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