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 30struct ahash_request_priv { 31 crypto_completion_t complete; 32 void *data; 33 u8 *result; 34 void *ubuf[] CRYPTO_MINALIGN_ATTR; 35}; 36 37static 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 43static 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 67static int hash_walk_new_entry(struct crypto_hash_walk *walk) 68{ 69 struct scatterlist *sg; 70 71 sg = walk->sg; 72 walk->offset = sg->offset; 73 walk->pg = sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT); 74 walk->offset = offset_in_page(walk->offset); 75 walk->entrylen = sg->length; 76 77 if (walk->entrylen > walk->total) 78 walk->entrylen = walk->total; 79 walk->total -= walk->entrylen; 80 81 return hash_walk_next(walk); 82} 83 84int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err) 85{ 86 unsigned int alignmask = walk->alignmask; 87 unsigned int nbytes = walk->entrylen; 88 89 walk->data -= walk->offset; 90 91 if (nbytes && walk->offset & alignmask && !err) { 92 walk->offset = ALIGN(walk->offset, alignmask + 1); 93 walk->data += walk->offset; 94 95 nbytes = min(nbytes, 96 ((unsigned int)(PAGE_SIZE)) - walk->offset); 97 walk->entrylen -= nbytes; 98 99 return nbytes; 100 } 101 102 if (walk->flags & CRYPTO_ALG_ASYNC) 103 kunmap(walk->pg); 104 else { 105 kunmap_atomic(walk->data); 106 /* 107 * The may sleep test only makes sense for sync users. 108 * Async users don't need to sleep here anyway. 109 */ 110 crypto_yield(walk->flags); 111 } 112 113 if (err) 114 return err; 115 116 if (nbytes) { 117 walk->offset = 0; 118 walk->pg++; 119 return hash_walk_next(walk); 120 } 121 122 if (!walk->total) 123 return 0; 124 125 walk->sg = sg_next(walk->sg); 126 127 return hash_walk_new_entry(walk); 128} 129EXPORT_SYMBOL_GPL(crypto_hash_walk_done); 130 131int crypto_hash_walk_first(struct ahash_request *req, 132 struct crypto_hash_walk *walk) 133{ 134 walk->total = req->nbytes; 135 136 if (!walk->total) { 137 walk->entrylen = 0; 138 return 0; 139 } 140 141 walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req)); 142 walk->sg = req->src; 143 walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK; 144 145 return hash_walk_new_entry(walk); 146} 147EXPORT_SYMBOL_GPL(crypto_hash_walk_first); 148 149int crypto_ahash_walk_first(struct ahash_request *req, 150 struct crypto_hash_walk *walk) 151{ 152 walk->total = req->nbytes; 153 154 if (!walk->total) { 155 walk->entrylen = 0; 156 return 0; 157 } 158 159 walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req)); 160 walk->sg = req->src; 161 walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK; 162 walk->flags |= CRYPTO_ALG_ASYNC; 163 164 BUILD_BUG_ON(CRYPTO_TFM_REQ_MASK & CRYPTO_ALG_ASYNC); 165 166 return hash_walk_new_entry(walk); 167} 168EXPORT_SYMBOL_GPL(crypto_ahash_walk_first); 169 170int crypto_hash_walk_first_compat(struct hash_desc *hdesc, 171 struct crypto_hash_walk *walk, 172 struct scatterlist *sg, unsigned int len) 173{ 174 walk->total = len; 175 176 if (!walk->total) { 177 walk->entrylen = 0; 178 return 0; 179 } 180 181 walk->alignmask = crypto_hash_alignmask(hdesc->tfm); 182 walk->sg = sg; 183 walk->flags = hdesc->flags & CRYPTO_TFM_REQ_MASK; 184 185 return hash_walk_new_entry(walk); 186} 187 188static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key, 189 unsigned int keylen) 190{ 191 unsigned long alignmask = crypto_ahash_alignmask(tfm); 192 int ret; 193 u8 *buffer, *alignbuffer; 194 unsigned long absize; 195 196 absize = keylen + alignmask; 197 buffer = kmalloc(absize, GFP_KERNEL); 198 if (!buffer) 199 return -ENOMEM; 200 201 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); 202 memcpy(alignbuffer, key, keylen); 203 ret = tfm->setkey(tfm, alignbuffer, keylen); 204 kzfree(buffer); 205 return ret; 206} 207 208int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key, 209 unsigned int keylen) 210{ 211 unsigned long alignmask = crypto_ahash_alignmask(tfm); 212 213 if ((unsigned long)key & alignmask) 214 return ahash_setkey_unaligned(tfm, key, keylen); 215 216 return tfm->setkey(tfm, key, keylen); 217} 218EXPORT_SYMBOL_GPL(crypto_ahash_setkey); 219 220static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key, 221 unsigned int keylen) 222{ 223 return -ENOSYS; 224} 225 226static inline unsigned int ahash_align_buffer_size(unsigned len, 227 unsigned long mask) 228{ 229 return len + (mask & ~(crypto_tfm_ctx_alignment() - 1)); 230} 231 232static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt) 233{ 234 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 235 unsigned long alignmask = crypto_ahash_alignmask(tfm); 236 unsigned int ds = crypto_ahash_digestsize(tfm); 237 struct ahash_request_priv *priv; 238 239 priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask), 240 (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? 241 GFP_KERNEL : GFP_ATOMIC); 242 if (!priv) 243 return -ENOMEM; 244 245 /* 246 * WARNING: Voodoo programming below! 247 * 248 * The code below is obscure and hard to understand, thus explanation 249 * is necessary. See include/crypto/hash.h and include/linux/crypto.h 250 * to understand the layout of structures used here! 251 * 252 * The code here will replace portions of the ORIGINAL request with 253 * pointers to new code and buffers so the hashing operation can store 254 * the result in aligned buffer. We will call the modified request 255 * an ADJUSTED request. 256 * 257 * The newly mangled request will look as such: 258 * 259 * req { 260 * .result = ADJUSTED[new aligned buffer] 261 * .base.complete = ADJUSTED[pointer to completion function] 262 * .base.data = ADJUSTED[*req (pointer to self)] 263 * .priv = ADJUSTED[new priv] { 264 * .result = ORIGINAL(result) 265 * .complete = ORIGINAL(base.complete) 266 * .data = ORIGINAL(base.data) 267 * } 268 */ 269 270 priv->result = req->result; 271 priv->complete = req->base.complete; 272 priv->data = req->base.data; 273 /* 274 * WARNING: We do not backup req->priv here! The req->priv 275 * is for internal use of the Crypto API and the 276 * user must _NOT_ _EVER_ depend on it's content! 277 */ 278 279 req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1); 280 req->base.complete = cplt; 281 req->base.data = req; 282 req->priv = priv; 283 284 return 0; 285} 286 287static void ahash_restore_req(struct ahash_request *req) 288{ 289 struct ahash_request_priv *priv = req->priv; 290 291 /* Restore the original crypto request. */ 292 req->result = priv->result; 293 req->base.complete = priv->complete; 294 req->base.data = priv->data; 295 req->priv = NULL; 296 297 /* Free the req->priv.priv from the ADJUSTED request. */ 298 kzfree(priv); 299} 300 301static void ahash_op_unaligned_finish(struct ahash_request *req, int err) 302{ 303 struct ahash_request_priv *priv = req->priv; 304 305 if (err == -EINPROGRESS) 306 return; 307 308 if (!err) 309 memcpy(priv->result, req->result, 310 crypto_ahash_digestsize(crypto_ahash_reqtfm(req))); 311 312 ahash_restore_req(req); 313} 314 315static void ahash_op_unaligned_done(struct crypto_async_request *req, int err) 316{ 317 struct ahash_request *areq = req->data; 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_op_unaligned_finish(areq, err); 330 331 /* Complete the ORIGINAL request. */ 332 areq->base.complete(&areq->base, err); 333} 334 335static 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 ahash_op_unaligned_finish(req, err); 346 347 return err; 348} 349 350static int crypto_ahash_op(struct ahash_request *req, 351 int (*op)(struct ahash_request *)) 352{ 353 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 354 unsigned long alignmask = crypto_ahash_alignmask(tfm); 355 356 if ((unsigned long)req->result & alignmask) 357 return ahash_op_unaligned(req, op); 358 359 return op(req); 360} 361 362int crypto_ahash_final(struct ahash_request *req) 363{ 364 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final); 365} 366EXPORT_SYMBOL_GPL(crypto_ahash_final); 367 368int crypto_ahash_finup(struct ahash_request *req) 369{ 370 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup); 371} 372EXPORT_SYMBOL_GPL(crypto_ahash_finup); 373 374int crypto_ahash_digest(struct ahash_request *req) 375{ 376 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->digest); 377} 378EXPORT_SYMBOL_GPL(crypto_ahash_digest); 379 380static void ahash_def_finup_finish2(struct ahash_request *req, int err) 381{ 382 struct ahash_request_priv *priv = req->priv; 383 384 if (err == -EINPROGRESS) 385 return; 386 387 if (!err) 388 memcpy(priv->result, req->result, 389 crypto_ahash_digestsize(crypto_ahash_reqtfm(req))); 390 391 ahash_restore_req(req); 392} 393 394static void ahash_def_finup_done2(struct crypto_async_request *req, int err) 395{ 396 struct ahash_request *areq = req->data; 397 398 ahash_def_finup_finish2(areq, err); 399 400 areq->base.complete(&areq->base, err); 401} 402 403static int ahash_def_finup_finish1(struct ahash_request *req, int err) 404{ 405 if (err) 406 goto out; 407 408 req->base.complete = ahash_def_finup_done2; 409 req->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP; 410 err = crypto_ahash_reqtfm(req)->final(req); 411 412out: 413 ahash_def_finup_finish2(req, err); 414 return err; 415} 416 417static void ahash_def_finup_done1(struct crypto_async_request *req, int err) 418{ 419 struct ahash_request *areq = req->data; 420 421 err = ahash_def_finup_finish1(areq, err); 422 423 areq->base.complete(&areq->base, err); 424} 425 426static int ahash_def_finup(struct ahash_request *req) 427{ 428 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 429 int err; 430 431 err = ahash_save_req(req, ahash_def_finup_done1); 432 if (err) 433 return err; 434 435 err = tfm->update(req); 436 return ahash_def_finup_finish1(req, err); 437} 438 439static int ahash_no_export(struct ahash_request *req, void *out) 440{ 441 return -ENOSYS; 442} 443 444static int ahash_no_import(struct ahash_request *req, const void *in) 445{ 446 return -ENOSYS; 447} 448 449static int crypto_ahash_init_tfm(struct crypto_tfm *tfm) 450{ 451 struct crypto_ahash *hash = __crypto_ahash_cast(tfm); 452 struct ahash_alg *alg = crypto_ahash_alg(hash); 453 454 hash->setkey = ahash_nosetkey; 455 hash->has_setkey = false; 456 hash->export = ahash_no_export; 457 hash->import = ahash_no_import; 458 459 if (tfm->__crt_alg->cra_type != &crypto_ahash_type) 460 return crypto_init_shash_ops_async(tfm); 461 462 hash->init = alg->init; 463 hash->update = alg->update; 464 hash->final = alg->final; 465 hash->finup = alg->finup ?: ahash_def_finup; 466 hash->digest = alg->digest; 467 468 if (alg->setkey) { 469 hash->setkey = alg->setkey; 470 hash->has_setkey = true; 471 } 472 if (alg->export) 473 hash->export = alg->export; 474 if (alg->import) 475 hash->import = alg->import; 476 477 return 0; 478} 479 480static unsigned int crypto_ahash_extsize(struct crypto_alg *alg) 481{ 482 if (alg->cra_type == &crypto_ahash_type) 483 return alg->cra_ctxsize; 484 485 return sizeof(struct crypto_shash *); 486} 487 488#ifdef CONFIG_NET 489static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg) 490{ 491 struct crypto_report_hash rhash; 492 493 strncpy(rhash.type, "ahash", sizeof(rhash.type)); 494 495 rhash.blocksize = alg->cra_blocksize; 496 rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize; 497 498 if (nla_put(skb, CRYPTOCFGA_REPORT_HASH, 499 sizeof(struct crypto_report_hash), &rhash)) 500 goto nla_put_failure; 501 return 0; 502 503nla_put_failure: 504 return -EMSGSIZE; 505} 506#else 507static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg) 508{ 509 return -ENOSYS; 510} 511#endif 512 513static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg) 514 __attribute__ ((unused)); 515static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg) 516{ 517 seq_printf(m, "type : ahash\n"); 518 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ? 519 "yes" : "no"); 520 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); 521 seq_printf(m, "digestsize : %u\n", 522 __crypto_hash_alg_common(alg)->digestsize); 523} 524 525const struct crypto_type crypto_ahash_type = { 526 .extsize = crypto_ahash_extsize, 527 .init_tfm = crypto_ahash_init_tfm, 528#ifdef CONFIG_PROC_FS 529 .show = crypto_ahash_show, 530#endif 531 .report = crypto_ahash_report, 532 .maskclear = ~CRYPTO_ALG_TYPE_MASK, 533 .maskset = CRYPTO_ALG_TYPE_AHASH_MASK, 534 .type = CRYPTO_ALG_TYPE_AHASH, 535 .tfmsize = offsetof(struct crypto_ahash, base), 536}; 537EXPORT_SYMBOL_GPL(crypto_ahash_type); 538 539struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type, 540 u32 mask) 541{ 542 return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask); 543} 544EXPORT_SYMBOL_GPL(crypto_alloc_ahash); 545 546static int ahash_prepare_alg(struct ahash_alg *alg) 547{ 548 struct crypto_alg *base = &alg->halg.base; 549 550 if (alg->halg.digestsize > PAGE_SIZE / 8 || 551 alg->halg.statesize > PAGE_SIZE / 8 || 552 alg->halg.statesize == 0) 553 return -EINVAL; 554 555 base->cra_type = &crypto_ahash_type; 556 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; 557 base->cra_flags |= CRYPTO_ALG_TYPE_AHASH; 558 559 return 0; 560} 561 562int crypto_register_ahash(struct ahash_alg *alg) 563{ 564 struct crypto_alg *base = &alg->halg.base; 565 int err; 566 567 err = ahash_prepare_alg(alg); 568 if (err) 569 return err; 570 571 return crypto_register_alg(base); 572} 573EXPORT_SYMBOL_GPL(crypto_register_ahash); 574 575int crypto_unregister_ahash(struct ahash_alg *alg) 576{ 577 return crypto_unregister_alg(&alg->halg.base); 578} 579EXPORT_SYMBOL_GPL(crypto_unregister_ahash); 580 581int ahash_register_instance(struct crypto_template *tmpl, 582 struct ahash_instance *inst) 583{ 584 int err; 585 586 err = ahash_prepare_alg(&inst->alg); 587 if (err) 588 return err; 589 590 return crypto_register_instance(tmpl, ahash_crypto_instance(inst)); 591} 592EXPORT_SYMBOL_GPL(ahash_register_instance); 593 594void ahash_free_instance(struct crypto_instance *inst) 595{ 596 crypto_drop_spawn(crypto_instance_ctx(inst)); 597 kfree(ahash_instance(inst)); 598} 599EXPORT_SYMBOL_GPL(ahash_free_instance); 600 601int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn, 602 struct hash_alg_common *alg, 603 struct crypto_instance *inst) 604{ 605 return crypto_init_spawn2(&spawn->base, &alg->base, inst, 606 &crypto_ahash_type); 607} 608EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn); 609 610struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask) 611{ 612 struct crypto_alg *alg; 613 614 alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask); 615 return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg); 616} 617EXPORT_SYMBOL_GPL(ahash_attr_alg); 618 619MODULE_LICENSE("GPL"); 620MODULE_DESCRIPTION("Asynchronous cryptographic hash type"); 621