1 /* 2 * Asynchronous Cryptographic Hash operations. 3 * 4 * This is the asynchronous version of hash.c with notification of 5 * completion via a callback. 6 * 7 * Copyright (c) 2008 Loc Ho <lho@amcc.com> 8 * 9 * This program is free software; you can redistribute it and/or modify it 10 * under the terms of the GNU General Public License as published by the Free 11 * Software Foundation; either version 2 of the License, or (at your option) 12 * any later version. 13 * 14 */ 15 16 #include <crypto/internal/hash.h> 17 #include <crypto/scatterwalk.h> 18 #include <linux/bug.h> 19 #include <linux/err.h> 20 #include <linux/kernel.h> 21 #include <linux/module.h> 22 #include <linux/sched.h> 23 #include <linux/slab.h> 24 #include <linux/seq_file.h> 25 #include <linux/cryptouser.h> 26 #include <linux/compiler.h> 27 #include <net/netlink.h> 28 29 #include "internal.h" 30 31 struct ahash_request_priv { 32 crypto_completion_t complete; 33 void *data; 34 u8 *result; 35 u32 flags; 36 void *ubuf[] CRYPTO_MINALIGN_ATTR; 37 }; 38 39 static inline struct ahash_alg *crypto_ahash_alg(struct crypto_ahash *hash) 40 { 41 return container_of(crypto_hash_alg_common(hash), struct ahash_alg, 42 halg); 43 } 44 45 static int hash_walk_next(struct crypto_hash_walk *walk) 46 { 47 unsigned int alignmask = walk->alignmask; 48 unsigned int offset = walk->offset; 49 unsigned int nbytes = min(walk->entrylen, 50 ((unsigned int)(PAGE_SIZE)) - offset); 51 52 if (walk->flags & CRYPTO_ALG_ASYNC) 53 walk->data = kmap(walk->pg); 54 else 55 walk->data = kmap_atomic(walk->pg); 56 walk->data += offset; 57 58 if (offset & alignmask) { 59 unsigned int unaligned = alignmask + 1 - (offset & alignmask); 60 61 if (nbytes > unaligned) 62 nbytes = unaligned; 63 } 64 65 walk->entrylen -= nbytes; 66 return nbytes; 67 } 68 69 static int hash_walk_new_entry(struct crypto_hash_walk *walk) 70 { 71 struct scatterlist *sg; 72 73 sg = walk->sg; 74 walk->offset = sg->offset; 75 walk->pg = sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT); 76 walk->offset = offset_in_page(walk->offset); 77 walk->entrylen = sg->length; 78 79 if (walk->entrylen > walk->total) 80 walk->entrylen = walk->total; 81 walk->total -= walk->entrylen; 82 83 return hash_walk_next(walk); 84 } 85 86 int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err) 87 { 88 unsigned int alignmask = walk->alignmask; 89 unsigned int nbytes = walk->entrylen; 90 91 walk->data -= walk->offset; 92 93 if (nbytes && walk->offset & alignmask && !err) { 94 walk->offset = ALIGN(walk->offset, alignmask + 1); 95 nbytes = min(nbytes, 96 ((unsigned int)(PAGE_SIZE)) - walk->offset); 97 walk->entrylen -= nbytes; 98 99 if (nbytes) { 100 walk->data += walk->offset; 101 return nbytes; 102 } 103 } 104 105 if (walk->flags & CRYPTO_ALG_ASYNC) 106 kunmap(walk->pg); 107 else { 108 kunmap_atomic(walk->data); 109 /* 110 * The may sleep test only makes sense for sync users. 111 * Async users don't need to sleep here anyway. 112 */ 113 crypto_yield(walk->flags); 114 } 115 116 if (err) 117 return err; 118 119 if (nbytes) { 120 walk->offset = 0; 121 walk->pg++; 122 return hash_walk_next(walk); 123 } 124 125 if (!walk->total) 126 return 0; 127 128 walk->sg = sg_next(walk->sg); 129 130 return hash_walk_new_entry(walk); 131 } 132 EXPORT_SYMBOL_GPL(crypto_hash_walk_done); 133 134 int crypto_hash_walk_first(struct ahash_request *req, 135 struct crypto_hash_walk *walk) 136 { 137 walk->total = req->nbytes; 138 139 if (!walk->total) { 140 walk->entrylen = 0; 141 return 0; 142 } 143 144 walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req)); 145 walk->sg = req->src; 146 walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK; 147 148 return hash_walk_new_entry(walk); 149 } 150 EXPORT_SYMBOL_GPL(crypto_hash_walk_first); 151 152 int crypto_ahash_walk_first(struct ahash_request *req, 153 struct crypto_hash_walk *walk) 154 { 155 walk->total = req->nbytes; 156 157 if (!walk->total) { 158 walk->entrylen = 0; 159 return 0; 160 } 161 162 walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req)); 163 walk->sg = req->src; 164 walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK; 165 walk->flags |= CRYPTO_ALG_ASYNC; 166 167 BUILD_BUG_ON(CRYPTO_TFM_REQ_MASK & CRYPTO_ALG_ASYNC); 168 169 return hash_walk_new_entry(walk); 170 } 171 EXPORT_SYMBOL_GPL(crypto_ahash_walk_first); 172 173 static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key, 174 unsigned int keylen) 175 { 176 unsigned long alignmask = crypto_ahash_alignmask(tfm); 177 int ret; 178 u8 *buffer, *alignbuffer; 179 unsigned long absize; 180 181 absize = keylen + alignmask; 182 buffer = kmalloc(absize, GFP_KERNEL); 183 if (!buffer) 184 return -ENOMEM; 185 186 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); 187 memcpy(alignbuffer, key, keylen); 188 ret = tfm->setkey(tfm, alignbuffer, keylen); 189 kzfree(buffer); 190 return ret; 191 } 192 193 int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key, 194 unsigned int keylen) 195 { 196 unsigned long alignmask = crypto_ahash_alignmask(tfm); 197 int err; 198 199 if ((unsigned long)key & alignmask) 200 err = ahash_setkey_unaligned(tfm, key, keylen); 201 else 202 err = tfm->setkey(tfm, key, keylen); 203 204 if (err) 205 return err; 206 207 crypto_ahash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY); 208 return 0; 209 } 210 EXPORT_SYMBOL_GPL(crypto_ahash_setkey); 211 212 static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key, 213 unsigned int keylen) 214 { 215 return -ENOSYS; 216 } 217 218 static inline unsigned int ahash_align_buffer_size(unsigned len, 219 unsigned long mask) 220 { 221 return len + (mask & ~(crypto_tfm_ctx_alignment() - 1)); 222 } 223 224 static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt) 225 { 226 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 227 unsigned long alignmask = crypto_ahash_alignmask(tfm); 228 unsigned int ds = crypto_ahash_digestsize(tfm); 229 struct ahash_request_priv *priv; 230 231 priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask), 232 (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? 233 GFP_KERNEL : GFP_ATOMIC); 234 if (!priv) 235 return -ENOMEM; 236 237 /* 238 * WARNING: Voodoo programming below! 239 * 240 * The code below is obscure and hard to understand, thus explanation 241 * is necessary. See include/crypto/hash.h and include/linux/crypto.h 242 * to understand the layout of structures used here! 243 * 244 * The code here will replace portions of the ORIGINAL request with 245 * pointers to new code and buffers so the hashing operation can store 246 * the result in aligned buffer. We will call the modified request 247 * an ADJUSTED request. 248 * 249 * The newly mangled request will look as such: 250 * 251 * req { 252 * .result = ADJUSTED[new aligned buffer] 253 * .base.complete = ADJUSTED[pointer to completion function] 254 * .base.data = ADJUSTED[*req (pointer to self)] 255 * .priv = ADJUSTED[new priv] { 256 * .result = ORIGINAL(result) 257 * .complete = ORIGINAL(base.complete) 258 * .data = ORIGINAL(base.data) 259 * } 260 */ 261 262 priv->result = req->result; 263 priv->complete = req->base.complete; 264 priv->data = req->base.data; 265 priv->flags = req->base.flags; 266 267 /* 268 * WARNING: We do not backup req->priv here! The req->priv 269 * is for internal use of the Crypto API and the 270 * user must _NOT_ _EVER_ depend on it's content! 271 */ 272 273 req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1); 274 req->base.complete = cplt; 275 req->base.data = req; 276 req->priv = priv; 277 278 return 0; 279 } 280 281 static void ahash_restore_req(struct ahash_request *req, int err) 282 { 283 struct ahash_request_priv *priv = req->priv; 284 285 if (!err) 286 memcpy(priv->result, req->result, 287 crypto_ahash_digestsize(crypto_ahash_reqtfm(req))); 288 289 /* Restore the original crypto request. */ 290 req->result = priv->result; 291 292 ahash_request_set_callback(req, priv->flags, 293 priv->complete, priv->data); 294 req->priv = NULL; 295 296 /* Free the req->priv.priv from the ADJUSTED request. */ 297 kzfree(priv); 298 } 299 300 static void ahash_notify_einprogress(struct ahash_request *req) 301 { 302 struct ahash_request_priv *priv = req->priv; 303 struct crypto_async_request oreq; 304 305 oreq.data = priv->data; 306 307 priv->complete(&oreq, -EINPROGRESS); 308 } 309 310 static void ahash_op_unaligned_done(struct crypto_async_request *req, int err) 311 { 312 struct ahash_request *areq = req->data; 313 314 if (err == -EINPROGRESS) { 315 ahash_notify_einprogress(areq); 316 return; 317 } 318 319 /* 320 * Restore the original request, see ahash_op_unaligned() for what 321 * goes where. 322 * 323 * The "struct ahash_request *req" here is in fact the "req.base" 324 * from the ADJUSTED request from ahash_op_unaligned(), thus as it 325 * is a pointer to self, it is also the ADJUSTED "req" . 326 */ 327 328 /* First copy req->result into req->priv.result */ 329 ahash_restore_req(areq, err); 330 331 /* Complete the ORIGINAL request. */ 332 areq->base.complete(&areq->base, err); 333 } 334 335 static int ahash_op_unaligned(struct ahash_request *req, 336 int (*op)(struct ahash_request *)) 337 { 338 int err; 339 340 err = ahash_save_req(req, ahash_op_unaligned_done); 341 if (err) 342 return err; 343 344 err = op(req); 345 if (err == -EINPROGRESS || err == -EBUSY) 346 return err; 347 348 ahash_restore_req(req, err); 349 350 return err; 351 } 352 353 static int crypto_ahash_op(struct ahash_request *req, 354 int (*op)(struct ahash_request *)) 355 { 356 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 357 unsigned long alignmask = crypto_ahash_alignmask(tfm); 358 359 if ((unsigned long)req->result & alignmask) 360 return ahash_op_unaligned(req, op); 361 362 return op(req); 363 } 364 365 int crypto_ahash_final(struct ahash_request *req) 366 { 367 int ret; 368 369 ret = crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final); 370 crypto_stat_ahash_final(req, ret); 371 return ret; 372 } 373 EXPORT_SYMBOL_GPL(crypto_ahash_final); 374 375 int crypto_ahash_finup(struct ahash_request *req) 376 { 377 int ret; 378 379 ret = crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup); 380 crypto_stat_ahash_final(req, ret); 381 return ret; 382 } 383 EXPORT_SYMBOL_GPL(crypto_ahash_finup); 384 385 int crypto_ahash_digest(struct ahash_request *req) 386 { 387 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 388 int ret; 389 390 if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) 391 ret = -ENOKEY; 392 else 393 ret = crypto_ahash_op(req, tfm->digest); 394 crypto_stat_ahash_final(req, ret); 395 return ret; 396 } 397 EXPORT_SYMBOL_GPL(crypto_ahash_digest); 398 399 static void ahash_def_finup_done2(struct crypto_async_request *req, int err) 400 { 401 struct ahash_request *areq = req->data; 402 403 if (err == -EINPROGRESS) 404 return; 405 406 ahash_restore_req(areq, err); 407 408 areq->base.complete(&areq->base, err); 409 } 410 411 static int ahash_def_finup_finish1(struct ahash_request *req, int err) 412 { 413 if (err) 414 goto out; 415 416 req->base.complete = ahash_def_finup_done2; 417 418 err = crypto_ahash_reqtfm(req)->final(req); 419 if (err == -EINPROGRESS || err == -EBUSY) 420 return err; 421 422 out: 423 ahash_restore_req(req, err); 424 return err; 425 } 426 427 static void ahash_def_finup_done1(struct crypto_async_request *req, int err) 428 { 429 struct ahash_request *areq = req->data; 430 431 if (err == -EINPROGRESS) { 432 ahash_notify_einprogress(areq); 433 return; 434 } 435 436 areq->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP; 437 438 err = ahash_def_finup_finish1(areq, err); 439 if (areq->priv) 440 return; 441 442 areq->base.complete(&areq->base, err); 443 } 444 445 static int ahash_def_finup(struct ahash_request *req) 446 { 447 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 448 int err; 449 450 err = ahash_save_req(req, ahash_def_finup_done1); 451 if (err) 452 return err; 453 454 err = tfm->update(req); 455 if (err == -EINPROGRESS || err == -EBUSY) 456 return err; 457 458 return ahash_def_finup_finish1(req, err); 459 } 460 461 static int crypto_ahash_init_tfm(struct crypto_tfm *tfm) 462 { 463 struct crypto_ahash *hash = __crypto_ahash_cast(tfm); 464 struct ahash_alg *alg = crypto_ahash_alg(hash); 465 466 hash->setkey = ahash_nosetkey; 467 468 if (tfm->__crt_alg->cra_type != &crypto_ahash_type) 469 return crypto_init_shash_ops_async(tfm); 470 471 hash->init = alg->init; 472 hash->update = alg->update; 473 hash->final = alg->final; 474 hash->finup = alg->finup ?: ahash_def_finup; 475 hash->digest = alg->digest; 476 hash->export = alg->export; 477 hash->import = alg->import; 478 479 if (alg->setkey) { 480 hash->setkey = alg->setkey; 481 if (!(alg->halg.base.cra_flags & CRYPTO_ALG_OPTIONAL_KEY)) 482 crypto_ahash_set_flags(hash, CRYPTO_TFM_NEED_KEY); 483 } 484 485 return 0; 486 } 487 488 static unsigned int crypto_ahash_extsize(struct crypto_alg *alg) 489 { 490 if (alg->cra_type != &crypto_ahash_type) 491 return sizeof(struct crypto_shash *); 492 493 return crypto_alg_extsize(alg); 494 } 495 496 #ifdef CONFIG_NET 497 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg) 498 { 499 struct crypto_report_hash rhash; 500 501 strncpy(rhash.type, "ahash", sizeof(rhash.type)); 502 503 rhash.blocksize = alg->cra_blocksize; 504 rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize; 505 506 if (nla_put(skb, CRYPTOCFGA_REPORT_HASH, 507 sizeof(struct crypto_report_hash), &rhash)) 508 goto nla_put_failure; 509 return 0; 510 511 nla_put_failure: 512 return -EMSGSIZE; 513 } 514 #else 515 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg) 516 { 517 return -ENOSYS; 518 } 519 #endif 520 521 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg) 522 __maybe_unused; 523 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg) 524 { 525 seq_printf(m, "type : ahash\n"); 526 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ? 527 "yes" : "no"); 528 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); 529 seq_printf(m, "digestsize : %u\n", 530 __crypto_hash_alg_common(alg)->digestsize); 531 } 532 533 const struct crypto_type crypto_ahash_type = { 534 .extsize = crypto_ahash_extsize, 535 .init_tfm = crypto_ahash_init_tfm, 536 #ifdef CONFIG_PROC_FS 537 .show = crypto_ahash_show, 538 #endif 539 .report = crypto_ahash_report, 540 .maskclear = ~CRYPTO_ALG_TYPE_MASK, 541 .maskset = CRYPTO_ALG_TYPE_AHASH_MASK, 542 .type = CRYPTO_ALG_TYPE_AHASH, 543 .tfmsize = offsetof(struct crypto_ahash, base), 544 }; 545 EXPORT_SYMBOL_GPL(crypto_ahash_type); 546 547 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type, 548 u32 mask) 549 { 550 return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask); 551 } 552 EXPORT_SYMBOL_GPL(crypto_alloc_ahash); 553 554 int crypto_has_ahash(const char *alg_name, u32 type, u32 mask) 555 { 556 return crypto_type_has_alg(alg_name, &crypto_ahash_type, type, mask); 557 } 558 EXPORT_SYMBOL_GPL(crypto_has_ahash); 559 560 static int ahash_prepare_alg(struct ahash_alg *alg) 561 { 562 struct crypto_alg *base = &alg->halg.base; 563 564 if (alg->halg.digestsize > HASH_MAX_DIGESTSIZE || 565 alg->halg.statesize > HASH_MAX_STATESIZE || 566 alg->halg.statesize == 0) 567 return -EINVAL; 568 569 base->cra_type = &crypto_ahash_type; 570 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; 571 base->cra_flags |= CRYPTO_ALG_TYPE_AHASH; 572 573 return 0; 574 } 575 576 int crypto_register_ahash(struct ahash_alg *alg) 577 { 578 struct crypto_alg *base = &alg->halg.base; 579 int err; 580 581 err = ahash_prepare_alg(alg); 582 if (err) 583 return err; 584 585 return crypto_register_alg(base); 586 } 587 EXPORT_SYMBOL_GPL(crypto_register_ahash); 588 589 int crypto_unregister_ahash(struct ahash_alg *alg) 590 { 591 return crypto_unregister_alg(&alg->halg.base); 592 } 593 EXPORT_SYMBOL_GPL(crypto_unregister_ahash); 594 595 int crypto_register_ahashes(struct ahash_alg *algs, int count) 596 { 597 int i, ret; 598 599 for (i = 0; i < count; i++) { 600 ret = crypto_register_ahash(&algs[i]); 601 if (ret) 602 goto err; 603 } 604 605 return 0; 606 607 err: 608 for (--i; i >= 0; --i) 609 crypto_unregister_ahash(&algs[i]); 610 611 return ret; 612 } 613 EXPORT_SYMBOL_GPL(crypto_register_ahashes); 614 615 void crypto_unregister_ahashes(struct ahash_alg *algs, int count) 616 { 617 int i; 618 619 for (i = count - 1; i >= 0; --i) 620 crypto_unregister_ahash(&algs[i]); 621 } 622 EXPORT_SYMBOL_GPL(crypto_unregister_ahashes); 623 624 int ahash_register_instance(struct crypto_template *tmpl, 625 struct ahash_instance *inst) 626 { 627 int err; 628 629 err = ahash_prepare_alg(&inst->alg); 630 if (err) 631 return err; 632 633 return crypto_register_instance(tmpl, ahash_crypto_instance(inst)); 634 } 635 EXPORT_SYMBOL_GPL(ahash_register_instance); 636 637 void ahash_free_instance(struct crypto_instance *inst) 638 { 639 crypto_drop_spawn(crypto_instance_ctx(inst)); 640 kfree(ahash_instance(inst)); 641 } 642 EXPORT_SYMBOL_GPL(ahash_free_instance); 643 644 int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn, 645 struct hash_alg_common *alg, 646 struct crypto_instance *inst) 647 { 648 return crypto_init_spawn2(&spawn->base, &alg->base, inst, 649 &crypto_ahash_type); 650 } 651 EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn); 652 653 struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask) 654 { 655 struct crypto_alg *alg; 656 657 alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask); 658 return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg); 659 } 660 EXPORT_SYMBOL_GPL(ahash_attr_alg); 661 662 bool crypto_hash_alg_has_setkey(struct hash_alg_common *halg) 663 { 664 struct crypto_alg *alg = &halg->base; 665 666 if (alg->cra_type != &crypto_ahash_type) 667 return crypto_shash_alg_has_setkey(__crypto_shash_alg(alg)); 668 669 return __crypto_ahash_alg(alg)->setkey != NULL; 670 } 671 EXPORT_SYMBOL_GPL(crypto_hash_alg_has_setkey); 672 673 MODULE_LICENSE("GPL"); 674 MODULE_DESCRIPTION("Asynchronous cryptographic hash type"); 675