt( &ctx, valid_len,
+                                       valid_buffer, valid_len,
+                                       valid_buffer, valid_len,
+                                       valid_buffer, valid_buffer,
+                                       NULL, valid_len ) );
+
+exit:
+    mbedtls_ccm_free( &ctx );
+    return;
+}
+/* END_CASE */
+
+/* BEGIN_CASE */
+void ccm_valid_param( )
+{
+    TEST_VALID_PARAM( mbedtls_ccm_free( NULL ) );
+exit:
+    return;
+}
+/* END_CASE */
diff --git a/tests/suites/test_suite_chacha20.function b/tests/suites/test_suite_chacha20.function
index 669d91e..49b389c 100644
--- a/tests/suites/test_suite_chacha20.function
+++ b/tests/suites/test_suite_chacha20.function
@@ -82,7 +82,7 @@
 }
 /* END_CASE */
 
-/* BEGIN_CASE */
+/* BEGIN_CASE depends_on:MBEDTLS_CHECK_PARAMS:!MBEDTLS_PARAM_FAILED_ALT */
 void chacha20_bad_params()
 {
     unsigned char key[32];
@@ -93,42 +93,38 @@
     size_t len = sizeof( src );
     mbedtls_chacha20_context ctx;
 
-    mbedtls_chacha20_init( NULL );
-    mbedtls_chacha20_free( NULL );
+    TEST_INVALID_PARAM( mbedtls_chacha20_init( NULL ) );
+    TEST_VALID_PARAM( mbedtls_chacha20_free( NULL ) );
 
-    mbedtls_chacha20_init( &ctx );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA,
+                            mbedtls_chacha20_setkey( NULL, key ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA,
+                            mbedtls_chacha20_setkey( &ctx, NULL ) );
 
-    TEST_ASSERT( mbedtls_chacha20_setkey( NULL, key )
-                 == MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_chacha20_setkey( &ctx, NULL )
-                 == MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA,
+                            mbedtls_chacha20_starts( NULL, nonce, counter ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA,
+                            mbedtls_chacha20_starts( &ctx, NULL, counter ) );
 
-    TEST_ASSERT( mbedtls_chacha20_starts( NULL, nonce, counter )
-                 == MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_chacha20_starts( &ctx, NULL, counter )
-                 == MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA,
+                            mbedtls_chacha20_update( NULL, 0, src, dst ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA,
+                            mbedtls_chacha20_update( &ctx, len, NULL, dst ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA,
+                            mbedtls_chacha20_update( &ctx, len, src, NULL ) );
 
-    TEST_ASSERT( mbedtls_chacha20_update( NULL, 0, src, dst )
-                 == MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_chacha20_update( &ctx, len, NULL, dst )
-                 == MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_chacha20_update( &ctx, len, src, NULL )
-                 == MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_chacha20_update( &ctx, 0, NULL, NULL )
-                 == 0 );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA,
+                            mbedtls_chacha20_crypt( NULL, nonce, counter, 0, src, dst ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA,
+                            mbedtls_chacha20_crypt( key, NULL, counter, 0, src, dst ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA,
+                            mbedtls_chacha20_crypt( key, nonce, counter, len, NULL, dst ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA,
+                            mbedtls_chacha20_crypt( key, nonce, counter, len, src, NULL ) );
 
-    mbedtls_chacha20_free( &ctx );
+exit:
+    return;
 
-    TEST_ASSERT( mbedtls_chacha20_crypt( NULL, nonce, counter, 0, src, dst )
-                 == MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_chacha20_crypt( key, NULL, counter, 0, src, dst )
-                 == MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_chacha20_crypt( key, nonce, counter, len, NULL, dst )
-                 == MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_chacha20_crypt( key, nonce, counter, len, src, NULL )
-                 == MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_chacha20_crypt( key, nonce, counter, 0, NULL, NULL )
-                 == 0 );
 }
 /* END_CASE */
 
diff --git a/tests/suites/test_suite_chachapoly.function b/tests/suites/test_suite_chachapoly.function
index 95dfd8a..8e56bf6 100644
--- a/tests/suites/test_suite_chachapoly.function
+++ b/tests/suites/test_suite_chachapoly.function
@@ -118,7 +118,7 @@
 }
 /* END_CASE */
 
-/* BEGIN_CASE */
+/* BEGIN_CASE depends_on:MBEDTLS_CHECK_PARAMS:!MBEDTLS_PARAM_FAILED_ALT */
 void chachapoly_bad_params()
 {
     unsigned char key[32];
@@ -138,124 +138,114 @@
     memset( output, 0x00, sizeof( output ) );
     memset( mac,    0x00, sizeof( mac ) );
 
-    mbedtls_chachapoly_init( NULL );
-    mbedtls_chachapoly_free( NULL );
+    TEST_INVALID_PARAM( mbedtls_chachapoly_init( NULL ) );
+    TEST_VALID_PARAM( mbedtls_chachapoly_free( NULL ) );
 
-    mbedtls_chachapoly_init( &ctx );
+    /* setkey */
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                            mbedtls_chachapoly_setkey( NULL, key ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                            mbedtls_chachapoly_setkey( &ctx, NULL ) );
 
-    TEST_ASSERT( mbedtls_chachapoly_setkey( NULL, key )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_chachapoly_setkey( &ctx, NULL )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-
-    TEST_ASSERT( mbedtls_chachapoly_encrypt_and_tag( NULL,
+    /* encrypt_and_tag */
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                            mbedtls_chachapoly_encrypt_and_tag( NULL,
                                       0, nonce,
                                       aad, 0,
-                                      input, output, mac )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_chachapoly_encrypt_and_tag( &ctx,
+                                      input, output, mac ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                            mbedtls_chachapoly_encrypt_and_tag( &ctx,
                                       0, NULL,
                                       aad, 0,
-                                      input, output, mac )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_chachapoly_encrypt_and_tag( &ctx,
+                                      input, output, mac ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                            mbedtls_chachapoly_encrypt_and_tag( &ctx,
                                       0, nonce,
                                       NULL, aad_len,
-                                      input, output, mac )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_chachapoly_encrypt_and_tag( &ctx,
+                                      input, output, mac ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                            mbedtls_chachapoly_encrypt_and_tag( &ctx,
                                       input_len, nonce,
                                       aad, 0,
-                                      NULL, output, mac )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_chachapoly_encrypt_and_tag( &ctx,
+                                      NULL, output, mac ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                            mbedtls_chachapoly_encrypt_and_tag( &ctx,
                                       input_len, nonce,
                                       aad, 0,
-                                      input, NULL, mac )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_chachapoly_encrypt_and_tag( &ctx,
+                                      input, NULL, mac ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                            mbedtls_chachapoly_encrypt_and_tag( &ctx,
                                       0, nonce,
                                       aad, 0,
-                                      input, output, NULL )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
+                                      input, output, NULL ) );
 
-    TEST_ASSERT( mbedtls_chachapoly_auth_decrypt( NULL,
+    /* auth_decrypt */
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                            mbedtls_chachapoly_auth_decrypt( NULL,
                                            0, nonce,
                                            aad, 0,
-                                           mac, input, output )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_chachapoly_auth_decrypt( &ctx,
+                                           mac, input, output ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                            mbedtls_chachapoly_auth_decrypt( &ctx,
                                            0, NULL,
                                            aad, 0,
-                                           mac, input, output )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_chachapoly_auth_decrypt( &ctx,
+                                           mac, input, output ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                            mbedtls_chachapoly_auth_decrypt( &ctx,
                                            0, nonce,
                                            NULL, aad_len,
-                                           mac, input, output )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_chachapoly_auth_decrypt( &ctx,
+                                           mac, input, output ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                            mbedtls_chachapoly_auth_decrypt( &ctx,
                                            0, nonce,
                                            aad, 0,
-                                           NULL, input, output )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_chachapoly_auth_decrypt( &ctx,
+                                           NULL, input, output ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                            mbedtls_chachapoly_auth_decrypt( &ctx,
                                            input_len, nonce,
                                            aad, 0,
-                                           mac, NULL, output )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_chachapoly_auth_decrypt( &ctx,
+                                           mac, NULL, output ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                            mbedtls_chachapoly_auth_decrypt( &ctx,
                                            input_len, nonce,
                                            aad, 0,
-                                           mac, input, NULL )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
+                                           mac, input, NULL ) );
 
-    TEST_ASSERT( mbedtls_chachapoly_encrypt_and_tag( &ctx,
-                                      0, nonce,
-                                      aad, aad_len,
-                                      NULL, NULL, mac )
-                 == 0 );
-    TEST_ASSERT( mbedtls_chachapoly_auth_decrypt( &ctx,
-                                           0, nonce,
-                                           aad, aad_len,
-                                           mac, NULL, NULL )
-                 == 0 );
+    /* starts */
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                            mbedtls_chachapoly_starts( NULL, nonce,
+                                               MBEDTLS_CHACHAPOLY_ENCRYPT ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                            mbedtls_chachapoly_starts( &ctx, NULL,
+                                               MBEDTLS_CHACHAPOLY_ENCRYPT ) );
 
-    TEST_ASSERT( mbedtls_chachapoly_encrypt_and_tag( &ctx,
-                                      input_len, nonce,
-                                      NULL, 0,
-                                      input, output, mac )
-                 == 0 );
-    TEST_ASSERT( mbedtls_chachapoly_auth_decrypt( &ctx,
-                                           input_len, nonce,
-                                           NULL, 0,
-                                           mac, input, output )
-                 == 0 );
+    /* update_aad */
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                            mbedtls_chachapoly_update_aad( NULL, aad,
+                                                           aad_len ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                            mbedtls_chachapoly_update_aad( &ctx, NULL,
+                                                           aad_len ) );
 
-    TEST_ASSERT( mbedtls_chachapoly_starts( NULL, nonce, MBEDTLS_CHACHAPOLY_ENCRYPT )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_chachapoly_starts( &ctx, NULL, MBEDTLS_CHACHAPOLY_ENCRYPT )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
+    /* update */
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                            mbedtls_chachapoly_update( NULL, input_len,
+                                                       input, output ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                            mbedtls_chachapoly_update( &ctx, input_len,
+                                                       NULL, output ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                            mbedtls_chachapoly_update( &ctx, input_len,
+                                                       input, NULL ) );
 
-    TEST_ASSERT( mbedtls_chachapoly_update_aad( NULL, aad, aad_len )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_chachapoly_update_aad( &ctx, NULL, aad_len )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-
-    TEST_ASSERT( mbedtls_chachapoly_update( NULL, input_len, input, output )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_chachapoly_update( &ctx, input_len, NULL, output )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_chachapoly_update( &ctx, input_len, input, NULL )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-
-    TEST_ASSERT( mbedtls_chachapoly_finish( NULL, mac )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_chachapoly_finish( &ctx, NULL )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
+    /* finish */
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                            mbedtls_chachapoly_finish( NULL, mac ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                            mbedtls_chachapoly_finish( &ctx, NULL ) );
 
 exit:
-    mbedtls_chachapoly_free( &ctx );
+    return;
 }
 /* END_CASE */
 
diff --git a/tests/suites/test_suite_dhm.data b/tests/suites/test_suite_dhm.data
index 734fd97..edebce0 100644
--- a/tests/suites/test_suite_dhm.data
+++ b/tests/suites/test_suite_dhm.data
@@ -1,3 +1,6 @@
+Diffie-Hellman parameter validation
+dhm_invalid_params:
+
 Diffie-Hellman full exchange #1
 dhm_do_dhm:10:"23":10:"5":0
 
diff --git a/tests/suites/test_suite_dhm.function b/tests/suites/test_suite_dhm.function
index 9a4c99c..8a05a38 100644
--- a/tests/suites/test_suite_dhm.function
+++ b/tests/suites/test_suite_dhm.function
@@ -7,6 +7,113 @@
  * END_DEPENDENCIES
  */
 
+/* BEGIN_CASE depends_on:MBEDTLS_CHECK_PARAMS:!MBEDTLS_PARAM_FAILED_ALT */
+void dhm_invalid_params( )
+{
+    mbedtls_dhm_context ctx;
+    unsigned char buf[42] = { 0 };
+    unsigned char *buf_null = NULL;
+    mbedtls_mpi X;
+    size_t const buflen = sizeof( buf );
+    size_t len;
+
+    TEST_INVALID_PARAM( mbedtls_dhm_init( NULL ) );
+    TEST_VALID_PARAM( mbedtls_dhm_free( NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_DHM_BAD_INPUT_DATA,
+                            mbedtls_dhm_read_params( NULL,
+                                                     (unsigned char**) &buf,
+                                                     buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_DHM_BAD_INPUT_DATA,
+                            mbedtls_dhm_read_params( &ctx, &buf_null, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_DHM_BAD_INPUT_DATA,
+                            mbedtls_dhm_read_params( &ctx, NULL, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_DHM_BAD_INPUT_DATA,
+                            mbedtls_dhm_read_params( &ctx,
+                                                     (unsigned char**) &buf,
+                                                     NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_DHM_BAD_INPUT_DATA,
+                            mbedtls_dhm_make_params( NULL, buflen,
+                                                     buf, &len,
+                                                     rnd_std_rand,
+                                                     NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_DHM_BAD_INPUT_DATA,
+                            mbedtls_dhm_make_params( &ctx, buflen,
+                                                     NULL, &len,
+                                                     rnd_std_rand,
+                                                     NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_DHM_BAD_INPUT_DATA,
+                            mbedtls_dhm_make_params( &ctx, buflen,
+                                                     buf, NULL,
+                                                     rnd_std_rand,
+                                                     NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_DHM_BAD_INPUT_DATA,
+                            mbedtls_dhm_make_params( &ctx, buflen,
+                                                     buf, &len,
+                                                     NULL,
+                                                     NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_DHM_BAD_INPUT_DATA,
+                            mbedtls_dhm_set_group( NULL, &X, &X ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_DHM_BAD_INPUT_DATA,
+                            mbedtls_dhm_set_group( &ctx, NULL, &X ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_DHM_BAD_INPUT_DATA,
+                            mbedtls_dhm_set_group( &ctx, &X, NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_DHM_BAD_INPUT_DATA,
+                            mbedtls_dhm_read_public( NULL, buf, buflen ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_DHM_BAD_INPUT_DATA,
+                            mbedtls_dhm_read_public( &ctx, NULL, buflen ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_DHM_BAD_INPUT_DATA,
+                            mbedtls_dhm_make_public( NULL, buflen,
+                                                     buf, buflen,
+                                                     rnd_std_rand,
+                                                     NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_DHM_BAD_INPUT_DATA,
+                            mbedtls_dhm_make_public( &ctx, buflen,
+                                                     NULL, buflen,
+                                                     rnd_std_rand,
+                                                     NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_DHM_BAD_INPUT_DATA,
+                            mbedtls_dhm_make_public( &ctx, buflen,
+                                                     buf, buflen,
+                                                     NULL,
+                                                     NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_DHM_BAD_INPUT_DATA,
+                            mbedtls_dhm_calc_secret( NULL, buf, buflen,
+                                                     &len, rnd_std_rand,
+                                                     NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_DHM_BAD_INPUT_DATA,
+                            mbedtls_dhm_calc_secret( &ctx, NULL, buflen,
+                                                     &len, rnd_std_rand,
+                                                     NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_DHM_BAD_INPUT_DATA,
+                            mbedtls_dhm_calc_secret( &ctx, buf, buflen,
+                                                     NULL, rnd_std_rand,
+                                                     NULL ) );
+
+#if defined(MBEDTLS_ASN1_PARSE_C)
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_DHM_BAD_INPUT_DATA,
+                            mbedtls_dhm_parse_dhm( NULL, buf, buflen ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_DHM_BAD_INPUT_DATA,
+                            mbedtls_dhm_parse_dhm( &ctx, NULL, buflen ) );
+
+#if defined(MBEDTLS_FS_IO)
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_DHM_BAD_INPUT_DATA,
+                            mbedtls_dhm_parse_dhmfile( NULL, "" ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_DHM_BAD_INPUT_DATA,
+                            mbedtls_dhm_parse_dhmfile( &ctx, NULL ) );
+#endif /* MBEDTLS_FS_IO */
+#endif /* MBEDTLS_ASN1_PARSE_C */
+
+exit:
+    return;
+}
+/* END_CASE */
+
 /* BEGIN_CASE */
 void dhm_do_dhm( int radix_P, char *input_P,
                  int radix_G, char *input_G, int result )
diff --git a/tests/suites/test_suite_ecdh.data b/tests/suites/test_suite_ecdh.data
index 89e5e3a..fe24ed4 100644
--- a/tests/suites/test_suite_ecdh.data
+++ b/tests/suites/test_suite_ecdh.data
@@ -1,3 +1,9 @@
+ECDH - Valid parameters
+ecdh_valid_param:
+
+ECDH - Invalid parameters
+ecdh_invalid_param:
+
 ECDH primitive random #1
 depends_on:MBEDTLS_ECP_DP_SECP192R1_ENABLED
 ecdh_primitive_random:MBEDTLS_ECP_DP_SECP192R1
diff --git a/tests/suites/test_suite_ecdh.function b/tests/suites/test_suite_ecdh.function
index 7144763..08a1686 100644
--- a/tests/suites/test_suite_ecdh.function
+++ b/tests/suites/test_suite_ecdh.function
@@ -8,6 +8,148 @@
  */
 
 /* BEGIN_CASE */
+void ecdh_valid_param( )
+{
+    TEST_VALID_PARAM( mbedtls_ecdh_free( NULL ) );
+}
+/* END_CASE */
+
+/* BEGIN_CASE depends_on:MBEDTLS_CHECK_PARAMS:!MBEDTLS_PARAM_FAILED_ALT */
+void ecdh_invalid_param( )
+{
+    mbedtls_ecp_group grp;
+    mbedtls_ecdh_context ctx;
+    mbedtls_mpi m;
+    mbedtls_ecp_point P;
+    mbedtls_ecp_keypair kp;
+    size_t olen;
+    unsigned char buf[42] = { 0 };
+    const unsigned char *buf_null = NULL;
+    size_t const buflen = sizeof( buf );
+    int invalid_side = 42;
+    mbedtls_ecp_group_id valid_grp = MBEDTLS_ECP_DP_SECP192R1;
+
+    TEST_INVALID_PARAM( mbedtls_ecdh_init( NULL ) );
+
+#if defined(MBEDTLS_ECP_RESTARTABLE)
+    TEST_INVALID_PARAM( mbedtls_ecdh_enable_restart( NULL ) );
+#endif /* MBEDTLS_ECP_RESTARTABLE */
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_gen_public( NULL, &m, &P,
+                                                     rnd_std_rand, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_gen_public( &grp, NULL, &P,
+                                                     rnd_std_rand, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_gen_public( &grp, &m, NULL,
+                                                     rnd_std_rand, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_gen_public( &grp, &m, &P,
+                                                     NULL, NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_compute_shared( NULL, &m, &P, &m,
+                                                         rnd_std_rand, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_compute_shared( &grp, NULL, &P, &m,
+                                                         rnd_std_rand, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_compute_shared( &grp, &m, NULL, &m,
+                                                         rnd_std_rand, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_compute_shared( &grp, &m, &P, NULL,
+                                                         rnd_std_rand, NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_setup( NULL, valid_grp ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_make_params( NULL, &olen,
+                                                      buf, buflen,
+                                                      rnd_std_rand, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_make_params( &ctx, NULL,
+                                                      buf, buflen,
+                                                      rnd_std_rand, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_make_params( &ctx, &olen,
+                                                      NULL, buflen,
+                                                      rnd_std_rand, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_make_params( &ctx, &olen,
+                                                      buf, buflen,
+                                                      NULL, NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_read_params( NULL,
+                                                  (const unsigned char**) &buf,
+                                                  buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_read_params( &ctx, &buf_null,
+                                                      buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_read_params( &ctx, NULL, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_read_params( &ctx,
+                                                  (const unsigned char**) &buf,
+                                                  NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_get_params( NULL, &kp,
+                                                     MBEDTLS_ECDH_OURS ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_get_params( &ctx, NULL,
+                                                     MBEDTLS_ECDH_OURS ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_get_params( &ctx, &kp,
+                                                     invalid_side ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_make_public( NULL, &olen,
+                                                      buf, buflen,
+                                                      rnd_std_rand,
+                                                      NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_make_public( &ctx, NULL,
+                                                      buf, buflen,
+                                                      rnd_std_rand,
+                                                      NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_make_public( &ctx, &olen,
+                                                      NULL, buflen,
+                                                      rnd_std_rand,
+                                                      NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_make_public( &ctx, &olen,
+                                                      buf, buflen,
+                                                      NULL,
+                                                      NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_read_public( NULL, buf, buflen ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_read_public( &ctx, NULL, buflen ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_calc_secret( NULL, &olen, buf, buflen,
+                                                      rnd_std_rand,
+                                                      NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_calc_secret( &ctx, NULL, buf, buflen,
+                                                      rnd_std_rand,
+                                                      NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdh_calc_secret( &ctx, &olen, NULL, buflen,
+                                                      rnd_std_rand,
+                                                      NULL ) );
+
+exit:
+    return;
+}
+/* END_CASE */
+
+/* BEGIN_CASE */
 void ecdh_primitive_random( int id )
 {
     mbedtls_ecp_group grp;
diff --git a/tests/suites/test_suite_ecdsa.data b/tests/suites/test_suite_ecdsa.data
index 7e6ec6c..59e209b 100644
--- a/tests/suites/test_suite_ecdsa.data
+++ b/tests/suites/test_suite_ecdsa.data
@@ -1,3 +1,6 @@
+ECDSA Parameter validation
+ecdsa_invalid_param:
+
 ECDSA primitive random #1
 depends_on:MBEDTLS_ECP_DP_SECP192R1_ENABLED
 ecdsa_prim_random:MBEDTLS_ECP_DP_SECP192R1
diff --git a/tests/suites/test_suite_ecdsa.function b/tests/suites/test_suite_ecdsa.function
index 7107832..22d92b6 100644
--- a/tests/suites/test_suite_ecdsa.function
+++ b/tests/suites/test_suite_ecdsa.function
@@ -7,6 +7,201 @@
  * END_DEPENDENCIES
  */
 
+/* BEGIN_CASE depends_on:MBEDTLS_CHECK_PARAMS:!MBEDTLS_PARAM_FAILED_ALT */
+void ecdsa_invalid_param( )
+{
+    mbedtls_ecdsa_context ctx;
+    mbedtls_ecp_keypair key;
+    mbedtls_ecp_group grp;
+    mbedtls_ecp_group_id valid_group = MBEDTLS_ECP_DP_SECP192R1;
+    mbedtls_ecp_point P;
+    mbedtls_md_type_t valid_md = MBEDTLS_MD_SHA256;
+    mbedtls_mpi m;
+    size_t slen;
+    unsigned char buf[42] = { 0 };
+
+    TEST_INVALID_PARAM( mbedtls_ecdsa_init( NULL ) );
+    TEST_VALID_PARAM( mbedtls_ecdsa_free( NULL ) );
+
+#if defined(MBEDTLS_ECP_RESTARTABLE)
+    TEST_INVALID_PARAM( mbedtls_ecdsa_restart_init( NULL ) );
+    TEST_VALID_PARAM( mbedtls_ecdsa_restart_free( NULL ) );
+#endif /* MBEDTLS_ECP_RESTARTABLE */
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdsa_sign( NULL, &m, &m, &m,
+                                                buf, sizeof( buf ),
+                                                rnd_std_rand, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecdsa_sign( &grp, NULL, &m, &m,
+                                                buf, sizeof( buf ),
+                                                rnd_std_rand, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_sign( &grp, &m, NULL, &m,
+                                                buf, sizeof( buf ),
+                                                rnd_std_rand, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_sign( &grp, &m, &m, NULL,
+                                                buf, sizeof( buf ),
+                                                rnd_std_rand, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_sign( &grp, &m, &m, &m,
+                                                NULL, sizeof( buf ),
+                                                rnd_std_rand, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_sign( &grp, &m, &m, &m,
+                                                buf, sizeof( buf ),
+                                                NULL, NULL ) );
+
+#if defined(MBEDTLS_ECDSA_DETERMINISTIC)
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_sign_det( NULL, &m, &m, &m,
+                                                buf, sizeof( buf ),
+                                                valid_md ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_sign_det( &grp, NULL, &m, &m,
+                                                buf, sizeof( buf ),
+                                                valid_md ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_sign_det( &grp, &m, NULL, &m,
+                                                buf, sizeof( buf ),
+                                                valid_md ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_sign_det( &grp, &m, &m, NULL,
+                                                buf, sizeof( buf ),
+                                                valid_md ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_sign_det( &grp, &m, &m, &m,
+                                                NULL, sizeof( buf ),
+                                                valid_md ) );
+#endif /* MBEDTLS_ECDSA_DETERMINISTIC */
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_verify( NULL,
+                                                  buf, sizeof( buf ),
+                                                  &P, &m, &m ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_verify( &grp,
+                                                  NULL, sizeof( buf ),
+                                                  &P, &m, &m ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_verify( &grp,
+                                                  buf, sizeof( buf ),
+                                                  NULL, &m, &m ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_verify( &grp,
+                                                  buf, sizeof( buf ),
+                                                  &P, NULL, &m ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_verify( &grp,
+                                                  buf, sizeof( buf ),
+                                                  &P, &m, NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_write_signature( NULL,
+                                                           valid_md,
+                                                           buf, sizeof( buf ),
+                                                           buf, &slen,
+                                                           rnd_std_rand,
+                                                           NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_write_signature( &ctx,
+                                                           valid_md,
+                                                           NULL, sizeof( buf ),
+                                                           buf, &slen,
+                                                           rnd_std_rand,
+                                                           NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_write_signature( &ctx,
+                                                           valid_md,
+                                                           buf, sizeof( buf ),
+                                                           NULL, &slen,
+                                                           rnd_std_rand,
+                                                           NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_write_signature( &ctx,
+                                                           valid_md,
+                                                           buf, sizeof( buf ),
+                                                           buf, NULL,
+                                                           rnd_std_rand,
+                                                           NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_write_signature_restartable( NULL,
+                                                           valid_md,
+                                                           buf, sizeof( buf ),
+                                                           buf, &slen,
+                                                           rnd_std_rand,
+                                                           NULL, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_write_signature_restartable( &ctx,
+                                                           valid_md,
+                                                           NULL, sizeof( buf ),
+                                                           buf, &slen,
+                                                           rnd_std_rand,
+                                                           NULL, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_write_signature_restartable( &ctx,
+                                                           valid_md,
+                                                           buf, sizeof( buf ),
+                                                           NULL, &slen,
+                                                           rnd_std_rand,
+                                                           NULL, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_write_signature_restartable( &ctx,
+                                                           valid_md,
+                                                           buf, sizeof( buf ),
+                                                           buf, NULL,
+                                                           rnd_std_rand,
+                                                           NULL, NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_read_signature( NULL,
+                                                        buf, sizeof( buf ),
+                                                        buf, sizeof( buf ) ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_read_signature( &ctx,
+                                                        NULL, sizeof( buf ),
+                                                        buf, sizeof( buf ) ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_read_signature( &ctx,
+                                                        buf, sizeof( buf ),
+                                                        NULL, sizeof( buf ) ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_read_signature_restartable( NULL,
+                                                        buf, sizeof( buf ),
+                                                        buf, sizeof( buf ),
+                                                        NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_read_signature_restartable( &ctx,
+                                                        NULL, sizeof( buf ),
+                                                        buf, sizeof( buf ),
+                                                        NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_read_signature_restartable( &ctx,
+                                                        buf, sizeof( buf ),
+                                                        NULL, sizeof( buf ),
+                                                        NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_genkey( NULL, valid_group,
+                                                  rnd_std_rand, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_genkey( &ctx, valid_group,
+                                                  NULL, NULL ) );
+
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_from_keypair( NULL, &key ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                       mbedtls_ecdsa_from_keypair( &ctx, NULL ) );
+
+exit:
+    return;
+}
+/* END_CASE */
+
 /* BEGIN_CASE */
 void ecdsa_prim_random( int id )
 {
diff --git a/tests/suites/test_suite_ecjpake.data b/tests/suites/test_suite_ecjpake.data
index 1a772a9..84c99c9 100644
--- a/tests/suites/test_suite_ecjpake.data
+++ b/tests/suites/test_suite_ecjpake.data
@@ -1,3 +1,6 @@
+ECJPAKE parameter validation
+ecjpake_invalid_param:
+
 ECJPAKE selftest
 ecjpake_selftest:
 
diff --git a/tests/suites/test_suite_ecjpake.function b/tests/suites/test_suite_ecjpake.function
index 9e4f7a3..d267295 100644
--- a/tests/suites/test_suite_ecjpake.function
+++ b/tests/suites/test_suite_ecjpake.function
@@ -98,6 +98,137 @@
  * END_DEPENDENCIES
  */
 
+/* BEGIN_CASE depends_on:MBEDTLS_CHECK_PARAMS:!MBEDTLS_PARAM_FAILED_ALT */
+void ecjpake_invalid_param( )
+{
+    mbedtls_ecjpake_context ctx;
+    unsigned char buf[42] = { 0 };
+    size_t olen;
+    size_t const len = sizeof( buf );
+    mbedtls_ecjpake_role valid_role = MBEDTLS_ECJPAKE_SERVER;
+    mbedtls_ecjpake_role invalid_role = (mbedtls_ecjpake_role) 42;
+    mbedtls_md_type_t valid_md = MBEDTLS_MD_SHA256;
+    mbedtls_ecp_group_id valid_group = MBEDTLS_ECP_DP_SECP256R1;
+
+    TEST_INVALID_PARAM( mbedtls_ecjpake_init( NULL ) );
+    TEST_VALID_PARAM( mbedtls_ecjpake_free( NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecjpake_setup( NULL,
+                                                   valid_role,
+                                                   valid_md,
+                                                   valid_group,
+                                                   buf, len ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecjpake_setup( &ctx,
+                                                   invalid_role,
+                                                   valid_md,
+                                                   valid_group,
+                                                   buf, len ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecjpake_setup( &ctx,
+                                                   valid_role,
+                                                   valid_md,
+                                                   valid_group,
+                                                   NULL, len ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecjpake_check( NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecjpake_write_round_one( NULL,
+                                                             buf, len,
+                                                             &olen,
+                                                             rnd_std_rand,
+                                                             NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecjpake_write_round_one( &ctx,
+                                                             NULL, len,
+                                                             &olen,
+                                                             rnd_std_rand,
+                                                             NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecjpake_write_round_one( &ctx,
+                                                             buf, len,
+                                                             NULL,
+                                                             rnd_std_rand,
+                                                             NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecjpake_write_round_one( &ctx,
+                                                             buf, len,
+                                                             &olen,
+                                                             NULL,
+                                                             NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecjpake_write_round_two( NULL,
+                                                             buf, len,
+                                                             &olen,
+                                                             rnd_std_rand,
+                                                             NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecjpake_write_round_two( &ctx,
+                                                             NULL, len,
+                                                             &olen,
+                                                             rnd_std_rand,
+                                                             NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecjpake_write_round_two( &ctx,
+                                                             buf, len,
+                                                             NULL,
+                                                             rnd_std_rand,
+                                                             NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecjpake_write_round_two( &ctx,
+                                                             buf, len,
+                                                             &olen,
+                                                             NULL,
+                                                             NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecjpake_read_round_one( NULL,
+                                                            buf, len ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecjpake_read_round_one( &ctx,
+                                                            NULL, len ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecjpake_read_round_two( NULL,
+                                                            buf, len ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecjpake_read_round_two( &ctx,
+                                                            NULL, len ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecjpake_derive_secret( NULL,
+                                                           buf, len,
+                                                           &olen,
+                                                           rnd_std_rand,
+                                                           NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecjpake_derive_secret( &ctx,
+                                                           NULL, len,
+                                                           &olen,
+                                                           rnd_std_rand,
+                                                           NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecjpake_derive_secret( &ctx,
+                                                           buf, len,
+                                                           NULL,
+                                                           rnd_std_rand,
+                                                           NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecjpake_derive_secret( &ctx,
+                                                           buf, len,
+                                                           &olen,
+                                                           NULL,
+                                                           NULL ) );
+
+exit:
+    return;
+}
+/* END_CASE */
+
 /* BEGIN_CASE depends_on:MBEDTLS_SELF_TEST */
 void ecjpake_selftest(  )
 {
diff --git a/tests/suites/test_suite_ecp.data b/tests/suites/test_suite_ecp.data
index 321a1b4..30d5ec6 100644
--- a/tests/suites/test_suite_ecp.data
+++ b/tests/suites/test_suite_ecp.data
@@ -1,3 +1,9 @@
+ECP valid params
+ecp_valid_param:
+
+ECP invalid params
+ecp_invalid_param:
+
 ECP curve info #1
 depends_on:MBEDTLS_ECP_DP_BP512R1_ENABLED
 mbedtls_ecp_curve_info:MBEDTLS_ECP_DP_BP512R1:28:512:"brainpoolP512r1"
@@ -46,10 +52,6 @@
 depends_on:MBEDTLS_ECP_DP_SECP224K1_ENABLED
 ecp_check_pub:MBEDTLS_ECP_DP_SECP224K1:"E2000000000000BB3A13D43B323337383935321F0603551D":"100101FF040830060101FF02010A30220603551D0E041B04636FC0C0":"101":MBEDTLS_ERR_ECP_INVALID_KEY
 
-ECP write binary #0 (zero, bad format)
-depends_on:MBEDTLS_ECP_DP_SECP192R1_ENABLED
-ecp_write_binary:MBEDTLS_ECP_DP_SECP192R1:"01":"01":"00":ECP_PF_UNKNOWN:"00":1:MBEDTLS_ERR_ECP_BAD_INPUT_DATA
-
 ECP write binary #1 (zero, uncompressed, buffer just fits)
 depends_on:MBEDTLS_ECP_DP_SECP192R1_ENABLED
 ecp_write_binary:MBEDTLS_ECP_DP_SECP192R1:"01":"01":"00":MBEDTLS_ECP_PF_UNCOMPRESSED:"00":1:0
diff --git a/tests/suites/test_suite_ecp.function b/tests/suites/test_suite_ecp.function
index 65c487e..606ddd2 100644
--- a/tests/suites/test_suite_ecp.function
+++ b/tests/suites/test_suite_ecp.function
@@ -14,6 +14,349 @@
  */
 
 /* BEGIN_CASE */
+void ecp_valid_param( )
+{
+    TEST_VALID_PARAM( mbedtls_ecp_group_free( NULL ) );
+    TEST_VALID_PARAM( mbedtls_ecp_keypair_free( NULL ) );
+    TEST_VALID_PARAM( mbedtls_ecp_point_free( NULL ) );
+
+#if defined(MBEDTLS_ECP_RESTARTABLE)
+    TEST_VALID_PARAM( mbedtls_ecp_restart_free( NULL ) );
+#endif /* MBEDTLS_ECP_RESTARTABLE */
+
+exit:
+    return;
+}
+/* END_CASE */
+
+/* BEGIN_CASE depends_on:MBEDTLS_CHECK_PARAMS:!MBEDTLS_PARAM_FAILED_ALT */
+void ecp_invalid_param( )
+{
+    mbedtls_ecp_group grp;
+    mbedtls_ecp_keypair kp;
+    mbedtls_ecp_point P;
+    mbedtls_mpi m;
+    const char *x = "deadbeef";
+    int valid_fmt   = MBEDTLS_ECP_PF_UNCOMPRESSED;
+    int invalid_fmt = 42;
+    size_t olen;
+    unsigned char buf[42] = { 0 };
+    const unsigned char *null_buf = NULL;
+    mbedtls_ecp_group_id valid_group = MBEDTLS_ECP_DP_SECP192R1;
+    mbedtls_ecp_restart_ctx restart_ctx;
+
+    TEST_INVALID_PARAM( mbedtls_ecp_point_init( NULL ) );
+    TEST_INVALID_PARAM( mbedtls_ecp_keypair_init( NULL ) );
+    TEST_INVALID_PARAM( mbedtls_ecp_group_init( NULL ) );
+
+#if defined(MBEDTLS_ECP_RESTARTABLE)
+    TEST_INVALID_PARAM( mbedtls_ecp_restart_init( NULL ) );
+    TEST_INVALID_PARAM( mbedtls_ecp_check_budget( NULL, &restart_ctx, 42 ) );
+#endif /* MBEDTLS_ECP_RESTARTABLE */
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_copy( NULL, &P ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_copy( &P, NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_group_copy( NULL, &grp ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_group_copy( &grp, NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_gen_privkey( NULL,
+                                                     &m,
+                                                     rnd_std_rand,
+                                                     NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_gen_privkey( &grp,
+                                                     NULL,
+                                                     rnd_std_rand,
+                                                     NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_gen_privkey( &grp,
+                                                     &m,
+                                                     NULL,
+                                                     NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_set_zero( NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_is_zero( NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_point_cmp( NULL, &P ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_point_cmp( &P, NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_point_read_string( NULL, 2,
+                                                           x, x ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_point_read_string( &P, 2,
+                                                           NULL, x ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_point_read_string( &P, 2,
+                                                           x, NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_point_write_binary( NULL, &P,
+                                                      valid_fmt,
+                                                      &olen,
+                                                      buf, sizeof( buf ) ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_point_write_binary( &grp, NULL,
+                                                      valid_fmt,
+                                                      &olen,
+                                                      buf, sizeof( buf ) ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_point_write_binary( &grp, &P,
+                                                      invalid_fmt,
+                                                      &olen,
+                                                      buf, sizeof( buf ) ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_point_write_binary( &grp, &P,
+                                                      valid_fmt,
+                                                      NULL,
+                                                      buf, sizeof( buf ) ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_point_write_binary( &grp, &P,
+                                                      valid_fmt,
+                                                      &olen,
+                                                      NULL, sizeof( buf ) ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_point_read_binary( NULL, &P, buf,
+                                                     sizeof( buf ) ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_point_read_binary( &grp, NULL, buf,
+                                                     sizeof( buf ) ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_point_read_binary( &grp, &P, NULL,
+                                                     sizeof( buf ) ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_tls_read_point( NULL, &P,
+                                                 (const unsigned char **) &buf,
+                                                 sizeof( buf ) ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_tls_read_point( &grp, NULL,
+                                                 (const unsigned char **) &buf,
+                                                 sizeof( buf ) ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_tls_read_point( &grp, &P, &null_buf,
+                                                        sizeof( buf ) ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_tls_read_point( &grp, &P, NULL,
+                                                    sizeof( buf ) ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_tls_write_point( NULL, &P,
+                                                     valid_fmt,
+                                                     &olen,
+                                                     buf,
+                                                     sizeof( buf ) ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_tls_write_point( &grp, NULL,
+                                                     valid_fmt,
+                                                     &olen,
+                                                     buf,
+                                                     sizeof( buf ) ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_tls_write_point( &grp, &P,
+                                                     invalid_fmt,
+                                                     &olen,
+                                                     buf,
+                                                     sizeof( buf ) ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_tls_write_point( &grp, &P,
+                                                     valid_fmt,
+                                                     NULL,
+                                                     buf,
+                                                     sizeof( buf ) ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_tls_write_point( &grp, &P,
+                                                     valid_fmt,
+                                                     &olen,
+                                                     NULL,
+                                                     sizeof( buf ) ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_group_load( NULL, valid_group ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_tls_read_group( NULL,
+                                                 (const unsigned char **) &buf,
+                                                 sizeof( buf ) ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_tls_read_group( &grp, NULL,
+                                                        sizeof( buf ) ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_tls_read_group( &grp, &null_buf,
+                                                        sizeof( buf ) ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_tls_read_group_id( NULL,
+                                                 (const unsigned char **) &buf,
+                                                 sizeof( buf ) ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_tls_read_group_id( &valid_group, NULL,
+                                                        sizeof( buf ) ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_tls_read_group_id( &valid_group,
+                                                           &null_buf,
+                                                           sizeof( buf ) ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_tls_write_group( NULL, &olen,
+                                                       buf, sizeof( buf ) ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_tls_write_group( &grp, NULL,
+                                                       buf, sizeof( buf ) ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_tls_write_group( &grp, &olen,
+                                                       NULL, sizeof( buf ) ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_mul( NULL, &P, &m, &P,
+                                             rnd_std_rand, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_mul( &grp, NULL, &m, &P,
+                                             rnd_std_rand, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_mul( &grp, &P, NULL, &P,
+                                             rnd_std_rand, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_mul( &grp, &P, &m, NULL,
+                                             rnd_std_rand, NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_mul_restartable( NULL, &P, &m, &P,
+                                                 rnd_std_rand, NULL , NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_mul_restartable( &grp, NULL, &m, &P,
+                                                 rnd_std_rand, NULL , NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_mul_restartable( &grp, &P, NULL, &P,
+                                                 rnd_std_rand, NULL , NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_mul_restartable( &grp, &P, &m, NULL,
+                                                 rnd_std_rand, NULL , NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_muladd( NULL, &P, &m, &P,
+                                                &m, &P ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_muladd( &grp, NULL, &m, &P,
+                                                &m, &P ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_muladd( &grp, &P, NULL, &P,
+                                                &m, &P ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_muladd( &grp, &P, &m, NULL,
+                                                &m, &P ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_muladd( &grp, &P, &m, &P,
+                                                NULL, &P ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_muladd( &grp, &P, &m, &P,
+                                                &m, NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_muladd_restartable( NULL, &P, &m, &P,
+                                                            &m, &P, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_muladd_restartable( &grp, NULL, &m, &P,
+                                                            &m, &P, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_muladd_restartable( &grp, &P, NULL, &P,
+                                                            &m, &P, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_muladd_restartable( &grp, &P, &m, NULL,
+                                                            &m, &P, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_muladd_restartable( &grp, &P, &m, &P,
+                                                            NULL, &P, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_muladd_restartable( &grp, &P, &m, &P,
+                                                            &m, NULL, NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_check_pubkey( NULL, &P ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_check_pubkey( &grp, NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_check_pub_priv( NULL, &kp ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_check_pub_priv( &kp, NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_check_privkey( NULL, &m ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_check_privkey( &grp, NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_gen_keypair_base( NULL, &P,
+                                                          &m, &P,
+                                                          rnd_std_rand,
+                                                          NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_gen_keypair_base( &grp, NULL,
+                                                          &m, &P,
+                                                          rnd_std_rand,
+                                                          NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_gen_keypair_base( &grp, &P,
+                                                          NULL, &P,
+                                                          rnd_std_rand,
+                                                          NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_gen_keypair_base( &grp, &P,
+                                                          &m, NULL,
+                                                          rnd_std_rand,
+                                                          NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_gen_keypair_base( &grp, &P,
+                                                          &m, &P,
+                                                          NULL,
+                                                          NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_gen_keypair( NULL,
+                                                     &m, &P,
+                                                     rnd_std_rand,
+                                                     NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_gen_keypair( &grp,
+                                                     NULL, &P,
+                                                     rnd_std_rand,
+                                                     NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_gen_keypair( &grp,
+                                                     &m, NULL,
+                                                     rnd_std_rand,
+                                                     NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_gen_keypair( &grp,
+                                                     &m, &P,
+                                                     NULL,
+                                                     NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_gen_key( valid_group, NULL,
+                                                 rnd_std_rand, NULL ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
+                            mbedtls_ecp_gen_key( valid_group, &kp,
+                                                 NULL, NULL ) );
+
+exit:
+    return;
+}
+/* END_CASE */
+
+/* BEGIN_CASE */
 void mbedtls_ecp_curve_info( int id, int tls_id, int size, char * name )
 {
     const mbedtls_ecp_curve_info *by_id, *by_tls, *by_name;
diff --git a/tests/suites/test_suite_gcm.function b/tests/suites/test_suite_gcm.function
index 4d3bba1..1fcb681 100644
--- a/tests/suites/test_suite_gcm.function
+++ b/tests/suites/test_suite_gcm.function
@@ -103,6 +103,175 @@
 }
 /* END_CASE */
 
+/* BEGIN_CASE depends_on:MBEDTLS_CHECK_PARAMS:!MBEDTLS_PARAM_FAILED_ALT */
+void gcm_invalid_param( )
+{
+    mbedtls_gcm_context ctx;
+    unsigned char valid_buffer[] = { 0x01, 0x02, 0x03, 0x04, 0x05, 0x06 };
+    mbedtls_cipher_id_t valid_cipher = MBEDTLS_CIPHER_ID_AES;
+    int valid_mode = MBEDTLS_GCM_ENCRYPT;
+    int valid_len = sizeof(valid_buffer);
+    int valid_bitlen = 128, invalid_bitlen = 1;
+
+    mbedtls_gcm_init( &ctx );
+
+    /* mbedtls_gcm_init() */
+    TEST_INVALID_PARAM( mbedtls_gcm_init( NULL ) );
+
+    /* mbedtls_gcm_setkey */
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_GCM_BAD_INPUT,
+        mbedtls_gcm_setkey( NULL, valid_cipher, valid_buffer, valid_bitlen ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_GCM_BAD_INPUT,
+        mbedtls_gcm_setkey( &ctx, valid_cipher, NULL, valid_bitlen ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_GCM_BAD_INPUT,
+        mbedtls_gcm_setkey( &ctx, valid_cipher, valid_buffer, invalid_bitlen ) );
+
+    /* mbedtls_gcm_crypt_and_tag() */
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_GCM_BAD_INPUT,
+        mbedtls_gcm_crypt_and_tag( NULL, valid_mode, valid_len,
+                                   valid_buffer, valid_len,
+                                   valid_buffer, valid_len,
+                                   valid_buffer, valid_buffer,
+                                   valid_len, valid_buffer ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_GCM_BAD_INPUT,
+        mbedtls_gcm_crypt_and_tag( &ctx, valid_mode, valid_len,
+                                   NULL, valid_len,
+                                   valid_buffer, valid_len,
+                                   valid_buffer, valid_buffer,
+                                   valid_len, valid_buffer ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_GCM_BAD_INPUT,
+        mbedtls_gcm_crypt_and_tag( &ctx, valid_mode, valid_len,
+                                   valid_buffer, valid_len,
+                                   NULL, valid_len,
+                                   valid_buffer, valid_buffer,
+                                   valid_len, valid_buffer ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_GCM_BAD_INPUT,
+        mbedtls_gcm_crypt_and_tag( &ctx, valid_mode, valid_len,
+                                   valid_buffer, valid_len,
+                                   valid_buffer, valid_len,
+                                   NULL, valid_buffer,
+                                   valid_len, valid_buffer ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_GCM_BAD_INPUT,
+        mbedtls_gcm_crypt_and_tag( &ctx, valid_mode, valid_len,
+                                   valid_buffer, valid_len,
+                                   valid_buffer, valid_len,
+                                   valid_buffer, NULL,
+                                   valid_len, valid_buffer ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_GCM_BAD_INPUT,
+        mbedtls_gcm_crypt_and_tag( &ctx, valid_mode, valid_len,
+                                   valid_buffer, valid_len,
+                                   valid_buffer, valid_len,
+                                   valid_buffer, valid_buffer,
+                                   valid_len, NULL ) );
+
+    /* mbedtls_gcm_auth_decrypt() */
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_GCM_BAD_INPUT,
+        mbedtls_gcm_auth_decrypt( NULL, valid_len,
+                                  valid_buffer, valid_len,
+                                  valid_buffer, valid_len,
+                                  valid_buffer, valid_len,
+                                  valid_buffer, valid_buffer) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_GCM_BAD_INPUT,
+        mbedtls_gcm_auth_decrypt( &ctx, valid_len,
+                                  NULL, valid_len,
+                                  valid_buffer, valid_len,
+                                  valid_buffer, valid_len,
+                                  valid_buffer, valid_buffer) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_GCM_BAD_INPUT,
+        mbedtls_gcm_auth_decrypt( &ctx, valid_len,
+                                  valid_buffer, valid_len,
+                                  NULL, valid_len,
+                                  valid_buffer, valid_len,
+                                  valid_buffer, valid_buffer) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_GCM_BAD_INPUT,
+        mbedtls_gcm_auth_decrypt( &ctx, valid_len,
+                                  valid_buffer, valid_len,
+                                  valid_buffer, valid_len,
+                                  NULL, valid_len,
+                                  valid_buffer, valid_buffer) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_GCM_BAD_INPUT,
+        mbedtls_gcm_auth_decrypt( &ctx, valid_len,
+                                  valid_buffer, valid_len,
+                                  valid_buffer, valid_len,
+                                  valid_buffer, valid_len,
+                                  NULL, valid_buffer) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_GCM_BAD_INPUT,
+        mbedtls_gcm_auth_decrypt( &ctx, valid_len,
+                                  valid_buffer, valid_len,
+                                  valid_buffer, valid_len,
+                                  valid_buffer, valid_len,
+                                  valid_buffer, NULL) );
+
+    /* mbedtls_gcm_starts() */
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_GCM_BAD_INPUT,
+        mbedtls_gcm_starts( NULL, valid_mode,
+                            valid_buffer, valid_len,
+                            valid_buffer, valid_len ) );
+
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_GCM_BAD_INPUT,
+        mbedtls_gcm_starts( &ctx, valid_mode,
+                            NULL, valid_len,
+                            valid_buffer, valid_len ) );
+
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_GCM_BAD_INPUT,
+        mbedtls_gcm_starts( &ctx, valid_mode,
+                            valid_buffer, valid_len,
+                            NULL, valid_len ) );
+
+    /* mbedtls_gcm_update() */
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_GCM_BAD_INPUT,
+        mbedtls_gcm_update( NULL, valid_len,
+                            valid_buffer, valid_buffer ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_GCM_BAD_INPUT,
+        mbedtls_gcm_update( &ctx, valid_len,
+                            NULL, valid_buffer ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_GCM_BAD_INPUT,
+        mbedtls_gcm_update( &ctx, valid_len,
+                            valid_buffer, NULL ) );
+
+    /* mbedtls_gcm_finish() */
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_GCM_BAD_INPUT,
+        mbedtls_gcm_finish( NULL, valid_buffer, valid_len ) );
+    TEST_INVALID_PARAM_RET(
+        MBEDTLS_ERR_GCM_BAD_INPUT,
+        mbedtls_gcm_finish( &ctx, NULL, valid_len ) );
+
+exit:
+    mbedtls_gcm_free( &ctx );
+}
+/* END_CASE */
+
+/* BEGIN_CASE */
+void gcm_valid_param( )
+{
+    TEST_VALID_PARAM( mbedtls_gcm_free( NULL ) );
+exit:
+    return;
+}
+/* END_CASE */
+
 /* BEGIN_CASE depends_on:MBEDTLS_SELF_TEST */
 void gcm_selftest(  )
 {
diff --git a/tests/suites/test_suite_gcm.misc.data b/tests/suites/test_suite_gcm.misc.data
new file mode 100644
index 0000000..cf01526
--- /dev/null
+++ b/tests/suites/test_suite_gcm.misc.data
@@ -0,0 +1,5 @@
+GCM - Invalid parameters
+gcm_invalid_param:
+
+GCM - Valid parameters
+gcm_valid_param:
diff --git a/tests/suites/test_suite_poly1305.function b/tests/suites/test_suite_poly1305.function
index 62d2ad9..066bb39 100644
--- a/tests/suites/test_suite_poly1305.function
+++ b/tests/suites/test_suite_poly1305.function
@@ -88,7 +88,7 @@
 }
 /* END_CASE */
 
-/* BEGIN_CASE */
+/* BEGIN_CASE depends_on:MBEDTLS_CHECK_PARAMS:!MBEDTLS_PARAM_FAILED_ALT */
 void poly1305_bad_params()
 {
     unsigned char src[1];
@@ -97,38 +97,33 @@
     size_t src_len = sizeof( src );
     mbedtls_poly1305_context ctx;
 
-    mbedtls_poly1305_init( NULL );
-    mbedtls_poly1305_free( NULL );
+    TEST_INVALID_PARAM( mbedtls_poly1305_init( NULL ) );
+    TEST_VALID_PARAM( mbedtls_poly1305_free( NULL ) );
 
-    mbedtls_poly1305_init( &ctx );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                 mbedtls_poly1305_starts( NULL, key ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                 mbedtls_poly1305_starts( &ctx, NULL ) );
 
-    TEST_ASSERT( mbedtls_poly1305_starts( NULL, key )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_poly1305_starts( &ctx, NULL )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                 mbedtls_poly1305_update( NULL, src, 0 ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                 mbedtls_poly1305_update( &ctx, NULL, src_len ) );
 
-    TEST_ASSERT( mbedtls_poly1305_update( NULL, src, 0 )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_poly1305_update( &ctx, NULL, src_len )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_poly1305_update( &ctx, NULL, 0 )
-                 == 0 );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                 mbedtls_poly1305_finish( NULL, mac ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                 mbedtls_poly1305_finish( &ctx, NULL ) );
 
-    TEST_ASSERT( mbedtls_poly1305_finish( NULL, mac )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_poly1305_finish( &ctx, NULL )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                 mbedtls_poly1305_mac( NULL, src, 0, mac ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                 mbedtls_poly1305_mac( key, NULL, src_len, mac ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA,
+                 mbedtls_poly1305_mac( key, src, 0, NULL ) );
 
-    TEST_ASSERT( mbedtls_poly1305_mac( NULL, src, 0, mac )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_poly1305_mac( key, NULL, src_len, mac )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_poly1305_mac( key, src, 0, NULL )
-                 == MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
-    TEST_ASSERT( mbedtls_poly1305_mac( key, NULL, 0, mac )
-                 == 0 );
-
-    mbedtls_poly1305_free( &ctx );
+exit:
+    return;
 }
 /* END_CASE */
 
diff --git a/tests/suites/test_suite_shax.data b/tests/suites/test_suite_shax.data
index ee8074d..2f65c23 100644
--- a/tests/suites/test_suite_shax.data
+++ b/tests/suites/test_suite_shax.data
@@ -1,3 +1,9 @@
+SHA-1 - Valid parameters
+sha1_valid_param:
+
+SHA-1 - Invalid parameters
+sha1_invalid_param:
+
 # Test the operation of SHA-1 and SHA-2
 SHA-1 Test Vector NIST CAVS #1
 depends_on:MBEDTLS_SHA1_C
@@ -39,6 +45,12 @@
 depends_on:MBEDTLS_SHA1_C
 mbedtls_sha1:"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":"11863b483809ef88413ca9b0084ac4a5390640af"
 
+SHA-256 Valid parameters
+sha256_valid_param:
+
+SHA-256 Invalid parameters
+sha256_invalid_param:
+
 SHA-224 Test Vector NIST CAVS #1
 depends_on:MBEDTLS_SHA256_C
 sha224:"":"d14a028c2a3a2bc9476102bb288234c415a2b01f828ea62ac5b3e42f"
@@ -95,6 +107,12 @@
 depends_on:MBEDTLS_SHA256_C
 mbedtls_sha256:"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":"4109cdbec3240ad74cc6c37f39300f70fede16e21efc77f7865998714aad0b5e"
 
+SHA-512 Invalid parameters
+sha512_invalid_param:
+
+SHA-512 Valid parameters
+sha512_valid_param:
+
 SHA-384 Test Vector NIST CAVS #1
 depends_on:MBEDTLS_SHA512_C
 sha384:"":"38b060a751ac96384cd9327eb1b1e36a21fdb71114be07434c0cc7bf63f6e1da274edebfe76f65fbd51ad2f14898b95b"
diff --git a/tests/suites/test_suite_shax.function b/tests/suites/test_suite_shax.function
index 147ae0e..e621f49 100644
--- a/tests/suites/test_suite_shax.function
+++ b/tests/suites/test_suite_shax.function
@@ -5,6 +5,53 @@
 /* END_HEADER */
 
 /* BEGIN_CASE depends_on:MBEDTLS_SHA1_C */
+void sha1_valid_param( )
+{
+    TEST_VALID_PARAM( mbedtls_sha1_free( NULL ) );
+}
+/* END_CASE */
+
+/* BEGIN_CASE depends_on:MBEDTLS_SHA1_C:MBEDTLS_CHECK_PARAMS:!MBEDTLS_PARAM_FAILED_ALT */
+void sha1_invalid_param( )
+{
+    mbedtls_sha1_context ctx;
+    unsigned char buf[64] = { 0 };
+    size_t const buflen = sizeof( buf );
+
+    TEST_INVALID_PARAM( mbedtls_sha1_init( NULL ) );
+
+    TEST_INVALID_PARAM( mbedtls_sha1_clone( NULL, &ctx ) );
+    TEST_INVALID_PARAM( mbedtls_sha1_clone( &ctx, NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA1_BAD_INPUT_DATA,
+                            mbedtls_sha1_starts_ret( NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA1_BAD_INPUT_DATA,
+                            mbedtls_sha1_update_ret( NULL, buf, buflen ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA1_BAD_INPUT_DATA,
+                            mbedtls_sha1_update_ret( &ctx, NULL, buflen ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA1_BAD_INPUT_DATA,
+                            mbedtls_sha1_finish_ret( NULL, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA1_BAD_INPUT_DATA,
+                            mbedtls_sha1_finish_ret( &ctx, NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA1_BAD_INPUT_DATA,
+                            mbedtls_internal_sha1_process( NULL, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA1_BAD_INPUT_DATA,
+                            mbedtls_internal_sha1_process( &ctx, NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA1_BAD_INPUT_DATA,
+                            mbedtls_sha1_ret( NULL, buflen, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA1_BAD_INPUT_DATA,
+                            mbedtls_sha1_ret( buf, buflen, NULL ) );
+
+exit:
+    return;
+}
+/* END_CASE */
+
+/* BEGIN_CASE depends_on:MBEDTLS_SHA1_C */
 void mbedtls_sha1( data_t * src_str, data_t * hex_hash_string )
 {
     unsigned char output[41];
@@ -19,6 +66,62 @@
 /* END_CASE */
 
 /* BEGIN_CASE depends_on:MBEDTLS_SHA256_C */
+void sha256_valid_param( )
+{
+    TEST_VALID_PARAM( mbedtls_sha256_free( NULL ) );
+}
+/* END_CASE */
+
+/* BEGIN_CASE depends_on:MBEDTLS_SHA256_C:MBEDTLS_CHECK_PARAMS:!MBEDTLS_PARAM_FAILED_ALT */
+void sha256_invalid_param( )
+{
+    mbedtls_sha256_context ctx;
+    unsigned char buf[64] = { 0 };
+    size_t const buflen = sizeof( buf );
+    int valid_type = 0;
+    int invalid_type = 42;
+
+    TEST_INVALID_PARAM( mbedtls_sha256_init( NULL ) );
+
+    TEST_INVALID_PARAM( mbedtls_sha256_clone( NULL, &ctx ) );
+    TEST_INVALID_PARAM( mbedtls_sha256_clone( &ctx, NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA256_BAD_INPUT_DATA,
+                            mbedtls_sha256_starts_ret( NULL, valid_type ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA256_BAD_INPUT_DATA,
+                            mbedtls_sha256_starts_ret( &ctx, invalid_type ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA256_BAD_INPUT_DATA,
+                            mbedtls_sha256_update_ret( NULL, buf, buflen ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA256_BAD_INPUT_DATA,
+                            mbedtls_sha256_update_ret( &ctx, NULL, buflen ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA256_BAD_INPUT_DATA,
+                            mbedtls_sha256_finish_ret( NULL, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA256_BAD_INPUT_DATA,
+                            mbedtls_sha256_finish_ret( &ctx, NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA256_BAD_INPUT_DATA,
+                            mbedtls_internal_sha256_process( NULL, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA256_BAD_INPUT_DATA,
+                            mbedtls_internal_sha256_process( &ctx, NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA256_BAD_INPUT_DATA,
+                            mbedtls_sha256_ret( NULL, buflen,
+                                                buf, valid_type ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA256_BAD_INPUT_DATA,
+                            mbedtls_sha256_ret( buf, buflen,
+                                                NULL, valid_type ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA256_BAD_INPUT_DATA,
+                            mbedtls_sha256_ret( buf, buflen,
+                                                buf, invalid_type ) );
+
+exit:
+    return;
+}
+/* END_CASE */
+
+/* BEGIN_CASE depends_on:MBEDTLS_SHA256_C */
 void sha224( data_t * src_str, data_t * hex_hash_string )
 {
     unsigned char output[57];
@@ -47,6 +150,62 @@
 /* END_CASE */
 
 /* BEGIN_CASE depends_on:MBEDTLS_SHA512_C */
+void sha512_valid_param( )
+{
+    TEST_VALID_PARAM( mbedtls_sha512_free( NULL ) );
+}
+/* END_CASE */
+
+/* BEGIN_CASE depends_on:MBEDTLS_SHA512_C:MBEDTLS_CHECK_PARAMS:!MBEDTLS_PARAM_FAILED_ALT */
+void sha512_invalid_param( )
+{
+    mbedtls_sha512_context ctx;
+    unsigned char buf[64] = { 0 };
+    size_t const buflen = sizeof( buf );
+    int valid_type = 0;
+    int invalid_type = 42;
+
+    TEST_INVALID_PARAM( mbedtls_sha512_init( NULL ) );
+
+    TEST_INVALID_PARAM( mbedtls_sha512_clone( NULL, &ctx ) );
+    TEST_INVALID_PARAM( mbedtls_sha512_clone( &ctx, NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA512_BAD_INPUT_DATA,
+                            mbedtls_sha512_starts_ret( NULL, valid_type ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA512_BAD_INPUT_DATA,
+                            mbedtls_sha512_starts_ret( &ctx, invalid_type ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA512_BAD_INPUT_DATA,
+                            mbedtls_sha512_update_ret( NULL, buf, buflen ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA512_BAD_INPUT_DATA,
+                            mbedtls_sha512_update_ret( &ctx, NULL, buflen ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA512_BAD_INPUT_DATA,
+                            mbedtls_sha512_finish_ret( NULL, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA512_BAD_INPUT_DATA,
+                            mbedtls_sha512_finish_ret( &ctx, NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA512_BAD_INPUT_DATA,
+                            mbedtls_internal_sha512_process( NULL, buf ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA512_BAD_INPUT_DATA,
+                            mbedtls_internal_sha512_process( &ctx, NULL ) );
+
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA512_BAD_INPUT_DATA,
+                            mbedtls_sha512_ret( NULL, buflen,
+                                                buf, valid_type ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA512_BAD_INPUT_DATA,
+                            mbedtls_sha512_ret( buf, buflen,
+                                                NULL, valid_type ) );
+    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_SHA512_BAD_INPUT_DATA,
+                            mbedtls_sha512_ret( buf, buflen,
+                                                buf, invalid_type ) );
+
+exit:
+    return;
+}
+/* END_CASE */
+
+/* BEGIN_CASE depends_on:MBEDTLS_SHA512_C */
 void sha384( data_t * src_str, data_t * hex_hash_string )
 {
     unsigned char output[97];