mbed TLS Build
Diff: include/mbedtls/cipher.h
- Revision:
- 0:cdf462088d13
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/include/mbedtls/cipher.h Thu Jan 05 00:18:44 2017 +0000 @@ -0,0 +1,709 @@ +/** + * \file cipher.h + * + * \brief Generic cipher wrapper. + * + * \author Adriaan de Jong <dejong@fox-it.com> + * + * Copyright (C) 2006-2015, ARM Limited, 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 <stddef.h> + +#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) +#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 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_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 + +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; + +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; + +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; + +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; + +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 cipher functions to be called in a generic way. + */ +typedef struct { + /** Full cipher identifier (e.g. MBEDTLS_CIPHER_AES_256_CBC) */ + mbedtls_cipher_type_t type; + + /** Cipher mode (e.g. 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) */ + unsigned int key_bitlen; + + /** Name of the cipher */ + const char * name; + + /** IV/NONCE size, in bytes. + * For cipher that accept many sizes: recommended size */ + unsigned int iv_size; + + /** Flags for variable IV size, variable key size, etc. */ + int flags; + + /** block size, in bytes */ + unsigned int block_size; + + /** 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 context's key has been initialised for */ + mbedtls_operation_t operation; + +#if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING) + /** Padding functions to use, if relevant for 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 */ + unsigned char unprocessed_data[MBEDTLS_MAX_BLOCK_LENGTH]; + + /** Number of bytes that still need processing */ + 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; + + /** 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 Returns the list of ciphers supported by the generic cipher module. + * + * \return a statically allocated array of ciphers, the last entry + * is 0. + */ +const int *mbedtls_cipher_list( void ); + +/** + * \brief Returns 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. + */ +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. + * + * \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. + */ +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. + * + * \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) + * + * \return the cipher information structure associated with the + * given cipher_type, 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) + */ +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. + */ +void mbedtls_cipher_free( mbedtls_cipher_context_t *ctx ); + +/** + * \brief Initialises and fills the cipher context structure with + * the appropriate values. + * + * \note Currently also clears structure. In future versions you + * will be required to call mbedtls_cipher_init() on the structure + * first. + * + * \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 + * cipher-specific context failed. + */ +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. + * + * \param ctx cipher's context. Must have been initialised. + * + * \return size of the cipher's blocks, or 0 if ctx has not been + * initialised. + */ +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 Returns the mode of operation for the cipher. + * (e.g. MBEDTLS_MODE_CBC) + * + * \param ctx cipher's context. Must have been initialised. + * + * \return mode of operation, or MBEDTLS_MODE_NONE if ctx + * has not been initialised. + */ +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 Returns the size of the cipher's IV/NONCE in bytes. + * + * \param ctx cipher's context. Must have been initialised. + * + * \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. + */ +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 Returns the type of the given cipher. + * + * \param ctx cipher's context. Must have been initialised. + * + * \return type of the cipher, or MBEDTLS_CIPHER_NONE if ctx has + * not been initialised. + */ +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 Returns the name of the given cipher, as a string. + * + * \param ctx cipher's context. Must have been initialised. + * + * \return name of the cipher, or NULL if ctx was not initialised. + */ +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 Returns the key length of the cipher. + * + * \param ctx cipher's context. Must have been initialised. + * + * \return cipher's key length, in bits, or + * MBEDTLS_KEY_LENGTH_NONE if ctx has not been + * initialised. + */ +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 Returns the operation of the given cipher. + * + * \param ctx cipher's context. Must have been initialised. + * + * \return operation (MBEDTLS_ENCRYPT or MBEDTLS_DECRYPT), + * or MBEDTLS_OPERATION_NONE if ctx has not been + * initialised. + */ +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 Set 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 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. + * + * \returns 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 Set padding mode, for cipher modes that use padding. + * (Default: PKCS7 padding.) + * + * \param ctx generic cipher context + * \param mode padding mode + * + * \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 + * 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 + * + * \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. + * + * \returns 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. + */ +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 + * + * \param ctx generic cipher context + * + * \returns 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(). + * + * \param ctx generic cipher context + * \param ad Additional data to use. + * \param ad_len Length of ad. + * + * \return 0 on success, or a specific error code. + */ +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) + * + * \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. + * + * \returns 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 ilen 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. + * + * \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. + * + * \returns 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. + */ +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. + * 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 + * + * \return 0 on success, or a specific error code. + */ +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. + * 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 + * + * \return 0 on success, or a specific error code. + */ +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). + * + * \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. + * + * \note Some ciphers don't use IVs nor NONCE. For these + * ciphers, use iv = NULL and iv_len = 0. + * + * \returns 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. + */ +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 Generic autenticated encryption (AEAD ciphers). + * + * \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 + * + * \returns 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 Generic autenticated decryption (AEAD ciphers). + * + * \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 + * + * \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. + * + * \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. + */ +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 */