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 The Mbed TLS Contributors 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 47 #ifndef MBEDTLS_CCM_H 48 #define MBEDTLS_CCM_H 49 50 #if !defined(MBEDTLS_CONFIG_FILE) 51 #include "mbedtls/config.h" 52 #else 53 #include MBEDTLS_CONFIG_FILE 54 #endif 55 56 #include "mbedtls/cipher.h" 57 58 #define MBEDTLS_ERR_CCM_BAD_INPUT -0x000D /**< Bad input parameters to the function. */ 59 #define MBEDTLS_ERR_CCM_AUTH_FAILED -0x000F /**< Authenticated decryption failed. */ 60 61 /* MBEDTLS_ERR_CCM_HW_ACCEL_FAILED is deprecated and should not be used. */ 62 #define MBEDTLS_ERR_CCM_HW_ACCEL_FAILED -0x0011 /**< CCM hardware accelerator failed. */ 63 64 #ifdef __cplusplus 65 extern "C" { 66 #endif 67 68 #if !defined(MBEDTLS_CCM_ALT) 69 // Regular implementation 70 // 71 72 /** 73 * \brief The CCM context-type definition. The CCM context is passed 74 * to the APIs called. 75 */ 76 typedef struct mbedtls_ccm_context 77 { 78 mbedtls_cipher_context_t cipher_ctx; /*!< The cipher context used. */ 79 } 80 mbedtls_ccm_context; 81 82 #else /* MBEDTLS_CCM_ALT */ 83 #include "ccm_alt.h" 84 #endif /* MBEDTLS_CCM_ALT */ 85 86 /** 87 * \brief This function initializes the specified CCM context, 88 * to make references valid, and prepare the context 89 * for mbedtls_ccm_setkey() or mbedtls_ccm_free(). 90 * 91 * \param ctx The CCM context to initialize. This must not be \c NULL. 92 */ 93 void mbedtls_ccm_init( mbedtls_ccm_context *ctx ); 94 95 /** 96 * \brief This function initializes the CCM context set in the 97 * \p ctx parameter and sets the encryption key. 98 * 99 * \param ctx The CCM context to initialize. This must be an initialized 100 * context. 101 * \param cipher The 128-bit block cipher to use. 102 * \param key The encryption key. This must not be \c NULL. 103 * \param keybits The key size in bits. This must be acceptable by the cipher. 104 * 105 * \return \c 0 on success. 106 * \return A CCM or cipher-specific error code on failure. 107 */ 108 int mbedtls_ccm_setkey( mbedtls_ccm_context *ctx, 109 mbedtls_cipher_id_t cipher, 110 const unsigned char *key, 111 unsigned int keybits ); 112 113 /** 114 * \brief This function releases and clears the specified CCM context 115 * and underlying cipher sub-context. 116 * 117 * \param ctx The CCM context to clear. If this is \c NULL, the function 118 * has no effect. Otherwise, this must be initialized. 119 */ 120 void mbedtls_ccm_free( mbedtls_ccm_context *ctx ); 121 122 /** 123 * \brief This function encrypts a buffer using CCM. 124 * 125 * \note The tag is written to a separate buffer. To concatenate 126 * the \p tag with the \p output, as done in <em>RFC-3610: 127 * Counter with CBC-MAC (CCM)</em>, use 128 * \p tag = \p output + \p length, and make sure that the 129 * output buffer is at least \p length + \p tag_len wide. 130 * 131 * \param ctx The CCM context to use for encryption. This must be 132 * initialized and bound to a key. 133 * \param length The length of the input data in Bytes. 134 * \param iv The initialization vector (nonce). This must be a readable 135 * buffer of at least \p iv_len Bytes. 136 * \param iv_len The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12, 137 * or 13. The length L of the message length field is 138 * 15 - \p iv_len. 139 * \param add The additional data field. If \p add_len is greater than 140 * zero, \p add must be a readable buffer of at least that 141 * length. 142 * \param add_len The length of additional data in Bytes. 143 * This must be less than `2^16 - 2^8`. 144 * \param input The buffer holding the input data. If \p length is greater 145 * than zero, \p input must be a readable buffer of at least 146 * that length. 147 * \param output The buffer holding the output data. If \p length is greater 148 * than zero, \p output must be a writable buffer of at least 149 * that length. 150 * \param tag The buffer holding the authentication field. This must be a 151 * writable buffer of at least \p tag_len Bytes. 152 * \param tag_len The length of the authentication field to generate in Bytes: 153 * 4, 6, 8, 10, 12, 14 or 16. 154 * 155 * \return \c 0 on success. 156 * \return A CCM or cipher-specific error code on failure. 157 */ 158 int mbedtls_ccm_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length, 159 const unsigned char *iv, size_t iv_len, 160 const unsigned char *add, size_t add_len, 161 const unsigned char *input, unsigned char *output, 162 unsigned char *tag, size_t tag_len ); 163 164 /** 165 * \brief This function encrypts a buffer using CCM*. 166 * 167 * \note The tag is written to a separate buffer. To concatenate 168 * the \p tag with the \p output, as done in <em>RFC-3610: 169 * Counter with CBC-MAC (CCM)</em>, use 170 * \p tag = \p output + \p length, and make sure that the 171 * output buffer is at least \p length + \p tag_len wide. 172 * 173 * \note When using this function in a variable tag length context, 174 * the tag length has to be encoded into the \p iv passed to 175 * this function. 176 * 177 * \param ctx The CCM context to use for encryption. This must be 178 * initialized and bound to a key. 179 * \param length The length of the input data in Bytes. 180 * \param iv The initialization vector (nonce). This must be a readable 181 * buffer of at least \p iv_len Bytes. 182 * \param iv_len The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12, 183 * or 13. The length L of the message length field is 184 * 15 - \p iv_len. 185 * \param add The additional data field. This must be a readable buffer of 186 * at least \p add_len Bytes. 187 * \param add_len The length of additional data in Bytes. 188 * This must be less than 2^16 - 2^8. 189 * \param input The buffer holding the input data. If \p length is greater 190 * than zero, \p input must be a readable buffer of at least 191 * that length. 192 * \param output The buffer holding the output data. If \p length is greater 193 * than zero, \p output must be a writable buffer of at least 194 * that length. 195 * \param tag The buffer holding the authentication field. This must be a 196 * writable buffer of at least \p tag_len Bytes. 197 * \param tag_len The length of the authentication field to generate in Bytes: 198 * 0, 4, 6, 8, 10, 12, 14 or 16. 199 * 200 * \warning Passing \c 0 as \p tag_len means that the message is no 201 * longer authenticated. 202 * 203 * \return \c 0 on success. 204 * \return A CCM or cipher-specific error code on failure. 205 */ 206 int mbedtls_ccm_star_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length, 207 const unsigned char *iv, size_t iv_len, 208 const unsigned char *add, size_t add_len, 209 const unsigned char *input, unsigned char *output, 210 unsigned char *tag, size_t tag_len ); 211 212 /** 213 * \brief This function performs a CCM authenticated decryption of a 214 * buffer. 215 * 216 * \param ctx The CCM context to use for decryption. This must be 217 * initialized and bound to a key. 218 * \param length The length of the input data in Bytes. 219 * \param iv The initialization vector (nonce). This must be a readable 220 * buffer of at least \p iv_len Bytes. 221 * \param iv_len The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12, 222 * or 13. The length L of the message length field is 223 * 15 - \p iv_len. 224 * \param add The additional data field. This must be a readable buffer 225 * of at least that \p add_len Bytes.. 226 * \param add_len The length of additional data in Bytes. 227 * This must be less than 2^16 - 2^8. 228 * \param input The buffer holding the input data. If \p length is greater 229 * than zero, \p input must be a readable buffer of at least 230 * that length. 231 * \param output The buffer holding the output data. If \p length is greater 232 * than zero, \p output must be a writable buffer of at least 233 * that length. 234 * \param tag The buffer holding the authentication field. This must be a 235 * readable buffer of at least \p tag_len Bytes. 236 * \param tag_len The length of the authentication field to generate in Bytes: 237 * 4, 6, 8, 10, 12, 14 or 16. 238 * 239 * \return \c 0 on success. This indicates that the message is authentic. 240 * \return #MBEDTLS_ERR_CCM_AUTH_FAILED if the tag does not match. 241 * \return A cipher-specific error code on calculation failure. 242 */ 243 int mbedtls_ccm_auth_decrypt( mbedtls_ccm_context *ctx, size_t length, 244 const unsigned char *iv, size_t iv_len, 245 const unsigned char *add, size_t add_len, 246 const unsigned char *input, unsigned char *output, 247 const unsigned char *tag, size_t tag_len ); 248 249 /** 250 * \brief This function performs a CCM* authenticated decryption of a 251 * buffer. 252 * 253 * \note When using this function in a variable tag length context, 254 * the tag length has to be decoded from \p iv and passed to 255 * this function as \p tag_len. (\p tag needs to be adjusted 256 * accordingly.) 257 * 258 * \param ctx The CCM context to use for decryption. This must be 259 * initialized and bound to a key. 260 * \param length The length of the input data in Bytes. 261 * \param iv The initialization vector (nonce). This must be a readable 262 * buffer of at least \p iv_len Bytes. 263 * \param iv_len The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12, 264 * or 13. The length L of the message length field is 265 * 15 - \p iv_len. 266 * \param add The additional data field. This must be a readable buffer of 267 * at least that \p add_len Bytes. 268 * \param add_len The length of additional data in Bytes. 269 * This must be less than 2^16 - 2^8. 270 * \param input The buffer holding the input data. If \p length is greater 271 * than zero, \p input must be a readable buffer of at least 272 * that length. 273 * \param output The buffer holding the output data. If \p length is greater 274 * than zero, \p output must be a writable buffer of at least 275 * that length. 276 * \param tag The buffer holding the authentication field. This must be a 277 * readable buffer of at least \p tag_len Bytes. 278 * \param tag_len The length of the authentication field in Bytes. 279 * 0, 4, 6, 8, 10, 12, 14 or 16. 280 * 281 * \warning Passing \c 0 as \p tag_len means that the message is nos 282 * longer authenticated. 283 * 284 * \return \c 0 on success. 285 * \return #MBEDTLS_ERR_CCM_AUTH_FAILED if the tag does not match. 286 * \return A cipher-specific error code on calculation failure. 287 */ 288 int mbedtls_ccm_star_auth_decrypt( mbedtls_ccm_context *ctx, size_t length, 289 const unsigned char *iv, size_t iv_len, 290 const unsigned char *add, size_t add_len, 291 const unsigned char *input, unsigned char *output, 292 const unsigned char *tag, size_t tag_len ); 293 294 #if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C) 295 /** 296 * \brief The CCM checkup routine. 297 * 298 * \return \c 0 on success. 299 * \return \c 1 on failure. 300 */ 301 int mbedtls_ccm_self_test( int verbose ); 302 #endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */ 303 304 #ifdef __cplusplus 305 } 306 #endif 307 308 #endif /* MBEDTLS_CCM_H */ 309