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/internal/hash.h>
  12 #include <crypto/scatterwalk.h>
  13 #include <linux/bug.h>
  14 #include <linux/err.h>
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/sched.h>
  18 #include <linux/slab.h>
  19 #include <linux/seq_file.h>
  20 #include <linux/cryptouser.h>
  21 #include <linux/compiler.h>
  22 #include <net/netlink.h>
  23
  24 #include "internal.h"
  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         if (walk->flags & CRYPTO_ALG_ASYNC)
  48                 walk->data = kmap(walk->pg);
  49         else
  50                 walk->data = kmap_atomic(walk->pg);
  51         walk->data += offset;
  52
  53         if (offset & alignmask) {
  54                 unsigned int unaligned = alignmask + 1 - (offset & alignmask);
  55
  56                 if (nbytes > unaligned)
  57                         nbytes = unaligned;
  58         }
  59
  60         walk->entrylen -= nbytes;
  61         return nbytes;
  62 }
  63
  64 static int hash_walk_new_entry(struct crypto_hash_walk *walk)
  65 {
  66         struct scatterlist *sg;
  67
  68         sg = walk->sg;
  69         walk->offset = sg->offset;
  70         walk->pg = sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
  71         walk->offset = offset_in_page(walk->offset);
  72         walk->entrylen = sg->length;
  73
  74         if (walk->entrylen > walk->total)
  75                 walk->entrylen = walk->total;
  76         walk->total -= walk->entrylen;
  77
  78         return hash_walk_next(walk);
  79 }
  80
  81 int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
  82 {
  83         unsigned int alignmask = walk->alignmask;
  84
  85         walk->data -= walk->offset;
  86
  87         if (walk->entrylen && (walk->offset & alignmask) && !err) {
  88                 unsigned int nbytes;
  89
  90                 walk->offset = ALIGN(walk->offset, alignmask + 1);
  91                 nbytes = min(walk->entrylen,
  92                              (unsigned int)(PAGE_SIZE - walk->offset));
  93                 if (nbytes) {
  94                         walk->entrylen -= nbytes;
  95                         walk->data += walk->offset;
  96                         return nbytes;
  97                 }
  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 (walk->entrylen) {
 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 = 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                 walk->entrylen = 0;
 136                 return 0;
 137         }
 138
 139         walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
 140         walk->sg = req->src;
 141         walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK;
 142
 143         return hash_walk_new_entry(walk);
 144 }
 145 EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
 146
 147 int crypto_ahash_walk_first(struct ahash_request *req,
 148                             struct crypto_hash_walk *walk)
 149 {
 150         walk->total = req->nbytes;
 151
 152         if (!walk->total) {
 153                 walk->entrylen = 0;
 154                 return 0;
 155         }
 156
 157         walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
 158         walk->sg = req->src;
 159         walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK;
 160         walk->flags |= CRYPTO_ALG_ASYNC;
 161
 162         BUILD_BUG_ON(CRYPTO_TFM_REQ_MASK & CRYPTO_ALG_ASYNC);
 163
 164         return hash_walk_new_entry(walk);
 165 }
 166 EXPORT_SYMBOL_GPL(crypto_ahash_walk_first);
 167
 168 static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
 169                                 unsigned int keylen)
 170 {
 171         unsigned long alignmask = crypto_ahash_alignmask(tfm);
 172         int ret;
 173         u8 *buffer, *alignbuffer;
 174         unsigned long absize;
 175
 176         absize = keylen + alignmask;
 177         buffer = kmalloc(absize, GFP_KERNEL);
 178         if (!buffer)
 179                 return -ENOMEM;
 180
 181         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
 182         memcpy(alignbuffer, key, keylen);
 183         ret = tfm->setkey(tfm, alignbuffer, keylen);
 184         kzfree(buffer);
 185         return ret;
 186 }
 187
 188 static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
 189                           unsigned int keylen)
 190 {
 191         return -ENOSYS;
 192 }
 193
 194 static void ahash_set_needkey(struct crypto_ahash *tfm)
 195 {
 196         const struct hash_alg_common *alg = crypto_hash_alg_common(tfm);
 197
 198         if (tfm->setkey != ahash_nosetkey &&
 199             !(alg->base.cra_flags & CRYPTO_ALG_OPTIONAL_KEY))
 200                 crypto_ahash_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
 201 }
 202
 203 int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
 204                         unsigned int keylen)
 205 {
 206         unsigned long alignmask = crypto_ahash_alignmask(tfm);
 207         int err;
 208
 209         if ((unsigned long)key & alignmask)
 210                 err = ahash_setkey_unaligned(tfm, key, keylen);
 211         else
 212                 err = tfm->setkey(tfm, key, keylen);
 213
 214         if (unlikely(err)) {
 215                 ahash_set_needkey(tfm);
 216                 return err;
 217         }
 218
 219         crypto_ahash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
 220         return 0;
 221 }
 222 EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
 223
 224 static inline unsigned int ahash_align_buffer_size(unsigned len,
 225                                                    unsigned long mask)
 226 {
 227         return len + (mask & ~(crypto_tfm_ctx_alignment() - 1));
 228 }
 229
 230 static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt)
 231 {
 232         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 233         unsigned long alignmask = crypto_ahash_alignmask(tfm);
 234         unsigned int ds = crypto_ahash_digestsize(tfm);
 235         struct ahash_request_priv *priv;
 236
 237         priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
 238                        (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
 239                        GFP_KERNEL : GFP_ATOMIC);
 240         if (!priv)
 241                 return -ENOMEM;
 242
 243         /*
 244          * WARNING: Voodoo programming below!
 245          *
 246          * The code below is obscure and hard to understand, thus explanation
 247          * is necessary. See include/crypto/hash.h and include/linux/crypto.h
 248          * to understand the layout of structures used here!
 249          *
 250          * The code here will replace portions of the ORIGINAL request with
 251          * pointers to new code and buffers so the hashing operation can store
 252          * the result in aligned buffer. We will call the modified request
 253          * an ADJUSTED request.
 254          *
 255          * The newly mangled request will look as such:
 256          *
 257          * req {
 258          *   .result        = ADJUSTED[new aligned buffer]
 259          *   .base.complete = ADJUSTED[pointer to completion function]
 260          *   .base.data     = ADJUSTED[*req (pointer to self)]
 261          *   .priv          = ADJUSTED[new priv] {
 262          *           .result   = ORIGINAL(result)
 263          *           .complete = ORIGINAL(base.complete)
 264          *           .data     = ORIGINAL(base.data)
 265          *   }
 266          */
 267
 268         priv->result = req->result;
 269         priv->complete = req->base.complete;
 270         priv->data = req->base.data;
 271         priv->flags = req->base.flags;
 272
 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
 287 static void ahash_restore_req(struct ahash_request *req, int err)
 288 {
 289         struct ahash_request_priv *priv = req->priv;
 290
 291         if (!err)
 292                 memcpy(priv->result, req->result,
 293                        crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
 294
 295         /* Restore the original crypto request. */
 296         req->result = priv->result;
 297
 298         ahash_request_set_callback(req, priv->flags,
 299                                    priv->complete, priv->data);
 300         req->priv = NULL;
 301
 302         /* Free the req->priv.priv from the ADJUSTED request. */
 303         kzfree(priv);
 304 }
 305
 306 static void ahash_notify_einprogress(struct ahash_request *req)
 307 {
 308         struct ahash_request_priv *priv = req->priv;
 309         struct crypto_async_request oreq;
 310
 311         oreq.data = priv->data;
 312
 313         priv->complete(&oreq, -EINPROGRESS);
 314 }
 315
 316 static void ahash_op_unaligned_done(struct crypto_async_request *req, int err)
 317 {
 318         struct ahash_request *areq = req->data;
 319
 320         if (err == -EINPROGRESS) {
 321                 ahash_notify_einprogress(areq);
 322                 return;
 323         }
 324
 325         /*
 326          * Restore the original request, see ahash_op_unaligned() for what
 327          * goes where.
 328          *
 329          * The "struct ahash_request *req" here is in fact the "req.base"
 330          * from the ADJUSTED request from ahash_op_unaligned(), thus as it
 331          * is a pointer to self, it is also the ADJUSTED "req" .
 332          */
 333
 334         /* First copy req->result into req->priv.result */
 335         ahash_restore_req(areq, err);
 336
 337         /* Complete the ORIGINAL request. */
 338         areq->base.complete(&areq->base, err);
 339 }
 340
 341 static int ahash_op_unaligned(struct ahash_request *req,
 342                               int (*op)(struct ahash_request *))
 343 {
 344         int err;
 345
 346         err = ahash_save_req(req, ahash_op_unaligned_done);
 347         if (err)
 348                 return err;
 349
 350         err = op(req);
 351         if (err == -EINPROGRESS || err == -EBUSY)
 352                 return err;
 353
 354         ahash_restore_req(req, err);
 355
 356         return err;
 357 }
 358
 359 static int crypto_ahash_op(struct ahash_request *req,
 360                            int (*op)(struct ahash_request *))
 361 {
 362         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 363         unsigned long alignmask = crypto_ahash_alignmask(tfm);
 364
 365         if ((unsigned long)req->result & alignmask)
 366                 return ahash_op_unaligned(req, op);
 367
 368         return op(req);
 369 }
 370
 371 int crypto_ahash_final(struct ahash_request *req)
 372 {
 373         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 374         struct crypto_alg *alg = tfm->base.__crt_alg;
 375         unsigned int nbytes = req->nbytes;
 376         int ret;
 377
 378         crypto_stats_get(alg);
 379         ret = crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final);
 380         crypto_stats_ahash_final(nbytes, ret, alg);
 381         return ret;
 382 }
 383 EXPORT_SYMBOL_GPL(crypto_ahash_final);
 384
 385 int crypto_ahash_finup(struct ahash_request *req)
 386 {
 387         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 388         struct crypto_alg *alg = tfm->base.__crt_alg;
 389         unsigned int nbytes = req->nbytes;
 390         int ret;
 391
 392         crypto_stats_get(alg);
 393         ret = crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup);
 394         crypto_stats_ahash_final(nbytes, ret, alg);
 395         return ret;
 396 }
 397 EXPORT_SYMBOL_GPL(crypto_ahash_finup);
 398
 399 int crypto_ahash_digest(struct ahash_request *req)
 400 {
 401         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 402         struct crypto_alg *alg = tfm->base.__crt_alg;
 403         unsigned int nbytes = req->nbytes;
 404         int ret;
 405
 406         crypto_stats_get(alg);
 407         if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
 408                 ret = -ENOKEY;
 409         else
 410                 ret = crypto_ahash_op(req, tfm->digest);
 411         crypto_stats_ahash_final(nbytes, ret, alg);
 412         return ret;
 413 }
 414 EXPORT_SYMBOL_GPL(crypto_ahash_digest);
 415
 416 static void ahash_def_finup_done2(struct crypto_async_request *req, int err)
 417 {
 418         struct ahash_request *areq = req->data;
 419
 420         if (err == -EINPROGRESS)
 421                 return;
 422
 423         ahash_restore_req(areq, err);
 424
 425         areq->base.complete(&areq->base, err);
 426 }
 427
 428 static int ahash_def_finup_finish1(struct ahash_request *req, int err)
 429 {
 430         if (err)
 431                 goto out;
 432
 433         req->base.complete = ahash_def_finup_done2;
 434
 435         err = crypto_ahash_reqtfm(req)->final(req);
 436         if (err == -EINPROGRESS || err == -EBUSY)
 437                 return err;
 438
 439 out:
 440         ahash_restore_req(req, err);
 441         return err;
 442 }
 443
 444 static void ahash_def_finup_done1(struct crypto_async_request *req, int err)
 445 {
 446         struct ahash_request *areq = req->data;
 447
 448         if (err == -EINPROGRESS) {
 449                 ahash_notify_einprogress(areq);
 450                 return;
 451         }
 452
 453         areq->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 454
 455         err = ahash_def_finup_finish1(areq, err);
 456         if (areq->priv)
 457                 return;
 458
 459         areq->base.complete(&areq->base, err);
 460 }
 461
 462 static int ahash_def_finup(struct ahash_request *req)
 463 {
 464         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 465         int err;
 466
 467         err = ahash_save_req(req, ahash_def_finup_done1);
 468         if (err)
 469                 return err;
 470
 471         err = tfm->update(req);
 472         if (err == -EINPROGRESS || err == -EBUSY)
 473                 return err;
 474
 475         return ahash_def_finup_finish1(req, err);
 476 }
 477
 478 static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
 479 {
 480         struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
 481         struct ahash_alg *alg = crypto_ahash_alg(hash);
 482
 483         hash->setkey = ahash_nosetkey;
 484
 485         if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
 486                 return crypto_init_shash_ops_async(tfm);
 487
 488         hash->init = alg->init;
 489         hash->update = alg->update;
 490         hash->final = alg->final;
 491         hash->finup = alg->finup ?: ahash_def_finup;
 492         hash->digest = alg->digest;
 493         hash->export = alg->export;
 494         hash->import = alg->import;
 495
 496         if (alg->setkey) {
 497                 hash->setkey = alg->setkey;
 498                 ahash_set_needkey(hash);
 499         }
 500
 501         return 0;
 502 }
 503
 504 static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
 505 {
 506         if (alg->cra_type != &crypto_ahash_type)
 507                 return sizeof(struct crypto_shash *);
 508
 509         return crypto_alg_extsize(alg);
 510 }
 511
 512 #ifdef CONFIG_NET
 513 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
 514 {
 515         struct crypto_report_hash rhash;
 516
 517         memset(&rhash, 0, sizeof(rhash));
 518
 519         strscpy(rhash.type, "ahash", sizeof(rhash.type));
 520
 521         rhash.blocksize = alg->cra_blocksize;
 522         rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize;
 523
 524         return nla_put(skb, CRYPTOCFGA_REPORT_HASH, sizeof(rhash), &rhash);
 525 }
 526 #else
 527 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
 528 {
 529         return -ENOSYS;
 530 }
 531 #endif
 532
 533 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
 534         __maybe_unused;
 535 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
 536 {
 537         seq_printf(m, "type         : ahash\n");
 538         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 539                                              "yes" : "no");
 540         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 541         seq_printf(m, "digestsize   : %u\n",
 542                    __crypto_hash_alg_common(alg)->digestsize);
 543 }
 544
 545 const struct crypto_type crypto_ahash_type = {
 546         .extsize = crypto_ahash_extsize,
 547         .init_tfm = crypto_ahash_init_tfm,
 548 #ifdef CONFIG_PROC_FS
 549         .show = crypto_ahash_show,
 550 #endif
 551         .report = crypto_ahash_report,
 552         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 553         .maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
 554         .type = CRYPTO_ALG_TYPE_AHASH,
 555         .tfmsize = offsetof(struct crypto_ahash, base),
 556 };
 557 EXPORT_SYMBOL_GPL(crypto_ahash_type);
 558
 559 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
 560                                         u32 mask)
 561 {
 562         return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
 563 }
 564 EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
 565
 566 int crypto_has_ahash(const char *alg_name, u32 type, u32 mask)
 567 {
 568         return crypto_type_has_alg(alg_name, &crypto_ahash_type, type, mask);
 569 }
 570 EXPORT_SYMBOL_GPL(crypto_has_ahash);
 571
 572 static int ahash_prepare_alg(struct ahash_alg *alg)
 573 {
 574         struct crypto_alg *base = &alg->halg.base;
 575
 576         if (alg->halg.digestsize > HASH_MAX_DIGESTSIZE ||
 577             alg->halg.statesize > HASH_MAX_STATESIZE ||
 578             alg->halg.statesize == 0)
 579                 return -EINVAL;
 580
 581         base->cra_type = &crypto_ahash_type;
 582         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 583         base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
 584
 585         return 0;
 586 }
 587
 588 int crypto_register_ahash(struct ahash_alg *alg)
 589 {
 590         struct crypto_alg *base = &alg->halg.base;
 591         int err;
 592
 593         err = ahash_prepare_alg(alg);
 594         if (err)
 595                 return err;
 596
 597         return crypto_register_alg(base);
 598 }
 599 EXPORT_SYMBOL_GPL(crypto_register_ahash);
 600
 601 int crypto_unregister_ahash(struct ahash_alg *alg)
 602 {
 603         return crypto_unregister_alg(&alg->halg.base);
 604 }
 605 EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
 606
 607 int crypto_register_ahashes(struct ahash_alg *algs, int count)
 608 {
 609         int i, ret;
 610
 611         for (i = 0; i < count; i++) {
 612                 ret = crypto_register_ahash(&algs[i]);
 613                 if (ret)
 614                         goto err;
 615         }
 616
 617         return 0;
 618
 619 err:
 620         for (--i; i >= 0; --i)
 621                 crypto_unregister_ahash(&algs[i]);
 622
 623         return ret;
 624 }
 625 EXPORT_SYMBOL_GPL(crypto_register_ahashes);
 626
 627 void crypto_unregister_ahashes(struct ahash_alg *algs, int count)
 628 {
 629         int i;
 630
 631         for (i = count - 1; i >= 0; --i)
 632                 crypto_unregister_ahash(&algs[i]);
 633 }
 634 EXPORT_SYMBOL_GPL(crypto_unregister_ahashes);
 635
 636 int ahash_register_instance(struct crypto_template *tmpl,
 637                             struct ahash_instance *inst)
 638 {
 639         int err;
 640
 641         err = ahash_prepare_alg(&inst->alg);
 642         if (err)
 643                 return err;
 644
 645         return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
 646 }
 647 EXPORT_SYMBOL_GPL(ahash_register_instance);
 648
 649 void ahash_free_instance(struct crypto_instance *inst)
 650 {
 651         crypto_drop_spawn(crypto_instance_ctx(inst));
 652         kfree(ahash_instance(inst));
 653 }
 654 EXPORT_SYMBOL_GPL(ahash_free_instance);
 655
 656 int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn,
 657                             struct hash_alg_common *alg,
 658                             struct crypto_instance *inst)
 659 {
 660         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 661                                   &crypto_ahash_type);
 662 }
 663 EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn);
 664
 665 struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 666 {
 667         struct crypto_alg *alg;
 668
 669         alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask);
 670         return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg);
 671 }
 672 EXPORT_SYMBOL_GPL(ahash_attr_alg);
 673
 674 bool crypto_hash_alg_has_setkey(struct hash_alg_common *halg)
 675 {
 676         struct crypto_alg *alg = &halg->base;
 677
 678         if (alg->cra_type != &crypto_ahash_type)
 679                 return crypto_shash_alg_has_setkey(__crypto_shash_alg(alg));
 680
 681         return __crypto_ahash_alg(alg)->setkey != NULL;
 682 }
 683 EXPORT_SYMBOL_GPL(crypto_hash_alg_has_setkey);
 684
 685 MODULE_LICENSE("GPL");
 686 MODULE_DESCRIPTION("Asynchronous cryptographic hash type");