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/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/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/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