1 /** 2 * \file ccm.h 3 * 4 * \brief This file provides an API for the CCM authenticated encryption 5 * mode for block ciphers. 6 * 7 * CCM combines Counter mode encryption with CBC-MAC authentication 8 * for 128-bit block ciphers. 9 * 10 * Input to CCM includes the following elements: 11 * <ul><li>Payload - data that is both authenticated and encrypted.</li> 12 * <li>Associated data (Adata) - data that is authenticated but not 13 * encrypted, For example, a header.</li> 14 * <li>Nonce - A unique value that is assigned to the payload and the 15 * associated data.</li></ul> 16 * 17 * Definition of CCM: 18 * http://csrc.nist.gov/publications/nistpubs/800-38C/SP800-38C_updated-July20_2007.pdf 19 * RFC 3610 "Counter with CBC-MAC (CCM)" 20 * 21 * Related: 22 * RFC 5116 "An Interface and Algorithms for Authenticated Encryption" 23 * 24 * Definition of CCM*: 25 * IEEE 802.15.4 - IEEE Standard for Local and metropolitan area networks 26 * Integer representation is fixed most-significant-octet-first order and 27 * the representation of octets is most-significant-bit-first order. This is 28 * consistent with RFC 3610. 29 */ 30 /* 31 * Copyright (C) 2006-2018, Arm Limited (or its affiliates), All Rights Reserved 32 * SPDX-License-Identifier: Apache-2.0 33 * 34 * Licensed under the Apache License, Version 2.0 (the "License"); you may 35 * not use this file except in compliance with the License. 36 * You may obtain a copy of the License at 37 * 38 * http://www.apache.org/licenses/LICENSE-2.0 39 * 40 * Unless required by applicable law or agreed to in writing, software 41 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 42 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 43 * See the License for the specific language governing permissions and 44 * limitations under the License. 45 * 46 * This file is part of Mbed TLS (https://tls.mbed.org) 47 */ 48 49 #ifndef MBEDTLS_CCM_H 50 #define MBEDTLS_CCM_H 51 52 #if !defined(MBEDTLS_CONFIG_FILE) 53 #include "config.h" 54 #else 55 #include MBEDTLS_CONFIG_FILE 56 #endif 57 58 #include "cipher.h" 59 60 #define MBEDTLS_ERR_CCM_BAD_INPUT -0x000D /**< Bad input parameters to the function. */ 61 #define MBEDTLS_ERR_CCM_AUTH_FAILED -0x000F /**< Authenticated decryption failed. */ 62 63 /* MBEDTLS_ERR_CCM_HW_ACCEL_FAILED is deprecated and should not be used. */ 64 #define MBEDTLS_ERR_CCM_HW_ACCEL_FAILED -0x0011 /**< CCM hardware accelerator failed. */ 65 66 #ifdef __cplusplus 67 extern "C" { 68 #endif 69 70 #if !defined(MBEDTLS_CCM_ALT) 71 // Regular implementation 72 // 73 74 /** 75 * \brief The CCM context-type definition. The CCM context is passed 76 * to the APIs called. 77 */ 78 typedef struct mbedtls_ccm_context 79 { 80 mbedtls_cipher_context_t cipher_ctx; /*!< The cipher context used. */ 81 } 82 mbedtls_ccm_context; 83 84 #else /* MBEDTLS_CCM_ALT */ 85 #include "ccm_alt.h" 86 #endif /* MBEDTLS_CCM_ALT */ 87 88 /** 89 * \brief This function initializes the specified CCM context, 90 * to make references valid, and prepare the context 91 * for mbedtls_ccm_setkey() or mbedtls_ccm_free(). 92 * 93 * \param ctx The CCM context to initialize. This must not be \c NULL. 94 */ 95 void mbedtls_ccm_init( mbedtls_ccm_context *ctx ); 96 97 /** 98 * \brief This function initializes the CCM context set in the 99 * \p ctx parameter and sets the encryption key. 100 * 101 * \param ctx The CCM context to initialize. This must be an initialized 102 * context. 103 * \param cipher The 128-bit block cipher to use. 104 * \param key The encryption key. This must not be \c NULL. 105 * \param keybits The key size in bits. This must be acceptable by the cipher. 106 * 107 * \return \c 0 on success. 108 * \return A CCM or cipher-specific error code on failure. 109 */ 110 int mbedtls_ccm_setkey( mbedtls_ccm_context *ctx, 111 mbedtls_cipher_id_t cipher, 112 const unsigned char *key, 113 unsigned int keybits ); 114 115 /** 116 * \brief This function releases and clears the specified CCM context 117 * and underlying cipher sub-context. 118 * 119 * \param ctx The CCM context to clear. If this is \c NULL, the function 120 * has no effect. Otherwise, this must be initialized. 121 */ 122 void mbedtls_ccm_free( mbedtls_ccm_context *ctx ); 123 124 /** 125 * \brief This function encrypts a buffer using CCM. 126 * 127 * \note The tag is written to a separate buffer. To concatenate 128 * the \p tag with the \p output, as done in <em>RFC-3610: 129 * Counter with CBC-MAC (CCM)</em>, use 130 * \p tag = \p output + \p length, and make sure that the 131 * output buffer is at least \p length + \p tag_len wide. 132 * 133 * \param ctx The CCM context to use for encryption. This must be 134 * initialized and bound to a key. 135 * \param length The length of the input data in Bytes. 136 * \param iv The initialization vector (nonce). This must be a readable 137 * buffer of at least \p iv_len Bytes. 138 * \param iv_len The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12, 139 * or 13. The length L of the message length field is 140 * 15 - \p iv_len. 141 * \param add The additional data field. If \p add_len is greater than 142 * zero, \p add must be a readable buffer of at least that 143 * length. 144 * \param add_len The length of additional data in Bytes. 145 * This must be less than `2^16 - 2^8`. 146 * \param input The buffer holding the input data. If \p length is greater 147 * than zero, \p input must be a readable buffer of at least 148 * that length. 149 * \param output The buffer holding the output data. If \p length is greater 150 * than zero, \p output must be a writable buffer of at least 151 * that length. 152 * \param tag The buffer holding the authentication field. This must be a 153 * readable buffer of at least \p tag_len Bytes. 154 * \param tag_len The length of the authentication field to generate in Bytes: 155 * 4, 6, 8, 10, 12, 14 or 16. 156 * 157 * \return \c 0 on success. 158 * \return A CCM or cipher-specific error code on failure. 159 */ 160 int mbedtls_ccm_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length, 161 const unsigned char *iv, size_t iv_len, 162 const unsigned char *add, size_t add_len, 163 const unsigned char *input, unsigned char *output, 164 unsigned char *tag, size_t tag_len ); 165 166 /** 167 * \brief This function encrypts a buffer using CCM*. 168 * 169 * \note The tag is written to a separate buffer. To concatenate 170 * the \p tag with the \p output, as done in <em>RFC-3610: 171 * Counter with CBC-MAC (CCM)</em>, use 172 * \p tag = \p output + \p length, and make sure that the 173 * output buffer is at least \p length + \p tag_len wide. 174 * 175 * \note When using this function in a variable tag length context, 176 * the tag length has to be encoded into the \p iv passed to 177 * this function. 178 * 179 * \param ctx The CCM context to use for encryption. This must be 180 * initialized and bound to a key. 181 * \param length The length of the input data in Bytes. 182 * \param iv The initialization vector (nonce). This must be a readable 183 * buffer of at least \p iv_len Bytes. 184 * \param iv_len The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12, 185 * or 13. The length L of the message length field is 186 * 15 - \p iv_len. 187 * \param add The additional data field. This must be a readable buffer of 188 * at least \p add_len Bytes. 189 * \param add_len The length of additional data in Bytes. 190 * This must be less than 2^16 - 2^8. 191 * \param input The buffer holding the input data. If \p length is greater 192 * than zero, \p input must be a readable buffer of at least 193 * that length. 194 * \param output The buffer holding the output data. If \p length is greater 195 * than zero, \p output must be a writable buffer of at least 196 * that length. 197 * \param tag The buffer holding the authentication field. This must be a 198 * readable buffer of at least \p tag_len Bytes. 199 * \param tag_len The length of the authentication field to generate in Bytes: 200 * 0, 4, 6, 8, 10, 12, 14 or 16. 201 * 202 * \warning Passing \c 0 as \p tag_len means that the message is no 203 * longer authenticated. 204 * 205 * \return \c 0 on success. 206 * \return A CCM or cipher-specific error code on failure. 207 */ 208 int mbedtls_ccm_star_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length, 209 const unsigned char *iv, size_t iv_len, 210 const unsigned char *add, size_t add_len, 211 const unsigned char *input, unsigned char *output, 212 unsigned char *tag, size_t tag_len ); 213 214 /** 215 * \brief This function performs a CCM authenticated decryption of a 216 * buffer. 217 * 218 * \param ctx The CCM context to use for decryption. This must be 219 * initialized and bound to a key. 220 * \param length The length of the input data in Bytes. 221 * \param iv The initialization vector (nonce). This must be a readable 222 * buffer of at least \p iv_len Bytes. 223 * \param iv_len The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12, 224 * or 13. The length L of the message length field is 225 * 15 - \p iv_len. 226 * \param add The additional data field. This must be a readable buffer 227 * of at least that \p add_len Bytes.. 228 * \param add_len The length of additional data in Bytes. 229 * This must be less than 2^16 - 2^8. 230 * \param input The buffer holding the input data. If \p length is greater 231 * than zero, \p input must be a readable buffer of at least 232 * that length. 233 * \param output The buffer holding the output data. If \p length is greater 234 * than zero, \p output must be a writable buffer of at least 235 * that length. 236 * \param tag The buffer holding the authentication field. This must be a 237 * readable buffer of at least \p tag_len Bytes. 238 * \param tag_len The length of the authentication field to generate in Bytes: 239 * 4, 6, 8, 10, 12, 14 or 16. 240 * 241 * \return \c 0 on success. This indicates that the message is authentic. 242 * \return #MBEDTLS_ERR_CCM_AUTH_FAILED if the tag does not match. 243 * \return A cipher-specific error code on calculation failure. 244 */ 245 int mbedtls_ccm_auth_decrypt( mbedtls_ccm_context *ctx, size_t length, 246 const unsigned char *iv, size_t iv_len, 247 const unsigned char *add, size_t add_len, 248 const unsigned char *input, unsigned char *output, 249 const unsigned char *tag, size_t tag_len ); 250 251 /** 252 * \brief This function performs a CCM* authenticated decryption of a 253 * buffer. 254 * 255 * \note When using this function in a variable tag length context, 256 * the tag length has to be decoded from \p iv and passed to 257 * this function as \p tag_len. (\p tag needs to be adjusted 258 * accordingly.) 259 * 260 * \param ctx The CCM context to use for decryption. This must be 261 * initialized and bound to a key. 262 * \param length The length of the input data in Bytes. 263 * \param iv The initialization vector (nonce). This must be a readable 264 * buffer of at least \p iv_len Bytes. 265 * \param iv_len The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12, 266 * or 13. The length L of the message length field is 267 * 15 - \p iv_len. 268 * \param add The additional data field. This must be a readable buffer of 269 * at least that \p add_len Bytes. 270 * \param add_len The length of additional data in Bytes. 271 * This must be less than 2^16 - 2^8. 272 * \param input The buffer holding the input data. If \p length is greater 273 * than zero, \p input must be a readable buffer of at least 274 * that length. 275 * \param output The buffer holding the output data. If \p length is greater 276 * than zero, \p output must be a writable buffer of at least 277 * that length. 278 * \param tag The buffer holding the authentication field. This must be a 279 * readable buffer of at least \p tag_len Bytes. 280 * \param tag_len The length of the authentication field in Bytes. 281 * 0, 4, 6, 8, 10, 12, 14 or 16. 282 * 283 * \warning Passing \c 0 as \p tag_len means that the message is nos 284 * longer authenticated. 285 * 286 * \return \c 0 on success. 287 * \return #MBEDTLS_ERR_CCM_AUTH_FAILED if the tag does not match. 288 * \return A cipher-specific error code on calculation failure. 289 */ 290 int mbedtls_ccm_star_auth_decrypt( mbedtls_ccm_context *ctx, size_t length, 291 const unsigned char *iv, size_t iv_len, 292 const unsigned char *add, size_t add_len, 293 const unsigned char *input, unsigned char *output, 294 const unsigned char *tag, size_t tag_len ); 295 296 #if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C) 297 /** 298 * \brief The CCM checkup routine. 299 * 300 * \return \c 0 on success. 301 * \return \c 1 on failure. 302 */ 303 int mbedtls_ccm_self_test( int verbose ); 304 #endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */ 305 306 #ifdef __cplusplus 307 } 308 #endif 309 310 #endif /* MBEDTLS_CCM_H */ 311