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 The Mbed TLS Contributors 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 26 #ifndef MBEDTLS_CMAC_H 27 #define MBEDTLS_CMAC_H 28 29 #if !defined(MBEDTLS_CONFIG_FILE) 30 #include "mbedtls/config.h" 31 #else 32 #include MBEDTLS_CONFIG_FILE 33 #endif 34 35 #include "mbedtls/cipher.h" 36 37 #ifdef __cplusplus 38 extern "C" { 39 #endif 40 41 /* MBEDTLS_ERR_CMAC_HW_ACCEL_FAILED is deprecated and should not be used. */ 42 #define MBEDTLS_ERR_CMAC_HW_ACCEL_FAILED -0x007A /**< CMAC hardware accelerator failed. */ 43 44 #define MBEDTLS_AES_BLOCK_SIZE 16 45 #define MBEDTLS_DES3_BLOCK_SIZE 8 46 47 #if defined(MBEDTLS_AES_C) 48 #define MBEDTLS_CIPHER_BLKSIZE_MAX 16 /**< The longest block used by CMAC is that of AES. */ 49 #else 50 #define MBEDTLS_CIPHER_BLKSIZE_MAX 8 /**< The longest block used by CMAC is that of 3DES. */ 51 #endif 52 53 #if !defined(MBEDTLS_CMAC_ALT) 54 55 /** 56 * The CMAC context structure. 57 */ 58 struct mbedtls_cmac_context_t 59 { 60 /** The internal state of the CMAC algorithm. */ 61 unsigned char state[MBEDTLS_CIPHER_BLKSIZE_MAX]; 62 63 /** Unprocessed data - either data that was not block aligned and is still 64 * pending processing, or the final block. */ 65 unsigned char unprocessed_block[MBEDTLS_CIPHER_BLKSIZE_MAX]; 66 67 /** The length of data pending processing. */ 68 size_t unprocessed_len; 69 }; 70 71 #else /* !MBEDTLS_CMAC_ALT */ 72 #include "cmac_alt.h" 73 #endif /* !MBEDTLS_CMAC_ALT */ 74 75 /** 76 * \brief This function sets the CMAC key, and prepares to authenticate 77 * the input data. 78 * Must be called with an initialized cipher context. 79 * 80 * \param ctx The cipher context used for the CMAC operation, initialized 81 * as one of the following types: MBEDTLS_CIPHER_AES_128_ECB, 82 * MBEDTLS_CIPHER_AES_192_ECB, MBEDTLS_CIPHER_AES_256_ECB, 83 * or MBEDTLS_CIPHER_DES_EDE3_ECB. 84 * \param key The CMAC key. 85 * \param keybits The length of the CMAC key in bits. 86 * Must be supported by the cipher. 87 * 88 * \return \c 0 on success. 89 * \return A cipher-specific error code on failure. 90 */ 91 int mbedtls_cipher_cmac_starts( mbedtls_cipher_context_t *ctx, 92 const unsigned char *key, size_t keybits ); 93 94 /** 95 * \brief This function feeds an input buffer into an ongoing CMAC 96 * computation. 97 * 98 * It is called between mbedtls_cipher_cmac_starts() or 99 * mbedtls_cipher_cmac_reset(), and mbedtls_cipher_cmac_finish(). 100 * Can be called repeatedly. 101 * 102 * \param ctx The cipher context used for the CMAC operation. 103 * \param input The buffer holding the input data. 104 * \param ilen The length of the input data. 105 * 106 * \return \c 0 on success. 107 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA 108 * if parameter verification fails. 109 */ 110 int mbedtls_cipher_cmac_update( mbedtls_cipher_context_t *ctx, 111 const unsigned char *input, size_t ilen ); 112 113 /** 114 * \brief This function finishes the CMAC operation, and writes 115 * the result to the output buffer. 116 * 117 * It is called after mbedtls_cipher_cmac_update(). 118 * It can be followed by mbedtls_cipher_cmac_reset() and 119 * mbedtls_cipher_cmac_update(), or mbedtls_cipher_free(). 120 * 121 * \param ctx The cipher context used for the CMAC operation. 122 * \param output The output buffer for the CMAC checksum result. 123 * 124 * \return \c 0 on success. 125 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA 126 * if parameter verification fails. 127 */ 128 int mbedtls_cipher_cmac_finish( mbedtls_cipher_context_t *ctx, 129 unsigned char *output ); 130 131 /** 132 * \brief This function prepares the authentication of another 133 * message with the same key as the previous CMAC 134 * operation. 135 * 136 * It is called after mbedtls_cipher_cmac_finish() 137 * and before mbedtls_cipher_cmac_update(). 138 * 139 * \param ctx The cipher context used for the CMAC operation. 140 * 141 * \return \c 0 on success. 142 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA 143 * if parameter verification fails. 144 */ 145 int mbedtls_cipher_cmac_reset( mbedtls_cipher_context_t *ctx ); 146 147 /** 148 * \brief This function calculates the full generic CMAC 149 * on the input buffer with the provided key. 150 * 151 * The function allocates the context, performs the 152 * calculation, and frees the context. 153 * 154 * The CMAC result is calculated as 155 * output = generic CMAC(cmac key, input buffer). 156 * 157 * 158 * \param cipher_info The cipher information. 159 * \param key The CMAC key. 160 * \param keylen The length of the CMAC key in bits. 161 * \param input The buffer holding the input data. 162 * \param ilen The length of the input data. 163 * \param output The buffer for the generic CMAC result. 164 * 165 * \return \c 0 on success. 166 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA 167 * if parameter verification fails. 168 */ 169 int mbedtls_cipher_cmac( const mbedtls_cipher_info_t *cipher_info, 170 const unsigned char *key, size_t keylen, 171 const unsigned char *input, size_t ilen, 172 unsigned char *output ); 173 174 #if defined(MBEDTLS_AES_C) 175 /** 176 * \brief This function implements the AES-CMAC-PRF-128 pseudorandom 177 * function, as defined in 178 * <em>RFC-4615: The Advanced Encryption Standard-Cipher-based 179 * Message Authentication Code-Pseudo-Random Function-128 180 * (AES-CMAC-PRF-128) Algorithm for the Internet Key 181 * Exchange Protocol (IKE).</em> 182 * 183 * \param key The key to use. 184 * \param key_len The key length in Bytes. 185 * \param input The buffer holding the input data. 186 * \param in_len The length of the input data in Bytes. 187 * \param output The buffer holding the generated 16 Bytes of 188 * pseudorandom output. 189 * 190 * \return \c 0 on success. 191 */ 192 int mbedtls_aes_cmac_prf_128( const unsigned char *key, size_t key_len, 193 const unsigned char *input, size_t in_len, 194 unsigned char output[16] ); 195 #endif /* MBEDTLS_AES_C */ 196 197 #if defined(MBEDTLS_SELF_TEST) && ( defined(MBEDTLS_AES_C) || defined(MBEDTLS_DES_C) ) 198 /** 199 * \brief The CMAC checkup routine. 200 * 201 * \return \c 0 on success. 202 * \return \c 1 on failure. 203 */ 204 int mbedtls_cmac_self_test( int verbose ); 205 #endif /* MBEDTLS_SELF_TEST && ( MBEDTLS_AES_C || MBEDTLS_DES_C ) */ 206 207 #ifdef __cplusplus 208 } 209 #endif 210 211 #endif /* MBEDTLS_CMAC_H */ 212