1 /** 2 * \file md.h 3 * 4 * \brief This file contains the generic message-digest wrapper. 5 * 6 * \author Adriaan de Jong <dejong@fox-it.com> 7 */ 8 /* 9 * Copyright The Mbed TLS Contributors 10 * SPDX-License-Identifier: Apache-2.0 11 * 12 * Licensed under the Apache License, Version 2.0 (the "License"); you may 13 * not use this file except in compliance with the License. 14 * You may obtain a copy of the License at 15 * 16 * http://www.apache.org/licenses/LICENSE-2.0 17 * 18 * Unless required by applicable law or agreed to in writing, software 19 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 20 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 21 * See the License for the specific language governing permissions and 22 * limitations under the License. 23 */ 24 25 #ifndef MBEDTLS_MD_H 26 #define MBEDTLS_MD_H 27 #include "mbedtls/private_access.h" 28 29 #include <stddef.h> 30 31 #include "mbedtls/build_info.h" 32 #include "mbedtls/platform_util.h" 33 34 /** The selected feature is not available. */ 35 #define MBEDTLS_ERR_MD_FEATURE_UNAVAILABLE -0x5080 36 /** Bad input parameters to function. */ 37 #define MBEDTLS_ERR_MD_BAD_INPUT_DATA -0x5100 38 /** Failed to allocate memory. */ 39 #define MBEDTLS_ERR_MD_ALLOC_FAILED -0x5180 40 /** Opening or reading of file failed. */ 41 #define MBEDTLS_ERR_MD_FILE_IO_ERROR -0x5200 42 43 #ifdef __cplusplus 44 extern "C" { 45 #endif 46 47 /** 48 * \brief Supported message digests. 49 * 50 * \warning MD5 and SHA-1 are considered weak message digests and 51 * their use constitutes a security risk. We recommend considering 52 * stronger message digests instead. 53 * 54 */ 55 typedef enum { 56 MBEDTLS_MD_NONE=0, /**< None. */ 57 MBEDTLS_MD_MD5, /**< The MD5 message digest. */ 58 MBEDTLS_MD_SHA1, /**< The SHA-1 message digest. */ 59 MBEDTLS_MD_SHA224, /**< The SHA-224 message digest. */ 60 MBEDTLS_MD_SHA256, /**< The SHA-256 message digest. */ 61 MBEDTLS_MD_SHA384, /**< The SHA-384 message digest. */ 62 MBEDTLS_MD_SHA512, /**< The SHA-512 message digest. */ 63 MBEDTLS_MD_RIPEMD160, /**< The RIPEMD-160 message digest. */ 64 } mbedtls_md_type_t; 65 66 #if defined(MBEDTLS_SHA512_C) 67 #define MBEDTLS_MD_MAX_SIZE 64 /* longest known is SHA512 */ 68 #else 69 #define MBEDTLS_MD_MAX_SIZE 32 /* longest known is SHA256 or less */ 70 #endif 71 72 #if defined(MBEDTLS_SHA512_C) 73 #define MBEDTLS_MD_MAX_BLOCK_SIZE 128 74 #else 75 #define MBEDTLS_MD_MAX_BLOCK_SIZE 64 76 #endif 77 78 /** 79 * Opaque struct. 80 * 81 * Constructed using either #mbedtls_md_info_from_string or 82 * #mbedtls_md_info_from_type. 83 * 84 * Fields can be accessed with #mbedtls_md_get_size, 85 * #mbedtls_md_get_type and #mbedtls_md_get_name. 86 */ 87 /* Defined internally in library/md_wrap.h. */ 88 typedef struct mbedtls_md_info_t mbedtls_md_info_t; 89 90 /** 91 * The generic message-digest context. 92 */ 93 typedef struct mbedtls_md_context_t 94 { 95 /** Information about the associated message digest. */ 96 const mbedtls_md_info_t *MBEDTLS_PRIVATE(md_info); 97 98 /** The digest-specific context. */ 99 void *MBEDTLS_PRIVATE(md_ctx); 100 101 /** The HMAC part of the context. */ 102 void *MBEDTLS_PRIVATE(hmac_ctx); 103 } mbedtls_md_context_t; 104 105 /** 106 * \brief This function returns the list of digests supported by the 107 * generic digest module. 108 * 109 * \note The list starts with the strongest available hashes. 110 * 111 * \return A statically allocated array of digests. Each element 112 * in the returned list is an integer belonging to the 113 * message-digest enumeration #mbedtls_md_type_t. 114 * The last entry is 0. 115 */ 116 const int *mbedtls_md_list( void ); 117 118 /** 119 * \brief This function returns the message-digest information 120 * associated with the given digest name. 121 * 122 * \param md_name The name of the digest to search for. 123 * 124 * \return The message-digest information associated with \p md_name. 125 * \return NULL if the associated message-digest information is not found. 126 */ 127 const mbedtls_md_info_t *mbedtls_md_info_from_string( const char *md_name ); 128 129 /** 130 * \brief This function returns the message-digest information 131 * associated with the given digest type. 132 * 133 * \param md_type The type of digest to search for. 134 * 135 * \return The message-digest information associated with \p md_type. 136 * \return NULL if the associated message-digest information is not found. 137 */ 138 const mbedtls_md_info_t *mbedtls_md_info_from_type( mbedtls_md_type_t md_type ); 139 140 /** 141 * \brief This function returns the message-digest information 142 * from the given context. 143 * 144 * \param ctx The context from which to extract the information. 145 * This must be initialized (or \c NULL). 146 * 147 * \return The message-digest information associated with \p ctx. 148 * \return \c NULL if \p ctx is \c NULL. 149 */ 150 const mbedtls_md_info_t *mbedtls_md_info_from_ctx( 151 const mbedtls_md_context_t *ctx ); 152 153 /** 154 * \brief This function initializes a message-digest context without 155 * binding it to a particular message-digest algorithm. 156 * 157 * This function should always be called first. It prepares the 158 * context for mbedtls_md_setup() for binding it to a 159 * message-digest algorithm. 160 */ 161 void mbedtls_md_init( mbedtls_md_context_t *ctx ); 162 163 /** 164 * \brief This function clears the internal structure of \p ctx and 165 * frees any embedded internal structure, but does not free 166 * \p ctx itself. 167 * 168 * If you have called mbedtls_md_setup() on \p ctx, you must 169 * call mbedtls_md_free() when you are no longer using the 170 * context. 171 * Calling this function if you have previously 172 * called mbedtls_md_init() and nothing else is optional. 173 * You must not call this function if you have not called 174 * mbedtls_md_init(). 175 */ 176 void mbedtls_md_free( mbedtls_md_context_t *ctx ); 177 178 179 /** 180 * \brief This function selects the message digest algorithm to use, 181 * and allocates internal structures. 182 * 183 * It should be called after mbedtls_md_init() or 184 * mbedtls_md_free(). Makes it necessary to call 185 * mbedtls_md_free() later. 186 * 187 * \param ctx The context to set up. 188 * \param md_info The information structure of the message-digest algorithm 189 * to use. 190 * \param hmac Defines if HMAC is used. 0: HMAC is not used (saves some memory), 191 * or non-zero: HMAC is used with this context. 192 * 193 * \return \c 0 on success. 194 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification 195 * failure. 196 * \return #MBEDTLS_ERR_MD_ALLOC_FAILED on memory-allocation failure. 197 */ 198 MBEDTLS_CHECK_RETURN_TYPICAL 199 int mbedtls_md_setup( mbedtls_md_context_t *ctx, const mbedtls_md_info_t *md_info, int hmac ); 200 201 /** 202 * \brief This function clones the state of a message-digest 203 * context. 204 * 205 * \note You must call mbedtls_md_setup() on \c dst before calling 206 * this function. 207 * 208 * \note The two contexts must have the same type, 209 * for example, both are SHA-256. 210 * 211 * \warning This function clones the message-digest state, not the 212 * HMAC state. 213 * 214 * \param dst The destination context. 215 * \param src The context to be cloned. 216 * 217 * \return \c 0 on success. 218 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification failure. 219 */ 220 MBEDTLS_CHECK_RETURN_TYPICAL 221 int mbedtls_md_clone( mbedtls_md_context_t *dst, 222 const mbedtls_md_context_t *src ); 223 224 /** 225 * \brief This function extracts the message-digest size from the 226 * message-digest information structure. 227 * 228 * \param md_info The information structure of the message-digest algorithm 229 * to use. 230 * 231 * \return The size of the message-digest output in Bytes. 232 */ 233 unsigned char mbedtls_md_get_size( const mbedtls_md_info_t *md_info ); 234 235 /** 236 * \brief This function extracts the message-digest type from the 237 * message-digest information structure. 238 * 239 * \param md_info The information structure of the message-digest algorithm 240 * to use. 241 * 242 * \return The type of the message digest. 243 */ 244 mbedtls_md_type_t mbedtls_md_get_type( const mbedtls_md_info_t *md_info ); 245 246 /** 247 * \brief This function extracts the message-digest name from the 248 * message-digest information structure. 249 * 250 * \param md_info The information structure of the message-digest algorithm 251 * to use. 252 * 253 * \return The name of the message digest. 254 */ 255 const char *mbedtls_md_get_name( const mbedtls_md_info_t *md_info ); 256 257 /** 258 * \brief This function starts a message-digest computation. 259 * 260 * You must call this function after setting up the context 261 * with mbedtls_md_setup(), and before passing data with 262 * mbedtls_md_update(). 263 * 264 * \param ctx The generic message-digest context. 265 * 266 * \return \c 0 on success. 267 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification 268 * failure. 269 */ 270 MBEDTLS_CHECK_RETURN_TYPICAL 271 int mbedtls_md_starts( mbedtls_md_context_t *ctx ); 272 273 /** 274 * \brief This function feeds an input buffer into an ongoing 275 * message-digest computation. 276 * 277 * You must call mbedtls_md_starts() before calling this 278 * function. You may call this function multiple times. 279 * Afterwards, call mbedtls_md_finish(). 280 * 281 * \param ctx The generic message-digest context. 282 * \param input The buffer holding the input data. 283 * \param ilen The length of the input data. 284 * 285 * \return \c 0 on success. 286 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification 287 * failure. 288 */ 289 MBEDTLS_CHECK_RETURN_TYPICAL 290 int mbedtls_md_update( mbedtls_md_context_t *ctx, const unsigned char *input, size_t ilen ); 291 292 /** 293 * \brief This function finishes the digest operation, 294 * and writes the result to the output buffer. 295 * 296 * Call this function after a call to mbedtls_md_starts(), 297 * followed by any number of calls to mbedtls_md_update(). 298 * Afterwards, you may either clear the context with 299 * mbedtls_md_free(), or call mbedtls_md_starts() to reuse 300 * the context for another digest operation with the same 301 * algorithm. 302 * 303 * \param ctx The generic message-digest context. 304 * \param output The buffer for the generic message-digest checksum result. 305 * 306 * \return \c 0 on success. 307 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification 308 * failure. 309 */ 310 MBEDTLS_CHECK_RETURN_TYPICAL 311 int mbedtls_md_finish( mbedtls_md_context_t *ctx, unsigned char *output ); 312 313 /** 314 * \brief This function calculates the message-digest of a buffer, 315 * with respect to a configurable message-digest algorithm 316 * in a single call. 317 * 318 * The result is calculated as 319 * Output = message_digest(input buffer). 320 * 321 * \param md_info The information structure of the message-digest algorithm 322 * to use. 323 * \param input The buffer holding the data. 324 * \param ilen The length of the input data. 325 * \param output The generic message-digest checksum result. 326 * 327 * \return \c 0 on success. 328 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification 329 * failure. 330 */ 331 MBEDTLS_CHECK_RETURN_TYPICAL 332 int mbedtls_md( const mbedtls_md_info_t *md_info, const unsigned char *input, size_t ilen, 333 unsigned char *output ); 334 335 #if defined(MBEDTLS_FS_IO) 336 /** 337 * \brief This function calculates the message-digest checksum 338 * result of the contents of the provided file. 339 * 340 * The result is calculated as 341 * Output = message_digest(file contents). 342 * 343 * \param md_info The information structure of the message-digest algorithm 344 * to use. 345 * \param path The input file name. 346 * \param output The generic message-digest checksum result. 347 * 348 * \return \c 0 on success. 349 * \return #MBEDTLS_ERR_MD_FILE_IO_ERROR on an I/O error accessing 350 * the file pointed by \p path. 351 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA if \p md_info was NULL. 352 */ 353 MBEDTLS_CHECK_RETURN_TYPICAL 354 int mbedtls_md_file( const mbedtls_md_info_t *md_info, const char *path, 355 unsigned char *output ); 356 #endif /* MBEDTLS_FS_IO */ 357 358 /** 359 * \brief This function sets the HMAC key and prepares to 360 * authenticate a new message. 361 * 362 * Call this function after mbedtls_md_setup(), to use 363 * the MD context for an HMAC calculation, then call 364 * mbedtls_md_hmac_update() to provide the input data, and 365 * mbedtls_md_hmac_finish() to get the HMAC value. 366 * 367 * \param ctx The message digest context containing an embedded HMAC 368 * context. 369 * \param key The HMAC secret key. 370 * \param keylen The length of the HMAC key in Bytes. 371 * 372 * \return \c 0 on success. 373 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification 374 * failure. 375 */ 376 MBEDTLS_CHECK_RETURN_TYPICAL 377 int mbedtls_md_hmac_starts( mbedtls_md_context_t *ctx, const unsigned char *key, 378 size_t keylen ); 379 380 /** 381 * \brief This function feeds an input buffer into an ongoing HMAC 382 * computation. 383 * 384 * Call mbedtls_md_hmac_starts() or mbedtls_md_hmac_reset() 385 * before calling this function. 386 * You may call this function multiple times to pass the 387 * input piecewise. 388 * Afterwards, call mbedtls_md_hmac_finish(). 389 * 390 * \param ctx The message digest context containing an embedded HMAC 391 * context. 392 * \param input The buffer holding the input data. 393 * \param ilen The length of the input data. 394 * 395 * \return \c 0 on success. 396 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification 397 * failure. 398 */ 399 MBEDTLS_CHECK_RETURN_TYPICAL 400 int mbedtls_md_hmac_update( mbedtls_md_context_t *ctx, const unsigned char *input, 401 size_t ilen ); 402 403 /** 404 * \brief This function finishes the HMAC operation, and writes 405 * the result to the output buffer. 406 * 407 * Call this function after mbedtls_md_hmac_starts() and 408 * mbedtls_md_hmac_update() to get the HMAC value. Afterwards 409 * you may either call mbedtls_md_free() to clear the context, 410 * or call mbedtls_md_hmac_reset() to reuse the context with 411 * the same HMAC key. 412 * 413 * \param ctx The message digest context containing an embedded HMAC 414 * context. 415 * \param output The generic HMAC checksum result. 416 * 417 * \return \c 0 on success. 418 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification 419 * failure. 420 */ 421 MBEDTLS_CHECK_RETURN_TYPICAL 422 int mbedtls_md_hmac_finish( mbedtls_md_context_t *ctx, unsigned char *output); 423 424 /** 425 * \brief This function prepares to authenticate a new message with 426 * the same key as the previous HMAC operation. 427 * 428 * You may call this function after mbedtls_md_hmac_finish(). 429 * Afterwards call mbedtls_md_hmac_update() to pass the new 430 * input. 431 * 432 * \param ctx The message digest context containing an embedded HMAC 433 * context. 434 * 435 * \return \c 0 on success. 436 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification 437 * failure. 438 */ 439 MBEDTLS_CHECK_RETURN_TYPICAL 440 int mbedtls_md_hmac_reset( mbedtls_md_context_t *ctx ); 441 442 /** 443 * \brief This function calculates the full generic HMAC 444 * on the input buffer with the provided key. 445 * 446 * The function allocates the context, performs the 447 * calculation, and frees the context. 448 * 449 * The HMAC result is calculated as 450 * output = generic HMAC(hmac key, input buffer). 451 * 452 * \param md_info The information structure of the message-digest algorithm 453 * to use. 454 * \param key The HMAC secret key. 455 * \param keylen The length of the HMAC secret key in Bytes. 456 * \param input The buffer holding the input data. 457 * \param ilen The length of the input data. 458 * \param output The generic HMAC result. 459 * 460 * \return \c 0 on success. 461 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification 462 * failure. 463 */ 464 MBEDTLS_CHECK_RETURN_TYPICAL 465 int mbedtls_md_hmac( const mbedtls_md_info_t *md_info, const unsigned char *key, size_t keylen, 466 const unsigned char *input, size_t ilen, 467 unsigned char *output ); 468 469 /* Internal use */ 470 MBEDTLS_CHECK_RETURN_TYPICAL 471 int mbedtls_md_process( mbedtls_md_context_t *ctx, const unsigned char *data ); 472 473 #ifdef __cplusplus 474 } 475 #endif 476 477 #endif /* MBEDTLS_MD_H */ 478
