1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Asynchronous Cryptographic Hash operations. 4 * 5 * This is the asynchronous version of hash.c with notification of 6 * completion via a callback. 7 * 8 * Copyright (c) 2008 Loc Ho <lho@amcc.com> 9 */ 10 11 #include <crypto/internal/hash.h> 12 #include <crypto/scatterwalk.h> 13 #include <linux/bug.h> 14 #include <linux/err.h> 15 #include <linux/kernel.h> 16 #include <linux/module.h> 17 #include <linux/sched.h> 18 #include <linux/slab.h> 19 #include <linux/seq_file.h> 20 #include <linux/cryptouser.h> 21 #include <linux/compiler.h> 22 #include <net/netlink.h> 23 24 #include "internal.h" 25 26 static const struct crypto_type crypto_ahash_type; 27 28 struct ahash_request_priv { 29 crypto_completion_t complete; 30 void *data; 31 u8 *result; 32 u32 flags; 33 void *ubuf[] CRYPTO_MINALIGN_ATTR; 34 }; 35 36 static inline struct ahash_alg *crypto_ahash_alg(struct crypto_ahash *hash) 37 { 38 return container_of(crypto_hash_alg_common(hash), struct ahash_alg, 39 halg); 40 } 41 42 static int hash_walk_next(struct crypto_hash_walk *walk) 43 { 44 unsigned int alignmask = walk->alignmask; 45 unsigned int offset = walk->offset; 46 unsigned int nbytes = min(walk->entrylen, 47 ((unsigned int)(PAGE_SIZE)) - offset); 48 49 if (walk->flags & CRYPTO_ALG_ASYNC) 50 walk->data = kmap(walk->pg); 51 else 52 walk->data = kmap_atomic(walk->pg); 53 walk->data += offset; 54 55 if (offset & alignmask) { 56 unsigned int unaligned = alignmask + 1 - (offset & alignmask); 57 58 if (nbytes > unaligned) 59 nbytes = unaligned; 60 } 61 62 walk->entrylen -= nbytes; 63 return nbytes; 64 } 65 66 static int hash_walk_new_entry(struct crypto_hash_walk *walk) 67 { 68 struct scatterlist *sg; 69 70 sg = walk->sg; 71 walk->offset = sg->offset; 72 walk->pg = sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT); 73 walk->offset = offset_in_page(walk->offset); 74 walk->entrylen = sg->length; 75 76 if (walk->entrylen > walk->total) 77 walk->entrylen = walk->total; 78 walk->total -= walk->entrylen; 79 80 return hash_walk_next(walk); 81 } 82 83 int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err) 84 { 85 unsigned int alignmask = walk->alignmask; 86 87 walk->data -= walk->offset; 88 89 if (walk->entrylen && (walk->offset & alignmask) && !err) { 90 unsigned int nbytes; 91 92 walk->offset = ALIGN(walk->offset, alignmask + 1); 93 nbytes = min(walk->entrylen, 94 (unsigned int)(PAGE_SIZE - walk->offset)); 95 if (nbytes) { 96 walk->entrylen -= nbytes; 97 walk->data += walk->offset; 98 return nbytes; 99 } 100 } 101 102 if (walk->flags & CRYPTO_ALG_ASYNC) 103 kunmap(walk->pg); 104 else { 105 kunmap_atomic(walk->data); 106 /* 107 * The may sleep test only makes sense for sync users. 108 * Async users don't need to sleep here anyway. 109 */ 110 crypto_yield(walk->flags); 111 } 112 113 if (err) 114 return err; 115 116 if (walk->entrylen) { 117 walk->offset = 0; 118 walk->pg++; 119 return hash_walk_next(walk); 120 } 121 122 if (!walk->total) 123 return 0; 124 125 walk->sg = sg_next(walk->sg); 126 127 return hash_walk_new_entry(walk); 128 } 129 EXPORT_SYMBOL_GPL(crypto_hash_walk_done); 130 131 int crypto_hash_walk_first(struct ahash_request *req, 132 struct crypto_hash_walk *walk) 133 { 134 walk->total = req->nbytes; 135 136 if (!walk->total) { 137 walk->entrylen = 0; 138 return 0; 139 } 140 141 walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req)); 142 walk->sg = req->src; 143 walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK; 144 145 return hash_walk_new_entry(walk); 146 } 147 EXPORT_SYMBOL_GPL(crypto_hash_walk_first); 148 149 int crypto_ahash_walk_first(struct ahash_request *req, 150 struct crypto_hash_walk *walk) 151 { 152 walk->total = req->nbytes; 153 154 if (!walk->total) { 155 walk->entrylen = 0; 156 return 0; 157 } 158 159 walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req)); 160 walk->sg = req->src; 161 walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK; 162 walk->flags |= CRYPTO_ALG_ASYNC; 163 164 BUILD_BUG_ON(CRYPTO_TFM_REQ_MASK & CRYPTO_ALG_ASYNC); 165 166 return hash_walk_new_entry(walk); 167 } 168 EXPORT_SYMBOL_GPL(crypto_ahash_walk_first); 169 170 static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key, 171 unsigned int keylen) 172 { 173 unsigned long alignmask = crypto_ahash_alignmask(tfm); 174 int ret; 175 u8 *buffer, *alignbuffer; 176 unsigned long absize; 177 178 absize = keylen + alignmask; 179 buffer = kmalloc(absize, GFP_KERNEL); 180 if (!buffer) 181 return -ENOMEM; 182 183 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); 184 memcpy(alignbuffer, key, keylen); 185 ret = tfm->setkey(tfm, alignbuffer, keylen); 186 kfree_sensitive(buffer); 187 return ret; 188 } 189 190 static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key, 191 unsigned int keylen) 192 { 193 return -ENOSYS; 194 } 195 196 static void ahash_set_needkey(struct crypto_ahash *tfm) 197 { 198 const struct hash_alg_common *alg = crypto_hash_alg_common(tfm); 199 200 if (tfm->setkey != ahash_nosetkey && 201 !(alg->base.cra_flags & CRYPTO_ALG_OPTIONAL_KEY)) 202 crypto_ahash_set_flags(tfm, CRYPTO_TFM_NEED_KEY); 203 } 204 205 int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key, 206 unsigned int keylen) 207 { 208 unsigned long alignmask = crypto_ahash_alignmask(tfm); 209 int err; 210 211 if ((unsigned long)key & alignmask) 212 err = ahash_setkey_unaligned(tfm, key, keylen); 213 else 214 err = tfm->setkey(tfm, key, keylen); 215 216 if (unlikely(err)) { 217 ahash_set_needkey(tfm); 218 return err; 219 } 220 221 crypto_ahash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY); 222 return 0; 223 } 224 EXPORT_SYMBOL_GPL(crypto_ahash_setkey); 225 226 static inline unsigned int ahash_align_buffer_size(unsigned len, 227 unsigned long mask) 228 { 229 return len + (mask & ~(crypto_tfm_ctx_alignment() - 1)); 230 } 231 232 static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt) 233 { 234 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 235 unsigned long alignmask = crypto_ahash_alignmask(tfm); 236 unsigned int ds = crypto_ahash_digestsize(tfm); 237 struct ahash_request_priv *priv; 238 239 priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask), 240 (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? 241 GFP_KERNEL : GFP_ATOMIC); 242 if (!priv) 243 return -ENOMEM; 244 245 /* 246 * WARNING: Voodoo programming below! 247 * 248 * The code below is obscure and hard to understand, thus explanation 249 * is necessary. See include/crypto/hash.h and include/linux/crypto.h 250 * to understand the layout of structures used here! 251 * 252 * The code here will replace portions of the ORIGINAL request with 253 * pointers to new code and buffers so the hashing operation can store 254 * the result in aligned buffer. We will call the modified request 255 * an ADJUSTED request. 256 * 257 * The newly mangled request will look as such: 258 * 259 * req { 260 * .result = ADJUSTED[new aligned buffer] 261 * .base.complete = ADJUSTED[pointer to completion function] 262 * .base.data = ADJUSTED[*req (pointer to self)] 263 * .priv = ADJUSTED[new priv] { 264 * .result = ORIGINAL(result) 265 * .complete = ORIGINAL(base.complete) 266 * .data = ORIGINAL(base.data) 267 * } 268 */ 269 270 priv->result = req->result; 271 priv->complete = req->base.complete; 272 priv->data = req->base.data; 273 priv->flags = req->base.flags; 274 275 /* 276 * WARNING: We do not backup req->priv here! The req->priv 277 * is for internal use of the Crypto API and the 278 * user must _NOT_ _EVER_ depend on it's content! 279 */ 280 281 req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1); 282 req->base.complete = cplt; 283 req->base.data = req; 284 req->priv = priv; 285 286 return 0; 287 } 288 289 static void ahash_restore_req(struct ahash_request *req, int err) 290 { 291 struct ahash_request_priv *priv = req->priv; 292 293 if (!err) 294 memcpy(priv->result, req->result, 295 crypto_ahash_digestsize(crypto_ahash_reqtfm(req))); 296 297 /* Restore the original crypto request. */ 298 req->result = priv->result; 299 300 ahash_request_set_callback(req, priv->flags, 301 priv->complete, priv->data); 302 req->priv = NULL; 303 304 /* Free the req->priv.priv from the ADJUSTED request. */ 305 kfree_sensitive(priv); 306 } 307 308 static void ahash_notify_einprogress(struct ahash_request *req) 309 { 310 struct ahash_request_priv *priv = req->priv; 311 struct crypto_async_request oreq; 312 313 oreq.data = priv->data; 314 315 priv->complete(&oreq, -EINPROGRESS); 316 } 317 318 static void ahash_op_unaligned_done(struct crypto_async_request *req, int err) 319 { 320 struct ahash_request *areq = req->data; 321 322 if (err == -EINPROGRESS) { 323 ahash_notify_einprogress(areq); 324 return; 325 } 326 327 /* 328 * Restore the original request, see ahash_op_unaligned() for what 329 * goes where. 330 * 331 * The "struct ahash_request *req" here is in fact the "req.base" 332 * from the ADJUSTED request from ahash_op_unaligned(), thus as it 333 * is a pointer to self, it is also the ADJUSTED "req" . 334 */ 335 336 /* First copy req->result into req->priv.result */ 337 ahash_restore_req(areq, err); 338 339 /* Complete the ORIGINAL request. */ 340 areq->base.complete(&areq->base, err); 341 } 342 343 static int ahash_op_unaligned(struct ahash_request *req, 344 int (*op)(struct ahash_request *)) 345 { 346 int err; 347 348 err = ahash_save_req(req, ahash_op_unaligned_done); 349 if (err) 350 return err; 351 352 err = op(req); 353 if (err == -EINPROGRESS || err == -EBUSY) 354 return err; 355 356 ahash_restore_req(req, err); 357 358 return err; 359 } 360 361 static int crypto_ahash_op(struct ahash_request *req, 362 int (*op)(struct ahash_request *)) 363 { 364 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 365 unsigned long alignmask = crypto_ahash_alignmask(tfm); 366 367 if ((unsigned long)req->result & alignmask) 368 return ahash_op_unaligned(req, op); 369 370 return op(req); 371 } 372 373 int crypto_ahash_final(struct ahash_request *req) 374 { 375 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 376 struct crypto_alg *alg = tfm->base.__crt_alg; 377 unsigned int nbytes = req->nbytes; 378 int ret; 379 380 crypto_stats_get(alg); 381 ret = crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final); 382 crypto_stats_ahash_final(nbytes, ret, alg); 383 return ret; 384 } 385 EXPORT_SYMBOL_GPL(crypto_ahash_final); 386 387 int crypto_ahash_finup(struct ahash_request *req) 388 { 389 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 390 struct crypto_alg *alg = tfm->base.__crt_alg; 391 unsigned int nbytes = req->nbytes; 392 int ret; 393 394 crypto_stats_get(alg); 395 ret = crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup); 396 crypto_stats_ahash_final(nbytes, ret, alg); 397 return ret; 398 } 399 EXPORT_SYMBOL_GPL(crypto_ahash_finup); 400 401 int crypto_ahash_digest(struct ahash_request *req) 402 { 403 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 404 struct crypto_alg *alg = tfm->base.__crt_alg; 405 unsigned int nbytes = req->nbytes; 406 int ret; 407 408 crypto_stats_get(alg); 409 if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) 410 ret = -ENOKEY; 411 else 412 ret = crypto_ahash_op(req, tfm->digest); 413 crypto_stats_ahash_final(nbytes, ret, alg); 414 return ret; 415 } 416 EXPORT_SYMBOL_GPL(crypto_ahash_digest); 417 418 static void ahash_def_finup_done2(struct crypto_async_request *req, int err) 419 { 420 struct ahash_request *areq = req->data; 421 422 if (err == -EINPROGRESS) 423 return; 424 425 ahash_restore_req(areq, err); 426 427 areq->base.complete(&areq->base, err); 428 } 429 430 static int ahash_def_finup_finish1(struct ahash_request *req, int err) 431 { 432 if (err) 433 goto out; 434 435 req->base.complete = ahash_def_finup_done2; 436 437 err = crypto_ahash_reqtfm(req)->final(req); 438 if (err == -EINPROGRESS || err == -EBUSY) 439 return err; 440 441 out: 442 ahash_restore_req(req, err); 443 return err; 444 } 445 446 static void ahash_def_finup_done1(struct crypto_async_request *req, int err) 447 { 448 struct ahash_request *areq = req->data; 449 450 if (err == -EINPROGRESS) { 451 ahash_notify_einprogress(areq); 452 return; 453 } 454 455 areq->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP; 456 457 err = ahash_def_finup_finish1(areq, err); 458 if (areq->priv) 459 return; 460 461 areq->base.complete(&areq->base, err); 462 } 463 464 static int ahash_def_finup(struct ahash_request *req) 465 { 466 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 467 int err; 468 469 err = ahash_save_req(req, ahash_def_finup_done1); 470 if (err) 471 return err; 472 473 err = tfm->update(req); 474 if (err == -EINPROGRESS || err == -EBUSY) 475 return err; 476 477 return ahash_def_finup_finish1(req, err); 478 } 479 480 static int crypto_ahash_init_tfm(struct crypto_tfm *tfm) 481 { 482 struct crypto_ahash *hash = __crypto_ahash_cast(tfm); 483 struct ahash_alg *alg = crypto_ahash_alg(hash); 484 485 hash->setkey = ahash_nosetkey; 486 487 if (tfm->__crt_alg->cra_type != &crypto_ahash_type) 488 return crypto_init_shash_ops_async(tfm); 489 490 hash->init = alg->init; 491 hash->update = alg->update; 492 hash->final = alg->final; 493 hash->finup = alg->finup ?: ahash_def_finup; 494 hash->digest = alg->digest; 495 hash->export = alg->export; 496 hash->import = alg->import; 497 498 if (alg->setkey) { 499 hash->setkey = alg->setkey; 500 ahash_set_needkey(hash); 501 } 502 503 return 0; 504 } 505 506 static unsigned int crypto_ahash_extsize(struct crypto_alg *alg) 507 { 508 if (alg->cra_type != &crypto_ahash_type) 509 return sizeof(struct crypto_shash *); 510 511 return crypto_alg_extsize(alg); 512 } 513 514 static void crypto_ahash_free_instance(struct crypto_instance *inst) 515 { 516 struct ahash_instance *ahash = ahash_instance(inst); 517 518 ahash->free(ahash); 519 } 520 521 #ifdef CONFIG_NET 522 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg) 523 { 524 struct crypto_report_hash rhash; 525 526 memset(&rhash, 0, sizeof(rhash)); 527 528 strscpy(rhash.type, "ahash", sizeof(rhash.type)); 529 530 rhash.blocksize = alg->cra_blocksize; 531 rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize; 532 533 return nla_put(skb, CRYPTOCFGA_REPORT_HASH, sizeof(rhash), &rhash); 534 } 535 #else 536 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg) 537 { 538 return -ENOSYS; 539 } 540 #endif 541 542 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg) 543 __maybe_unused; 544 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg) 545 { 546 seq_printf(m, "type : ahash\n"); 547 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ? 548 "yes" : "no"); 549 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); 550 seq_printf(m, "digestsize : %u\n", 551 __crypto_hash_alg_common(alg)->digestsize); 552 } 553 554 static const struct crypto_type crypto_ahash_type = { 555 .extsize = crypto_ahash_extsize, 556 .init_tfm = crypto_ahash_init_tfm, 557 .free = crypto_ahash_free_instance, 558 #ifdef CONFIG_PROC_FS 559 .show = crypto_ahash_show, 560 #endif 561 .report = crypto_ahash_report, 562 .maskclear = ~CRYPTO_ALG_TYPE_MASK, 563 .maskset = CRYPTO_ALG_TYPE_AHASH_MASK, 564 .type = CRYPTO_ALG_TYPE_AHASH, 565 .tfmsize = offsetof(struct crypto_ahash, base), 566 }; 567 568 int crypto_grab_ahash(struct crypto_ahash_spawn *spawn, 569 struct crypto_instance *inst, 570 const char *name, u32 type, u32 mask) 571 { 572 spawn->base.frontend = &crypto_ahash_type; 573 return crypto_grab_spawn(&spawn->base, inst, name, type, mask); 574 } 575 EXPORT_SYMBOL_GPL(crypto_grab_ahash); 576 577 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type, 578 u32 mask) 579 { 580 return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask); 581 } 582 EXPORT_SYMBOL_GPL(crypto_alloc_ahash); 583 584 int crypto_has_ahash(const char *alg_name, u32 type, u32 mask) 585 { 586 return crypto_type_has_alg(alg_name, &crypto_ahash_type, type, mask); 587 } 588 EXPORT_SYMBOL_GPL(crypto_has_ahash); 589 590 static int ahash_prepare_alg(struct ahash_alg *alg) 591 { 592 struct crypto_alg *base = &alg->halg.base; 593 594 if (alg->halg.digestsize > HASH_MAX_DIGESTSIZE || 595 alg->halg.statesize > HASH_MAX_STATESIZE || 596 alg->halg.statesize == 0) 597 return -EINVAL; 598 599 base->cra_type = &crypto_ahash_type; 600 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; 601 base->cra_flags |= CRYPTO_ALG_TYPE_AHASH; 602 603 return 0; 604 } 605 606 int crypto_register_ahash(struct ahash_alg *alg) 607 { 608 struct crypto_alg *base = &alg->halg.base; 609 int err; 610 611 err = ahash_prepare_alg(alg); 612 if (err) 613 return err; 614 615 return crypto_register_alg(base); 616 } 617 EXPORT_SYMBOL_GPL(crypto_register_ahash); 618 619 void crypto_unregister_ahash(struct ahash_alg *alg) 620 { 621 crypto_unregister_alg(&alg->halg.base); 622 } 623 EXPORT_SYMBOL_GPL(crypto_unregister_ahash); 624 625 int crypto_register_ahashes(struct ahash_alg *algs, int count) 626 { 627 int i, ret; 628 629 for (i = 0; i < count; i++) { 630 ret = crypto_register_ahash(&algs[i]); 631 if (ret) 632 goto err; 633 } 634 635 return 0; 636 637 err: 638 for (--i; i >= 0; --i) 639 crypto_unregister_ahash(&algs[i]); 640 641 return ret; 642 } 643 EXPORT_SYMBOL_GPL(crypto_register_ahashes); 644 645 void crypto_unregister_ahashes(struct ahash_alg *algs, int count) 646 { 647 int i; 648 649 for (i = count - 1; i >= 0; --i) 650 crypto_unregister_ahash(&algs[i]); 651 } 652 EXPORT_SYMBOL_GPL(crypto_unregister_ahashes); 653 654 int ahash_register_instance(struct crypto_template *tmpl, 655 struct ahash_instance *inst) 656 { 657 int err; 658 659 if (WARN_ON(!inst->free)) 660 return -EINVAL; 661 662 err = ahash_prepare_alg(&inst->alg); 663 if (err) 664 return err; 665 666 return crypto_register_instance(tmpl, ahash_crypto_instance(inst)); 667 } 668 EXPORT_SYMBOL_GPL(ahash_register_instance); 669 670 bool crypto_hash_alg_has_setkey(struct hash_alg_common *halg) 671 { 672 struct crypto_alg *alg = &halg->base; 673 674 if (alg->cra_type != &crypto_ahash_type) 675 return crypto_shash_alg_has_setkey(__crypto_shash_alg(alg)); 676 677 return __crypto_ahash_alg(alg)->setkey != NULL; 678 } 679 EXPORT_SYMBOL_GPL(crypto_hash_alg_has_setkey); 680 681 MODULE_LICENSE("GPL"); 682 MODULE_DESCRIPTION("Asynchronous cryptographic hash type"); 683