/** * \file cipher.h * * \brief The generic cipher wrapper. * * \author Adriaan de Jong */ /* * 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 * not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * 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) */ #ifndef MBEDTLS_CIPHER_H #define MBEDTLS_CIPHER_H #if !defined(MBEDTLS_CONFIG_FILE) #include "config.h" #else #include MBEDTLS_CONFIG_FILE #endif #include #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CCM_C) #define MBEDTLS_CIPHER_MODE_AEAD #endif #if defined(MBEDTLS_CIPHER_MODE_CBC) #define MBEDTLS_CIPHER_MODE_WITH_PADDING #endif #if defined(MBEDTLS_ARC4_C) || defined(MBEDTLS_CIPHER_NULL_CIPHER) #define MBEDTLS_CIPHER_MODE_STREAM #endif #if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \ !defined(inline) && !defined(__cplusplus) #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. */ #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. */ #ifdef __cplusplus extern "C" { #endif /** * \brief An enumeration of supported ciphers. * * \warning ARC4 and DES are considered weak ciphers and their use * constitutes a security risk. We recommend considering stronger * ciphers instead. */ typedef enum { MBEDTLS_CIPHER_ID_NONE = 0, MBEDTLS_CIPHER_ID_NULL, MBEDTLS_CIPHER_ID_AES, MBEDTLS_CIPHER_ID_DES, MBEDTLS_CIPHER_ID_3DES, MBEDTLS_CIPHER_ID_CAMELLIA, MBEDTLS_CIPHER_ID_BLOWFISH, MBEDTLS_CIPHER_ID_ARC4, } mbedtls_cipher_id_t; /** * \brief An enumeration of supported (cipher, mode) pairs. * * \warning ARC4 and DES are considered weak ciphers and their use * constitutes a security risk. We recommend considering stronger * ciphers instead. */ typedef enum { MBEDTLS_CIPHER_NONE = 0, MBEDTLS_CIPHER_NULL, MBEDTLS_CIPHER_AES_128_ECB, MBEDTLS_CIPHER_AES_192_ECB, MBEDTLS_CIPHER_AES_256_ECB, MBEDTLS_CIPHER_AES_128_CBC, MBEDTLS_CIPHER_AES_192_CBC, MBEDTLS_CIPHER_AES_256_CBC, MBEDTLS_CIPHER_AES_128_CFB128, MBEDTLS_CIPHER_AES_192_CFB128, MBEDTLS_CIPHER_AES_256_CFB128, MBEDTLS_CIPHER_AES_128_CTR, MBEDTLS_CIPHER_AES_192_CTR, MBEDTLS_CIPHER_AES_256_CTR, MBEDTLS_CIPHER_AES_128_GCM, MBEDTLS_CIPHER_AES_192_GCM, MBEDTLS_CIPHER_AES_256_GCM, MBEDTLS_CIPHER_CAMELLIA_128_ECB, MBEDTLS_CIPHER_CAMELLIA_192_ECB, MBEDTLS_CIPHER_CAMELLIA_256_ECB, MBEDTLS_CIPHER_CAMELLIA_128_CBC, MBEDTLS_CIPHER_CAMELLIA_192_CBC, MBEDTLS_CIPHER_CAMELLIA_256_CBC, MBEDTLS_CIPHER_CAMELLIA_128_CFB128, MBEDTLS_CIPHER_CAMELLIA_192_CFB128, MBEDTLS_CIPHER_CAMELLIA_256_CFB128, MBEDTLS_CIPHER_CAMELLIA_128_CTR, MBEDTLS_CIPHER_CAMELLIA_192_CTR, MBEDTLS_CIPHER_CAMELLIA_256_CTR, MBEDTLS_CIPHER_CAMELLIA_128_GCM, MBEDTLS_CIPHER_CAMELLIA_192_GCM, MBEDTLS_CIPHER_CAMELLIA_256_GCM, MBEDTLS_CIPHER_DES_ECB, MBEDTLS_CIPHER_DES_CBC, MBEDTLS_CIPHER_DES_EDE_ECB, MBEDTLS_CIPHER_DES_EDE_CBC, MBEDTLS_CIPHER_DES_EDE3_ECB, MBEDTLS_CIPHER_DES_EDE3_CBC, MBEDTLS_CIPHER_BLOWFISH_ECB, MBEDTLS_CIPHER_BLOWFISH_CBC, MBEDTLS_CIPHER_BLOWFISH_CFB64, MBEDTLS_CIPHER_BLOWFISH_CTR, MBEDTLS_CIPHER_ARC4_128, MBEDTLS_CIPHER_AES_128_CCM, MBEDTLS_CIPHER_AES_192_CCM, MBEDTLS_CIPHER_AES_256_CCM, MBEDTLS_CIPHER_CAMELLIA_128_CCM, MBEDTLS_CIPHER_CAMELLIA_192_CCM, MBEDTLS_CIPHER_CAMELLIA_256_CCM, } mbedtls_cipher_type_t; /** Supported cipher modes. */ typedef enum { MBEDTLS_MODE_NONE = 0, MBEDTLS_MODE_ECB, MBEDTLS_MODE_CBC, MBEDTLS_MODE_CFB, MBEDTLS_MODE_OFB, /* Unused! */ MBEDTLS_MODE_CTR, MBEDTLS_MODE_GCM, MBEDTLS_MODE_STREAM, 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_cipher_padding_t; /** Type of operation. */ typedef enum { MBEDTLS_OPERATION_NONE = -1, MBEDTLS_DECRYPT = 0, MBEDTLS_ENCRYPT, } mbedtls_operation_t; enum { /** Undefined key length. */ MBEDTLS_KEY_LENGTH_NONE = 0, /** 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. */ MBEDTLS_KEY_LENGTH_DES_EDE = 128, /** 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. */ #define MBEDTLS_MAX_IV_LENGTH 16 /** Maximum block size of any cipher, in Bytes. */ #define MBEDTLS_MAX_BLOCK_LENGTH 16 /** * Base cipher information (opaque struct). */ typedef struct mbedtls_cipher_base_t mbedtls_cipher_base_t; /** * CMAC context (opaque struct). */ typedef struct mbedtls_cmac_context_t mbedtls_cmac_context_t; /** * Cipher information. Allows calling cipher functions * in a generic way. */ typedef struct { /** Full cipher identifier. For example, * MBEDTLS_CIPHER_AES_256_CBC. */ mbedtls_cipher_type_t type; /** The cipher mode. For example, MBEDTLS_MODE_CBC. */ mbedtls_cipher_mode_t mode; /** 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. */ const char * name; /** IV or nonce size, in Bytes. * For ciphers that accept variable IV sizes, * this is the recommended size. */ unsigned int iv_size; /** Flags to set. For example, if the cipher supports variable IV sizes or variable key sizes. */ int flags; /** The block size, in Bytes. */ unsigned int block_size; /** Struct for base cipher information and functions. */ const mbedtls_cipher_base_t *base; } mbedtls_cipher_info_t; /** * Generic cipher context. */ typedef struct { /** Information about the associated cipher. */ const mbedtls_cipher_info_t *cipher_info; /** Key length to use. */ int key_bitlen; /** 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 * 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 input that has not been processed yet. */ unsigned char unprocessed_data[MBEDTLS_MAX_BLOCK_LENGTH]; /** Number of Bytes that have not been processed yet. */ size_t unprocessed_len; /** 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. */ size_t iv_size; /** The cipher-specific context. */ void *cipher_ctx; #if defined(MBEDTLS_CMAC_C) /** CMAC-specific context. */ mbedtls_cmac_context_t *cmac_ctx; #endif } mbedtls_cipher_context_t; /** * \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 zero. */ const int *mbedtls_cipher_list( void ); /** * \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 \p cipher_name, or NULL if not found. */ const mbedtls_cipher_info_t *mbedtls_cipher_info_from_string( const char *cipher_name ); /** * \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 \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 This function retrieves the cipher-information * structure associated with the given cipher ID, * key size and mode. * * \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 \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 This function initializes a \p cipher_context as NONE. */ void mbedtls_cipher_init( mbedtls_cipher_context_t *ctx ); /** * \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 This function initializes and fills the cipher-context * structure with the appropriate values. It also clears * the structure. * * \param ctx The context to initialize. May not be NULL. * \param cipher_info The cipher to use. * * \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 This function returns the block size of the given cipher. * * \param ctx The context of the cipher. Must be initialized. * * \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 ) { if( NULL == ctx || NULL == ctx->cipher_info ) return 0; return ctx->cipher_info->block_size; } /** * \brief This function returns the mode of operation for * the cipher. For example, MBEDTLS_MODE_CBC. * * \param ctx The context of the cipher. Must be initialized. * * \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 ) { if( NULL == ctx || NULL == ctx->cipher_info ) return MBEDTLS_MODE_NONE; return ctx->cipher_info->mode; } /** * \brief This function returns the size of the IV or nonce * of the cipher, in Bytes. * * \param ctx The context of the cipher. Must be initialized. * * \return */ static inline int mbedtls_cipher_get_iv_size( const mbedtls_cipher_context_t *ctx ) { if( NULL == ctx || NULL == ctx->cipher_info ) return 0; if( ctx->iv_size != 0 ) return (int) ctx->iv_size; return (int) ctx->cipher_info->iv_size; } /** * \brief This function returns the type of the given cipher. * * \param ctx The context of the cipher. Must be initialized. * * \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 ) { if( NULL == ctx || NULL == ctx->cipher_info ) return MBEDTLS_CIPHER_NONE; return ctx->cipher_info->type; } /** * \brief This function returns the name of the given cipher * as a string. * * \param ctx The context of the cipher. Must be initialized. * * \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 ) { if( NULL == ctx || NULL == ctx->cipher_info ) return 0; return ctx->cipher_info->name; } /** * \brief This function returns the key length of the cipher. * * \param ctx The context of the cipher. Must be initialized. * * \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 ) { if( NULL == ctx || NULL == ctx->cipher_info ) return MBEDTLS_KEY_LENGTH_NONE; return (int) ctx->cipher_info->key_bitlen; } /** * \brief This function returns the operation of the given cipher. * * \param ctx The context of the cipher. Must be initialized. * * \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 ) { if( NULL == ctx || NULL == ctx->cipher_info ) return MBEDTLS_OPERATION_NONE; return ctx->operation; } /** * \brief This function sets the key to use with the given context. * * \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 The key length to use, in bits. * \param operation The operation that the key will be used for: * #MBEDTLS_ENCRYPT or #MBEDTLS_DECRYPT. * * \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, int key_bitlen, const mbedtls_operation_t operation ); #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING) /** * \brief This function sets the padding mode, for cipher modes * that use padding. * * The default passing mode is PKCS7 padding. * * \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 This function sets the initialization vector (IV) * or nonce. * * \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 \c 0 on success, or #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA * * \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 This function resets the cipher state. * * \param ctx The generic cipher context. * * \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 This function adds additional data for AEAD ciphers. * Only supported with GCM. Must be called * exactly once, after mbedtls_cipher_reset(). * * \param ctx The generic cipher context. * \param ad The additional data to use. * \param ad_len the Length of \p ad. * * \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 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 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 \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 * error code. * * \note If the underlying cipher is GCM, all calls to this * 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 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 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 \c 0 on success, #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if * parameter verification fails, * #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 * 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 This function writes a tag for AEAD ciphers. * Only supported with GCM. * Must be called after mbedtls_cipher_finish(). * * \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 \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 This function checks the tag for AEAD ciphers. * Only supported with GCM. * Must be called after mbedtls_cipher_finish(). * * \param ctx The generic cipher context. * \param tag The buffer holding the tag. * \param tag_len The length of the tag to check. * * \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 The generic all-in-one encryption/decryption function, * for all ciphers except AEAD constructs. * * \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 do not use IVs nor nonce. For these * ciphers, use \p iv = NULL and \p iv_len = 0. * * \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 on * failure for any other reason. */ int mbedtls_cipher_crypt( mbedtls_cipher_context_t *ctx, const unsigned char *iv, size_t iv_len, const unsigned char *input, size_t ilen, unsigned char *output, size_t *olen ); #if defined(MBEDTLS_CIPHER_MODE_AEAD) /** * \brief The generic autenticated encryption (AEAD) function. * * \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 \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, const unsigned char *ad, size_t ad_len, const unsigned char *input, size_t ilen, unsigned char *output, size_t *olen, unsigned char *tag, size_t tag_len ); /** * \brief The generic autenticated decryption (AEAD) function. * * \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 \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 being * used, making this interface safer. */ int mbedtls_cipher_auth_decrypt( mbedtls_cipher_context_t *ctx, const unsigned char *iv, size_t iv_len, const unsigned char *ad, size_t ad_len, const unsigned char *input, size_t ilen, unsigned char *output, size_t *olen, const unsigned char *tag, size_t tag_len ); #endif /* MBEDTLS_CIPHER_MODE_AEAD */ #ifdef __cplusplus } #endif #endif /* MBEDTLS_CIPHER_H */