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 walk->data += walk->offset; 96 97 nbytes = min(nbytes, 98 ((unsigned int)(PAGE_SIZE)) - walk->offset); 99 walk->entrylen -= nbytes; 100 101 return nbytes; 102 } 103 104 if (walk->flags & CRYPTO_ALG_ASYNC) 105 kunmap(walk->pg); 106 else { 107 kunmap_atomic(walk->data); 108 /* 109 * The may sleep test only makes sense for sync users. 110 * Async users don't need to sleep here anyway. 111 */ 112 crypto_yield(walk->flags); 113 } 114 115 if (err) 116 return err; 117 118 if (nbytes) { 119 walk->offset = 0; 120 walk->pg++; 121 return hash_walk_next(walk); 122 } 123 124 if (!walk->total) 125 return 0; 126 127 walk->sg = sg_next(walk->sg); 128 129 return hash_walk_new_entry(walk); 130 } 131 EXPORT_SYMBOL_GPL(crypto_hash_walk_done); 132 133 int crypto_hash_walk_first(struct ahash_request *req, 134 struct crypto_hash_walk *walk) 135 { 136 walk->total = req->nbytes; 137 138 if (!walk->total) { 139 walk->entrylen = 0; 140 return 0; 141 } 142 143 walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req)); 144 walk->sg = req->src; 145 walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK; 146 147 return hash_walk_new_entry(walk); 148 } 149 EXPORT_SYMBOL_GPL(crypto_hash_walk_first); 150 151 int crypto_ahash_walk_first(struct ahash_request *req, 152 struct crypto_hash_walk *walk) 153 { 154 walk->total = req->nbytes; 155 156 if (!walk->total) { 157 walk->entrylen = 0; 158 return 0; 159 } 160 161 walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req)); 162 walk->sg = req->src; 163 walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK; 164 walk->flags |= CRYPTO_ALG_ASYNC; 165 166 BUILD_BUG_ON(CRYPTO_TFM_REQ_MASK & CRYPTO_ALG_ASYNC); 167 168 return hash_walk_new_entry(walk); 169 } 170 EXPORT_SYMBOL_GPL(crypto_ahash_walk_first); 171 172 static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key, 173 unsigned int keylen) 174 { 175 unsigned long alignmask = crypto_ahash_alignmask(tfm); 176 int ret; 177 u8 *buffer, *alignbuffer; 178 unsigned long absize; 179 180 absize = keylen + alignmask; 181 buffer = kmalloc(absize, GFP_KERNEL); 182 if (!buffer) 183 return -ENOMEM; 184 185 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); 186 memcpy(alignbuffer, key, keylen); 187 ret = tfm->setkey(tfm, alignbuffer, keylen); 188 kzfree(buffer); 189 return ret; 190 } 191 192 int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key, 193 unsigned int keylen) 194 { 195 unsigned long alignmask = crypto_ahash_alignmask(tfm); 196 int err; 197 198 if ((unsigned long)key & alignmask) 199 err = ahash_setkey_unaligned(tfm, key, keylen); 200 else 201 err = tfm->setkey(tfm, key, keylen); 202 203 if (err) 204 return err; 205 206 crypto_ahash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY); 207 return 0; 208 } 209 EXPORT_SYMBOL_GPL(crypto_ahash_setkey); 210 211 static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key, 212 unsigned int keylen) 213 { 214 return -ENOSYS; 215 } 216 217 static inline unsigned int ahash_align_buffer_size(unsigned len, 218 unsigned long mask) 219 { 220 return len + (mask & ~(crypto_tfm_ctx_alignment() - 1)); 221 } 222 223 static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt) 224 { 225 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 226 unsigned long alignmask = crypto_ahash_alignmask(tfm); 227 unsigned int ds = crypto_ahash_digestsize(tfm); 228 struct ahash_request_priv *priv; 229 230 priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask), 231 (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? 232 GFP_KERNEL : GFP_ATOMIC); 233 if (!priv) 234 return -ENOMEM; 235 236 /* 237 * WARNING: Voodoo programming below! 238 * 239 * The code below is obscure and hard to understand, thus explanation 240 * is necessary. See include/crypto/hash.h and include/linux/crypto.h 241 * to understand the layout of structures used here! 242 * 243 * The code here will replace portions of the ORIGINAL request with 244 * pointers to new code and buffers so the hashing operation can store 245 * the result in aligned buffer. We will call the modified request 246 * an ADJUSTED request. 247 * 248 * The newly mangled request will look as such: 249 * 250 * req { 251 * .result = ADJUSTED[new aligned buffer] 252 * .base.complete = ADJUSTED[pointer to completion function] 253 * .base.data = ADJUSTED[*req (pointer to self)] 254 * .priv = ADJUSTED[new priv] { 255 * .result = ORIGINAL(result) 256 * .complete = ORIGINAL(base.complete) 257 * .data = ORIGINAL(base.data) 258 * } 259 */ 260 261 priv->result = req->result; 262 priv->complete = req->base.complete; 263 priv->data = req->base.data; 264 priv->flags = req->base.flags; 265 266 /* 267 * WARNING: We do not backup req->priv here! The req->priv 268 * is for internal use of the Crypto API and the 269 * user must _NOT_ _EVER_ depend on it's content! 270 */ 271 272 req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1); 273 req->base.complete = cplt; 274 req->base.data = req; 275 req->priv = priv; 276 277 return 0; 278 } 279 280 static void ahash_restore_req(struct ahash_request *req, int err) 281 { 282 struct ahash_request_priv *priv = req->priv; 283 284 if (!err) 285 memcpy(priv->result, req->result, 286 crypto_ahash_digestsize(crypto_ahash_reqtfm(req))); 287 288 /* Restore the original crypto request. */ 289 req->result = priv->result; 290 291 ahash_request_set_callback(req, priv->flags, 292 priv->complete, priv->data); 293 req->priv = NULL; 294 295 /* Free the req->priv.priv from the ADJUSTED request. */ 296 kzfree(priv); 297 } 298 299 static void ahash_notify_einprogress(struct ahash_request *req) 300 { 301 struct ahash_request_priv *priv = req->priv; 302 struct crypto_async_request oreq; 303 304 oreq.data = priv->data; 305 306 priv->complete(&oreq, -EINPROGRESS); 307 } 308 309 static void ahash_op_unaligned_done(struct crypto_async_request *req, int err) 310 { 311 struct ahash_request *areq = req->data; 312 313 if (err == -EINPROGRESS) { 314 ahash_notify_einprogress(areq); 315 return; 316 } 317 318 /* 319 * Restore the original request, see ahash_op_unaligned() for what 320 * goes where. 321 * 322 * The "struct ahash_request *req" here is in fact the "req.base" 323 * from the ADJUSTED request from ahash_op_unaligned(), thus as it 324 * is a pointer to self, it is also the ADJUSTED "req" . 325 */ 326 327 /* First copy req->result into req->priv.result */ 328 ahash_restore_req(areq, err); 329 330 /* Complete the ORIGINAL request. */ 331 areq->base.complete(&areq->base, err); 332 } 333 334 static int ahash_op_unaligned(struct ahash_request *req, 335 int (*op)(struct ahash_request *)) 336 { 337 int err; 338 339 err = ahash_save_req(req, ahash_op_unaligned_done); 340 if (err) 341 return err; 342 343 err = op(req); 344 if (err == -EINPROGRESS || err == -EBUSY) 345 return err; 346 347 ahash_restore_req(req, err); 348 349 return err; 350 } 351 352 static int crypto_ahash_op(struct ahash_request *req, 353 int (*op)(struct ahash_request *)) 354 { 355 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 356 unsigned long alignmask = crypto_ahash_alignmask(tfm); 357 358 if ((unsigned long)req->result & alignmask) 359 return ahash_op_unaligned(req, op); 360 361 return op(req); 362 } 363 364 int crypto_ahash_final(struct ahash_request *req) 365 { 366 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final); 367 } 368 EXPORT_SYMBOL_GPL(crypto_ahash_final); 369 370 int crypto_ahash_finup(struct ahash_request *req) 371 { 372 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup); 373 } 374 EXPORT_SYMBOL_GPL(crypto_ahash_finup); 375 376 int crypto_ahash_digest(struct ahash_request *req) 377 { 378 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 379 380 if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) 381 return -ENOKEY; 382 383 return crypto_ahash_op(req, tfm->digest); 384 } 385 EXPORT_SYMBOL_GPL(crypto_ahash_digest); 386 387 static void ahash_def_finup_done2(struct crypto_async_request *req, int err) 388 { 389 struct ahash_request *areq = req->data; 390 391 if (err == -EINPROGRESS) 392 return; 393 394 ahash_restore_req(areq, err); 395 396 areq->base.complete(&areq->base, err); 397 } 398 399 static int ahash_def_finup_finish1(struct ahash_request *req, int err) 400 { 401 if (err) 402 goto out; 403 404 req->base.complete = ahash_def_finup_done2; 405 406 err = crypto_ahash_reqtfm(req)->final(req); 407 if (err == -EINPROGRESS || err == -EBUSY) 408 return err; 409 410 out: 411 ahash_restore_req(req, err); 412 return err; 413 } 414 415 static void ahash_def_finup_done1(struct crypto_async_request *req, int err) 416 { 417 struct ahash_request *areq = req->data; 418 419 if (err == -EINPROGRESS) { 420 ahash_notify_einprogress(areq); 421 return; 422 } 423 424 areq->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP; 425 426 err = ahash_def_finup_finish1(areq, err); 427 if (areq->priv) 428 return; 429 430 areq->base.complete(&areq->base, err); 431 } 432 433 static int ahash_def_finup(struct ahash_request *req) 434 { 435 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 436 int err; 437 438 err = ahash_save_req(req, ahash_def_finup_done1); 439 if (err) 440 return err; 441 442 err = tfm->update(req); 443 if (err == -EINPROGRESS || err == -EBUSY) 444 return err; 445 446 return ahash_def_finup_finish1(req, err); 447 } 448 449 static int ahash_no_export(struct ahash_request *req, void *out) 450 { 451 return -ENOSYS; 452 } 453 454 static int ahash_no_import(struct ahash_request *req, const void *in) 455 { 456 return -ENOSYS; 457 } 458 459 static int crypto_ahash_init_tfm(struct crypto_tfm *tfm) 460 { 461 struct crypto_ahash *hash = __crypto_ahash_cast(tfm); 462 struct ahash_alg *alg = crypto_ahash_alg(hash); 463 464 hash->setkey = ahash_nosetkey; 465 hash->export = ahash_no_export; 466 hash->import = ahash_no_import; 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; 476 477 if (alg->setkey) { 478 hash->setkey = alg->setkey; 479 if (!(alg->halg.base.cra_flags & CRYPTO_ALG_OPTIONAL_KEY)) 480 crypto_ahash_set_flags(hash, CRYPTO_TFM_NEED_KEY); 481 } 482 if (alg->export) 483 hash->export = alg->export; 484 if (alg->import) 485 hash->import = alg->import; 486 487 return 0; 488 } 489 490 static unsigned int crypto_ahash_extsize(struct crypto_alg *alg) 491 { 492 if (alg->cra_type != &crypto_ahash_type) 493 return sizeof(struct crypto_shash *); 494 495 return crypto_alg_extsize(alg); 496 } 497 498 #ifdef CONFIG_NET 499 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg) 500 { 501 struct crypto_report_hash rhash; 502 503 strncpy(rhash.type, "ahash", sizeof(rhash.type)); 504 505 rhash.blocksize = alg->cra_blocksize; 506 rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize; 507 508 if (nla_put(skb, CRYPTOCFGA_REPORT_HASH, 509 sizeof(struct crypto_report_hash), &rhash)) 510 goto nla_put_failure; 511 return 0; 512 513 nla_put_failure: 514 return -EMSGSIZE; 515 } 516 #else 517 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg) 518 { 519 return -ENOSYS; 520 } 521 #endif 522 523 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg) 524 __maybe_unused; 525 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg) 526 { 527 seq_printf(m, "type : ahash\n"); 528 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ? 529 "yes" : "no"); 530 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); 531 seq_printf(m, "digestsize : %u\n", 532 __crypto_hash_alg_common(alg)->digestsize); 533 } 534 535 const struct crypto_type crypto_ahash_type = { 536 .extsize = crypto_ahash_extsize, 537 .init_tfm = crypto_ahash_init_tfm, 538 #ifdef CONFIG_PROC_FS 539 .show = crypto_ahash_show, 540 #endif 541 .report = crypto_ahash_report, 542 .maskclear = ~CRYPTO_ALG_TYPE_MASK, 543 .maskset = CRYPTO_ALG_TYPE_AHASH_MASK, 544 .type = CRYPTO_ALG_TYPE_AHASH, 545 .tfmsize = offsetof(struct crypto_ahash, base), 546 }; 547 EXPORT_SYMBOL_GPL(crypto_ahash_type); 548 549 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type, 550 u32 mask) 551 { 552 return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask); 553 } 554 EXPORT_SYMBOL_GPL(crypto_alloc_ahash); 555 556 int crypto_has_ahash(const char *alg_name, u32 type, u32 mask) 557 { 558 return crypto_type_has_alg(alg_name, &crypto_ahash_type, type, mask); 559 } 560 EXPORT_SYMBOL_GPL(crypto_has_ahash); 561 562 static int ahash_prepare_alg(struct ahash_alg *alg) 563 { 564 struct crypto_alg *base = &alg->halg.base; 565 566 if (alg->halg.digestsize > PAGE_SIZE / 8 || 567 alg->halg.statesize > PAGE_SIZE / 8 || 568 alg->halg.statesize == 0) 569 return -EINVAL; 570 571 base->cra_type = &crypto_ahash_type; 572 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; 573 base->cra_flags |= CRYPTO_ALG_TYPE_AHASH; 574 575 return 0; 576 } 577 578 int crypto_register_ahash(struct ahash_alg *alg) 579 { 580 struct crypto_alg *base = &alg->halg.base; 581 int err; 582 583 err = ahash_prepare_alg(alg); 584 if (err) 585 return err; 586 587 return crypto_register_alg(base); 588 } 589 EXPORT_SYMBOL_GPL(crypto_register_ahash); 590 591 int crypto_unregister_ahash(struct ahash_alg *alg) 592 { 593 return crypto_unregister_alg(&alg->halg.base); 594 } 595 EXPORT_SYMBOL_GPL(crypto_unregister_ahash); 596 597 int crypto_register_ahashes(struct ahash_alg *algs, int count) 598 { 599 int i, ret; 600 601 for (i = 0; i < count; i++) { 602 ret = crypto_register_ahash(&algs[i]); 603 if (ret) 604 goto err; 605 } 606 607 return 0; 608 609 err: 610 for (--i; i >= 0; --i) 611 crypto_unregister_ahash(&algs[i]); 612 613 return ret; 614 } 615 EXPORT_SYMBOL_GPL(crypto_register_ahashes); 616 617 void crypto_unregister_ahashes(struct ahash_alg *algs, int count) 618 { 619 int i; 620 621 for (i = count - 1; i >= 0; --i) 622 crypto_unregister_ahash(&algs[i]); 623 } 624 EXPORT_SYMBOL_GPL(crypto_unregister_ahashes); 625 626 int ahash_register_instance(struct crypto_template *tmpl, 627 struct ahash_instance *inst) 628 { 629 int err; 630 631 err = ahash_prepare_alg(&inst->alg); 632 if (err) 633 return err; 634 635 return crypto_register_instance(tmpl, ahash_crypto_instance(inst)); 636 } 637 EXPORT_SYMBOL_GPL(ahash_register_instance); 638 639 void ahash_free_instance(struct crypto_instance *inst) 640 { 641 crypto_drop_spawn(crypto_instance_ctx(inst)); 642 kfree(ahash_instance(inst)); 643 } 644 EXPORT_SYMBOL_GPL(ahash_free_instance); 645 646 int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn, 647 struct hash_alg_common *alg, 648 struct crypto_instance *inst) 649 { 650 return crypto_init_spawn2(&spawn->base, &alg->base, inst, 651 &crypto_ahash_type); 652 } 653 EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn); 654 655 struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask) 656 { 657 struct crypto_alg *alg; 658 659 alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask); 660 return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg); 661 } 662 EXPORT_SYMBOL_GPL(ahash_attr_alg); 663 664 bool crypto_hash_alg_has_setkey(struct hash_alg_common *halg) 665 { 666 struct crypto_alg *alg = &halg->base; 667 668 if (alg->cra_type != &crypto_ahash_type) 669 return crypto_shash_alg_has_setkey(__crypto_shash_alg(alg)); 670 671 return __crypto_ahash_alg(alg)->setkey != NULL; 672 } 673 EXPORT_SYMBOL_GPL(crypto_hash_alg_has_setkey); 674 675 MODULE_LICENSE("GPL"); 676 MODULE_DESCRIPTION("Asynchronous cryptographic hash type"); 677