crypto/ahash.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Asynchronous Cryptographic Hash operations.
   4  *
   5  * This is the asynchronous version of hash.c with notification of
   6  * completion via a callback.
   7  *
   8  * Copyright (c) 2008 Loc Ho <lho@amcc.com>
   9  */
  10
  11 #include <crypto/scatterwalk.h>
  12 #include <linux/cryptouser.h>
  13 #include <linux/err.h>
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/sched.h>
  17 #include <linux/slab.h>
  18 #include <linux/seq_file.h>
  19 #include <linux/string.h>
  20 #include <net/netlink.h>
  21
  22 #include "hash.h"
  23
  24 static const struct crypto_type crypto_ahash_type;
  25
  26 struct ahash_request_priv {
  27         crypto_completion_t complete;
  28         void *data;
  29         u8 *result;
  30         u32 flags;
  31         void *ubuf[] CRYPTO_MINALIGN_ATTR;
  32 };
  33
  34 static inline struct ahash_alg *crypto_ahash_alg(struct crypto_ahash *hash)
  35 {
  36         return container_of(crypto_hash_alg_common(hash), struct ahash_alg,
  37                             halg);
  38 }
  39
  40 static int hash_walk_next(struct crypto_hash_walk *walk)
  41 {
  42         unsigned int alignmask = walk->alignmask;
  43         unsigned int offset = walk->offset;
  44         unsigned int nbytes = min(walk->entrylen,
  45                                   ((unsigned int)(PAGE_SIZE)) - offset);
  46
  47         walk->data = kmap_local_page(walk->pg);
  48         walk->data += offset;
  49
  50         if (offset & alignmask) {
  51                 unsigned int unaligned = alignmask + 1 - (offset & alignmask);
  52
  53                 if (nbytes > unaligned)
  54                         nbytes = unaligned;
  55         }
  56
  57         walk->entrylen -= nbytes;
  58         return nbytes;
  59 }
  60
  61 static int hash_walk_new_entry(struct crypto_hash_walk *walk)
  62 {
  63         struct scatterlist *sg;
  64
  65         sg = walk->sg;
  66         walk->offset = sg->offset;
  67         walk->pg = sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
  68         walk->offset = offset_in_page(walk->offset);
  69         walk->entrylen = sg->length;
  70
  71         if (walk->entrylen > walk->total)
  72                 walk->entrylen = walk->total;
  73         walk->total -= walk->entrylen;
  74
  75         return hash_walk_next(walk);
  76 }
  77
  78 int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
  79 {
  80         unsigned int alignmask = walk->alignmask;
  81
  82         walk->data -= walk->offset;
  83
  84         if (walk->entrylen && (walk->offset & alignmask) && !err) {
  85                 unsigned int nbytes;
  86
  87                 walk->offset = ALIGN(walk->offset, alignmask + 1);
  88                 nbytes = min(walk->entrylen,
  89                              (unsigned int)(PAGE_SIZE - walk->offset));
  90                 if (nbytes) {
  91                         walk->entrylen -= nbytes;
  92                         walk->data += walk->offset;
  93                         return nbytes;
  94                 }
  95         }
  96
  97         kunmap_local(walk->data);
  98         crypto_yield(walk->flags);
  99
 100         if (err)
 101                 return err;
 102
 103         if (walk->entrylen) {
 104                 walk->offset = 0;
 105                 walk->pg++;
 106                 return hash_walk_next(walk);
 107         }
 108
 109         if (!walk->total)
 110                 return 0;
 111
 112         walk->sg = sg_next(walk->sg);
 113
 114         return hash_walk_new_entry(walk);
 115 }
 116 EXPORT_SYMBOL_GPL(crypto_hash_walk_done);
 117
 118 int crypto_hash_walk_first(struct ahash_request *req,
 119                            struct crypto_hash_walk *walk)
 120 {
 121         walk->total = req->nbytes;
 122
 123         if (!walk->total) {
 124                 walk->entrylen = 0;
 125                 return 0;
 126         }
 127
 128         walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
 129         walk->sg = req->src;
 130         walk->flags = req->base.flags;
 131
 132         return hash_walk_new_entry(walk);
 133 }
 134 EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
 135
 136 static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
 137                                 unsigned int keylen)
 138 {
 139         unsigned long alignmask = crypto_ahash_alignmask(tfm);
 140         int ret;
 141         u8 *buffer, *alignbuffer;
 142         unsigned long absize;
 143
 144         absize = keylen + alignmask;
 145         buffer = kmalloc(absize, GFP_KERNEL);
 146         if (!buffer)
 147                 return -ENOMEM;
 148
 149         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
 150         memcpy(alignbuffer, key, keylen);
 151         ret = tfm->setkey(tfm, alignbuffer, keylen);
 152         kfree_sensitive(buffer);
 153         return ret;
 154 }
 155
 156 static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
 157                           unsigned int keylen)
 158 {
 159         return -ENOSYS;
 160 }
 161
 162 static void ahash_set_needkey(struct crypto_ahash *tfm)
 163 {
 164         const struct hash_alg_common *alg = crypto_hash_alg_common(tfm);
 165
 166         if (tfm->setkey != ahash_nosetkey &&
 167             !(alg->base.cra_flags & CRYPTO_ALG_OPTIONAL_KEY))
 168                 crypto_ahash_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
 169 }
 170
 171 int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
 172                         unsigned int keylen)
 173 {
 174         unsigned long alignmask = crypto_ahash_alignmask(tfm);
 175         int err;
 176
 177         if ((unsigned long)key & alignmask)
 178                 err = ahash_setkey_unaligned(tfm, key, keylen);
 179         else
 180                 err = tfm->setkey(tfm, key, keylen);
 181
 182         if (unlikely(err)) {
 183                 ahash_set_needkey(tfm);
 184                 return err;
 185         }
 186
 187         crypto_ahash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
 188         return 0;
 189 }
 190 EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
 191
 192 static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt,
 193                           bool has_state)
 194 {
 195         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 196         unsigned long alignmask = crypto_ahash_alignmask(tfm);
 197         unsigned int ds = crypto_ahash_digestsize(tfm);
 198         struct ahash_request *subreq;
 199         unsigned int subreq_size;
 200         unsigned int reqsize;
 201         u8 *result;
 202         gfp_t gfp;
 203         u32 flags;
 204
 205         subreq_size = sizeof(*subreq);
 206         reqsize = crypto_ahash_reqsize(tfm);
 207         reqsize = ALIGN(reqsize, crypto_tfm_ctx_alignment());
 208         subreq_size += reqsize;
 209         subreq_size += ds;
 210         subreq_size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
 211
 212         flags = ahash_request_flags(req);
 213         gfp = (flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?  GFP_KERNEL : GFP_ATOMIC;
 214         subreq = kmalloc(subreq_size, gfp);
 215         if (!subreq)
 216                 return -ENOMEM;
 217
 218         ahash_request_set_tfm(subreq, tfm);
 219         ahash_request_set_callback(subreq, flags, cplt, req);
 220
 221         result = (u8 *)(subreq + 1) + reqsize;
 222         result = PTR_ALIGN(result, alignmask + 1);
 223
 224         ahash_request_set_crypt(subreq, req->src, result, req->nbytes);
 225
 226         if (has_state) {
 227                 void *state;
 228
 229                 state = kmalloc(crypto_ahash_statesize(tfm), gfp);
 230                 if (!state) {
 231                         kfree(subreq);
 232                         return -ENOMEM;
 233                 }
 234
 235                 crypto_ahash_export(req, state);
 236                 crypto_ahash_import(subreq, state);
 237                 kfree_sensitive(state);
 238         }
 239
 240         req->priv = subreq;
 241
 242         return 0;
 243 }
 244
 245 static void ahash_restore_req(struct ahash_request *req, int err)
 246 {
 247         struct ahash_request *subreq = req->priv;
 248
 249         if (!err)
 250                 memcpy(req->result, subreq->result,
 251                        crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
 252
 253         req->priv = NULL;
 254
 255         kfree_sensitive(subreq);
 256 }
 257
 258 static void ahash_op_unaligned_done(void *data, int err)
 259 {
 260         struct ahash_request *areq = data;
 261
 262         if (err == -EINPROGRESS)
 263                 goto out;
 264
 265         /* First copy req->result into req->priv.result */
 266         ahash_restore_req(areq, err);
 267
 268 out:
 269         /* Complete the ORIGINAL request. */
 270         ahash_request_complete(areq, err);
 271 }
 272
 273 static int ahash_op_unaligned(struct ahash_request *req,
 274                               int (*op)(struct ahash_request *),
 275                               bool has_state)
 276 {
 277         int err;
 278
 279         err = ahash_save_req(req, ahash_op_unaligned_done, has_state);
 280         if (err)
 281                 return err;
 282
 283         err = op(req->priv);
 284         if (err == -EINPROGRESS || err == -EBUSY)
 285                 return err;
 286
 287         ahash_restore_req(req, err);
 288
 289         return err;
 290 }
 291
 292 static int crypto_ahash_op(struct ahash_request *req,
 293                            int (*op)(struct ahash_request *),
 294                            bool has_state)
 295 {
 296         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 297         unsigned long alignmask = crypto_ahash_alignmask(tfm);
 298         int err;
 299
 300         if ((unsigned long)req->result & alignmask)
 301                 err = ahash_op_unaligned(req, op, has_state);
 302         else
 303                 err = op(req);
 304
 305         return crypto_hash_errstat(crypto_hash_alg_common(tfm), err);
 306 }
 307
 308 int crypto_ahash_final(struct ahash_request *req)
 309 {
 310         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 311         struct hash_alg_common *alg = crypto_hash_alg_common(tfm);
 312
 313         if (IS_ENABLED(CONFIG_CRYPTO_STATS))
 314                 atomic64_inc(&hash_get_stat(alg)->hash_cnt);
 315
 316         return crypto_ahash_op(req, tfm->final, true);
 317 }
 318 EXPORT_SYMBOL_GPL(crypto_ahash_final);
 319
 320 int crypto_ahash_finup(struct ahash_request *req)
 321 {
 322         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 323         struct hash_alg_common *alg = crypto_hash_alg_common(tfm);
 324
 325         if (IS_ENABLED(CONFIG_CRYPTO_STATS)) {
 326                 struct crypto_istat_hash *istat = hash_get_stat(alg);
 327
 328                 atomic64_inc(&istat->hash_cnt);
 329                 atomic64_add(req->nbytes, &istat->hash_tlen);
 330         }
 331
 332         return crypto_ahash_op(req, tfm->finup, true);
 333 }
 334 EXPORT_SYMBOL_GPL(crypto_ahash_finup);
 335
 336 int crypto_ahash_digest(struct ahash_request *req)
 337 {
 338         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 339         struct hash_alg_common *alg = crypto_hash_alg_common(tfm);
 340
 341         if (IS_ENABLED(CONFIG_CRYPTO_STATS)) {
 342                 struct crypto_istat_hash *istat = hash_get_stat(alg);
 343
 344                 atomic64_inc(&istat->hash_cnt);
 345                 atomic64_add(req->nbytes, &istat->hash_tlen);
 346         }
 347
 348         if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
 349                 return crypto_hash_errstat(alg, -ENOKEY);
 350
 351         return crypto_ahash_op(req, tfm->digest, false);
 352 }
 353 EXPORT_SYMBOL_GPL(crypto_ahash_digest);
 354
 355 static void ahash_def_finup_done2(void *data, int err)
 356 {
 357         struct ahash_request *areq = data;
 358
 359         if (err == -EINPROGRESS)
 360                 return;
 361
 362         ahash_restore_req(areq, err);
 363
 364         ahash_request_complete(areq, err);
 365 }
 366
 367 static int ahash_def_finup_finish1(struct ahash_request *req, int err)
 368 {
 369         struct ahash_request *subreq = req->priv;
 370
 371         if (err)
 372                 goto out;
 373
 374         subreq->base.complete = ahash_def_finup_done2;
 375
 376         err = crypto_ahash_reqtfm(req)->final(subreq);
 377         if (err == -EINPROGRESS || err == -EBUSY)
 378                 return err;
 379
 380 out:
 381         ahash_restore_req(req, err);
 382         return err;
 383 }
 384
 385 static void ahash_def_finup_done1(void *data, int err)
 386 {
 387         struct ahash_request *areq = data;
 388         struct ahash_request *subreq;
 389
 390         if (err == -EINPROGRESS)
 391                 goto out;
 392
 393         subreq = areq->priv;
 394         subreq->base.flags &= CRYPTO_TFM_REQ_MAY_BACKLOG;
 395
 396         err = ahash_def_finup_finish1(areq, err);
 397         if (err == -EINPROGRESS || err == -EBUSY)
 398                 return;
 399
 400 out:
 401         ahash_request_complete(areq, err);
 402 }
 403
 404 static int ahash_def_finup(struct ahash_request *req)
 405 {
 406         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 407         int err;
 408
 409         err = ahash_save_req(req, ahash_def_finup_done1, true);
 410         if (err)
 411                 return err;
 412
 413         err = tfm->update(req->priv);
 414         if (err == -EINPROGRESS || err == -EBUSY)
 415                 return err;
 416
 417         return ahash_def_finup_finish1(req, err);
 418 }
 419
 420 static void crypto_ahash_exit_tfm(struct crypto_tfm *tfm)
 421 {
 422         struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
 423         struct ahash_alg *alg = crypto_ahash_alg(hash);
 424
 425         alg->exit_tfm(hash);
 426 }
 427
 428 static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
 429 {
 430         struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
 431         struct ahash_alg *alg = crypto_ahash_alg(hash);
 432
 433         hash->setkey = ahash_nosetkey;
 434
 435         if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
 436                 return crypto_init_shash_ops_async(tfm);
 437
 438         hash->init = alg->init;
 439         hash->update = alg->update;
 440         hash->final = alg->final;
 441         hash->finup = alg->finup ?: ahash_def_finup;
 442         hash->digest = alg->digest;
 443         hash->export = alg->export;
 444         hash->import = alg->import;
 445
 446         if (alg->setkey) {
 447                 hash->setkey = alg->setkey;
 448                 ahash_set_needkey(hash);
 449         }
 450
 451         if (alg->exit_tfm)
 452                 tfm->exit = crypto_ahash_exit_tfm;
 453
 454         return alg->init_tfm ? alg->init_tfm(hash) : 0;
 455 }
 456
 457 static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
 458 {
 459         if (alg->cra_type != &crypto_ahash_type)
 460                 return sizeof(struct crypto_shash *);
 461
 462         return crypto_alg_extsize(alg);
 463 }
 464
 465 static void crypto_ahash_free_instance(struct crypto_instance *inst)
 466 {
 467         struct ahash_instance *ahash = ahash_instance(inst);
 468
 469         ahash->free(ahash);
 470 }
 471
 472 static int __maybe_unused crypto_ahash_report(
 473         struct sk_buff *skb, struct crypto_alg *alg)
 474 {
 475         struct crypto_report_hash rhash;
 476
 477         memset(&rhash, 0, sizeof(rhash));
 478
 479         strscpy(rhash.type, "ahash", sizeof(rhash.type));
 480
 481         rhash.blocksize = alg->cra_blocksize;
 482         rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize;
 483
 484         return nla_put(skb, CRYPTOCFGA_REPORT_HASH, sizeof(rhash), &rhash);
 485 }
 486
 487 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
 488         __maybe_unused;
 489 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
 490 {
 491         seq_printf(m, "type         : ahash\n");
 492         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 493                                              "yes" : "no");
 494         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 495         seq_printf(m, "digestsize   : %u\n",
 496                    __crypto_hash_alg_common(alg)->digestsize);
 497 }
 498
 499 static int __maybe_unused crypto_ahash_report_stat(
 500         struct sk_buff *skb, struct crypto_alg *alg)
 501 {
 502         return crypto_hash_report_stat(skb, alg, "ahash");
 503 }
 504
 505 static const struct crypto_type crypto_ahash_type = {
 506         .extsize = crypto_ahash_extsize,
 507         .init_tfm = crypto_ahash_init_tfm,
 508         .free = crypto_ahash_free_instance,
 509 #ifdef CONFIG_PROC_FS
 510         .show = crypto_ahash_show,
 511 #endif
 512 #ifdef CONFIG_CRYPTO_USER
 513         .report = crypto_ahash_report,
 514 #endif
 515 #ifdef CONFIG_CRYPTO_STATS
 516         .report_stat = crypto_ahash_report_stat,
 517 #endif
 518         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 519         .maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
 520         .type = CRYPTO_ALG_TYPE_AHASH,
 521         .tfmsize = offsetof(struct crypto_ahash, base),
 522 };
 523
 524 int crypto_grab_ahash(struct crypto_ahash_spawn *spawn,
 525                       struct crypto_instance *inst,
 526                       const char *name, u32 type, u32 mask)
 527 {
 528         spawn->base.frontend = &crypto_ahash_type;
 529         return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
 530 }
 531 EXPORT_SYMBOL_GPL(crypto_grab_ahash);
 532
 533 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
 534                                         u32 mask)
 535 {
 536         return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
 537 }
 538 EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
 539
 540 int crypto_has_ahash(const char *alg_name, u32 type, u32 mask)
 541 {
 542         return crypto_type_has_alg(alg_name, &crypto_ahash_type, type, mask);
 543 }
 544 EXPORT_SYMBOL_GPL(crypto_has_ahash);
 545
 546 struct crypto_ahash *crypto_clone_ahash(struct crypto_ahash *hash)
 547 {
 548         struct hash_alg_common *halg = crypto_hash_alg_common(hash);
 549         struct crypto_tfm *tfm = crypto_ahash_tfm(hash);
 550         struct crypto_ahash *nhash;
 551         struct ahash_alg *alg;
 552         int err;
 553
 554         if (!crypto_hash_alg_has_setkey(halg)) {
 555                 tfm = crypto_tfm_get(tfm);
 556                 if (IS_ERR(tfm))
 557                         return ERR_CAST(tfm);
 558
 559                 return hash;
 560         }
 561
 562         nhash = crypto_clone_tfm(&crypto_ahash_type, tfm);
 563
 564         if (IS_ERR(nhash))
 565                 return nhash;
 566
 567         nhash->init = hash->init;
 568         nhash->update = hash->update;
 569         nhash->final = hash->final;
 570         nhash->finup = hash->finup;
 571         nhash->digest = hash->digest;
 572         nhash->export = hash->export;
 573         nhash->import = hash->import;
 574         nhash->setkey = hash->setkey;
 575         nhash->reqsize = hash->reqsize;
 576
 577         if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
 578                 return crypto_clone_shash_ops_async(nhash, hash);
 579
 580         err = -ENOSYS;
 581         alg = crypto_ahash_alg(hash);
 582         if (!alg->clone_tfm)
 583                 goto out_free_nhash;
 584
 585         err = alg->clone_tfm(nhash, hash);
 586         if (err)
 587                 goto out_free_nhash;
 588
 589         return nhash;
 590
 591 out_free_nhash:
 592         crypto_free_ahash(nhash);
 593         return ERR_PTR(err);
 594 }
 595 EXPORT_SYMBOL_GPL(crypto_clone_ahash);
 596
 597 static int ahash_prepare_alg(struct ahash_alg *alg)
 598 {
 599         struct crypto_alg *base = &alg->halg.base;
 600         int err;
 601
 602         if (alg->halg.statesize == 0)
 603                 return -EINVAL;
 604
 605         err = hash_prepare_alg(&alg->halg);
 606         if (err)
 607                 return err;
 608
 609         base->cra_type = &crypto_ahash_type;
 610         base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
 611
 612         return 0;
 613 }
 614
 615 int crypto_register_ahash(struct ahash_alg *alg)
 616 {
 617         struct crypto_alg *base = &alg->halg.base;
 618         int err;
 619
 620         err = ahash_prepare_alg(alg);
 621         if (err)
 622                 return err;
 623
 624         return crypto_register_alg(base);
 625 }
 626 EXPORT_SYMBOL_GPL(crypto_register_ahash);
 627
 628 void crypto_unregister_ahash(struct ahash_alg *alg)
 629 {
 630         crypto_unregister_alg(&alg->halg.base);
 631 }
 632 EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
 633
 634 int crypto_register_ahashes(struct ahash_alg *algs, int count)
 635 {
 636         int i, ret;
 637
 638         for (i = 0; i < count; i++) {
 639                 ret = crypto_register_ahash(&algs[i]);
 640                 if (ret)
 641                         goto err;
 642         }
 643
 644         return 0;
 645
 646 err:
 647         for (--i; i >= 0; --i)
 648                 crypto_unregister_ahash(&algs[i]);
 649
 650         return ret;
 651 }
 652 EXPORT_SYMBOL_GPL(crypto_register_ahashes);
 653
 654 void crypto_unregister_ahashes(struct ahash_alg *algs, int count)
 655 {
 656         int i;
 657
 658         for (i = count - 1; i >= 0; --i)
 659                 crypto_unregister_ahash(&algs[i]);
 660 }
 661 EXPORT_SYMBOL_GPL(crypto_unregister_ahashes);
 662
 663 int ahash_register_instance(struct crypto_template *tmpl,
 664                             struct ahash_instance *inst)
 665 {
 666         int err;
 667
 668         if (WARN_ON(!inst->free))
 669                 return -EINVAL;
 670
 671         err = ahash_prepare_alg(&inst->alg);
 672         if (err)
 673                 return err;
 674
 675         return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
 676 }
 677 EXPORT_SYMBOL_GPL(ahash_register_instance);
 678
 679 bool crypto_hash_alg_has_setkey(struct hash_alg_common *halg)
 680 {
 681         struct crypto_alg *alg = &halg->base;
 682
 683         if (alg->cra_type != &crypto_ahash_type)
 684                 return crypto_shash_alg_has_setkey(__crypto_shash_alg(alg));
 685
 686         return __crypto_ahash_alg(alg)->setkey != NULL;
 687 }
 688 EXPORT_SYMBOL_GPL(crypto_hash_alg_has_setkey);
 689
 690 MODULE_LICENSE("GPL");
 691 MODULE_DESCRIPTION("Asynchronous cryptographic hash type");