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