/** * \file cmac.h * * \brief The Cipher-based Message Authentication Code (CMAC) Mode for * Authentication. */ /* * Copyright (C) 2015-2018, 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_CMAC_H #define MBEDTLS_CMAC_H #include "mbedtls/cipher.h" #ifdef __cplusplus extern "C" { #endif #define MBEDTLS_ERR_CMAC_HW_ACCEL_FAILED -0x007A /**< CMAC hardware accelerator failed. */ #define MBEDTLS_AES_BLOCK_SIZE 16 #define MBEDTLS_DES3_BLOCK_SIZE 8 #if defined(MBEDTLS_AES_C) #define MBEDTLS_CIPHER_BLKSIZE_MAX 16 /* The longest block used by CMAC is that of AES. */ #else #define MBEDTLS_CIPHER_BLKSIZE_MAX 8 /* The longest block used by CMAC is that of 3DES. */ #endif #if !defined(MBEDTLS_CMAC_ALT) /** * The CMAC context structure. */ struct mbedtls_cmac_context_t { /** The internal state of the CMAC algorithm. */ unsigned char state[MBEDTLS_CIPHER_BLKSIZE_MAX]; /** Unprocessed data - either data that was not block aligned and is still * pending processing, or the final block. */ unsigned char unprocessed_block[MBEDTLS_CIPHER_BLKSIZE_MAX]; /** The length of data pending processing. */ size_t unprocessed_len; }; /** * \brief This function sets the CMAC key, and prepares to authenticate * the input data. * Must be called with an initialized cipher context. * * \param ctx The cipher context used for the CMAC operation, initialized * as one of the following types: * \param key The CMAC key. * \param keybits The length of the CMAC key in bits. * Must be supported by the cipher. * * \return \c 0 on success, or a cipher-specific error code. */ int mbedtls_cipher_cmac_starts( mbedtls_cipher_context_t *ctx, const unsigned char *key, size_t keybits ); /** * \brief This function feeds an input buffer into an ongoing CMAC * computation. * * It is called between mbedtls_cipher_cmac_starts() or * mbedtls_cipher_cmac_reset(), and mbedtls_cipher_cmac_finish(). * Can be called repeatedly. * * \param ctx The cipher context used for the CMAC operation. * \param input The buffer holding the input data. * \param ilen The length of the input data. * * \returns \c 0 on success, or #MBEDTLS_ERR_MD_BAD_INPUT_DATA * if parameter verification fails. */ int mbedtls_cipher_cmac_update( mbedtls_cipher_context_t *ctx, const unsigned char *input, size_t ilen ); /** * \brief This function finishes the CMAC operation, and writes * the result to the output buffer. * * It is called after mbedtls_cipher_cmac_update(). * It can be followed by mbedtls_cipher_cmac_reset() and * mbedtls_cipher_cmac_update(), or mbedtls_cipher_free(). * * \param ctx The cipher context used for the CMAC operation. * \param output The output buffer for the CMAC checksum result. * * \returns \c 0 on success, or #MBEDTLS_ERR_MD_BAD_INPUT_DATA * if parameter verification fails. */ int mbedtls_cipher_cmac_finish( mbedtls_cipher_context_t *ctx, unsigned char *output ); /** * \brief This function prepares the authentication of another * message with the same key as the previous CMAC * operation. * * It is called after mbedtls_cipher_cmac_finish() * and before mbedtls_cipher_cmac_update(). * * \param ctx The cipher context used for the CMAC operation. * * \returns \c 0 on success, or #MBEDTLS_ERR_MD_BAD_INPUT_DATA * if parameter verification fails. */ int mbedtls_cipher_cmac_reset( mbedtls_cipher_context_t *ctx ); /** * \brief This function calculates the full generic CMAC * on the input buffer with the provided key. * * The function allocates the context, performs the * calculation, and frees the context. * * The CMAC result is calculated as * output = generic CMAC(cmac key, input buffer). * * * \param cipher_info The cipher information. * \param key The CMAC key. * \param keylen The length of the CMAC key in bits. * \param input The buffer holding the input data. * \param ilen The length of the input data. * \param output The buffer for the generic CMAC result. * * \returns \c 0 on success, or #MBEDTLS_ERR_MD_BAD_INPUT_DATA * if parameter verification fails. */ int mbedtls_cipher_cmac( const mbedtls_cipher_info_t *cipher_info, const unsigned char *key, size_t keylen, const unsigned char *input, size_t ilen, unsigned char *output ); #if defined(MBEDTLS_AES_C) /** * \brief This function implements the AES-CMAC-PRF-128 pseudorandom * function, as defined in * RFC-4615: The Advanced Encryption Standard-Cipher-based * Message Authentication Code-Pseudo-Random Function-128 * (AES-CMAC-PRF-128) Algorithm for the Internet Key * Exchange Protocol (IKE). * * \param key The key to use. * \param key_len The key length in Bytes. * \param input The buffer holding the input data. * \param in_len The length of the input data in Bytes. * \param output The buffer holding the generated 16 Bytes of * pseudorandom output. * * \return \c 0 on success. */ int mbedtls_aes_cmac_prf_128( const unsigned char *key, size_t key_len, const unsigned char *input, size_t in_len, unsigned char output[16] ); #endif /* MBEDTLS_AES_C */ #ifdef __cplusplus } #endif #else /* !MBEDTLS_CMAC_ALT */ #include "cmac_alt.h" #endif /* !MBEDTLS_CMAC_ALT */ #ifdef __cplusplus extern "C" { #endif #if defined(MBEDTLS_SELF_TEST) && ( defined(MBEDTLS_AES_C) || defined(MBEDTLS_DES_C) ) /** * \brief The CMAC checkup routine. * * \return \c 0 on success, or \c 1 on failure. */ int mbedtls_cmac_self_test( int verbose ); #endif /* MBEDTLS_SELF_TEST && ( MBEDTLS_AES_C || MBEDTLS_DES_C ) */ #ifdef __cplusplus } #endif #endif /* MBEDTLS_CMAC_H */