Document parameter preconditions for Blowfish module
diff --git a/include/mbedtls/blowfish.h b/include/mbedtls/blowfish.h
index 922d8f8..d904269 100644
--- a/include/mbedtls/blowfish.h
+++ b/include/mbedtls/blowfish.h
@@ -76,40 +76,51 @@
#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.
+ * 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
+ * is a no-op. 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.
*
- * \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. Must be a readable buffer of
+ * length \p keybits Bits.
+ * \param keybits The length of \p key in Bits. 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.
*
- * \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. Must be a readable buffer of size 8 Bytes.
+ * \param input The output block. Must be a writable buffer of size 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,
@@ -118,7 +129,7 @@
#if defined(MBEDTLS_CIPHER_MODE_CBC)
/**
- * \brief Blowfish-CBC buffer encryption/decryption
+ * \brief Perform a Blowfish-CBC buffer encryption/decryption
* Length should be a multiple of the block
* size (8 bytes)
*
@@ -130,15 +141,21 @@
* 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.
+ * \param iv The initialization vector. This must be an RW buffer
+ * of length \c 8 Bytes. It is updated by this function.
+ * \param input The input data. Must be a readable buffer of length
+ * \p length Bytes. If \p length if \c 0, it may be \c NULL.
+ * \param output The output data. Must be a writable buffer of length
+ * \p length Bytes. If \p length if \c 0, it may be \c NULL.
*
- * \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 +167,7 @@
#if defined(MBEDTLS_CIPHER_MODE_CFB)
/**
- * \brief Blowfish CFB buffer encryption/decryption.
+ * \brief Perform a Blowfish CFB buffer encryption/decryption.
*
* \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 +177,25 @@
* 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.
+ * It is updated by this function to support the aforementioned
+ * streaming usage.
+ * \param iv The initialization vector. Must be an RW buffer of
+ * size \c 8 Bytes. It is updated after use.
+ * \param input The input data. Must be a readable buffer of length
+ * \p length Bytes. If \p length if \c 0, it may be \c NULL.
+ * \param output The output data. Must be a writable buffer of length
+ * \p length Bytes. If \p length if \c 0, it may be \c NULL.
*
- * \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 +208,7 @@
#if defined(MBEDTLS_CIPHER_MODE_CTR)
/**
- * \brief Blowfish-CTR buffer encryption/decryption
+ * \brief Perform a Blowfish-CTR buffer encryption/decryption.
*
* \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 +251,24 @@
* 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
+ * 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 an RW
+ * buffer of length \c 8 Bytes.
+ * \param stream_block The saved stream-block for resuming. This must point to
+ * an RW buffer of length \c 8 Bytes.
+ * \param input The input data. Must be a readable buffer of length
+ * \p length Bytes. If \p length if \c 0, it may be \c NULL.
+ * \param output The output data. Must be a writable buffer of length
+ * \p length Bytes. If \p length if \c 0, it may be \c NULL.
*
- * \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,