1 /** 2 * \file cmac.h 3 * 4 * \brief This file contains CMAC definitions and functions. 5 * 6 * The Cipher-based Message Authentication Code (CMAC) Mode for 7 * Authentication is defined in <em>RFC-4493: The AES-CMAC Algorithm</em>. 8 */ 9 /* 10 * Copyright (C) 2015-2018, Arm Limited (or its affiliates), All Rights Reserved 11 * SPDX-License-Identifier: Apache-2.0 12 * 13 * Licensed under the Apache License, Version 2.0 (the "License"); you may 14 * not use this file except in compliance with the License. 15 * You may obtain a copy of the License at 16 * 17 * http://www.apache.org/licenses/LICENSE-2.0 18 * 19 * Unless required by applicable law or agreed to in writing, software 20 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 21 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 22 * See the License for the specific language governing permissions and 23 * limitations under the License. 24 * 25 * This file is part of Mbed TLS (https://tls.mbed.org) 26 */ 27 28 #ifndef MBEDTLS_CMAC_H 29 #define MBEDTLS_CMAC_H 30 31 #include "cipher.h" 32 33 #ifdef __cplusplus 34 extern "C" { 35 #endif 36 37 /* MBEDTLS_ERR_CMAC_HW_ACCEL_FAILED is deprecated and should not be used. */ 38 #define MBEDTLS_ERR_CMAC_HW_ACCEL_FAILED -0x007A /**< CMAC hardware accelerator failed. */ 39 40 #define MBEDTLS_AES_BLOCK_SIZE 16 41 #define MBEDTLS_DES3_BLOCK_SIZE 8 42 43 #if defined(MBEDTLS_AES_C) 44 #define MBEDTLS_CIPHER_BLKSIZE_MAX 16 /**< The longest block used by CMAC is that of AES. */ 45 #else 46 #define MBEDTLS_CIPHER_BLKSIZE_MAX 8 /**< The longest block used by CMAC is that of 3DES. */ 47 #endif 48 49 #if !defined(MBEDTLS_CMAC_ALT) 50 51 /** 52 * The CMAC context structure. 53 */ 54 struct mbedtls_cmac_context_t 55 { 56 /** The internal state of the CMAC algorithm. */ 57 unsigned char state[MBEDTLS_CIPHER_BLKSIZE_MAX]; 58 59 /** Unprocessed data - either data that was not block aligned and is still 60 * pending processing, or the final block. */ 61 unsigned char unprocessed_block[MBEDTLS_CIPHER_BLKSIZE_MAX]; 62 63 /** The length of data pending processing. */ 64 size_t unprocessed_len; 65 }; 66 67 #else /* !MBEDTLS_CMAC_ALT */ 68 #include "cmac_alt.h" 69 #endif /* !MBEDTLS_CMAC_ALT */ 70 71 /** 72 * \brief This function sets the CMAC key, and prepares to authenticate 73 * the input data. 74 * Must be called with an initialized cipher context. 75 * 76 * \param ctx The cipher context used for the CMAC operation, initialized 77 * as one of the following types: MBEDTLS_CIPHER_AES_128_ECB, 78 * MBEDTLS_CIPHER_AES_192_ECB, MBEDTLS_CIPHER_AES_256_ECB, 79 * or MBEDTLS_CIPHER_DES_EDE3_ECB. 80 * \param key The CMAC key. 81 * \param keybits The length of the CMAC key in bits. 82 * Must be supported by the cipher. 83 * 84 * \return \c 0 on success. 85 * \return A cipher-specific error code on failure. 86 */ 87 int mbedtls_cipher_cmac_starts( mbedtls_cipher_context_t *ctx, 88 const unsigned char *key, size_t keybits ); 89 90 /** 91 * \brief This function feeds an input buffer into an ongoing CMAC 92 * computation. 93 * 94 * It is called between mbedtls_cipher_cmac_starts() or 95 * mbedtls_cipher_cmac_reset(), and mbedtls_cipher_cmac_finish(). 96 * Can be called repeatedly. 97 * 98 * \param ctx The cipher context used for the CMAC operation. 99 * \param input The buffer holding the input data. 100 * \param ilen The length of the input data. 101 * 102 * \return \c 0 on success. 103 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA 104 * if parameter verification fails. 105 */ 106 int mbedtls_cipher_cmac_update( mbedtls_cipher_context_t *ctx, 107 const unsigned char *input, size_t ilen ); 108 109 /** 110 * \brief This function finishes the CMAC operation, and writes 111 * the result to the output buffer. 112 * 113 * It is called after mbedtls_cipher_cmac_update(). 114 * It can be followed by mbedtls_cipher_cmac_reset() and 115 * mbedtls_cipher_cmac_update(), or mbedtls_cipher_free(). 116 * 117 * \param ctx The cipher context used for the CMAC operation. 118 * \param output The output buffer for the CMAC checksum result. 119 * 120 * \return \c 0 on success. 121 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA 122 * if parameter verification fails. 123 */ 124 int mbedtls_cipher_cmac_finish( mbedtls_cipher_context_t *ctx, 125 unsigned char *output ); 126 127 /** 128 * \brief This function prepares the authentication of another 129 * message with the same key as the previous CMAC 130 * operation. 131 * 132 * It is called after mbedtls_cipher_cmac_finish() 133 * and before mbedtls_cipher_cmac_update(). 134 * 135 * \param ctx The cipher context used for the CMAC operation. 136 * 137 * \return \c 0 on success. 138 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA 139 * if parameter verification fails. 140 */ 141 int mbedtls_cipher_cmac_reset( mbedtls_cipher_context_t *ctx ); 142 143 /** 144 * \brief This function calculates the full generic CMAC 145 * on the input buffer with the provided key. 146 * 147 * The function allocates the context, performs the 148 * calculation, and frees the context. 149 * 150 * The CMAC result is calculated as 151 * output = generic CMAC(cmac key, input buffer). 152 * 153 * 154 * \param cipher_info The cipher information. 155 * \param key The CMAC key. 156 * \param keylen The length of the CMAC key in bits. 157 * \param input The buffer holding the input data. 158 * \param ilen The length of the input data. 159 * \param output The buffer for the generic CMAC result. 160 * 161 * \return \c 0 on success. 162 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA 163 * if parameter verification fails. 164 */ 165 int mbedtls_cipher_cmac( const mbedtls_cipher_info_t *cipher_info, 166 const unsigned char *key, size_t keylen, 167 const unsigned char *input, size_t ilen, 168 unsigned char *output ); 169 170 #if defined(MBEDTLS_AES_C) 171 /** 172 * \brief This function implements the AES-CMAC-PRF-128 pseudorandom 173 * function, as defined in 174 * <em>RFC-4615: The Advanced Encryption Standard-Cipher-based 175 * Message Authentication Code-Pseudo-Random Function-128 176 * (AES-CMAC-PRF-128) Algorithm for the Internet Key 177 * Exchange Protocol (IKE).</em> 178 * 179 * \param key The key to use. 180 * \param key_len The key length in Bytes. 181 * \param input The buffer holding the input data. 182 * \param in_len The length of the input data in Bytes. 183 * \param output The buffer holding the generated 16 Bytes of 184 * pseudorandom output. 185 * 186 * \return \c 0 on success. 187 */ 188 int mbedtls_aes_cmac_prf_128( const unsigned char *key, size_t key_len, 189 const unsigned char *input, size_t in_len, 190 unsigned char output[16] ); 191 #endif /* MBEDTLS_AES_C */ 192 193 #if defined(MBEDTLS_SELF_TEST) && ( defined(MBEDTLS_AES_C) || defined(MBEDTLS_DES_C) ) 194 /** 195 * \brief The CMAC checkup routine. 196 * 197 * \return \c 0 on success. 198 * \return \c 1 on failure. 199 */ 200 int mbedtls_cmac_self_test( int verbose ); 201 #endif /* MBEDTLS_SELF_TEST && ( MBEDTLS_AES_C || MBEDTLS_DES_C ) */ 202 203 #ifdef __cplusplus 204 } 205 #endif 206 207 #endif /* MBEDTLS_CMAC_H */ 208