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 if (nbytes > unaligned) 59 nbytes = unaligned; 60 } 61 62 walk->entrylen -= nbytes; 63 return nbytes; 64 } 65 66 static int hash_walk_new_entry(struct crypto_hash_walk *walk) 67 { 68 struct scatterlist *sg; 69 70 sg = walk->sg; 71 walk->pg = sg_page(sg); 72 walk->offset = sg->offset; 73 walk->entrylen = sg->length; 74 75 if (walk->entrylen > walk->total) 76 walk->entrylen = walk->total; 77 walk->total -= walk->entrylen; 78 79 return hash_walk_next(walk); 80 } 81 82 int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err) 83 { 84 unsigned int alignmask = walk->alignmask; 85 unsigned int nbytes = walk->entrylen; 86 87 walk->data -= walk->offset; 88 89 if (nbytes && walk->offset & alignmask && !err) { 90 walk->offset = ALIGN(walk->offset, alignmask + 1); 91 walk->data += walk->offset; 92 93 nbytes = min(nbytes, 94 ((unsigned int)(PAGE_SIZE)) - walk->offset); 95 walk->entrylen -= nbytes; 96 97 return nbytes; 98 } 99 100 if (walk->flags & CRYPTO_ALG_ASYNC) 101 kunmap(walk->pg); 102 else { 103 kunmap_atomic(walk->data); 104 /* 105 * The may sleep test only makes sense for sync users. 106 * Async users don't need to sleep here anyway. 107 */ 108 crypto_yield(walk->flags); 109 } 110 111 if (err) 112 return err; 113 114 if (nbytes) { 115 walk->offset = 0; 116 walk->pg++; 117 return hash_walk_next(walk); 118 } 119 120 if (!walk->total) 121 return 0; 122 123 walk->sg = scatterwalk_sg_next(walk->sg); 124 125 return hash_walk_new_entry(walk); 126 } 127 EXPORT_SYMBOL_GPL(crypto_hash_walk_done); 128 129 int crypto_hash_walk_first(struct ahash_request *req, 130 struct crypto_hash_walk *walk) 131 { 132 walk->total = req->nbytes; 133 134 if (!walk->total) 135 return 0; 136 137 walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req)); 138 walk->sg = req->src; 139 walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK; 140 141 return hash_walk_new_entry(walk); 142 } 143 EXPORT_SYMBOL_GPL(crypto_hash_walk_first); 144 145 int crypto_ahash_walk_first(struct ahash_request *req, 146 struct crypto_hash_walk *walk) 147 { 148 walk->total = req->nbytes; 149 150 if (!walk->total) 151 return 0; 152 153 walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req)); 154 walk->sg = req->src; 155 walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK; 156 walk->flags |= CRYPTO_ALG_ASYNC; 157 158 BUILD_BUG_ON(CRYPTO_TFM_REQ_MASK & CRYPTO_ALG_ASYNC); 159 160 return hash_walk_new_entry(walk); 161 } 162 EXPORT_SYMBOL_GPL(crypto_ahash_walk_first); 163 164 int crypto_hash_walk_first_compat(struct hash_desc *hdesc, 165 struct crypto_hash_walk *walk, 166 struct scatterlist *sg, unsigned int len) 167 { 168 walk->total = len; 169 170 if (!walk->total) 171 return 0; 172 173 walk->alignmask = crypto_hash_alignmask(hdesc->tfm); 174 walk->sg = sg; 175 walk->flags = hdesc->flags & CRYPTO_TFM_REQ_MASK; 176 177 return hash_walk_new_entry(walk); 178 } 179 180 static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key, 181 unsigned int keylen) 182 { 183 unsigned long alignmask = crypto_ahash_alignmask(tfm); 184 int ret; 185 u8 *buffer, *alignbuffer; 186 unsigned long absize; 187 188 absize = keylen + alignmask; 189 buffer = kmalloc(absize, GFP_KERNEL); 190 if (!buffer) 191 return -ENOMEM; 192 193 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); 194 memcpy(alignbuffer, key, keylen); 195 ret = tfm->setkey(tfm, alignbuffer, keylen); 196 kzfree(buffer); 197 return ret; 198 } 199 200 int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key, 201 unsigned int keylen) 202 { 203 unsigned long alignmask = crypto_ahash_alignmask(tfm); 204 205 if ((unsigned long)key & alignmask) 206 return ahash_setkey_unaligned(tfm, key, keylen); 207 208 return tfm->setkey(tfm, key, keylen); 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 /* 266 * WARNING: We do not backup req->priv here! The req->priv 267 * is for internal use of the Crypto API and the 268 * user must _NOT_ _EVER_ depend on it's content! 269 */ 270 271 req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1); 272 req->base.complete = cplt; 273 req->base.data = req; 274 req->priv = priv; 275 276 return 0; 277 } 278 279 static void ahash_restore_req(struct ahash_request *req) 280 { 281 struct ahash_request_priv *priv = req->priv; 282 283 /* Restore the original crypto request. */ 284 req->result = priv->result; 285 req->base.complete = priv->complete; 286 req->base.data = priv->data; 287 req->priv = NULL; 288 289 /* Free the req->priv.priv from the ADJUSTED request. */ 290 kzfree(priv); 291 } 292 293 static void ahash_op_unaligned_finish(struct ahash_request *req, int err) 294 { 295 struct ahash_request_priv *priv = req->priv; 296 297 if (err == -EINPROGRESS) 298 return; 299 300 if (!err) 301 memcpy(priv->result, req->result, 302 crypto_ahash_digestsize(crypto_ahash_reqtfm(req))); 303 304 ahash_restore_req(req); 305 } 306 307 static void ahash_op_unaligned_done(struct crypto_async_request *req, int err) 308 { 309 struct ahash_request *areq = req->data; 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_op_unaligned_finish(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 ahash_op_unaligned_finish(req, err); 338 339 return err; 340 } 341 342 static int crypto_ahash_op(struct ahash_request *req, 343 int (*op)(struct ahash_request *)) 344 { 345 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 346 unsigned long alignmask = crypto_ahash_alignmask(tfm); 347 348 if ((unsigned long)req->result & alignmask) 349 return ahash_op_unaligned(req, op); 350 351 return op(req); 352 } 353 354 int crypto_ahash_final(struct ahash_request *req) 355 { 356 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final); 357 } 358 EXPORT_SYMBOL_GPL(crypto_ahash_final); 359 360 int crypto_ahash_finup(struct ahash_request *req) 361 { 362 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup); 363 } 364 EXPORT_SYMBOL_GPL(crypto_ahash_finup); 365 366 int crypto_ahash_digest(struct ahash_request *req) 367 { 368 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->digest); 369 } 370 EXPORT_SYMBOL_GPL(crypto_ahash_digest); 371 372 static void ahash_def_finup_finish2(struct ahash_request *req, int err) 373 { 374 struct ahash_request_priv *priv = req->priv; 375 376 if (err == -EINPROGRESS) 377 return; 378 379 if (!err) 380 memcpy(priv->result, req->result, 381 crypto_ahash_digestsize(crypto_ahash_reqtfm(req))); 382 383 ahash_restore_req(req); 384 } 385 386 static void ahash_def_finup_done2(struct crypto_async_request *req, int err) 387 { 388 struct ahash_request *areq = req->data; 389 390 ahash_def_finup_finish2(areq, err); 391 392 areq->base.complete(&areq->base, err); 393 } 394 395 static int ahash_def_finup_finish1(struct ahash_request *req, int err) 396 { 397 if (err) 398 goto out; 399 400 req->base.complete = ahash_def_finup_done2; 401 req->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP; 402 err = crypto_ahash_reqtfm(req)->final(req); 403 404 out: 405 ahash_def_finup_finish2(req, err); 406 return err; 407 } 408 409 static void ahash_def_finup_done1(struct crypto_async_request *req, int err) 410 { 411 struct ahash_request *areq = req->data; 412 413 err = ahash_def_finup_finish1(areq, err); 414 415 areq->base.complete(&areq->base, err); 416 } 417 418 static int ahash_def_finup(struct ahash_request *req) 419 { 420 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 421 int err; 422 423 err = ahash_save_req(req, ahash_def_finup_done1); 424 if (err) 425 return err; 426 427 err = tfm->update(req); 428 return ahash_def_finup_finish1(req, err); 429 } 430 431 static int ahash_no_export(struct ahash_request *req, void *out) 432 { 433 return -ENOSYS; 434 } 435 436 static int ahash_no_import(struct ahash_request *req, const void *in) 437 { 438 return -ENOSYS; 439 } 440 441 static int crypto_ahash_init_tfm(struct crypto_tfm *tfm) 442 { 443 struct crypto_ahash *hash = __crypto_ahash_cast(tfm); 444 struct ahash_alg *alg = crypto_ahash_alg(hash); 445 446 hash->setkey = ahash_nosetkey; 447 hash->export = ahash_no_export; 448 hash->import = ahash_no_import; 449 450 if (tfm->__crt_alg->cra_type != &crypto_ahash_type) 451 return crypto_init_shash_ops_async(tfm); 452 453 hash->init = alg->init; 454 hash->update = alg->update; 455 hash->final = alg->final; 456 hash->finup = alg->finup ?: ahash_def_finup; 457 hash->digest = alg->digest; 458 459 if (alg->setkey) 460 hash->setkey = alg->setkey; 461 if (alg->export) 462 hash->export = alg->export; 463 if (alg->import) 464 hash->import = alg->import; 465 466 return 0; 467 } 468 469 static unsigned int crypto_ahash_extsize(struct crypto_alg *alg) 470 { 471 if (alg->cra_type == &crypto_ahash_type) 472 return alg->cra_ctxsize; 473 474 return sizeof(struct crypto_shash *); 475 } 476 477 #ifdef CONFIG_NET 478 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg) 479 { 480 struct crypto_report_hash rhash; 481 482 strncpy(rhash.type, "ahash", sizeof(rhash.type)); 483 484 rhash.blocksize = alg->cra_blocksize; 485 rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize; 486 487 if (nla_put(skb, CRYPTOCFGA_REPORT_HASH, 488 sizeof(struct crypto_report_hash), &rhash)) 489 goto nla_put_failure; 490 return 0; 491 492 nla_put_failure: 493 return -EMSGSIZE; 494 } 495 #else 496 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg) 497 { 498 return -ENOSYS; 499 } 500 #endif 501 502 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg) 503 __attribute__ ((unused)); 504 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg) 505 { 506 seq_printf(m, "type : ahash\n"); 507 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ? 508 "yes" : "no"); 509 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); 510 seq_printf(m, "digestsize : %u\n", 511 __crypto_hash_alg_common(alg)->digestsize); 512 } 513 514 const struct crypto_type crypto_ahash_type = { 515 .extsize = crypto_ahash_extsize, 516 .init_tfm = crypto_ahash_init_tfm, 517 #ifdef CONFIG_PROC_FS 518 .show = crypto_ahash_show, 519 #endif 520 .report = crypto_ahash_report, 521 .maskclear = ~CRYPTO_ALG_TYPE_MASK, 522 .maskset = CRYPTO_ALG_TYPE_AHASH_MASK, 523 .type = CRYPTO_ALG_TYPE_AHASH, 524 .tfmsize = offsetof(struct crypto_ahash, base), 525 }; 526 EXPORT_SYMBOL_GPL(crypto_ahash_type); 527 528 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type, 529 u32 mask) 530 { 531 return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask); 532 } 533 EXPORT_SYMBOL_GPL(crypto_alloc_ahash); 534 535 static int ahash_prepare_alg(struct ahash_alg *alg) 536 { 537 struct crypto_alg *base = &alg->halg.base; 538 539 if (alg->halg.digestsize > PAGE_SIZE / 8 || 540 alg->halg.statesize > PAGE_SIZE / 8) 541 return -EINVAL; 542 543 base->cra_type = &crypto_ahash_type; 544 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; 545 base->cra_flags |= CRYPTO_ALG_TYPE_AHASH; 546 547 return 0; 548 } 549 550 int crypto_register_ahash(struct ahash_alg *alg) 551 { 552 struct crypto_alg *base = &alg->halg.base; 553 int err; 554 555 err = ahash_prepare_alg(alg); 556 if (err) 557 return err; 558 559 return crypto_register_alg(base); 560 } 561 EXPORT_SYMBOL_GPL(crypto_register_ahash); 562 563 int crypto_unregister_ahash(struct ahash_alg *alg) 564 { 565 return crypto_unregister_alg(&alg->halg.base); 566 } 567 EXPORT_SYMBOL_GPL(crypto_unregister_ahash); 568 569 int ahash_register_instance(struct crypto_template *tmpl, 570 struct ahash_instance *inst) 571 { 572 int err; 573 574 err = ahash_prepare_alg(&inst->alg); 575 if (err) 576 return err; 577 578 return crypto_register_instance(tmpl, ahash_crypto_instance(inst)); 579 } 580 EXPORT_SYMBOL_GPL(ahash_register_instance); 581 582 void ahash_free_instance(struct crypto_instance *inst) 583 { 584 crypto_drop_spawn(crypto_instance_ctx(inst)); 585 kfree(ahash_instance(inst)); 586 } 587 EXPORT_SYMBOL_GPL(ahash_free_instance); 588 589 int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn, 590 struct hash_alg_common *alg, 591 struct crypto_instance *inst) 592 { 593 return crypto_init_spawn2(&spawn->base, &alg->base, inst, 594 &crypto_ahash_type); 595 } 596 EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn); 597 598 struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask) 599 { 600 struct crypto_alg *alg; 601 602 alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask); 603 return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg); 604 } 605 EXPORT_SYMBOL_GPL(ahash_attr_alg); 606 607 MODULE_LICENSE("GPL"); 608 MODULE_DESCRIPTION("Asynchronous cryptographic hash type"); 609