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 <net/netlink.h> 27 28 #include "internal.h" 29 30 struct ahash_request_priv { 31 crypto_completion_t complete; 32 void *data; 33 u8 *result; 34 void *ubuf[] CRYPTO_MINALIGN_ATTR; 35 }; 36 37 static inline struct ahash_alg *crypto_ahash_alg(struct crypto_ahash *hash) 38 { 39 return container_of(crypto_hash_alg_common(hash), struct ahash_alg, 40 halg); 41 } 42 43 static int hash_walk_next(struct crypto_hash_walk *walk) 44 { 45 unsigned int alignmask = walk->alignmask; 46 unsigned int offset = walk->offset; 47 unsigned int nbytes = min(walk->entrylen, 48 ((unsigned int)(PAGE_SIZE)) - offset); 49 50 if (walk->flags & CRYPTO_ALG_ASYNC) 51 walk->data = kmap(walk->pg); 52 else 53 walk->data = kmap_atomic(walk->pg); 54 walk->data += offset; 55 56 if (offset & alignmask) { 57 unsigned int unaligned = alignmask + 1 - (offset & alignmask); 58 59 if (nbytes > unaligned) 60 nbytes = unaligned; 61 } 62 63 walk->entrylen -= nbytes; 64 return nbytes; 65 } 66 67 static int hash_walk_new_entry(struct crypto_hash_walk *walk) 68 { 69 struct scatterlist *sg; 70 71 sg = walk->sg; 72 walk->pg = sg_page(sg); 73 walk->offset = sg->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 unsigned int nbytes = walk->entrylen; 87 88 walk->data -= walk->offset; 89 90 if (nbytes && walk->offset & alignmask && !err) { 91 walk->offset = ALIGN(walk->offset, alignmask + 1); 92 walk->data += walk->offset; 93 94 nbytes = min(nbytes, 95 ((unsigned int)(PAGE_SIZE)) - walk->offset); 96 walk->entrylen -= nbytes; 97 98 return nbytes; 99 } 100 101 if (walk->flags & CRYPTO_ALG_ASYNC) 102 kunmap(walk->pg); 103 else { 104 kunmap_atomic(walk->data); 105 /* 106 * The may sleep test only makes sense for sync users. 107 * Async users don't need to sleep here anyway. 108 */ 109 crypto_yield(walk->flags); 110 } 111 112 if (err) 113 return err; 114 115 if (nbytes) { 116 walk->offset = 0; 117 walk->pg++; 118 return hash_walk_next(walk); 119 } 120 121 if (!walk->total) 122 return 0; 123 124 walk->sg = sg_next(walk->sg); 125 126 return hash_walk_new_entry(walk); 127 } 128 EXPORT_SYMBOL_GPL(crypto_hash_walk_done); 129 130 int crypto_hash_walk_first(struct ahash_request *req, 131 struct crypto_hash_walk *walk) 132 { 133 walk->total = req->nbytes; 134 135 if (!walk->total) { 136 walk->entrylen = 0; 137 return 0; 138 } 139 140 walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req)); 141 walk->sg = req->src; 142 walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK; 143 144 return hash_walk_new_entry(walk); 145 } 146 EXPORT_SYMBOL_GPL(crypto_hash_walk_first); 147 148 int crypto_ahash_walk_first(struct ahash_request *req, 149 struct crypto_hash_walk *walk) 150 { 151 walk->total = req->nbytes; 152 153 if (!walk->total) { 154 walk->entrylen = 0; 155 return 0; 156 } 157 158 walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req)); 159 walk->sg = req->src; 160 walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK; 161 walk->flags |= CRYPTO_ALG_ASYNC; 162 163 BUILD_BUG_ON(CRYPTO_TFM_REQ_MASK & CRYPTO_ALG_ASYNC); 164 165 return hash_walk_new_entry(walk); 166 } 167 EXPORT_SYMBOL_GPL(crypto_ahash_walk_first); 168 169 int crypto_hash_walk_first_compat(struct hash_desc *hdesc, 170 struct crypto_hash_walk *walk, 171 struct scatterlist *sg, unsigned int len) 172 { 173 walk->total = len; 174 175 if (!walk->total) { 176 walk->entrylen = 0; 177 return 0; 178 } 179 180 walk->alignmask = crypto_hash_alignmask(hdesc->tfm); 181 walk->sg = sg; 182 walk->flags = hdesc->flags & CRYPTO_TFM_REQ_MASK; 183 184 return hash_walk_new_entry(walk); 185 } 186 187 static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key, 188 unsigned int keylen) 189 { 190 unsigned long alignmask = crypto_ahash_alignmask(tfm); 191 int ret; 192 u8 *buffer, *alignbuffer; 193 unsigned long absize; 194 195 absize = keylen + alignmask; 196 buffer = kmalloc(absize, GFP_KERNEL); 197 if (!buffer) 198 return -ENOMEM; 199 200 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); 201 memcpy(alignbuffer, key, keylen); 202 ret = tfm->setkey(tfm, alignbuffer, keylen); 203 kzfree(buffer); 204 return ret; 205 } 206 207 int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key, 208 unsigned int keylen) 209 { 210 unsigned long alignmask = crypto_ahash_alignmask(tfm); 211 212 if ((unsigned long)key & alignmask) 213 return ahash_setkey_unaligned(tfm, key, keylen); 214 215 return tfm->setkey(tfm, key, keylen); 216 } 217 EXPORT_SYMBOL_GPL(crypto_ahash_setkey); 218 219 static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key, 220 unsigned int keylen) 221 { 222 return -ENOSYS; 223 } 224 225 static inline unsigned int ahash_align_buffer_size(unsigned len, 226 unsigned long mask) 227 { 228 return len + (mask & ~(crypto_tfm_ctx_alignment() - 1)); 229 } 230 231 static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt) 232 { 233 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 234 unsigned long alignmask = crypto_ahash_alignmask(tfm); 235 unsigned int ds = crypto_ahash_digestsize(tfm); 236 struct ahash_request_priv *priv; 237 238 priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask), 239 (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? 240 GFP_KERNEL : GFP_ATOMIC); 241 if (!priv) 242 return -ENOMEM; 243 244 /* 245 * WARNING: Voodoo programming below! 246 * 247 * The code below is obscure and hard to understand, thus explanation 248 * is necessary. See include/crypto/hash.h and include/linux/crypto.h 249 * to understand the layout of structures used here! 250 * 251 * The code here will replace portions of the ORIGINAL request with 252 * pointers to new code and buffers so the hashing operation can store 253 * the result in aligned buffer. We will call the modified request 254 * an ADJUSTED request. 255 * 256 * The newly mangled request will look as such: 257 * 258 * req { 259 * .result = ADJUSTED[new aligned buffer] 260 * .base.complete = ADJUSTED[pointer to completion function] 261 * .base.data = ADJUSTED[*req (pointer to self)] 262 * .priv = ADJUSTED[new priv] { 263 * .result = ORIGINAL(result) 264 * .complete = ORIGINAL(base.complete) 265 * .data = ORIGINAL(base.data) 266 * } 267 */ 268 269 priv->result = req->result; 270 priv->complete = req->base.complete; 271 priv->data = req->base.data; 272 /* 273 * WARNING: We do not backup req->priv here! The req->priv 274 * is for internal use of the Crypto API and the 275 * user must _NOT_ _EVER_ depend on it's content! 276 */ 277 278 req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1); 279 req->base.complete = cplt; 280 req->base.data = req; 281 req->priv = priv; 282 283 return 0; 284 } 285 286 static void ahash_restore_req(struct ahash_request *req) 287 { 288 struct ahash_request_priv *priv = req->priv; 289 290 /* Restore the original crypto request. */ 291 req->result = priv->result; 292 req->base.complete = priv->complete; 293 req->base.data = 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_op_unaligned_finish(struct ahash_request *req, int err) 301 { 302 struct ahash_request_priv *priv = req->priv; 303 304 if (err == -EINPROGRESS) 305 return; 306 307 if (!err) 308 memcpy(priv->result, req->result, 309 crypto_ahash_digestsize(crypto_ahash_reqtfm(req))); 310 311 ahash_restore_req(req); 312 } 313 314 static void ahash_op_unaligned_done(struct crypto_async_request *req, int err) 315 { 316 struct ahash_request *areq = req->data; 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_op_unaligned_finish(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 ahash_op_unaligned_finish(req, err); 345 346 return err; 347 } 348 349 static int crypto_ahash_op(struct ahash_request *req, 350 int (*op)(struct ahash_request *)) 351 { 352 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 353 unsigned long alignmask = crypto_ahash_alignmask(tfm); 354 355 if ((unsigned long)req->result & alignmask) 356 return ahash_op_unaligned(req, op); 357 358 return op(req); 359 } 360 361 int crypto_ahash_final(struct ahash_request *req) 362 { 363 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final); 364 } 365 EXPORT_SYMBOL_GPL(crypto_ahash_final); 366 367 int crypto_ahash_finup(struct ahash_request *req) 368 { 369 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup); 370 } 371 EXPORT_SYMBOL_GPL(crypto_ahash_finup); 372 373 int crypto_ahash_digest(struct ahash_request *req) 374 { 375 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->digest); 376 } 377 EXPORT_SYMBOL_GPL(crypto_ahash_digest); 378 379 static void ahash_def_finup_finish2(struct ahash_request *req, int err) 380 { 381 struct ahash_request_priv *priv = req->priv; 382 383 if (err == -EINPROGRESS) 384 return; 385 386 if (!err) 387 memcpy(priv->result, req->result, 388 crypto_ahash_digestsize(crypto_ahash_reqtfm(req))); 389 390 ahash_restore_req(req); 391 } 392 393 static void ahash_def_finup_done2(struct crypto_async_request *req, int err) 394 { 395 struct ahash_request *areq = req->data; 396 397 ahash_def_finup_finish2(areq, err); 398 399 areq->base.complete(&areq->base, err); 400 } 401 402 static int ahash_def_finup_finish1(struct ahash_request *req, int err) 403 { 404 if (err) 405 goto out; 406 407 req->base.complete = ahash_def_finup_done2; 408 req->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP; 409 err = crypto_ahash_reqtfm(req)->final(req); 410 411 out: 412 ahash_def_finup_finish2(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 err = ahash_def_finup_finish1(areq, err); 421 422 areq->base.complete(&areq->base, err); 423 } 424 425 static int ahash_def_finup(struct ahash_request *req) 426 { 427 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 428 int err; 429 430 err = ahash_save_req(req, ahash_def_finup_done1); 431 if (err) 432 return err; 433 434 err = tfm->update(req); 435 return ahash_def_finup_finish1(req, err); 436 } 437 438 static int ahash_no_export(struct ahash_request *req, void *out) 439 { 440 return -ENOSYS; 441 } 442 443 static int ahash_no_import(struct ahash_request *req, const void *in) 444 { 445 return -ENOSYS; 446 } 447 448 static int crypto_ahash_init_tfm(struct crypto_tfm *tfm) 449 { 450 struct crypto_ahash *hash = __crypto_ahash_cast(tfm); 451 struct ahash_alg *alg = crypto_ahash_alg(hash); 452 453 hash->setkey = ahash_nosetkey; 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 if (alg->export) 469 hash->export = alg->export; 470 if (alg->import) 471 hash->import = alg->import; 472 473 return 0; 474 } 475 476 static unsigned int crypto_ahash_extsize(struct crypto_alg *alg) 477 { 478 if (alg->cra_type == &crypto_ahash_type) 479 return alg->cra_ctxsize; 480 481 return sizeof(struct crypto_shash *); 482 } 483 484 #ifdef CONFIG_NET 485 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg) 486 { 487 struct crypto_report_hash rhash; 488 489 strncpy(rhash.type, "ahash", sizeof(rhash.type)); 490 491 rhash.blocksize = alg->cra_blocksize; 492 rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize; 493 494 if (nla_put(skb, CRYPTOCFGA_REPORT_HASH, 495 sizeof(struct crypto_report_hash), &rhash)) 496 goto nla_put_failure; 497 return 0; 498 499 nla_put_failure: 500 return -EMSGSIZE; 501 } 502 #else 503 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg) 504 { 505 return -ENOSYS; 506 } 507 #endif 508 509 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg) 510 __attribute__ ((unused)); 511 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg) 512 { 513 seq_printf(m, "type : ahash\n"); 514 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ? 515 "yes" : "no"); 516 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); 517 seq_printf(m, "digestsize : %u\n", 518 __crypto_hash_alg_common(alg)->digestsize); 519 } 520 521 const struct crypto_type crypto_ahash_type = { 522 .extsize = crypto_ahash_extsize, 523 .init_tfm = crypto_ahash_init_tfm, 524 #ifdef CONFIG_PROC_FS 525 .show = crypto_ahash_show, 526 #endif 527 .report = crypto_ahash_report, 528 .maskclear = ~CRYPTO_ALG_TYPE_MASK, 529 .maskset = CRYPTO_ALG_TYPE_AHASH_MASK, 530 .type = CRYPTO_ALG_TYPE_AHASH, 531 .tfmsize = offsetof(struct crypto_ahash, base), 532 }; 533 EXPORT_SYMBOL_GPL(crypto_ahash_type); 534 535 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type, 536 u32 mask) 537 { 538 return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask); 539 } 540 EXPORT_SYMBOL_GPL(crypto_alloc_ahash); 541 542 static int ahash_prepare_alg(struct ahash_alg *alg) 543 { 544 struct crypto_alg *base = &alg->halg.base; 545 546 if (alg->halg.digestsize > PAGE_SIZE / 8 || 547 alg->halg.statesize > PAGE_SIZE / 8 || 548 alg->halg.statesize == 0) 549 return -EINVAL; 550 551 base->cra_type = &crypto_ahash_type; 552 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; 553 base->cra_flags |= CRYPTO_ALG_TYPE_AHASH; 554 555 return 0; 556 } 557 558 int crypto_register_ahash(struct ahash_alg *alg) 559 { 560 struct crypto_alg *base = &alg->halg.base; 561 int err; 562 563 err = ahash_prepare_alg(alg); 564 if (err) 565 return err; 566 567 return crypto_register_alg(base); 568 } 569 EXPORT_SYMBOL_GPL(crypto_register_ahash); 570 571 int crypto_unregister_ahash(struct ahash_alg *alg) 572 { 573 return crypto_unregister_alg(&alg->halg.base); 574 } 575 EXPORT_SYMBOL_GPL(crypto_unregister_ahash); 576 577 int ahash_register_instance(struct crypto_template *tmpl, 578 struct ahash_instance *inst) 579 { 580 int err; 581 582 err = ahash_prepare_alg(&inst->alg); 583 if (err) 584 return err; 585 586 return crypto_register_instance(tmpl, ahash_crypto_instance(inst)); 587 } 588 EXPORT_SYMBOL_GPL(ahash_register_instance); 589 590 void ahash_free_instance(struct crypto_instance *inst) 591 { 592 crypto_drop_spawn(crypto_instance_ctx(inst)); 593 kfree(ahash_instance(inst)); 594 } 595 EXPORT_SYMBOL_GPL(ahash_free_instance); 596 597 int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn, 598 struct hash_alg_common *alg, 599 struct crypto_instance *inst) 600 { 601 return crypto_init_spawn2(&spawn->base, &alg->base, inst, 602 &crypto_ahash_type); 603 } 604 EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn); 605 606 struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask) 607 { 608 struct crypto_alg *alg; 609 610 alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask); 611 return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg); 612 } 613 EXPORT_SYMBOL_GPL(ahash_attr_alg); 614 615 MODULE_LICENSE("GPL"); 616 MODULE_DESCRIPTION("Asynchronous cryptographic hash type"); 617