diff --git a/include/mbedtls/cipher.h b/include/mbedtls/cipher.h index 97b9226f5..dc1bc5647 100644 --- a/include/mbedtls/cipher.h +++ b/include/mbedtls/cipher.h @@ -1,12 +1,12 @@ /** * \file cipher.h * - * \brief Generic cipher wrapper. + * \brief The generic cipher wrapper. * * \author Adriaan de Jong */ /* - * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved + * Copyright (C) 2006-2018, Arm Limited (or its affiliates), All Rights Reserved * SPDX-License-Identifier: Apache-2.0 * * Licensed under the Apache License, Version 2.0 (the "License"); you may @@ -21,7 +21,7 @@ * See the License for the specific language governing permissions and * limitations under the License. * - * This file is part of mbed TLS (https://tls.mbed.org) + * This file is part of Mbed TLS (https://tls.mbed.org) */ #ifndef MBEDTLS_CIPHER_H @@ -52,22 +52,23 @@ #define inline __inline #endif -#define MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE -0x6080 /**< The selected feature is not available. */ -#define MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA -0x6100 /**< Bad input parameters to function. */ -#define MBEDTLS_ERR_CIPHER_ALLOC_FAILED -0x6180 /**< Failed to allocate memory. */ -#define MBEDTLS_ERR_CIPHER_INVALID_PADDING -0x6200 /**< Input data contains invalid padding and is rejected. */ -#define MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED -0x6280 /**< Decryption of block requires a full block. */ -#define MBEDTLS_ERR_CIPHER_AUTH_FAILED -0x6300 /**< Authentication failed (for AEAD modes). */ -#define MBEDTLS_ERR_CIPHER_INVALID_CONTEXT -0x6380 /**< The context is invalid, eg because it was free()ed. */ -#define MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED -0x6400 /**< Cipher hardware accelerator failed. */ +#define MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE -0x6080 /**< The selected feature is not available. */ +#define MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA -0x6100 /**< Bad input parameters. */ +#define MBEDTLS_ERR_CIPHER_ALLOC_FAILED -0x6180 /**< Failed to allocate memory. */ +#define MBEDTLS_ERR_CIPHER_INVALID_PADDING -0x6200 /**< Input data contains invalid padding and is rejected. */ +#define MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED -0x6280 /**< Decryption of block requires a full block. */ +#define MBEDTLS_ERR_CIPHER_AUTH_FAILED -0x6300 /**< Authentication failed (for AEAD modes). */ +#define MBEDTLS_ERR_CIPHER_INVALID_CONTEXT -0x6380 /**< The context is invalid. For example, because it was freed. */ +#define MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED -0x6400 /**< Cipher hardware accelerator failed. */ -#define MBEDTLS_CIPHER_VARIABLE_IV_LEN 0x01 /**< Cipher accepts IVs of variable length */ -#define MBEDTLS_CIPHER_VARIABLE_KEY_LEN 0x02 /**< Cipher accepts keys of variable length */ +#define MBEDTLS_CIPHER_VARIABLE_IV_LEN 0x01 /**< Cipher accepts IVs of variable length. */ +#define MBEDTLS_CIPHER_VARIABLE_KEY_LEN 0x02 /**< Cipher accepts keys of variable length. */ #ifdef __cplusplus extern "C" { #endif +/** Supported cipher IDs. */ typedef enum { MBEDTLS_CIPHER_ID_NONE = 0, MBEDTLS_CIPHER_ID_NULL, @@ -79,6 +80,7 @@ typedef enum { MBEDTLS_CIPHER_ID_ARC4, } mbedtls_cipher_id_t; +/** Supported cipher types. */ typedef enum { MBEDTLS_CIPHER_NONE = 0, MBEDTLS_CIPHER_NULL, @@ -131,6 +133,7 @@ typedef enum { MBEDTLS_CIPHER_CAMELLIA_256_CCM, } mbedtls_cipher_type_t; +/** Supported cipher modes. */ typedef enum { MBEDTLS_MODE_NONE = 0, MBEDTLS_MODE_ECB, @@ -143,14 +146,16 @@ typedef enum { MBEDTLS_MODE_CCM, } mbedtls_cipher_mode_t; +/** Supported cipher padding types. */ typedef enum { - MBEDTLS_PADDING_PKCS7 = 0, /**< PKCS7 padding (default) */ - MBEDTLS_PADDING_ONE_AND_ZEROS, /**< ISO/IEC 7816-4 padding */ - MBEDTLS_PADDING_ZEROS_AND_LEN, /**< ANSI X.923 padding */ - MBEDTLS_PADDING_ZEROS, /**< zero padding (not reversible!) */ - MBEDTLS_PADDING_NONE, /**< never pad (full blocks only) */ + MBEDTLS_PADDING_PKCS7 = 0, /**< PKCS7 padding (default). */ + MBEDTLS_PADDING_ONE_AND_ZEROS, /**< ISO/IEC 7816-4 padding. */ + MBEDTLS_PADDING_ZEROS_AND_LEN, /**< ANSI X.923 padding. */ + MBEDTLS_PADDING_ZEROS, /**< zero padding (not reversible). */ + MBEDTLS_PADDING_NONE, /**< never pad (full blocks only). */ } mbedtls_cipher_padding_t; +/** Type of operation. */ typedef enum { MBEDTLS_OPERATION_NONE = -1, MBEDTLS_DECRYPT = 0, @@ -158,19 +163,19 @@ typedef enum { } mbedtls_operation_t; enum { - /** Undefined key length */ + /** Undefined key length. */ MBEDTLS_KEY_LENGTH_NONE = 0, - /** Key length, in bits (including parity), for DES keys */ + /** Key length, in bits (including parity), for DES keys. */ MBEDTLS_KEY_LENGTH_DES = 64, - /** Key length, in bits (including parity), for DES in two key EDE */ + /** Key length in bits, including parity, for DES in two-key EDE. */ MBEDTLS_KEY_LENGTH_DES_EDE = 128, - /** Key length, in bits (including parity), for DES in three-key EDE */ + /** Key length in bits, including parity, for DES in three-key EDE. */ MBEDTLS_KEY_LENGTH_DES_EDE3 = 192, }; -/** Maximum length of any IV, in bytes */ +/** Maximum length of any IV, in Bytes. */ #define MBEDTLS_MAX_IV_LENGTH 16 -/** Maximum block size of any cipher, in bytes */ +/** Maximum block size of any cipher, in Bytes. */ #define MBEDTLS_MAX_BLOCK_LENGTH 16 /** @@ -184,33 +189,40 @@ typedef struct mbedtls_cipher_base_t mbedtls_cipher_base_t; typedef struct mbedtls_cmac_context_t mbedtls_cmac_context_t; /** - * Cipher information. Allows cipher functions to be called in a generic way. + * Cipher information. Allows calling cipher functions + * in a generic way. */ typedef struct { - /** Full cipher identifier (e.g. MBEDTLS_CIPHER_AES_256_CBC) */ + /** Full cipher identifier. For example, + * MBEDTLS_CIPHER_AES_256_CBC. + */ mbedtls_cipher_type_t type; - /** Cipher mode (e.g. MBEDTLS_MODE_CBC) */ + /** The cipher mode. For example, MBEDTLS_MODE_CBC. */ mbedtls_cipher_mode_t mode; - /** Cipher key length, in bits (default length for variable sized ciphers) - * (Includes parity bits for ciphers like DES) */ + /** The cipher key length, in bits. This is the + * default length for variable sized ciphers. + * Includes parity bits for ciphers like DES. + */ unsigned int key_bitlen; - /** Name of the cipher */ + /** Name of the cipher. */ const char * name; - /** IV/NONCE size, in bytes. - * For cipher that accept many sizes: recommended size */ + /** IV or nonce size, in Bytes. + * For ciphers that accept variable IV sizes, + * this is the recommended size. + */ unsigned int iv_size; - /** Flags for variable IV size, variable key size, etc. */ + /** Flags to set. For example, if the cipher supports variable IV sizes or variable key sizes. */ int flags; - /** block size, in bytes */ + /** The block size, in Bytes. */ unsigned int block_size; - /** Base cipher information and functions */ + /** Struct for base cipher information and functions. */ const mbedtls_cipher_base_t *base; } mbedtls_cipher_info_t; @@ -219,125 +231,133 @@ typedef struct { * Generic cipher context. */ typedef struct { - /** Information about the associated cipher */ + /** Information about the associated cipher. */ const mbedtls_cipher_info_t *cipher_info; - /** Key length to use */ + /** Key length to use. */ int key_bitlen; - /** Operation that the context's key has been initialised for */ + /** Operation that the key of the context has been + * initialized for. + */ mbedtls_operation_t operation; #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING) - /** Padding functions to use, if relevant for cipher mode */ + /** Padding functions to use, if relevant for + * the specific cipher mode. + */ void (*add_padding)( unsigned char *output, size_t olen, size_t data_len ); int (*get_padding)( unsigned char *input, size_t ilen, size_t *data_len ); #endif - /** Buffer for data that hasn't been encrypted yet */ + /** Buffer for input that has not been processed yet. */ unsigned char unprocessed_data[MBEDTLS_MAX_BLOCK_LENGTH]; - /** Number of bytes that still need processing */ + /** Number of Bytes that have not been processed yet. */ size_t unprocessed_len; - /** Current IV or NONCE_COUNTER for CTR-mode */ + /** Current IV or NONCE_COUNTER for CTR-mode. */ unsigned char iv[MBEDTLS_MAX_IV_LENGTH]; - /** IV size in bytes (for ciphers with variable-length IVs) */ + /** IV size in Bytes, for ciphers with variable-length IVs. */ size_t iv_size; - /** Cipher-specific context */ + /** The cipher-specific context. */ void *cipher_ctx; #if defined(MBEDTLS_CMAC_C) - /** CMAC Specific context */ + /** CMAC-specific context. */ mbedtls_cmac_context_t *cmac_ctx; #endif } mbedtls_cipher_context_t; /** - * \brief Returns the list of ciphers supported by the generic cipher module. + * \brief This function retrieves the list of ciphers supported by the generic + * cipher module. * - * \return a statically allocated array of ciphers, the last entry - * is 0. + * \return A statically-allocated array of ciphers. The last entry + * is zero. */ const int *mbedtls_cipher_list( void ); /** - * \brief Returns the cipher information structure associated - * with the given cipher name. + * \brief This function retrieves the cipher-information + * structure associated with the given cipher name. * * \param cipher_name Name of the cipher to search for. * - * \return the cipher information structure associated with the - * given cipher_name, or NULL if not found. + * \return The cipher information structure associated with the + * given \p cipher_name, or NULL if not found. */ const mbedtls_cipher_info_t *mbedtls_cipher_info_from_string( const char *cipher_name ); /** - * \brief Returns the cipher information structure associated - * with the given cipher type. + * \brief This function retrieves the cipher-information + * structure associated with the given cipher type. * * \param cipher_type Type of the cipher to search for. * - * \return the cipher information structure associated with the - * given cipher_type, or NULL if not found. + * \return The cipher information structure associated with the + * given \p cipher_type, or NULL if not found. */ const mbedtls_cipher_info_t *mbedtls_cipher_info_from_type( const mbedtls_cipher_type_t cipher_type ); /** - * \brief Returns the cipher information structure associated - * with the given cipher id, key size and mode. + * \brief This function retrieves the cipher-information + * structure associated with the given cipher ID, + * key size and mode. * - * \param cipher_id Id of the cipher to search for - * (e.g. MBEDTLS_CIPHER_ID_AES) - * \param key_bitlen Length of the key in bits - * \param mode Cipher mode (e.g. MBEDTLS_MODE_CBC) + * \param cipher_id The ID of the cipher to search for. For example, + * #MBEDTLS_CIPHER_ID_AES. + * \param key_bitlen The length of the key in bits. + * \param mode The cipher mode. For example, #MBEDTLS_MODE_CBC. * - * \return the cipher information structure associated with the - * given cipher_type, or NULL if not found. + * \return The cipher information structure associated with the + * given \p cipher_id, or NULL if not found. */ const mbedtls_cipher_info_t *mbedtls_cipher_info_from_values( const mbedtls_cipher_id_t cipher_id, int key_bitlen, const mbedtls_cipher_mode_t mode ); /** - * \brief Initialize a cipher_context (as NONE) + * \brief This function initializes a \p cipher_context as NONE. */ void mbedtls_cipher_init( mbedtls_cipher_context_t *ctx ); /** - * \brief Free and clear the cipher-specific context of ctx. - * Freeing ctx itself remains the responsibility of the - * caller. + * \brief This function frees and clears the cipher-specific + * context of \p ctx. Freeing \p ctx itself remains the + * responsibility of the caller. */ void mbedtls_cipher_free( mbedtls_cipher_context_t *ctx ); + /** - * \brief Initialises and fills the cipher context structure with - * the appropriate values. + * \brief This function initializes and fills the cipher-context + * structure with the appropriate values. It also clears + * the structure. * - * \note Currently also clears structure. In future versions you - * will be required to call mbedtls_cipher_init() on the structure - * first. + * \param ctx The context to initialize. May not be NULL. + * \param cipher_info The cipher to use. * - * \param ctx context to initialise. May not be NULL. - * \param cipher_info cipher to use. - * - * \return 0 on success, - * MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on parameter failure, - * MBEDTLS_ERR_CIPHER_ALLOC_FAILED if allocation of the + * \return \c 0 on success, + * #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on parameter failure, + * #MBEDTLS_ERR_CIPHER_ALLOC_FAILED if allocation of the * cipher-specific context failed. + * + * \internal Currently, the function also clears the structure. + * In future versions, the caller will be required to call + * mbedtls_cipher_init() on the structure first. */ int mbedtls_cipher_setup( mbedtls_cipher_context_t *ctx, const mbedtls_cipher_info_t *cipher_info ); /** - * \brief Returns the block size of the given cipher. + * \brief This function returns the block size of the given cipher. * - * \param ctx cipher's context. Must have been initialised. + * \param ctx The context of the cipher. Must be initialized. * - * \return size of the cipher's blocks, or 0 if ctx has not been - * initialised. + * \return The size of the blocks of the cipher, or zero if \p ctx + * has not been initialized. */ static inline unsigned int mbedtls_cipher_get_block_size( const mbedtls_cipher_context_t *ctx ) { @@ -348,13 +368,13 @@ static inline unsigned int mbedtls_cipher_get_block_size( const mbedtls_cipher_c } /** - * \brief Returns the mode of operation for the cipher. - * (e.g. MBEDTLS_MODE_CBC) + * \brief This function returns the mode of operation for + * the cipher. For example, MBEDTLS_MODE_CBC. * - * \param ctx cipher's context. Must have been initialised. + * \param ctx The context of the cipher. Must be initialized. * - * \return mode of operation, or MBEDTLS_MODE_NONE if ctx - * has not been initialised. + * \return The mode of operation, or #MBEDTLS_MODE_NONE if + * \p ctx has not been initialized. */ static inline mbedtls_cipher_mode_t mbedtls_cipher_get_cipher_mode( const mbedtls_cipher_context_t *ctx ) { @@ -365,13 +385,14 @@ static inline mbedtls_cipher_mode_t mbedtls_cipher_get_cipher_mode( const mbedtl } /** - * \brief Returns the size of the cipher's IV/NONCE in bytes. + * \brief This function returns the size of the IV or nonce + * of the cipher, in Bytes. * - * \param ctx cipher's context. Must have been initialised. + * \param ctx The context of the cipher. Must be initialized. * - * \return If IV has not been set yet: (recommended) IV size - * (0 for ciphers not using IV/NONCE). - * If IV has already been set: actual size. + * \return */ static inline int mbedtls_cipher_get_iv_size( const mbedtls_cipher_context_t *ctx ) { @@ -385,12 +406,12 @@ static inline int mbedtls_cipher_get_iv_size( const mbedtls_cipher_context_t *ct } /** - * \brief Returns the type of the given cipher. + * \brief This function returns the type of the given cipher. * - * \param ctx cipher's context. Must have been initialised. + * \param ctx The context of the cipher. Must be initialized. * - * \return type of the cipher, or MBEDTLS_CIPHER_NONE if ctx has - * not been initialised. + * \return The type of the cipher, or #MBEDTLS_CIPHER_NONE if + * \p ctx has not been initialized. */ static inline mbedtls_cipher_type_t mbedtls_cipher_get_type( const mbedtls_cipher_context_t *ctx ) { @@ -401,11 +422,13 @@ static inline mbedtls_cipher_type_t mbedtls_cipher_get_type( const mbedtls_ciphe } /** - * \brief Returns the name of the given cipher, as a string. + * \brief This function returns the name of the given cipher + * as a string. * - * \param ctx cipher's context. Must have been initialised. + * \param ctx The context of the cipher. Must be initialized. * - * \return name of the cipher, or NULL if ctx was not initialised. + * \return The name of the cipher, or NULL if \p ctx has not + * been not initialized. */ static inline const char *mbedtls_cipher_get_name( const mbedtls_cipher_context_t *ctx ) { @@ -416,13 +439,13 @@ static inline const char *mbedtls_cipher_get_name( const mbedtls_cipher_context_ } /** - * \brief Returns the key length of the cipher. + * \brief This function returns the key length of the cipher. * - * \param ctx cipher's context. Must have been initialised. + * \param ctx The context of the cipher. Must be initialized. * - * \return cipher's key length, in bits, or - * MBEDTLS_KEY_LENGTH_NONE if ctx has not been - * initialised. + * \return The key length of the cipher in bits, or + * #MBEDTLS_KEY_LENGTH_NONE if ctx \p has not been + * initialized. */ static inline int mbedtls_cipher_get_key_bitlen( const mbedtls_cipher_context_t *ctx ) { @@ -433,13 +456,13 @@ static inline int mbedtls_cipher_get_key_bitlen( const mbedtls_cipher_context_t } /** - * \brief Returns the operation of the given cipher. + * \brief This function returns the operation of the given cipher. * - * \param ctx cipher's context. Must have been initialised. + * \param ctx The context of the cipher. Must be initialized. * - * \return operation (MBEDTLS_ENCRYPT or MBEDTLS_DECRYPT), - * or MBEDTLS_OPERATION_NONE if ctx has not been - * initialised. + * \return The type of operation: #MBEDTLS_ENCRYPT or + * #MBEDTLS_DECRYPT, or #MBEDTLS_OPERATION_NONE if \p ctx + * has not been initialized. */ static inline mbedtls_operation_t mbedtls_cipher_get_operation( const mbedtls_cipher_context_t *ctx ) { @@ -450,18 +473,18 @@ static inline mbedtls_operation_t mbedtls_cipher_get_operation( const mbedtls_ci } /** - * \brief Set the key to use with the given context. + * \brief This function sets the key to use with the given context. * - * \param ctx generic cipher context. May not be NULL. Must have been - * initialised using cipher_context_from_type or - * cipher_context_from_string. + * \param ctx The generic cipher context. May not be NULL. Must have + * been initialized using mbedtls_cipher_info_from_type() + * or mbedtls_cipher_info_from_string(). * \param key The key to use. - * \param key_bitlen key length to use, in bits. - * \param operation Operation that the key will be used for, either - * MBEDTLS_ENCRYPT or MBEDTLS_DECRYPT. + * \param key_bitlen The key length to use, in bits. + * \param operation The operation that the key will be used for: + * #MBEDTLS_ENCRYPT or #MBEDTLS_DECRYPT. * - * \returns 0 on success, MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if - * parameter verification fails or a cipher specific + * \returns \c 0 on success, #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if + * parameter verification fails, or a cipher-specific * error code. */ int mbedtls_cipher_setkey( mbedtls_cipher_context_t *ctx, const unsigned char *key, @@ -469,170 +492,176 @@ int mbedtls_cipher_setkey( mbedtls_cipher_context_t *ctx, const unsigned char *k #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING) /** - * \brief Set padding mode, for cipher modes that use padding. - * (Default: PKCS7 padding.) + * \brief This function sets the padding mode, for cipher modes + * that use padding. * - * \param ctx generic cipher context - * \param mode padding mode + * The default passing mode is PKCS7 padding. * - * \returns 0 on success, MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE - * if selected padding mode is not supported, or - * MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if the cipher mode + * \param ctx The generic cipher context. + * \param mode The padding mode. + * + * \returns \c 0 on success, #MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE + * if the selected padding mode is not supported, or + * #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if the cipher mode * does not support padding. */ int mbedtls_cipher_set_padding_mode( mbedtls_cipher_context_t *ctx, mbedtls_cipher_padding_t mode ); #endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */ /** - * \brief Set the initialization vector (IV) or nonce + * \brief This function sets the initialization vector (IV) + * or nonce. * - * \param ctx generic cipher context - * \param iv IV to use (or NONCE_COUNTER for CTR-mode ciphers) - * \param iv_len IV length for ciphers with variable-size IV; - * discarded by ciphers with fixed-size IV. + * \param ctx The generic cipher context. + * \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers. + * \param iv_len The IV length for ciphers with variable-size IV. + * This parameter is discarded by ciphers with fixed-size IV. * - * \returns 0 on success, or MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA + * \returns \c 0 on success, or #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA * - * \note Some ciphers don't use IVs nor NONCE. For these - * ciphers, this function has no effect. + * \note Some ciphers do not use IVs nor nonce. For these + * ciphers, this function has no effect. */ int mbedtls_cipher_set_iv( mbedtls_cipher_context_t *ctx, const unsigned char *iv, size_t iv_len ); /** - * \brief Finish preparation of the given context + * \brief This function resets the cipher state. * - * \param ctx generic cipher context + * \param ctx The generic cipher context. * - * \returns 0 on success, MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA - * if parameter verification fails. + * \returns \c 0 on success, #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA + * if parameter verification fails. */ int mbedtls_cipher_reset( mbedtls_cipher_context_t *ctx ); #if defined(MBEDTLS_GCM_C) /** - * \brief Add additional data (for AEAD ciphers). - * Currently only supported with GCM. - * Must be called exactly once, after mbedtls_cipher_reset(). + * \brief This function adds additional data for AEAD ciphers. + * Only supported with GCM. Must be called + * exactly once, after mbedtls_cipher_reset(). * - * \param ctx generic cipher context - * \param ad Additional data to use. - * \param ad_len Length of ad. + * \param ctx The generic cipher context. + * \param ad The additional data to use. + * \param ad_len the Length of \p ad. * - * \return 0 on success, or a specific error code. + * \return \c 0 on success, or a specific error code on failure. */ int mbedtls_cipher_update_ad( mbedtls_cipher_context_t *ctx, const unsigned char *ad, size_t ad_len ); #endif /* MBEDTLS_GCM_C */ /** - * \brief Generic cipher update function. Encrypts/decrypts - * using the given cipher context. Writes as many block - * size'd blocks of data as possible to output. Any data - * that cannot be written immediately will either be added - * to the next block, or flushed when cipher_final is - * called. - * Exception: for MBEDTLS_MODE_ECB, expects single block - * in size (e.g. 16 bytes for AES) + * \brief The generic cipher update function. It encrypts or + * decrypts using the given cipher context. Writes as + * many block-sized blocks of data as possible to output. + * Any data that cannot be written immediately is either + * added to the next block, or flushed when + * mbedtls_cipher_finish() is called. + * Exception: For MBEDTLS_MODE_ECB, expects a single block + * in size. For example, 16 Bytes for AES. * - * \param ctx generic cipher context - * \param input buffer holding the input data - * \param ilen length of the input data - * \param output buffer for the output data. Should be able to hold at - * least ilen + block_size. Cannot be the same buffer as - * input! - * \param olen length of the output data, will be filled with the - * actual number of bytes written. + * \param ctx The generic cipher context. + * \param input The buffer holding the input data. + * \param ilen The length of the input data. + * \param output The buffer for the output data. Must be able to hold at + * least \p ilen + block_size. Must not be the same buffer + * as input. + * \param olen The length of the output data, to be updated with the + * actual number of Bytes written. * - * \returns 0 on success, MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if + * \returns \c 0 on success, #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if * parameter verification fails, - * MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE on an - * unsupported mode for a cipher or a cipher specific + * #MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE on an + * unsupported mode for a cipher, or a cipher-specific * error code. * * \note If the underlying cipher is GCM, all calls to this - * function, except the last one before mbedtls_cipher_finish(), - * must have ilen a multiple of the block size. + * function, except the last one before + * mbedtls_cipher_finish(). Must have \p ilen as a + * multiple of the block_size. */ int mbedtls_cipher_update( mbedtls_cipher_context_t *ctx, const unsigned char *input, size_t ilen, unsigned char *output, size_t *olen ); /** - * \brief Generic cipher finalisation function. If data still - * needs to be flushed from an incomplete block, data - * contained within it will be padded with the size of - * the last block, and written to the output buffer. + * \brief The generic cipher finalization function. If data still + * needs to be flushed from an incomplete block, the data + * contained in it is padded to the size of + * the last block, and written to the \p output buffer. * - * \param ctx Generic cipher context - * \param output buffer to write data to. Needs block_size available. - * \param olen length of the data written to the output buffer. + * \param ctx The generic cipher context. + * \param output The buffer to write data to. Needs block_size available. + * \param olen The length of the data written to the \p output buffer. * - * \returns 0 on success, MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if + * \returns \c 0 on success, #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if * parameter verification fails, - * MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED if decryption + * #MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED if decryption * expected a full block but was not provided one, - * MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding - * while decrypting or a cipher specific error code. + * #MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding + * while decrypting, or a cipher-specific error code + * on failure for any other reason. */ int mbedtls_cipher_finish( mbedtls_cipher_context_t *ctx, unsigned char *output, size_t *olen ); #if defined(MBEDTLS_GCM_C) /** - * \brief Write tag for AEAD ciphers. - * Currently only supported with GCM. + * \brief This function writes a tag for AEAD ciphers. + * Only supported with GCM. * Must be called after mbedtls_cipher_finish(). * - * \param ctx Generic cipher context - * \param tag buffer to write the tag - * \param tag_len Length of the tag to write + * \param ctx The generic cipher context. + * \param tag The buffer to write the tag to. + * \param tag_len The length of the tag to write. * - * \return 0 on success, or a specific error code. + * \return \c 0 on success, or a specific error code on failure. */ int mbedtls_cipher_write_tag( mbedtls_cipher_context_t *ctx, unsigned char *tag, size_t tag_len ); /** - * \brief Check tag for AEAD ciphers. - * Currently only supported with GCM. + * \brief This function checks the tag for AEAD ciphers. + * Only supported with GCM. * Must be called after mbedtls_cipher_finish(). * - * \param ctx Generic cipher context - * \param tag Buffer holding the tag - * \param tag_len Length of the tag to check + * \param ctx The generic cipher context. + * \param tag The buffer holding the tag. + * \param tag_len The length of the tag to check. * - * \return 0 on success, or a specific error code. + * \return \c 0 on success, or a specific error code on failure. */ int mbedtls_cipher_check_tag( mbedtls_cipher_context_t *ctx, const unsigned char *tag, size_t tag_len ); #endif /* MBEDTLS_GCM_C */ /** - * \brief Generic all-in-one encryption/decryption - * (for all ciphers except AEAD constructs). + * \brief The generic all-in-one encryption/decryption function, + * for all ciphers except AEAD constructs. * - * \param ctx generic cipher context - * \param iv IV to use (or NONCE_COUNTER for CTR-mode ciphers) - * \param iv_len IV length for ciphers with variable-size IV; - * discarded by ciphers with fixed-size IV. - * \param input buffer holding the input data - * \param ilen length of the input data - * \param output buffer for the output data. Should be able to hold at - * least ilen + block_size. Cannot be the same buffer as - * input! - * \param olen length of the output data, will be filled with the - * actual number of bytes written. + * \param ctx The generic cipher context. + * \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers. + * \param iv_len The IV length for ciphers with variable-size IV. + * This parameter is discarded by ciphers with fixed-size + * IV. + * \param input The buffer holding the input data. + * \param ilen The length of the input data. + * \param output The buffer for the output data. Must be able to hold at + * least \p ilen + block_size. Must not be the same buffer + * as input. + * \param olen The length of the output data, to be updated with the + * actual number of Bytes written. * - * \note Some ciphers don't use IVs nor NONCE. For these - * ciphers, use iv = NULL and iv_len = 0. + * \note Some ciphers do not use IVs nor nonce. For these + * ciphers, use \p iv = NULL and \p iv_len = 0. * - * \returns 0 on success, or - * MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA, or - * MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED if decryption + * \returns \c 0 on success, or + * #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA, or + * #MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED if decryption * expected a full block but was not provided one, or - * MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding - * while decrypting, or - * a cipher specific error code. + * #MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding + * while decrypting, or a cipher-specific error code on + * failure for any other reason. */ int mbedtls_cipher_crypt( mbedtls_cipher_context_t *ctx, const unsigned char *iv, size_t iv_len, @@ -641,26 +670,26 @@ int mbedtls_cipher_crypt( mbedtls_cipher_context_t *ctx, #if defined(MBEDTLS_CIPHER_MODE_AEAD) /** - * \brief Generic autenticated encryption (AEAD ciphers). + * \brief The generic autenticated encryption (AEAD) function. * - * \param ctx generic cipher context - * \param iv IV to use (or NONCE_COUNTER for CTR-mode ciphers) - * \param iv_len IV length for ciphers with variable-size IV; - * discarded by ciphers with fixed-size IV. - * \param ad Additional data to authenticate. - * \param ad_len Length of ad. - * \param input buffer holding the input data - * \param ilen length of the input data - * \param output buffer for the output data. - * Should be able to hold at least ilen. - * \param olen length of the output data, will be filled with the - * actual number of bytes written. - * \param tag buffer for the authentication tag - * \param tag_len desired tag length + * \param ctx The generic cipher context. + * \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers. + * \param iv_len The IV length for ciphers with variable-size IV. + * This parameter is discarded by ciphers with fixed-size IV. + * \param ad The additional data to authenticate. + * \param ad_len The length of \p ad. + * \param input The buffer holding the input data. + * \param ilen The length of the input data. + * \param output The buffer for the output data. + * Must be able to hold at least \p ilen. + * \param olen The length of the output data, to be updated with the + * actual number of Bytes written. + * \param tag The buffer for the authentication tag. + * \param tag_len The desired length of the authentication tag. * - * \returns 0 on success, or - * MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA, or - * a cipher specific error code. + * \returns \c 0 on success, or + * #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA, or + * a cipher-specific error code. */ int mbedtls_cipher_auth_encrypt( mbedtls_cipher_context_t *ctx, const unsigned char *iv, size_t iv_len, @@ -670,31 +699,31 @@ int mbedtls_cipher_auth_encrypt( mbedtls_cipher_context_t *ctx, unsigned char *tag, size_t tag_len ); /** - * \brief Generic autenticated decryption (AEAD ciphers). + * \brief The generic autenticated decryption (AEAD) function. * - * \param ctx generic cipher context - * \param iv IV to use (or NONCE_COUNTER for CTR-mode ciphers) - * \param iv_len IV length for ciphers with variable-size IV; - * discarded by ciphers with fixed-size IV. - * \param ad Additional data to be authenticated. - * \param ad_len Length of ad. - * \param input buffer holding the input data - * \param ilen length of the input data - * \param output buffer for the output data. - * Should be able to hold at least ilen. - * \param olen length of the output data, will be filled with the - * actual number of bytes written. - * \param tag buffer holding the authentication tag - * \param tag_len length of the authentication tag + * \param ctx The generic cipher context. + * \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers. + * \param iv_len The IV length for ciphers with variable-size IV. + * This parameter is discarded by ciphers with fixed-size IV. + * \param ad The additional data to be authenticated. + * \param ad_len The length of \p ad. + * \param input The buffer holding the input data. + * \param ilen The length of the input data. + * \param output The buffer for the output data. + * Must be able to hold at least \p ilen. + * \param olen The length of the output data, to be updated with the + * actual number of Bytes written. + * \param tag The buffer holding the authentication tag. + * \param tag_len The length of the authentication tag. * - * \returns 0 on success, or - * MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA, or - * MBEDTLS_ERR_CIPHER_AUTH_FAILED if data isn't authentic, - * or a cipher specific error code. + * \returns \c 0 on success, or + * #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA, or + * #MBEDTLS_ERR_CIPHER_AUTH_FAILED if data is not authentic, + * or a cipher-specific error code on failure for any other reason. * * \note If the data is not authentic, then the output buffer - * is zeroed out to prevent the unauthentic plaintext to - * be used by mistake, making this interface safer. + * is zeroed out to prevent the unauthentic plaintext being + * used, making this interface safer. */ int mbedtls_cipher_auth_decrypt( mbedtls_cipher_context_t *ctx, const unsigned char *iv, size_t iv_len, diff --git a/library/error.c b/library/error.c index fdfa94ad0..f60268659 100644 --- a/library/error.c +++ b/library/error.c @@ -210,7 +210,7 @@ void mbedtls_strerror( int ret, char *buf, size_t buflen ) if( use_ret == -(MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE) ) mbedtls_snprintf( buf, buflen, "CIPHER - The selected feature is not available" ); if( use_ret == -(MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA) ) - mbedtls_snprintf( buf, buflen, "CIPHER - Bad input parameters to function" ); + mbedtls_snprintf( buf, buflen, "CIPHER - Bad input parameters" ); if( use_ret == -(MBEDTLS_ERR_CIPHER_ALLOC_FAILED) ) mbedtls_snprintf( buf, buflen, "CIPHER - Failed to allocate memory" ); if( use_ret == -(MBEDTLS_ERR_CIPHER_INVALID_PADDING) ) @@ -220,7 +220,7 @@ void mbedtls_strerror( int ret, char *buf, size_t buflen ) if( use_ret == -(MBEDTLS_ERR_CIPHER_AUTH_FAILED) ) mbedtls_snprintf( buf, buflen, "CIPHER - Authentication failed (for AEAD modes)" ); if( use_ret == -(MBEDTLS_ERR_CIPHER_INVALID_CONTEXT) ) - mbedtls_snprintf( buf, buflen, "CIPHER - The context is invalid, eg because it was free()ed" ); + mbedtls_snprintf( buf, buflen, "CIPHER - The context is invalid. For example, because it was freed" ); if( use_ret == -(MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED) ) mbedtls_snprintf( buf, buflen, "CIPHER - Cipher hardware accelerator failed" ); #endif /* MBEDTLS_CIPHER_C */