crypto/shash.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Synchronous Cryptographic Hash operations.
   4  *
   5  * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
   6  */
   7
   8 #include <crypto/scatterwalk.h>
   9 #include <crypto/internal/hash.h>
  10 #include <linux/err.h>
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/slab.h>
  14 #include <linux/seq_file.h>
  15 #include <linux/cryptouser.h>
  16 #include <net/netlink.h>
  17 #include <linux/compiler.h>
  18
  19 #include "internal.h"
  20
  21 #define MAX_SHASH_ALIGNMASK 63
  22
  23 static const struct crypto_type crypto_shash_type;
  24
  25 int shash_no_setkey(struct crypto_shash *tfm, const u8 *key,
  26                     unsigned int keylen)
  27 {
  28         return -ENOSYS;
  29 }
  30 EXPORT_SYMBOL_GPL(shash_no_setkey);
  31
  32 static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
  33                                   unsigned int keylen)
  34 {
  35         struct shash_alg *shash = crypto_shash_alg(tfm);
  36         unsigned long alignmask = crypto_shash_alignmask(tfm);
  37         unsigned long absize;
  38         u8 *buffer, *alignbuffer;
  39         int err;
  40
  41         absize = keylen + (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
  42         buffer = kmalloc(absize, GFP_ATOMIC);
  43         if (!buffer)
  44                 return -ENOMEM;
  45
  46         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  47         memcpy(alignbuffer, key, keylen);
  48         err = shash->setkey(tfm, alignbuffer, keylen);
  49         kfree_sensitive(buffer);
  50         return err;
  51 }
  52
  53 static void shash_set_needkey(struct crypto_shash *tfm, struct shash_alg *alg)
  54 {
  55         if (crypto_shash_alg_needs_key(alg))
  56                 crypto_shash_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
  57 }
  58
  59 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
  60                         unsigned int keylen)
  61 {
  62         struct shash_alg *shash = crypto_shash_alg(tfm);
  63         unsigned long alignmask = crypto_shash_alignmask(tfm);
  64         int err;
  65
  66         if ((unsigned long)key & alignmask)
  67                 err = shash_setkey_unaligned(tfm, key, keylen);
  68         else
  69                 err = shash->setkey(tfm, key, keylen);
  70
  71         if (unlikely(err)) {
  72                 shash_set_needkey(tfm, shash);
  73                 return err;
  74         }
  75
  76         crypto_shash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
  77         return 0;
  78 }
  79 EXPORT_SYMBOL_GPL(crypto_shash_setkey);
  80
  81 static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
  82                                   unsigned int len)
  83 {
  84         struct crypto_shash *tfm = desc->tfm;
  85         struct shash_alg *shash = crypto_shash_alg(tfm);
  86         unsigned long alignmask = crypto_shash_alignmask(tfm);
  87         unsigned int unaligned_len = alignmask + 1 -
  88                                      ((unsigned long)data & alignmask);
  89         /*
  90          * We cannot count on __aligned() working for large values:
  91          * https://patchwork.kernel.org/patch/9507697/
  92          */
  93         u8 ubuf[MAX_SHASH_ALIGNMASK * 2];
  94         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
  95         int err;
  96
  97         if (WARN_ON(buf + unaligned_len > ubuf + sizeof(ubuf)))
  98                 return -EINVAL;
  99
 100         if (unaligned_len > len)
 101                 unaligned_len = len;
 102
 103         memcpy(buf, data, unaligned_len);
 104         err = shash->update(desc, buf, unaligned_len);
 105         memset(buf, 0, unaligned_len);
 106
 107         return err ?:
 108                shash->update(desc, data + unaligned_len, len - unaligned_len);
 109 }
 110
 111 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
 112                         unsigned int len)
 113 {
 114         struct crypto_shash *tfm = desc->tfm;
 115         struct shash_alg *shash = crypto_shash_alg(tfm);
 116         unsigned long alignmask = crypto_shash_alignmask(tfm);
 117
 118         if ((unsigned long)data & alignmask)
 119                 return shash_update_unaligned(desc, data, len);
 120
 121         return shash->update(desc, data, len);
 122 }
 123 EXPORT_SYMBOL_GPL(crypto_shash_update);
 124
 125 static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
 126 {
 127         struct crypto_shash *tfm = desc->tfm;
 128         unsigned long alignmask = crypto_shash_alignmask(tfm);
 129         struct shash_alg *shash = crypto_shash_alg(tfm);
 130         unsigned int ds = crypto_shash_digestsize(tfm);
 131         /*
 132          * We cannot count on __aligned() working for large values:
 133          * https://patchwork.kernel.org/patch/9507697/
 134          */
 135         u8 ubuf[MAX_SHASH_ALIGNMASK + HASH_MAX_DIGESTSIZE];
 136         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
 137         int err;
 138
 139         if (WARN_ON(buf + ds > ubuf + sizeof(ubuf)))
 140                 return -EINVAL;
 141
 142         err = shash->final(desc, buf);
 143         if (err)
 144                 goto out;
 145
 146         memcpy(out, buf, ds);
 147
 148 out:
 149         memset(buf, 0, ds);
 150         return err;
 151 }
 152
 153 int crypto_shash_final(struct shash_desc *desc, u8 *out)
 154 {
 155         struct crypto_shash *tfm = desc->tfm;
 156         struct shash_alg *shash = crypto_shash_alg(tfm);
 157         unsigned long alignmask = crypto_shash_alignmask(tfm);
 158
 159         if ((unsigned long)out & alignmask)
 160                 return shash_final_unaligned(desc, out);
 161
 162         return shash->final(desc, out);
 163 }
 164 EXPORT_SYMBOL_GPL(crypto_shash_final);
 165
 166 static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
 167                                  unsigned int len, u8 *out)
 168 {
 169         return crypto_shash_update(desc, data, len) ?:
 170                crypto_shash_final(desc, out);
 171 }
 172
 173 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
 174                        unsigned int len, u8 *out)
 175 {
 176         struct crypto_shash *tfm = desc->tfm;
 177         struct shash_alg *shash = crypto_shash_alg(tfm);
 178         unsigned long alignmask = crypto_shash_alignmask(tfm);
 179
 180         if (((unsigned long)data | (unsigned long)out) & alignmask)
 181                 return shash_finup_unaligned(desc, data, len, out);
 182
 183         return shash->finup(desc, data, len, out);
 184 }
 185 EXPORT_SYMBOL_GPL(crypto_shash_finup);
 186
 187 static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
 188                                   unsigned int len, u8 *out)
 189 {
 190         return crypto_shash_init(desc) ?:
 191                crypto_shash_finup(desc, data, len, out);
 192 }
 193
 194 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
 195                         unsigned int len, u8 *out)
 196 {
 197         struct crypto_shash *tfm = desc->tfm;
 198         struct shash_alg *shash = crypto_shash_alg(tfm);
 199         unsigned long alignmask = crypto_shash_alignmask(tfm);
 200
 201         if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
 202                 return -ENOKEY;
 203
 204         if (((unsigned long)data | (unsigned long)out) & alignmask)
 205                 return shash_digest_unaligned(desc, data, len, out);
 206
 207         return shash->digest(desc, data, len, out);
 208 }
 209 EXPORT_SYMBOL_GPL(crypto_shash_digest);
 210
 211 int crypto_shash_tfm_digest(struct crypto_shash *tfm, const u8 *data,
 212                             unsigned int len, u8 *out)
 213 {
 214         SHASH_DESC_ON_STACK(desc, tfm);
 215         int err;
 216
 217         desc->tfm = tfm;
 218
 219         err = crypto_shash_digest(desc, data, len, out);
 220
 221         shash_desc_zero(desc);
 222
 223         return err;
 224 }
 225 EXPORT_SYMBOL_GPL(crypto_shash_tfm_digest);
 226
 227 static int shash_default_export(struct shash_desc *desc, void *out)
 228 {
 229         memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm));
 230         return 0;
 231 }
 232
 233 static int shash_default_import(struct shash_desc *desc, const void *in)
 234 {
 235         memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm));
 236         return 0;
 237 }
 238
 239 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 240                               unsigned int keylen)
 241 {
 242         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
 243
 244         return crypto_shash_setkey(*ctx, key, keylen);
 245 }
 246
 247 static int shash_async_init(struct ahash_request *req)
 248 {
 249         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 250         struct shash_desc *desc = ahash_request_ctx(req);
 251
 252         desc->tfm = *ctx;
 253
 254         return crypto_shash_init(desc);
 255 }
 256
 257 int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
 258 {
 259         struct crypto_hash_walk walk;
 260         int nbytes;
 261
 262         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
 263              nbytes = crypto_hash_walk_done(&walk, nbytes))
 264                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 265
 266         return nbytes;
 267 }
 268 EXPORT_SYMBOL_GPL(shash_ahash_update);
 269
 270 static int shash_async_update(struct ahash_request *req)
 271 {
 272         return shash_ahash_update(req, ahash_request_ctx(req));
 273 }
 274
 275 static int shash_async_final(struct ahash_request *req)
 276 {
 277         return crypto_shash_final(ahash_request_ctx(req), req->result);
 278 }
 279
 280 int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
 281 {
 282         struct crypto_hash_walk walk;
 283         int nbytes;
 284
 285         nbytes = crypto_hash_walk_first(req, &walk);
 286         if (!nbytes)
 287                 return crypto_shash_final(desc, req->result);
 288
 289         do {
 290                 nbytes = crypto_hash_walk_last(&walk) ?
 291                          crypto_shash_finup(desc, walk.data, nbytes,
 292                                             req->result) :
 293                          crypto_shash_update(desc, walk.data, nbytes);
 294                 nbytes = crypto_hash_walk_done(&walk, nbytes);
 295         } while (nbytes > 0);
 296
 297         return nbytes;
 298 }
 299 EXPORT_SYMBOL_GPL(shash_ahash_finup);
 300
 301 static int shash_async_finup(struct ahash_request *req)
 302 {
 303         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 304         struct shash_desc *desc = ahash_request_ctx(req);
 305
 306         desc->tfm = *ctx;
 307
 308         return shash_ahash_finup(req, desc);
 309 }
 310
 311 int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
 312 {
 313         unsigned int nbytes = req->nbytes;
 314         struct scatterlist *sg;
 315         unsigned int offset;
 316         int err;
 317
 318         if (nbytes &&
 319             (sg = req->src, offset = sg->offset,
 320              nbytes <= min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset))) {
 321                 void *data;
 322
 323                 data = kmap_atomic(sg_page(sg));
 324                 err = crypto_shash_digest(desc, data + offset, nbytes,
 325                                           req->result);
 326                 kunmap_atomic(data);
 327         } else
 328                 err = crypto_shash_init(desc) ?:
 329                       shash_ahash_finup(req, desc);
 330
 331         return err;
 332 }
 333 EXPORT_SYMBOL_GPL(shash_ahash_digest);
 334
 335 static int shash_async_digest(struct ahash_request *req)
 336 {
 337         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 338         struct shash_desc *desc = ahash_request_ctx(req);
 339
 340         desc->tfm = *ctx;
 341
 342         return shash_ahash_digest(req, desc);
 343 }
 344
 345 static int shash_async_export(struct ahash_request *req, void *out)
 346 {
 347         return crypto_shash_export(ahash_request_ctx(req), out);
 348 }
 349
 350 static int shash_async_import(struct ahash_request *req, const void *in)
 351 {
 352         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 353         struct shash_desc *desc = ahash_request_ctx(req);
 354
 355         desc->tfm = *ctx;
 356
 357         return crypto_shash_import(desc, in);
 358 }
 359
 360 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 361 {
 362         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 363
 364         crypto_free_shash(*ctx);
 365 }
 366
 367 int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 368 {
 369         struct crypto_alg *calg = tfm->__crt_alg;
 370         struct shash_alg *alg = __crypto_shash_alg(calg);
 371         struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
 372         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 373         struct crypto_shash *shash;
 374
 375         if (!crypto_mod_get(calg))
 376                 return -EAGAIN;
 377
 378         shash = crypto_create_tfm(calg, &crypto_shash_type);
 379         if (IS_ERR(shash)) {
 380                 crypto_mod_put(calg);
 381                 return PTR_ERR(shash);
 382         }
 383
 384         *ctx = shash;
 385         tfm->exit = crypto_exit_shash_ops_async;
 386
 387         crt->init = shash_async_init;
 388         crt->update = shash_async_update;
 389         crt->final = shash_async_final;
 390         crt->finup = shash_async_finup;
 391         crt->digest = shash_async_digest;
 392         if (crypto_shash_alg_has_setkey(alg))
 393                 crt->setkey = shash_async_setkey;
 394
 395         crypto_ahash_set_flags(crt, crypto_shash_get_flags(shash) &
 396                                     CRYPTO_TFM_NEED_KEY);
 397
 398         crt->export = shash_async_export;
 399         crt->import = shash_async_import;
 400
 401         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 402
 403         return 0;
 404 }
 405
 406 static void crypto_shash_exit_tfm(struct crypto_tfm *tfm)
 407 {
 408         struct crypto_shash *hash = __crypto_shash_cast(tfm);
 409         struct shash_alg *alg = crypto_shash_alg(hash);
 410
 411         alg->exit_tfm(hash);
 412 }
 413
 414 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
 415 {
 416         struct crypto_shash *hash = __crypto_shash_cast(tfm);
 417         struct shash_alg *alg = crypto_shash_alg(hash);
 418         int err;
 419
 420         hash->descsize = alg->descsize;
 421
 422         shash_set_needkey(hash, alg);
 423
 424         if (alg->exit_tfm)
 425                 tfm->exit = crypto_shash_exit_tfm;
 426
 427         if (!alg->init_tfm)
 428                 return 0;
 429
 430         err = alg->init_tfm(hash);
 431         if (err)
 432                 return err;
 433
 434         /* ->init_tfm() may have increased the descsize. */
 435         if (WARN_ON_ONCE(hash->descsize > HASH_MAX_DESCSIZE)) {
 436                 if (alg->exit_tfm)
 437                         alg->exit_tfm(hash);
 438                 return -EINVAL;
 439         }
 440
 441         return 0;
 442 }
 443
 444 static void crypto_shash_free_instance(struct crypto_instance *inst)
 445 {
 446         struct shash_instance *shash = shash_instance(inst);
 447
 448         shash->free(shash);
 449 }
 450
 451 #ifdef CONFIG_NET
 452 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 453 {
 454         struct crypto_report_hash rhash;
 455         struct shash_alg *salg = __crypto_shash_alg(alg);
 456
 457         memset(&rhash, 0, sizeof(rhash));
 458
 459         strscpy(rhash.type, "shash", sizeof(rhash.type));
 460
 461         rhash.blocksize = alg->cra_blocksize;
 462         rhash.digestsize = salg->digestsize;
 463
 464         return nla_put(skb, CRYPTOCFGA_REPORT_HASH, sizeof(rhash), &rhash);
 465 }
 466 #else
 467 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 468 {
 469         return -ENOSYS;
 470 }
 471 #endif
 472
 473 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 474         __maybe_unused;
 475 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 476 {
 477         struct shash_alg *salg = __crypto_shash_alg(alg);
 478
 479         seq_printf(m, "type         : shash\n");
 480         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 481         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 482 }
 483
 484 static const struct crypto_type crypto_shash_type = {
 485         .extsize = crypto_alg_extsize,
 486         .init_tfm = crypto_shash_init_tfm,
 487         .free = crypto_shash_free_instance,
 488 #ifdef CONFIG_PROC_FS
 489         .show = crypto_shash_show,
 490 #endif
 491         .report = crypto_shash_report,
 492         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 493         .maskset = CRYPTO_ALG_TYPE_MASK,
 494         .type = CRYPTO_ALG_TYPE_SHASH,
 495         .tfmsize = offsetof(struct crypto_shash, base),
 496 };
 497
 498 int crypto_grab_shash(struct crypto_shash_spawn *spawn,
 499                       struct crypto_instance *inst,
 500                       const char *name, u32 type, u32 mask)
 501 {
 502         spawn->base.frontend = &crypto_shash_type;
 503         return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
 504 }
 505 EXPORT_SYMBOL_GPL(crypto_grab_shash);
 506
 507 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 508                                         u32 mask)
 509 {
 510         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 511 }
 512 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 513
 514 int crypto_has_shash(const char *alg_name, u32 type, u32 mask)
 515 {
 516         return crypto_type_has_alg(alg_name, &crypto_shash_type, type, mask);
 517 }
 518 EXPORT_SYMBOL_GPL(crypto_has_shash);
 519
 520 static int shash_prepare_alg(struct shash_alg *alg)
 521 {
 522         struct crypto_alg *base = &alg->base;
 523
 524         if (alg->digestsize > HASH_MAX_DIGESTSIZE ||
 525             alg->descsize > HASH_MAX_DESCSIZE ||
 526             alg->statesize > HASH_MAX_STATESIZE)
 527                 return -EINVAL;
 528
 529         if (base->cra_alignmask > MAX_SHASH_ALIGNMASK)
 530                 return -EINVAL;
 531
 532         if ((alg->export && !alg->import) || (alg->import && !alg->export))
 533                 return -EINVAL;
 534
 535         base->cra_type = &crypto_shash_type;
 536         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 537         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 538
 539         if (!alg->finup)
 540                 alg->finup = shash_finup_unaligned;
 541         if (!alg->digest)
 542                 alg->digest = shash_digest_unaligned;
 543         if (!alg->export) {
 544                 alg->export = shash_default_export;
 545                 alg->import = shash_default_import;
 546                 alg->statesize = alg->descsize;
 547         }
 548         if (!alg->setkey)
 549                 alg->setkey = shash_no_setkey;
 550
 551         return 0;
 552 }
 553
 554 int crypto_register_shash(struct shash_alg *alg)
 555 {
 556         struct crypto_alg *base = &alg->base;
 557         int err;
 558
 559         err = shash_prepare_alg(alg);
 560         if (err)
 561                 return err;
 562
 563         return crypto_register_alg(base);
 564 }
 565 EXPORT_SYMBOL_GPL(crypto_register_shash);
 566
 567 void crypto_unregister_shash(struct shash_alg *alg)
 568 {
 569         crypto_unregister_alg(&alg->base);
 570 }
 571 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 572
 573 int crypto_register_shashes(struct shash_alg *algs, int count)
 574 {
 575         int i, ret;
 576
 577         for (i = 0; i < count; i++) {
 578                 ret = crypto_register_shash(&algs[i]);
 579                 if (ret)
 580                         goto err;
 581         }
 582
 583         return 0;
 584
 585 err:
 586         for (--i; i >= 0; --i)
 587                 crypto_unregister_shash(&algs[i]);
 588
 589         return ret;
 590 }
 591 EXPORT_SYMBOL_GPL(crypto_register_shashes);
 592
 593 void crypto_unregister_shashes(struct shash_alg *algs, int count)
 594 {
 595         int i;
 596
 597         for (i = count - 1; i >= 0; --i)
 598                 crypto_unregister_shash(&algs[i]);
 599 }
 600 EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
 601
 602 int shash_register_instance(struct crypto_template *tmpl,
 603                             struct shash_instance *inst)
 604 {
 605         int err;
 606
 607         if (WARN_ON(!inst->free))
 608                 return -EINVAL;
 609
 610         err = shash_prepare_alg(&inst->alg);
 611         if (err)
 612                 return err;
 613
 614         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 615 }
 616 EXPORT_SYMBOL_GPL(shash_register_instance);
 617
 618 void shash_free_singlespawn_instance(struct shash_instance *inst)
 619 {
 620         crypto_drop_spawn(shash_instance_ctx(inst));
 621         kfree(inst);
 622 }
 623 EXPORT_SYMBOL_GPL(shash_free_singlespawn_instance);
 624
 625 MODULE_LICENSE("GPL");
 626 MODULE_DESCRIPTION("Synchronous cryptographic hash type");