1 /* 2 * Hash: Hash algorithms under the crypto API 3 * 4 * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au> 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License as published by the Free 8 * Software Foundation; either version 2 of the License, or (at your option) 9 * any later version. 10 * 11 */ 12 13 #ifndef _CRYPTO_HASH_H 14 #define _CRYPTO_HASH_H 15 16 #include <linux/crypto.h> 17 #include <linux/string.h> 18 19 struct crypto_ahash; 20 21 /** 22 * DOC: Message Digest Algorithm Definitions 23 * 24 * These data structures define modular message digest algorithm 25 * implementations, managed via crypto_register_ahash(), 26 * crypto_register_shash(), crypto_unregister_ahash() and 27 * crypto_unregister_shash(). 28 */ 29 30 /** 31 * struct hash_alg_common - define properties of message digest 32 * @digestsize: Size of the result of the transformation. A buffer of this size 33 * must be available to the @final and @finup calls, so they can 34 * store the resulting hash into it. For various predefined sizes, 35 * search include/crypto/ using 36 * git grep _DIGEST_SIZE include/crypto. 37 * @statesize: Size of the block for partial state of the transformation. A 38 * buffer of this size must be passed to the @export function as it 39 * will save the partial state of the transformation into it. On the 40 * other side, the @import function will load the state from a 41 * buffer of this size as well. 42 * @base: Start of data structure of cipher algorithm. The common data 43 * structure of crypto_alg contains information common to all ciphers. 44 * The hash_alg_common data structure now adds the hash-specific 45 * information. 46 */ 47 struct hash_alg_common { 48 unsigned int digestsize; 49 unsigned int statesize; 50 51 struct crypto_alg base; 52 }; 53 54 struct ahash_request { 55 struct crypto_async_request base; 56 57 unsigned int nbytes; 58 struct scatterlist *src; 59 u8 *result; 60 61 /* This field may only be used by the ahash API code. */ 62 void *priv; 63 64 void *__ctx[] CRYPTO_MINALIGN_ATTR; 65 }; 66 67 #define AHASH_REQUEST_ON_STACK(name, ahash) \ 68 char __##name##_desc[sizeof(struct ahash_request) + \ 69 crypto_ahash_reqsize(ahash)] CRYPTO_MINALIGN_ATTR; \ 70 struct ahash_request *name = (void *)__##name##_desc 71 72 /** 73 * struct ahash_alg - asynchronous message digest definition 74 * @init: **[mandatory]** Initialize the transformation context. Intended only to initialize the 75 * state of the HASH transformation at the beginning. This shall fill in 76 * the internal structures used during the entire duration of the whole 77 * transformation. No data processing happens at this point. Driver code 78 * implementation must not use req->result. 79 * @update: **[mandatory]** Push a chunk of data into the driver for transformation. This 80 * function actually pushes blocks of data from upper layers into the 81 * driver, which then passes those to the hardware as seen fit. This 82 * function must not finalize the HASH transformation by calculating the 83 * final message digest as this only adds more data into the 84 * transformation. This function shall not modify the transformation 85 * context, as this function may be called in parallel with the same 86 * transformation object. Data processing can happen synchronously 87 * [SHASH] or asynchronously [AHASH] at this point. Driver must not use 88 * req->result. 89 * @final: **[mandatory]** Retrieve result from the driver. This function finalizes the 90 * transformation and retrieves the resulting hash from the driver and 91 * pushes it back to upper layers. No data processing happens at this 92 * point unless hardware requires it to finish the transformation 93 * (then the data buffered by the device driver is processed). 94 * @finup: **[optional]** Combination of @update and @final. This function is effectively a 95 * combination of @update and @final calls issued in sequence. As some 96 * hardware cannot do @update and @final separately, this callback was 97 * added to allow such hardware to be used at least by IPsec. Data 98 * processing can happen synchronously [SHASH] or asynchronously [AHASH] 99 * at this point. 100 * @digest: Combination of @init and @update and @final. This function 101 * effectively behaves as the entire chain of operations, @init, 102 * @update and @final issued in sequence. Just like @finup, this was 103 * added for hardware which cannot do even the @finup, but can only do 104 * the whole transformation in one run. Data processing can happen 105 * synchronously [SHASH] or asynchronously [AHASH] at this point. 106 * @setkey: Set optional key used by the hashing algorithm. Intended to push 107 * optional key used by the hashing algorithm from upper layers into 108 * the driver. This function can store the key in the transformation 109 * context or can outright program it into the hardware. In the former 110 * case, one must be careful to program the key into the hardware at 111 * appropriate time and one must be careful that .setkey() can be 112 * called multiple times during the existence of the transformation 113 * object. Not all hashing algorithms do implement this function as it 114 * is only needed for keyed message digests. SHAx/MDx/CRCx do NOT 115 * implement this function. HMAC(MDx)/HMAC(SHAx)/CMAC(AES) do implement 116 * this function. This function must be called before any other of the 117 * @init, @update, @final, @finup, @digest is called. No data 118 * processing happens at this point. 119 * @export: Export partial state of the transformation. This function dumps the 120 * entire state of the ongoing transformation into a provided block of 121 * data so it can be @import 'ed back later on. This is useful in case 122 * you want to save partial result of the transformation after 123 * processing certain amount of data and reload this partial result 124 * multiple times later on for multiple re-use. No data processing 125 * happens at this point. Driver must not use req->result. 126 * @import: Import partial state of the transformation. This function loads the 127 * entire state of the ongoing transformation from a provided block of 128 * data so the transformation can continue from this point onward. No 129 * data processing happens at this point. Driver must not use 130 * req->result. 131 * @halg: see struct hash_alg_common 132 */ 133 struct ahash_alg { 134 int (*init)(struct ahash_request *req); 135 int (*update)(struct ahash_request *req); 136 int (*final)(struct ahash_request *req); 137 int (*finup)(struct ahash_request *req); 138 int (*digest)(struct ahash_request *req); 139 int (*export)(struct ahash_request *req, void *out); 140 int (*import)(struct ahash_request *req, const void *in); 141 int (*setkey)(struct crypto_ahash *tfm, const u8 *key, 142 unsigned int keylen); 143 144 struct hash_alg_common halg; 145 }; 146 147 struct shash_desc { 148 struct crypto_shash *tfm; 149 u32 flags; 150 151 void *__ctx[] CRYPTO_MINALIGN_ATTR; 152 }; 153 154 #define SHASH_DESC_ON_STACK(shash, ctx) \ 155 char __##shash##_desc[sizeof(struct shash_desc) + \ 156 crypto_shash_descsize(ctx)] CRYPTO_MINALIGN_ATTR; \ 157 struct shash_desc *shash = (struct shash_desc *)__##shash##_desc 158 159 /** 160 * struct shash_alg - synchronous message digest definition 161 * @init: see struct ahash_alg 162 * @update: see struct ahash_alg 163 * @final: see struct ahash_alg 164 * @finup: see struct ahash_alg 165 * @digest: see struct ahash_alg 166 * @export: see struct ahash_alg 167 * @import: see struct ahash_alg 168 * @setkey: see struct ahash_alg 169 * @digestsize: see struct ahash_alg 170 * @statesize: see struct ahash_alg 171 * @descsize: Size of the operational state for the message digest. This state 172 * size is the memory size that needs to be allocated for 173 * shash_desc.__ctx 174 * @base: internally used 175 */ 176 struct shash_alg { 177 int (*init)(struct shash_desc *desc); 178 int (*update)(struct shash_desc *desc, const u8 *data, 179 unsigned int len); 180 int (*final)(struct shash_desc *desc, u8 *out); 181 int (*finup)(struct shash_desc *desc, const u8 *data, 182 unsigned int len, u8 *out); 183 int (*digest)(struct shash_desc *desc, const u8 *data, 184 unsigned int len, u8 *out); 185 int (*export)(struct shash_desc *desc, void *out); 186 int (*import)(struct shash_desc *desc, const void *in); 187 int (*setkey)(struct crypto_shash *tfm, const u8 *key, 188 unsigned int keylen); 189 190 unsigned int descsize; 191 192 /* These fields must match hash_alg_common. */ 193 unsigned int digestsize 194 __attribute__ ((aligned(__alignof__(struct hash_alg_common)))); 195 unsigned int statesize; 196 197 struct crypto_alg base; 198 }; 199 200 struct crypto_ahash { 201 int (*init)(struct ahash_request *req); 202 int (*update)(struct ahash_request *req); 203 int (*final)(struct ahash_request *req); 204 int (*finup)(struct ahash_request *req); 205 int (*digest)(struct ahash_request *req); 206 int (*export)(struct ahash_request *req, void *out); 207 int (*import)(struct ahash_request *req, const void *in); 208 int (*setkey)(struct crypto_ahash *tfm, const u8 *key, 209 unsigned int keylen); 210 211 unsigned int reqsize; 212 struct crypto_tfm base; 213 }; 214 215 struct crypto_shash { 216 unsigned int descsize; 217 struct crypto_tfm base; 218 }; 219 220 /** 221 * DOC: Asynchronous Message Digest API 222 * 223 * The asynchronous message digest API is used with the ciphers of type 224 * CRYPTO_ALG_TYPE_AHASH (listed as type "ahash" in /proc/crypto) 225 * 226 * The asynchronous cipher operation discussion provided for the 227 * CRYPTO_ALG_TYPE_ABLKCIPHER API applies here as well. 228 */ 229 230 static inline struct crypto_ahash *__crypto_ahash_cast(struct crypto_tfm *tfm) 231 { 232 return container_of(tfm, struct crypto_ahash, base); 233 } 234 235 /** 236 * crypto_alloc_ahash() - allocate ahash cipher handle 237 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the 238 * ahash cipher 239 * @type: specifies the type of the cipher 240 * @mask: specifies the mask for the cipher 241 * 242 * Allocate a cipher handle for an ahash. The returned struct 243 * crypto_ahash is the cipher handle that is required for any subsequent 244 * API invocation for that ahash. 245 * 246 * Return: allocated cipher handle in case of success; IS_ERR() is true in case 247 * of an error, PTR_ERR() returns the error code. 248 */ 249 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type, 250 u32 mask); 251 252 static inline struct crypto_tfm *crypto_ahash_tfm(struct crypto_ahash *tfm) 253 { 254 return &tfm->base; 255 } 256 257 /** 258 * crypto_free_ahash() - zeroize and free the ahash handle 259 * @tfm: cipher handle to be freed 260 */ 261 static inline void crypto_free_ahash(struct crypto_ahash *tfm) 262 { 263 crypto_destroy_tfm(tfm, crypto_ahash_tfm(tfm)); 264 } 265 266 /** 267 * crypto_has_ahash() - Search for the availability of an ahash. 268 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the 269 * ahash 270 * @type: specifies the type of the ahash 271 * @mask: specifies the mask for the ahash 272 * 273 * Return: true when the ahash is known to the kernel crypto API; false 274 * otherwise 275 */ 276 int crypto_has_ahash(const char *alg_name, u32 type, u32 mask); 277 278 static inline const char *crypto_ahash_alg_name(struct crypto_ahash *tfm) 279 { 280 return crypto_tfm_alg_name(crypto_ahash_tfm(tfm)); 281 } 282 283 static inline const char *crypto_ahash_driver_name(struct crypto_ahash *tfm) 284 { 285 return crypto_tfm_alg_driver_name(crypto_ahash_tfm(tfm)); 286 } 287 288 static inline unsigned int crypto_ahash_alignmask( 289 struct crypto_ahash *tfm) 290 { 291 return crypto_tfm_alg_alignmask(crypto_ahash_tfm(tfm)); 292 } 293 294 /** 295 * crypto_ahash_blocksize() - obtain block size for cipher 296 * @tfm: cipher handle 297 * 298 * The block size for the message digest cipher referenced with the cipher 299 * handle is returned. 300 * 301 * Return: block size of cipher 302 */ 303 static inline unsigned int crypto_ahash_blocksize(struct crypto_ahash *tfm) 304 { 305 return crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm)); 306 } 307 308 static inline struct hash_alg_common *__crypto_hash_alg_common( 309 struct crypto_alg *alg) 310 { 311 return container_of(alg, struct hash_alg_common, base); 312 } 313 314 static inline struct hash_alg_common *crypto_hash_alg_common( 315 struct crypto_ahash *tfm) 316 { 317 return __crypto_hash_alg_common(crypto_ahash_tfm(tfm)->__crt_alg); 318 } 319 320 /** 321 * crypto_ahash_digestsize() - obtain message digest size 322 * @tfm: cipher handle 323 * 324 * The size for the message digest created by the message digest cipher 325 * referenced with the cipher handle is returned. 326 * 327 * 328 * Return: message digest size of cipher 329 */ 330 static inline unsigned int crypto_ahash_digestsize(struct crypto_ahash *tfm) 331 { 332 return crypto_hash_alg_common(tfm)->digestsize; 333 } 334 335 /** 336 * crypto_ahash_statesize() - obtain size of the ahash state 337 * @tfm: cipher handle 338 * 339 * Return the size of the ahash state. With the crypto_ahash_export() 340 * function, the caller can export the state into a buffer whose size is 341 * defined with this function. 342 * 343 * Return: size of the ahash state 344 */ 345 static inline unsigned int crypto_ahash_statesize(struct crypto_ahash *tfm) 346 { 347 return crypto_hash_alg_common(tfm)->statesize; 348 } 349 350 static inline u32 crypto_ahash_get_flags(struct crypto_ahash *tfm) 351 { 352 return crypto_tfm_get_flags(crypto_ahash_tfm(tfm)); 353 } 354 355 static inline void crypto_ahash_set_flags(struct crypto_ahash *tfm, u32 flags) 356 { 357 crypto_tfm_set_flags(crypto_ahash_tfm(tfm), flags); 358 } 359 360 static inline void crypto_ahash_clear_flags(struct crypto_ahash *tfm, u32 flags) 361 { 362 crypto_tfm_clear_flags(crypto_ahash_tfm(tfm), flags); 363 } 364 365 /** 366 * crypto_ahash_reqtfm() - obtain cipher handle from request 367 * @req: asynchronous request handle that contains the reference to the ahash 368 * cipher handle 369 * 370 * Return the ahash cipher handle that is registered with the asynchronous 371 * request handle ahash_request. 372 * 373 * Return: ahash cipher handle 374 */ 375 static inline struct crypto_ahash *crypto_ahash_reqtfm( 376 struct ahash_request *req) 377 { 378 return __crypto_ahash_cast(req->base.tfm); 379 } 380 381 /** 382 * crypto_ahash_reqsize() - obtain size of the request data structure 383 * @tfm: cipher handle 384 * 385 * Return: size of the request data 386 */ 387 static inline unsigned int crypto_ahash_reqsize(struct crypto_ahash *tfm) 388 { 389 return tfm->reqsize; 390 } 391 392 static inline void *ahash_request_ctx(struct ahash_request *req) 393 { 394 return req->__ctx; 395 } 396 397 /** 398 * crypto_ahash_setkey - set key for cipher handle 399 * @tfm: cipher handle 400 * @key: buffer holding the key 401 * @keylen: length of the key in bytes 402 * 403 * The caller provided key is set for the ahash cipher. The cipher 404 * handle must point to a keyed hash in order for this function to succeed. 405 * 406 * Return: 0 if the setting of the key was successful; < 0 if an error occurred 407 */ 408 int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key, 409 unsigned int keylen); 410 411 /** 412 * crypto_ahash_finup() - update and finalize message digest 413 * @req: reference to the ahash_request handle that holds all information 414 * needed to perform the cipher operation 415 * 416 * This function is a "short-hand" for the function calls of 417 * crypto_ahash_update and crypto_ahash_final. The parameters have the same 418 * meaning as discussed for those separate functions. 419 * 420 * Return: see crypto_ahash_final() 421 */ 422 int crypto_ahash_finup(struct ahash_request *req); 423 424 /** 425 * crypto_ahash_final() - calculate message digest 426 * @req: reference to the ahash_request handle that holds all information 427 * needed to perform the cipher operation 428 * 429 * Finalize the message digest operation and create the message digest 430 * based on all data added to the cipher handle. The message digest is placed 431 * into the output buffer registered with the ahash_request handle. 432 * 433 * Return: 434 * 0 if the message digest was successfully calculated; 435 * -EINPROGRESS if data is feeded into hardware (DMA) or queued for later; 436 * -EBUSY if queue is full and request should be resubmitted later; 437 * other < 0 if an error occurred 438 */ 439 int crypto_ahash_final(struct ahash_request *req); 440 441 /** 442 * crypto_ahash_digest() - calculate message digest for a buffer 443 * @req: reference to the ahash_request handle that holds all information 444 * needed to perform the cipher operation 445 * 446 * This function is a "short-hand" for the function calls of crypto_ahash_init, 447 * crypto_ahash_update and crypto_ahash_final. The parameters have the same 448 * meaning as discussed for those separate three functions. 449 * 450 * Return: see crypto_ahash_final() 451 */ 452 int crypto_ahash_digest(struct ahash_request *req); 453 454 /** 455 * crypto_ahash_export() - extract current message digest state 456 * @req: reference to the ahash_request handle whose state is exported 457 * @out: output buffer of sufficient size that can hold the hash state 458 * 459 * This function exports the hash state of the ahash_request handle into the 460 * caller-allocated output buffer out which must have sufficient size (e.g. by 461 * calling crypto_ahash_statesize()). 462 * 463 * Return: 0 if the export was successful; < 0 if an error occurred 464 */ 465 static inline int crypto_ahash_export(struct ahash_request *req, void *out) 466 { 467 return crypto_ahash_reqtfm(req)->export(req, out); 468 } 469 470 /** 471 * crypto_ahash_import() - import message digest state 472 * @req: reference to ahash_request handle the state is imported into 473 * @in: buffer holding the state 474 * 475 * This function imports the hash state into the ahash_request handle from the 476 * input buffer. That buffer should have been generated with the 477 * crypto_ahash_export function. 478 * 479 * Return: 0 if the import was successful; < 0 if an error occurred 480 */ 481 static inline int crypto_ahash_import(struct ahash_request *req, const void *in) 482 { 483 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 484 485 if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) 486 return -ENOKEY; 487 488 return tfm->import(req, in); 489 } 490 491 /** 492 * crypto_ahash_init() - (re)initialize message digest handle 493 * @req: ahash_request handle that already is initialized with all necessary 494 * data using the ahash_request_* API functions 495 * 496 * The call (re-)initializes the message digest referenced by the ahash_request 497 * handle. Any potentially existing state created by previous operations is 498 * discarded. 499 * 500 * Return: see crypto_ahash_final() 501 */ 502 static inline int crypto_ahash_init(struct ahash_request *req) 503 { 504 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 505 506 if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) 507 return -ENOKEY; 508 509 return tfm->init(req); 510 } 511 512 /** 513 * crypto_ahash_update() - add data to message digest for processing 514 * @req: ahash_request handle that was previously initialized with the 515 * crypto_ahash_init call. 516 * 517 * Updates the message digest state of the &ahash_request handle. The input data 518 * is pointed to by the scatter/gather list registered in the &ahash_request 519 * handle 520 * 521 * Return: see crypto_ahash_final() 522 */ 523 static inline int crypto_ahash_update(struct ahash_request *req) 524 { 525 return crypto_ahash_reqtfm(req)->update(req); 526 } 527 528 /** 529 * DOC: Asynchronous Hash Request Handle 530 * 531 * The &ahash_request data structure contains all pointers to data 532 * required for the asynchronous cipher operation. This includes the cipher 533 * handle (which can be used by multiple &ahash_request instances), pointer 534 * to plaintext and the message digest output buffer, asynchronous callback 535 * function, etc. It acts as a handle to the ahash_request_* API calls in a 536 * similar way as ahash handle to the crypto_ahash_* API calls. 537 */ 538 539 /** 540 * ahash_request_set_tfm() - update cipher handle reference in request 541 * @req: request handle to be modified 542 * @tfm: cipher handle that shall be added to the request handle 543 * 544 * Allow the caller to replace the existing ahash handle in the request 545 * data structure with a different one. 546 */ 547 static inline void ahash_request_set_tfm(struct ahash_request *req, 548 struct crypto_ahash *tfm) 549 { 550 req->base.tfm = crypto_ahash_tfm(tfm); 551 } 552 553 /** 554 * ahash_request_alloc() - allocate request data structure 555 * @tfm: cipher handle to be registered with the request 556 * @gfp: memory allocation flag that is handed to kmalloc by the API call. 557 * 558 * Allocate the request data structure that must be used with the ahash 559 * message digest API calls. During 560 * the allocation, the provided ahash handle 561 * is registered in the request data structure. 562 * 563 * Return: allocated request handle in case of success, or NULL if out of memory 564 */ 565 static inline struct ahash_request *ahash_request_alloc( 566 struct crypto_ahash *tfm, gfp_t gfp) 567 { 568 struct ahash_request *req; 569 570 req = kmalloc(sizeof(struct ahash_request) + 571 crypto_ahash_reqsize(tfm), gfp); 572 573 if (likely(req)) 574 ahash_request_set_tfm(req, tfm); 575 576 return req; 577 } 578 579 /** 580 * ahash_request_free() - zeroize and free the request data structure 581 * @req: request data structure cipher handle to be freed 582 */ 583 static inline void ahash_request_free(struct ahash_request *req) 584 { 585 kzfree(req); 586 } 587 588 static inline void ahash_request_zero(struct ahash_request *req) 589 { 590 memzero_explicit(req, sizeof(*req) + 591 crypto_ahash_reqsize(crypto_ahash_reqtfm(req))); 592 } 593 594 static inline struct ahash_request *ahash_request_cast( 595 struct crypto_async_request *req) 596 { 597 return container_of(req, struct ahash_request, base); 598 } 599 600 /** 601 * ahash_request_set_callback() - set asynchronous callback function 602 * @req: request handle 603 * @flags: specify zero or an ORing of the flags 604 * CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and 605 * increase the wait queue beyond the initial maximum size; 606 * CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep 607 * @compl: callback function pointer to be registered with the request handle 608 * @data: The data pointer refers to memory that is not used by the kernel 609 * crypto API, but provided to the callback function for it to use. Here, 610 * the caller can provide a reference to memory the callback function can 611 * operate on. As the callback function is invoked asynchronously to the 612 * related functionality, it may need to access data structures of the 613 * related functionality which can be referenced using this pointer. The 614 * callback function can access the memory via the "data" field in the 615 * &crypto_async_request data structure provided to the callback function. 616 * 617 * This function allows setting the callback function that is triggered once 618 * the cipher operation completes. 619 * 620 * The callback function is registered with the &ahash_request handle and 621 * must comply with the following template:: 622 * 623 * void callback_function(struct crypto_async_request *req, int error) 624 */ 625 static inline void ahash_request_set_callback(struct ahash_request *req, 626 u32 flags, 627 crypto_completion_t compl, 628 void *data) 629 { 630 req->base.complete = compl; 631 req->base.data = data; 632 req->base.flags = flags; 633 } 634 635 /** 636 * ahash_request_set_crypt() - set data buffers 637 * @req: ahash_request handle to be updated 638 * @src: source scatter/gather list 639 * @result: buffer that is filled with the message digest -- the caller must 640 * ensure that the buffer has sufficient space by, for example, calling 641 * crypto_ahash_digestsize() 642 * @nbytes: number of bytes to process from the source scatter/gather list 643 * 644 * By using this call, the caller references the source scatter/gather list. 645 * The source scatter/gather list points to the data the message digest is to 646 * be calculated for. 647 */ 648 static inline void ahash_request_set_crypt(struct ahash_request *req, 649 struct scatterlist *src, u8 *result, 650 unsigned int nbytes) 651 { 652 req->src = src; 653 req->nbytes = nbytes; 654 req->result = result; 655 } 656 657 /** 658 * DOC: Synchronous Message Digest API 659 * 660 * The synchronous message digest API is used with the ciphers of type 661 * CRYPTO_ALG_TYPE_SHASH (listed as type "shash" in /proc/crypto) 662 * 663 * The message digest API is able to maintain state information for the 664 * caller. 665 * 666 * The synchronous message digest API can store user-related context in in its 667 * shash_desc request data structure. 668 */ 669 670 /** 671 * crypto_alloc_shash() - allocate message digest handle 672 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the 673 * message digest cipher 674 * @type: specifies the type of the cipher 675 * @mask: specifies the mask for the cipher 676 * 677 * Allocate a cipher handle for a message digest. The returned &struct 678 * crypto_shash is the cipher handle that is required for any subsequent 679 * API invocation for that message digest. 680 * 681 * Return: allocated cipher handle in case of success; IS_ERR() is true in case 682 * of an error, PTR_ERR() returns the error code. 683 */ 684 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type, 685 u32 mask); 686 687 static inline struct crypto_tfm *crypto_shash_tfm(struct crypto_shash *tfm) 688 { 689 return &tfm->base; 690 } 691 692 /** 693 * crypto_free_shash() - zeroize and free the message digest handle 694 * @tfm: cipher handle to be freed 695 */ 696 static inline void crypto_free_shash(struct crypto_shash *tfm) 697 { 698 crypto_destroy_tfm(tfm, crypto_shash_tfm(tfm)); 699 } 700 701 static inline const char *crypto_shash_alg_name(struct crypto_shash *tfm) 702 { 703 return crypto_tfm_alg_name(crypto_shash_tfm(tfm)); 704 } 705 706 static inline const char *crypto_shash_driver_name(struct crypto_shash *tfm) 707 { 708 return crypto_tfm_alg_driver_name(crypto_shash_tfm(tfm)); 709 } 710 711 static inline unsigned int crypto_shash_alignmask( 712 struct crypto_shash *tfm) 713 { 714 return crypto_tfm_alg_alignmask(crypto_shash_tfm(tfm)); 715 } 716 717 /** 718 * crypto_shash_blocksize() - obtain block size for cipher 719 * @tfm: cipher handle 720 * 721 * The block size for the message digest cipher referenced with the cipher 722 * handle is returned. 723 * 724 * Return: block size of cipher 725 */ 726 static inline unsigned int crypto_shash_blocksize(struct crypto_shash *tfm) 727 { 728 return crypto_tfm_alg_blocksize(crypto_shash_tfm(tfm)); 729 } 730 731 static inline struct shash_alg *__crypto_shash_alg(struct crypto_alg *alg) 732 { 733 return container_of(alg, struct shash_alg, base); 734 } 735 736 static inline struct shash_alg *crypto_shash_alg(struct crypto_shash *tfm) 737 { 738 return __crypto_shash_alg(crypto_shash_tfm(tfm)->__crt_alg); 739 } 740 741 /** 742 * crypto_shash_digestsize() - obtain message digest size 743 * @tfm: cipher handle 744 * 745 * The size for the message digest created by the message digest cipher 746 * referenced with the cipher handle is returned. 747 * 748 * Return: digest size of cipher 749 */ 750 static inline unsigned int crypto_shash_digestsize(struct crypto_shash *tfm) 751 { 752 return crypto_shash_alg(tfm)->digestsize; 753 } 754 755 static inline unsigned int crypto_shash_statesize(struct crypto_shash *tfm) 756 { 757 return crypto_shash_alg(tfm)->statesize; 758 } 759 760 static inline u32 crypto_shash_get_flags(struct crypto_shash *tfm) 761 { 762 return crypto_tfm_get_flags(crypto_shash_tfm(tfm)); 763 } 764 765 static inline void crypto_shash_set_flags(struct crypto_shash *tfm, u32 flags) 766 { 767 crypto_tfm_set_flags(crypto_shash_tfm(tfm), flags); 768 } 769 770 static inline void crypto_shash_clear_flags(struct crypto_shash *tfm, u32 flags) 771 { 772 crypto_tfm_clear_flags(crypto_shash_tfm(tfm), flags); 773 } 774 775 /** 776 * crypto_shash_descsize() - obtain the operational state size 777 * @tfm: cipher handle 778 * 779 * The size of the operational state the cipher needs during operation is 780 * returned for the hash referenced with the cipher handle. This size is 781 * required to calculate the memory requirements to allow the caller allocating 782 * sufficient memory for operational state. 783 * 784 * The operational state is defined with struct shash_desc where the size of 785 * that data structure is to be calculated as 786 * sizeof(struct shash_desc) + crypto_shash_descsize(alg) 787 * 788 * Return: size of the operational state 789 */ 790 static inline unsigned int crypto_shash_descsize(struct crypto_shash *tfm) 791 { 792 return tfm->descsize; 793 } 794 795 static inline void *shash_desc_ctx(struct shash_desc *desc) 796 { 797 return desc->__ctx; 798 } 799 800 /** 801 * crypto_shash_setkey() - set key for message digest 802 * @tfm: cipher handle 803 * @key: buffer holding the key 804 * @keylen: length of the key in bytes 805 * 806 * The caller provided key is set for the keyed message digest cipher. The 807 * cipher handle must point to a keyed message digest cipher in order for this 808 * function to succeed. 809 * 810 * Return: 0 if the setting of the key was successful; < 0 if an error occurred 811 */ 812 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key, 813 unsigned int keylen); 814 815 /** 816 * crypto_shash_digest() - calculate message digest for buffer 817 * @desc: see crypto_shash_final() 818 * @data: see crypto_shash_update() 819 * @len: see crypto_shash_update() 820 * @out: see crypto_shash_final() 821 * 822 * This function is a "short-hand" for the function calls of crypto_shash_init, 823 * crypto_shash_update and crypto_shash_final. The parameters have the same 824 * meaning as discussed for those separate three functions. 825 * 826 * Return: 0 if the message digest creation was successful; < 0 if an error 827 * occurred 828 */ 829 int crypto_shash_digest(struct shash_desc *desc, const u8 *data, 830 unsigned int len, u8 *out); 831 832 /** 833 * crypto_shash_export() - extract operational state for message digest 834 * @desc: reference to the operational state handle whose state is exported 835 * @out: output buffer of sufficient size that can hold the hash state 836 * 837 * This function exports the hash state of the operational state handle into the 838 * caller-allocated output buffer out which must have sufficient size (e.g. by 839 * calling crypto_shash_descsize). 840 * 841 * Return: 0 if the export creation was successful; < 0 if an error occurred 842 */ 843 static inline int crypto_shash_export(struct shash_desc *desc, void *out) 844 { 845 return crypto_shash_alg(desc->tfm)->export(desc, out); 846 } 847 848 /** 849 * crypto_shash_import() - import operational state 850 * @desc: reference to the operational state handle the state imported into 851 * @in: buffer holding the state 852 * 853 * This function imports the hash state into the operational state handle from 854 * the input buffer. That buffer should have been generated with the 855 * crypto_ahash_export function. 856 * 857 * Return: 0 if the import was successful; < 0 if an error occurred 858 */ 859 static inline int crypto_shash_import(struct shash_desc *desc, const void *in) 860 { 861 struct crypto_shash *tfm = desc->tfm; 862 863 if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) 864 return -ENOKEY; 865 866 return crypto_shash_alg(tfm)->import(desc, in); 867 } 868 869 /** 870 * crypto_shash_init() - (re)initialize message digest 871 * @desc: operational state handle that is already filled 872 * 873 * The call (re-)initializes the message digest referenced by the 874 * operational state handle. Any potentially existing state created by 875 * previous operations is discarded. 876 * 877 * Return: 0 if the message digest initialization was successful; < 0 if an 878 * error occurred 879 */ 880 static inline int crypto_shash_init(struct shash_desc *desc) 881 { 882 struct crypto_shash *tfm = desc->tfm; 883 884 if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) 885 return -ENOKEY; 886 887 return crypto_shash_alg(tfm)->init(desc); 888 } 889 890 /** 891 * crypto_shash_update() - add data to message digest for processing 892 * @desc: operational state handle that is already initialized 893 * @data: input data to be added to the message digest 894 * @len: length of the input data 895 * 896 * Updates the message digest state of the operational state handle. 897 * 898 * Return: 0 if the message digest update was successful; < 0 if an error 899 * occurred 900 */ 901 int crypto_shash_update(struct shash_desc *desc, const u8 *data, 902 unsigned int len); 903 904 /** 905 * crypto_shash_final() - calculate message digest 906 * @desc: operational state handle that is already filled with data 907 * @out: output buffer filled with the message digest 908 * 909 * Finalize the message digest operation and create the message digest 910 * based on all data added to the cipher handle. The message digest is placed 911 * into the output buffer. The caller must ensure that the output buffer is 912 * large enough by using crypto_shash_digestsize. 913 * 914 * Return: 0 if the message digest creation was successful; < 0 if an error 915 * occurred 916 */ 917 int crypto_shash_final(struct shash_desc *desc, u8 *out); 918 919 /** 920 * crypto_shash_finup() - calculate message digest of buffer 921 * @desc: see crypto_shash_final() 922 * @data: see crypto_shash_update() 923 * @len: see crypto_shash_update() 924 * @out: see crypto_shash_final() 925 * 926 * This function is a "short-hand" for the function calls of 927 * crypto_shash_update and crypto_shash_final. The parameters have the same 928 * meaning as discussed for those separate functions. 929 * 930 * Return: 0 if the message digest creation was successful; < 0 if an error 931 * occurred 932 */ 933 int crypto_shash_finup(struct shash_desc *desc, const u8 *data, 934 unsigned int len, u8 *out); 935 936 static inline void shash_desc_zero(struct shash_desc *desc) 937 { 938 memzero_explicit(desc, 939 sizeof(*desc) + crypto_shash_descsize(desc->tfm)); 940 } 941 942 #endif /* _CRYPTO_HASH_H */ 943