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); 196 197 if ((unsigned long)key & alignmask) 198 return ahash_setkey_unaligned(tfm, key, keylen); 199 200 return tfm->setkey(tfm, key, keylen); 201 } 202 EXPORT_SYMBOL_GPL(crypto_ahash_setkey); 203 204 static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key, 205 unsigned int keylen) 206 { 207 return -ENOSYS; 208 } 209 210 static inline unsigned int ahash_align_buffer_size(unsigned len, 211 unsigned long mask) 212 { 213 return len + (mask & ~(crypto_tfm_ctx_alignment() - 1)); 214 } 215 216 static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt) 217 { 218 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 219 unsigned long alignmask = crypto_ahash_alignmask(tfm); 220 unsigned int ds = crypto_ahash_digestsize(tfm); 221 struct ahash_request_priv *priv; 222 223 priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask), 224 (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? 225 GFP_KERNEL : GFP_ATOMIC); 226 if (!priv) 227 return -ENOMEM; 228 229 /* 230 * WARNING: Voodoo programming below! 231 * 232 * The code below is obscure and hard to understand, thus explanation 233 * is necessary. See include/crypto/hash.h and include/linux/crypto.h 234 * to understand the layout of structures used here! 235 * 236 * The code here will replace portions of the ORIGINAL request with 237 * pointers to new code and buffers so the hashing operation can store 238 * the result in aligned buffer. We will call the modified request 239 * an ADJUSTED request. 240 * 241 * The newly mangled request will look as such: 242 * 243 * req { 244 * .result = ADJUSTED[new aligned buffer] 245 * .base.complete = ADJUSTED[pointer to completion function] 246 * .base.data = ADJUSTED[*req (pointer to self)] 247 * .priv = ADJUSTED[new priv] { 248 * .result = ORIGINAL(result) 249 * .complete = ORIGINAL(base.complete) 250 * .data = ORIGINAL(base.data) 251 * } 252 */ 253 254 priv->result = req->result; 255 priv->complete = req->base.complete; 256 priv->data = req->base.data; 257 priv->flags = req->base.flags; 258 259 /* 260 * WARNING: We do not backup req->priv here! The req->priv 261 * is for internal use of the Crypto API and the 262 * user must _NOT_ _EVER_ depend on it's content! 263 */ 264 265 req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1); 266 req->base.complete = cplt; 267 req->base.data = req; 268 req->priv = priv; 269 270 return 0; 271 } 272 273 static void ahash_restore_req(struct ahash_request *req, int err) 274 { 275 struct ahash_request_priv *priv = req->priv; 276 277 if (!err) 278 memcpy(priv->result, req->result, 279 crypto_ahash_digestsize(crypto_ahash_reqtfm(req))); 280 281 /* Restore the original crypto request. */ 282 req->result = priv->result; 283 284 ahash_request_set_callback(req, priv->flags, 285 priv->complete, priv->data); 286 req->priv = NULL; 287 288 /* Free the req->priv.priv from the ADJUSTED request. */ 289 kzfree(priv); 290 } 291 292 static void ahash_notify_einprogress(struct ahash_request *req) 293 { 294 struct ahash_request_priv *priv = req->priv; 295 struct crypto_async_request oreq; 296 297 oreq.data = priv->data; 298 299 priv->complete(&oreq, -EINPROGRESS); 300 } 301 302 static void ahash_op_unaligned_done(struct crypto_async_request *req, int err) 303 { 304 struct ahash_request *areq = req->data; 305 306 if (err == -EINPROGRESS) { 307 ahash_notify_einprogress(areq); 308 return; 309 } 310 311 /* 312 * Restore the original request, see ahash_op_unaligned() for what 313 * goes where. 314 * 315 * The "struct ahash_request *req" here is in fact the "req.base" 316 * from the ADJUSTED request from ahash_op_unaligned(), thus as it 317 * is a pointer to self, it is also the ADJUSTED "req" . 318 */ 319 320 /* First copy req->result into req->priv.result */ 321 ahash_restore_req(areq, err); 322 323 /* Complete the ORIGINAL request. */ 324 areq->base.complete(&areq->base, err); 325 } 326 327 static int ahash_op_unaligned(struct ahash_request *req, 328 int (*op)(struct ahash_request *)) 329 { 330 int err; 331 332 err = ahash_save_req(req, ahash_op_unaligned_done); 333 if (err) 334 return err; 335 336 err = op(req); 337 if (err == -EINPROGRESS || err == -EBUSY) 338 return err; 339 340 ahash_restore_req(req, err); 341 342 return err; 343 } 344 345 static int crypto_ahash_op(struct ahash_request *req, 346 int (*op)(struct ahash_request *)) 347 { 348 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 349 unsigned long alignmask = crypto_ahash_alignmask(tfm); 350 351 if ((unsigned long)req->result & alignmask) 352 return ahash_op_unaligned(req, op); 353 354 return op(req); 355 } 356 357 int crypto_ahash_final(struct ahash_request *req) 358 { 359 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final); 360 } 361 EXPORT_SYMBOL_GPL(crypto_ahash_final); 362 363 int crypto_ahash_finup(struct ahash_request *req) 364 { 365 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup); 366 } 367 EXPORT_SYMBOL_GPL(crypto_ahash_finup); 368 369 int crypto_ahash_digest(struct ahash_request *req) 370 { 371 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->digest); 372 } 373 EXPORT_SYMBOL_GPL(crypto_ahash_digest); 374 375 static void ahash_def_finup_done2(struct crypto_async_request *req, int err) 376 { 377 struct ahash_request *areq = req->data; 378 379 if (err == -EINPROGRESS) 380 return; 381 382 ahash_restore_req(areq, err); 383 384 areq->base.complete(&areq->base, err); 385 } 386 387 static int ahash_def_finup_finish1(struct ahash_request *req, int err) 388 { 389 if (err) 390 goto out; 391 392 req->base.complete = ahash_def_finup_done2; 393 394 err = crypto_ahash_reqtfm(req)->final(req); 395 if (err == -EINPROGRESS || err == -EBUSY) 396 return err; 397 398 out: 399 ahash_restore_req(req, err); 400 return err; 401 } 402 403 static void ahash_def_finup_done1(struct crypto_async_request *req, int err) 404 { 405 struct ahash_request *areq = req->data; 406 407 if (err == -EINPROGRESS) { 408 ahash_notify_einprogress(areq); 409 return; 410 } 411 412 areq->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP; 413 414 err = ahash_def_finup_finish1(areq, err); 415 if (areq->priv) 416 return; 417 418 areq->base.complete(&areq->base, err); 419 } 420 421 static int ahash_def_finup(struct ahash_request *req) 422 { 423 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 424 int err; 425 426 err = ahash_save_req(req, ahash_def_finup_done1); 427 if (err) 428 return err; 429 430 err = tfm->update(req); 431 if (err == -EINPROGRESS || err == -EBUSY) 432 return err; 433 434 return ahash_def_finup_finish1(req, err); 435 } 436 437 static int ahash_no_export(struct ahash_request *req, void *out) 438 { 439 return -ENOSYS; 440 } 441 442 static int ahash_no_import(struct ahash_request *req, const void *in) 443 { 444 return -ENOSYS; 445 } 446 447 static int crypto_ahash_init_tfm(struct crypto_tfm *tfm) 448 { 449 struct crypto_ahash *hash = __crypto_ahash_cast(tfm); 450 struct ahash_alg *alg = crypto_ahash_alg(hash); 451 452 hash->setkey = ahash_nosetkey; 453 hash->has_setkey = false; 454 hash->export = ahash_no_export; 455 hash->import = ahash_no_import; 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; 465 466 if (alg->setkey) { 467 hash->setkey = alg->setkey; 468 hash->has_setkey = true; 469 } 470 if (alg->export) 471 hash->export = alg->export; 472 if (alg->import) 473 hash->import = alg->import; 474 475 return 0; 476 } 477 478 static unsigned int crypto_ahash_extsize(struct crypto_alg *alg) 479 { 480 if (alg->cra_type != &crypto_ahash_type) 481 return sizeof(struct crypto_shash *); 482 483 return crypto_alg_extsize(alg); 484 } 485 486 #ifdef CONFIG_NET 487 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg) 488 { 489 struct crypto_report_hash rhash; 490 491 strncpy(rhash.type, "ahash", sizeof(rhash.type)); 492 493 rhash.blocksize = alg->cra_blocksize; 494 rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize; 495 496 if (nla_put(skb, CRYPTOCFGA_REPORT_HASH, 497 sizeof(struct crypto_report_hash), &rhash)) 498 goto nla_put_failure; 499 return 0; 500 501 nla_put_failure: 502 return -EMSGSIZE; 503 } 504 #else 505 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg) 506 { 507 return -ENOSYS; 508 } 509 #endif 510 511 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg) 512 __maybe_unused; 513 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg) 514 { 515 seq_printf(m, "type : ahash\n"); 516 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ? 517 "yes" : "no"); 518 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); 519 seq_printf(m, "digestsize : %u\n", 520 __crypto_hash_alg_common(alg)->digestsize); 521 } 522 523 const struct crypto_type crypto_ahash_type = { 524 .extsize = crypto_ahash_extsize, 525 .init_tfm = crypto_ahash_init_tfm, 526 #ifdef CONFIG_PROC_FS 527 .show = crypto_ahash_show, 528 #endif 529 .report = crypto_ahash_report, 530 .maskclear = ~CRYPTO_ALG_TYPE_MASK, 531 .maskset = CRYPTO_ALG_TYPE_AHASH_MASK, 532 .type = CRYPTO_ALG_TYPE_AHASH, 533 .tfmsize = offsetof(struct crypto_ahash, base), 534 }; 535 EXPORT_SYMBOL_GPL(crypto_ahash_type); 536 537 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type, 538 u32 mask) 539 { 540 return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask); 541 } 542 EXPORT_SYMBOL_GPL(crypto_alloc_ahash); 543 544 int crypto_has_ahash(const char *alg_name, u32 type, u32 mask) 545 { 546 return crypto_type_has_alg(alg_name, &crypto_ahash_type, type, mask); 547 } 548 EXPORT_SYMBOL_GPL(crypto_has_ahash); 549 550 static int ahash_prepare_alg(struct ahash_alg *alg) 551 { 552 struct crypto_alg *base = &alg->halg.base; 553 554 if (alg->halg.digestsize > PAGE_SIZE / 8 || 555 alg->halg.statesize > PAGE_SIZE / 8 || 556 alg->halg.statesize == 0) 557 return -EINVAL; 558 559 base->cra_type = &crypto_ahash_type; 560 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; 561 base->cra_flags |= CRYPTO_ALG_TYPE_AHASH; 562 563 return 0; 564 } 565 566 int crypto_register_ahash(struct ahash_alg *alg) 567 { 568 struct crypto_alg *base = &alg->halg.base; 569 int err; 570 571 err = ahash_prepare_alg(alg); 572 if (err) 573 return err; 574 575 return crypto_register_alg(base); 576 } 577 EXPORT_SYMBOL_GPL(crypto_register_ahash); 578 579 int crypto_unregister_ahash(struct ahash_alg *alg) 580 { 581 return crypto_unregister_alg(&alg->halg.base); 582 } 583 EXPORT_SYMBOL_GPL(crypto_unregister_ahash); 584 585 int crypto_register_ahashes(struct ahash_alg *algs, int count) 586 { 587 int i, ret; 588 589 for (i = 0; i < count; i++) { 590 ret = crypto_register_ahash(&algs[i]); 591 if (ret) 592 goto err; 593 } 594 595 return 0; 596 597 err: 598 for (--i; i >= 0; --i) 599 crypto_unregister_ahash(&algs[i]); 600 601 return ret; 602 } 603 EXPORT_SYMBOL_GPL(crypto_register_ahashes); 604 605 void crypto_unregister_ahashes(struct ahash_alg *algs, int count) 606 { 607 int i; 608 609 for (i = count - 1; i >= 0; --i) 610 crypto_unregister_ahash(&algs[i]); 611 } 612 EXPORT_SYMBOL_GPL(crypto_unregister_ahashes); 613 614 int ahash_register_instance(struct crypto_template *tmpl, 615 struct ahash_instance *inst) 616 { 617 int err; 618 619 err = ahash_prepare_alg(&inst->alg); 620 if (err) 621 return err; 622 623 return crypto_register_instance(tmpl, ahash_crypto_instance(inst)); 624 } 625 EXPORT_SYMBOL_GPL(ahash_register_instance); 626 627 void ahash_free_instance(struct crypto_instance *inst) 628 { 629 crypto_drop_spawn(crypto_instance_ctx(inst)); 630 kfree(ahash_instance(inst)); 631 } 632 EXPORT_SYMBOL_GPL(ahash_free_instance); 633 634 int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn, 635 struct hash_alg_common *alg, 636 struct crypto_instance *inst) 637 { 638 return crypto_init_spawn2(&spawn->base, &alg->base, inst, 639 &crypto_ahash_type); 640 } 641 EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn); 642 643 struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask) 644 { 645 struct crypto_alg *alg; 646 647 alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask); 648 return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg); 649 } 650 EXPORT_SYMBOL_GPL(ahash_attr_alg); 651 652 MODULE_LICENSE("GPL"); 653 MODULE_DESCRIPTION("Asynchronous cryptographic hash type"); 654