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 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final); 368 } 369 EXPORT_SYMBOL_GPL(crypto_ahash_final); 370 371 int crypto_ahash_finup(struct ahash_request *req) 372 { 373 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup); 374 } 375 EXPORT_SYMBOL_GPL(crypto_ahash_finup); 376 377 int crypto_ahash_digest(struct ahash_request *req) 378 { 379 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 380 381 if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) 382 return -ENOKEY; 383 384 return crypto_ahash_op(req, tfm->digest); 385 } 386 EXPORT_SYMBOL_GPL(crypto_ahash_digest); 387 388 static void ahash_def_finup_done2(struct crypto_async_request *req, int err) 389 { 390 struct ahash_request *areq = req->data; 391 392 if (err == -EINPROGRESS) 393 return; 394 395 ahash_restore_req(areq, err); 396 397 areq->base.complete(&areq->base, err); 398 } 399 400 static int ahash_def_finup_finish1(struct ahash_request *req, int err) 401 { 402 if (err) 403 goto out; 404 405 req->base.complete = ahash_def_finup_done2; 406 407 err = crypto_ahash_reqtfm(req)->final(req); 408 if (err == -EINPROGRESS || err == -EBUSY) 409 return err; 410 411 out: 412 ahash_restore_req(req, err); 413 return err; 414 } 415 416 static void ahash_def_finup_done1(struct crypto_async_request *req, int err) 417 { 418 struct ahash_request *areq = req->data; 419 420 if (err == -EINPROGRESS) { 421 ahash_notify_einprogress(areq); 422 return; 423 } 424 425 areq->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP; 426 427 err = ahash_def_finup_finish1(areq, err); 428 if (areq->priv) 429 return; 430 431 areq->base.complete(&areq->base, err); 432 } 433 434 static int ahash_def_finup(struct ahash_request *req) 435 { 436 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 437 int err; 438 439 err = ahash_save_req(req, ahash_def_finup_done1); 440 if (err) 441 return err; 442 443 err = tfm->update(req); 444 if (err == -EINPROGRESS || err == -EBUSY) 445 return err; 446 447 return ahash_def_finup_finish1(req, err); 448 } 449 450 static int crypto_ahash_init_tfm(struct crypto_tfm *tfm) 451 { 452 struct crypto_ahash *hash = __crypto_ahash_cast(tfm); 453 struct ahash_alg *alg = crypto_ahash_alg(hash); 454 455 hash->setkey = ahash_nosetkey; 456 457 if (tfm->__crt_alg->cra_type != &crypto_ahash_type) 458 return crypto_init_shash_ops_async(tfm); 459 460 hash->init = alg->init; 461 hash->update = alg->update; 462 hash->final = alg->final; 463 hash->finup = alg->finup ?: ahash_def_finup; 464 hash->digest = alg->digest; 465 hash->export = alg->export; 466 hash->import = alg->import; 467 468 if (alg->setkey) { 469 hash->setkey = alg->setkey; 470 if (!(alg->halg.base.cra_flags & CRYPTO_ALG_OPTIONAL_KEY)) 471 crypto_ahash_set_flags(hash, CRYPTO_TFM_NEED_KEY); 472 } 473 474 return 0; 475 } 476 477 static unsigned int crypto_ahash_extsize(struct crypto_alg *alg) 478 { 479 if (alg->cra_type != &crypto_ahash_type) 480 return sizeof(struct crypto_shash *); 481 482 return crypto_alg_extsize(alg); 483 } 484 485 #ifdef CONFIG_NET 486 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg) 487 { 488 struct crypto_report_hash rhash; 489 490 strncpy(rhash.type, "ahash", sizeof(rhash.type)); 491 492 rhash.blocksize = alg->cra_blocksize; 493 rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize; 494 495 if (nla_put(skb, CRYPTOCFGA_REPORT_HASH, 496 sizeof(struct crypto_report_hash), &rhash)) 497 goto nla_put_failure; 498 return 0; 499 500 nla_put_failure: 501 return -EMSGSIZE; 502 } 503 #else 504 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg) 505 { 506 return -ENOSYS; 507 } 508 #endif 509 510 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg) 511 __maybe_unused; 512 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg) 513 { 514 seq_printf(m, "type : ahash\n"); 515 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ? 516 "yes" : "no"); 517 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); 518 seq_printf(m, "digestsize : %u\n", 519 __crypto_hash_alg_common(alg)->digestsize); 520 } 521 522 const struct crypto_type crypto_ahash_type = { 523 .extsize = crypto_ahash_extsize, 524 .init_tfm = crypto_ahash_init_tfm, 525 #ifdef CONFIG_PROC_FS 526 .show = crypto_ahash_show, 527 #endif 528 .report = crypto_ahash_report, 529 .maskclear = ~CRYPTO_ALG_TYPE_MASK, 530 .maskset = CRYPTO_ALG_TYPE_AHASH_MASK, 531 .type = CRYPTO_ALG_TYPE_AHASH, 532 .tfmsize = offsetof(struct crypto_ahash, base), 533 }; 534 EXPORT_SYMBOL_GPL(crypto_ahash_type); 535 536 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type, 537 u32 mask) 538 { 539 return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask); 540 } 541 EXPORT_SYMBOL_GPL(crypto_alloc_ahash); 542 543 int crypto_has_ahash(const char *alg_name, u32 type, u32 mask) 544 { 545 return crypto_type_has_alg(alg_name, &crypto_ahash_type, type, mask); 546 } 547 EXPORT_SYMBOL_GPL(crypto_has_ahash); 548 549 static int ahash_prepare_alg(struct ahash_alg *alg) 550 { 551 struct crypto_alg *base = &alg->halg.base; 552 553 if (alg->halg.digestsize > PAGE_SIZE / 8 || 554 alg->halg.statesize > PAGE_SIZE / 8 || 555 alg->halg.statesize == 0) 556 return -EINVAL; 557 558 base->cra_type = &crypto_ahash_type; 559 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; 560 base->cra_flags |= CRYPTO_ALG_TYPE_AHASH; 561 562 return 0; 563 } 564 565 int crypto_register_ahash(struct ahash_alg *alg) 566 { 567 struct crypto_alg *base = &alg->halg.base; 568 int err; 569 570 err = ahash_prepare_alg(alg); 571 if (err) 572 return err; 573 574 return crypto_register_alg(base); 575 } 576 EXPORT_SYMBOL_GPL(crypto_register_ahash); 577 578 int crypto_unregister_ahash(struct ahash_alg *alg) 579 { 580 return crypto_unregister_alg(&alg->halg.base); 581 } 582 EXPORT_SYMBOL_GPL(crypto_unregister_ahash); 583 584 int crypto_register_ahashes(struct ahash_alg *algs, int count) 585 { 586 int i, ret; 587 588 for (i = 0; i < count; i++) { 589 ret = crypto_register_ahash(&algs[i]); 590 if (ret) 591 goto err; 592 } 593 594 return 0; 595 596 err: 597 for (--i; i >= 0; --i) 598 crypto_unregister_ahash(&algs[i]); 599 600 return ret; 601 } 602 EXPORT_SYMBOL_GPL(crypto_register_ahashes); 603 604 void crypto_unregister_ahashes(struct ahash_alg *algs, int count) 605 { 606 int i; 607 608 for (i = count - 1; i >= 0; --i) 609 crypto_unregister_ahash(&algs[i]); 610 } 611 EXPORT_SYMBOL_GPL(crypto_unregister_ahashes); 612 613 int ahash_register_instance(struct crypto_template *tmpl, 614 struct ahash_instance *inst) 615 { 616 int err; 617 618 err = ahash_prepare_alg(&inst->alg); 619 if (err) 620 return err; 621 622 return crypto_register_instance(tmpl, ahash_crypto_instance(inst)); 623 } 624 EXPORT_SYMBOL_GPL(ahash_register_instance); 625 626 void ahash_free_instance(struct crypto_instance *inst) 627 { 628 crypto_drop_spawn(crypto_instance_ctx(inst)); 629 kfree(ahash_instance(inst)); 630 } 631 EXPORT_SYMBOL_GPL(ahash_free_instance); 632 633 int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn, 634 struct hash_alg_common *alg, 635 struct crypto_instance *inst) 636 { 637 return crypto_init_spawn2(&spawn->base, &alg->base, inst, 638 &crypto_ahash_type); 639 } 640 EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn); 641 642 struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask) 643 { 644 struct crypto_alg *alg; 645 646 alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask); 647 return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg); 648 } 649 EXPORT_SYMBOL_GPL(ahash_attr_alg); 650 651 bool crypto_hash_alg_has_setkey(struct hash_alg_common *halg) 652 { 653 struct crypto_alg *alg = &halg->base; 654 655 if (alg->cra_type != &crypto_ahash_type) 656 return crypto_shash_alg_has_setkey(__crypto_shash_alg(alg)); 657 658 return __crypto_ahash_alg(alg)->setkey != NULL; 659 } 660 EXPORT_SYMBOL_GPL(crypto_hash_alg_has_setkey); 661 662 MODULE_LICENSE("GPL"); 663 MODULE_DESCRIPTION("Asynchronous cryptographic hash type"); 664