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         kzfree(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_has_setkey(alg) &&
  66             !(alg->base.cra_flags & CRYPTO_ALG_OPTIONAL_KEY))
  67                 crypto_shash_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
  68 }
  69
  70 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
  71                         unsigned int keylen)
  72 {
  73         struct shash_alg *shash = crypto_shash_alg(tfm);
  74         unsigned long alignmask = crypto_shash_alignmask(tfm);
  75         int err;
  76
  77         if ((unsigned long)key & alignmask)
  78                 err = shash_setkey_unaligned(tfm, key, keylen);
  79         else
  80                 err = shash->setkey(tfm, key, keylen);
  81
  82         if (unlikely(err)) {
  83                 shash_set_needkey(tfm, shash);
  84                 return err;
  85         }
  86
  87         crypto_shash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
  88         return 0;
  89 }
  90 EXPORT_SYMBOL_GPL(crypto_shash_setkey);
  91
  92 static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
  93                                   unsigned int len)
  94 {
  95         struct crypto_shash *tfm = desc->tfm;
  96         struct shash_alg *shash = crypto_shash_alg(tfm);
  97         unsigned long alignmask = crypto_shash_alignmask(tfm);
  98         unsigned int unaligned_len = alignmask + 1 -
  99                                      ((unsigned long)data & alignmask);
 100         /*
 101          * We cannot count on __aligned() working for large values:
 102          * https://patchwork.kernel.org/patch/9507697/
 103          */
 104         u8 ubuf[MAX_ALGAPI_ALIGNMASK * 2];
 105         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
 106         int err;
 107
 108         if (WARN_ON(buf + unaligned_len > ubuf + sizeof(ubuf)))
 109                 return -EINVAL;
 110
 111         if (unaligned_len > len)
 112                 unaligned_len = len;
 113
 114         memcpy(buf, data, unaligned_len);
 115         err = shash->update(desc, buf, unaligned_len);
 116         memset(buf, 0, unaligned_len);
 117
 118         return err ?:
 119                shash->update(desc, data + unaligned_len, len - unaligned_len);
 120 }
 121
 122 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
 123                         unsigned int len)
 124 {
 125         struct crypto_shash *tfm = desc->tfm;
 126         struct shash_alg *shash = crypto_shash_alg(tfm);
 127         unsigned long alignmask = crypto_shash_alignmask(tfm);
 128
 129         if ((unsigned long)data & alignmask)
 130                 return shash_update_unaligned(desc, data, len);
 131
 132         return shash->update(desc, data, len);
 133 }
 134 EXPORT_SYMBOL_GPL(crypto_shash_update);
 135
 136 static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
 137 {
 138         struct crypto_shash *tfm = desc->tfm;
 139         unsigned long alignmask = crypto_shash_alignmask(tfm);
 140         struct shash_alg *shash = crypto_shash_alg(tfm);
 141         unsigned int ds = crypto_shash_digestsize(tfm);
 142         /*
 143          * We cannot count on __aligned() working for large values:
 144          * https://patchwork.kernel.org/patch/9507697/
 145          */
 146         u8 ubuf[MAX_ALGAPI_ALIGNMASK + HASH_MAX_DIGESTSIZE];
 147         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
 148         int err;
 149
 150         if (WARN_ON(buf + ds > ubuf + sizeof(ubuf)))
 151                 return -EINVAL;
 152
 153         err = shash->final(desc, buf);
 154         if (err)
 155                 goto out;
 156
 157         memcpy(out, buf, ds);
 158
 159 out:
 160         memset(buf, 0, ds);
 161         return err;
 162 }
 163
 164 int crypto_shash_final(struct shash_desc *desc, u8 *out)
 165 {
 166         struct crypto_shash *tfm = desc->tfm;
 167         struct shash_alg *shash = crypto_shash_alg(tfm);
 168         unsigned long alignmask = crypto_shash_alignmask(tfm);
 169
 170         if ((unsigned long)out & alignmask)
 171                 return shash_final_unaligned(desc, out);
 172
 173         return shash->final(desc, out);
 174 }
 175 EXPORT_SYMBOL_GPL(crypto_shash_final);
 176
 177 static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
 178                                  unsigned int len, u8 *out)
 179 {
 180         return crypto_shash_update(desc, data, len) ?:
 181                crypto_shash_final(desc, out);
 182 }
 183
 184 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
 185                        unsigned int len, u8 *out)
 186 {
 187         struct crypto_shash *tfm = desc->tfm;
 188         struct shash_alg *shash = crypto_shash_alg(tfm);
 189         unsigned long alignmask = crypto_shash_alignmask(tfm);
 190
 191         if (((unsigned long)data | (unsigned long)out) & alignmask)
 192                 return shash_finup_unaligned(desc, data, len, out);
 193
 194         return shash->finup(desc, data, len, out);
 195 }
 196 EXPORT_SYMBOL_GPL(crypto_shash_finup);
 197
 198 static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
 199                                   unsigned int len, u8 *out)
 200 {
 201         return crypto_shash_init(desc) ?:
 202                crypto_shash_finup(desc, data, len, out);
 203 }
 204
 205 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
 206                         unsigned int len, u8 *out)
 207 {
 208         struct crypto_shash *tfm = desc->tfm;
 209         struct shash_alg *shash = crypto_shash_alg(tfm);
 210         unsigned long alignmask = crypto_shash_alignmask(tfm);
 211
 212         if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
 213                 return -ENOKEY;
 214
 215         if (((unsigned long)data | (unsigned long)out) & alignmask)
 216                 return shash_digest_unaligned(desc, data, len, out);
 217
 218         return shash->digest(desc, data, len, out);
 219 }
 220 EXPORT_SYMBOL_GPL(crypto_shash_digest);
 221
 222 static int shash_default_export(struct shash_desc *desc, void *out)
 223 {
 224         memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm));
 225         return 0;
 226 }
 227
 228 static int shash_default_import(struct shash_desc *desc, const void *in)
 229 {
 230         memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm));
 231         return 0;
 232 }
 233
 234 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 235                               unsigned int keylen)
 236 {
 237         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
 238
 239         return crypto_shash_setkey(*ctx, key, keylen);
 240 }
 241
 242 static int shash_async_init(struct ahash_request *req)
 243 {
 244         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 245         struct shash_desc *desc = ahash_request_ctx(req);
 246
 247         desc->tfm = *ctx;
 248
 249         return crypto_shash_init(desc);
 250 }
 251
 252 int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
 253 {
 254         struct crypto_hash_walk walk;
 255         int nbytes;
 256
 257         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
 258              nbytes = crypto_hash_walk_done(&walk, nbytes))
 259                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 260
 261         return nbytes;
 262 }
 263 EXPORT_SYMBOL_GPL(shash_ahash_update);
 264
 265 static int shash_async_update(struct ahash_request *req)
 266 {
 267         return shash_ahash_update(req, ahash_request_ctx(req));
 268 }
 269
 270 static int shash_async_final(struct ahash_request *req)
 271 {
 272         return crypto_shash_final(ahash_request_ctx(req), req->result);
 273 }
 274
 275 int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
 276 {
 277         struct crypto_hash_walk walk;
 278         int nbytes;
 279
 280         nbytes = crypto_hash_walk_first(req, &walk);
 281         if (!nbytes)
 282                 return crypto_shash_final(desc, req->result);
 283
 284         do {
 285                 nbytes = crypto_hash_walk_last(&walk) ?
 286                          crypto_shash_finup(desc, walk.data, nbytes,
 287                                             req->result) :
 288                          crypto_shash_update(desc, walk.data, nbytes);
 289                 nbytes = crypto_hash_walk_done(&walk, nbytes);
 290         } while (nbytes > 0);
 291
 292         return nbytes;
 293 }
 294 EXPORT_SYMBOL_GPL(shash_ahash_finup);
 295
 296 static int shash_async_finup(struct ahash_request *req)
 297 {
 298         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 299         struct shash_desc *desc = ahash_request_ctx(req);
 300
 301         desc->tfm = *ctx;
 302
 303         return shash_ahash_finup(req, desc);
 304 }
 305
 306 int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
 307 {
 308         unsigned int nbytes = req->nbytes;
 309         struct scatterlist *sg;
 310         unsigned int offset;
 311         int err;
 312
 313         if (nbytes &&
 314             (sg = req->src, offset = sg->offset,
 315              nbytes <= min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset))) {
 316                 void *data;
 317
 318                 data = kmap_atomic(sg_page(sg));
 319                 err = crypto_shash_digest(desc, data + offset, nbytes,
 320                                           req->result);
 321                 kunmap_atomic(data);
 322         } else
 323                 err = crypto_shash_init(desc) ?:
 324                       shash_ahash_finup(req, desc);
 325
 326         return err;
 327 }
 328 EXPORT_SYMBOL_GPL(shash_ahash_digest);
 329
 330 static int shash_async_digest(struct ahash_request *req)
 331 {
 332         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 333         struct shash_desc *desc = ahash_request_ctx(req);
 334
 335         desc->tfm = *ctx;
 336
 337         return shash_ahash_digest(req, desc);
 338 }
 339
 340 static int shash_async_export(struct ahash_request *req, void *out)
 341 {
 342         return crypto_shash_export(ahash_request_ctx(req), out);
 343 }
 344
 345 static int shash_async_import(struct ahash_request *req, const void *in)
 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 crypto_shash_import(desc, in);
 353 }
 354
 355 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 356 {
 357         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 358
 359         crypto_free_shash(*ctx);
 360 }
 361
 362 int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 363 {
 364         struct crypto_alg *calg = tfm->__crt_alg;
 365         struct shash_alg *alg = __crypto_shash_alg(calg);
 366         struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
 367         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 368         struct crypto_shash *shash;
 369
 370         if (!crypto_mod_get(calg))
 371                 return -EAGAIN;
 372
 373         shash = crypto_create_tfm(calg, &crypto_shash_type);
 374         if (IS_ERR(shash)) {
 375                 crypto_mod_put(calg);
 376                 return PTR_ERR(shash);
 377         }
 378
 379         *ctx = shash;
 380         tfm->exit = crypto_exit_shash_ops_async;
 381
 382         crt->init = shash_async_init;
 383         crt->update = shash_async_update;
 384         crt->final = shash_async_final;
 385         crt->finup = shash_async_finup;
 386         crt->digest = shash_async_digest;
 387         if (crypto_shash_alg_has_setkey(alg))
 388                 crt->setkey = shash_async_setkey;
 389
 390         crypto_ahash_set_flags(crt, crypto_shash_get_flags(shash) &
 391                                     CRYPTO_TFM_NEED_KEY);
 392
 393         crt->export = shash_async_export;
 394         crt->import = shash_async_import;
 395
 396         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 397
 398         return 0;
 399 }
 400
 401 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
 402 {
 403         struct crypto_shash *hash = __crypto_shash_cast(tfm);
 404         struct shash_alg *alg = crypto_shash_alg(hash);
 405
 406         hash->descsize = alg->descsize;
 407
 408         shash_set_needkey(hash, alg);
 409
 410         return 0;
 411 }
 412
 413 #ifdef CONFIG_NET
 414 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 415 {
 416         struct crypto_report_hash rhash;
 417         struct shash_alg *salg = __crypto_shash_alg(alg);
 418
 419         memset(&rhash, 0, sizeof(rhash));
 420
 421         strscpy(rhash.type, "shash", sizeof(rhash.type));
 422
 423         rhash.blocksize = alg->cra_blocksize;
 424         rhash.digestsize = salg->digestsize;
 425
 426         return nla_put(skb, CRYPTOCFGA_REPORT_HASH, sizeof(rhash), &rhash);
 427 }
 428 #else
 429 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 430 {
 431         return -ENOSYS;
 432 }
 433 #endif
 434
 435 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 436         __maybe_unused;
 437 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 438 {
 439         struct shash_alg *salg = __crypto_shash_alg(alg);
 440
 441         seq_printf(m, "type         : shash\n");
 442         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 443         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 444 }
 445
 446 static const struct crypto_type crypto_shash_type = {
 447         .extsize = crypto_alg_extsize,
 448         .init_tfm = crypto_shash_init_tfm,
 449 #ifdef CONFIG_PROC_FS
 450         .show = crypto_shash_show,
 451 #endif
 452         .report = crypto_shash_report,
 453         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 454         .maskset = CRYPTO_ALG_TYPE_MASK,
 455         .type = CRYPTO_ALG_TYPE_SHASH,
 456         .tfmsize = offsetof(struct crypto_shash, base),
 457 };
 458
 459 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 460                                         u32 mask)
 461 {
 462         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 463 }
 464 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 465
 466 static int shash_prepare_alg(struct shash_alg *alg)
 467 {
 468         struct crypto_alg *base = &alg->base;
 469
 470         if (alg->digestsize > HASH_MAX_DIGESTSIZE ||
 471             alg->descsize > HASH_MAX_DESCSIZE ||
 472             alg->statesize > HASH_MAX_STATESIZE)
 473                 return -EINVAL;
 474
 475         if ((alg->export && !alg->import) || (alg->import && !alg->export))
 476                 return -EINVAL;
 477
 478         base->cra_type = &crypto_shash_type;
 479         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 480         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 481
 482         if (!alg->finup)
 483                 alg->finup = shash_finup_unaligned;
 484         if (!alg->digest)
 485                 alg->digest = shash_digest_unaligned;
 486         if (!alg->export) {
 487                 alg->export = shash_default_export;
 488                 alg->import = shash_default_import;
 489                 alg->statesize = alg->descsize;
 490         }
 491         if (!alg->setkey)
 492                 alg->setkey = shash_no_setkey;
 493
 494         return 0;
 495 }
 496
 497 int crypto_register_shash(struct shash_alg *alg)
 498 {
 499         struct crypto_alg *base = &alg->base;
 500         int err;
 501
 502         err = shash_prepare_alg(alg);
 503         if (err)
 504                 return err;
 505
 506         return crypto_register_alg(base);
 507 }
 508 EXPORT_SYMBOL_GPL(crypto_register_shash);
 509
 510 int crypto_unregister_shash(struct shash_alg *alg)
 511 {
 512         return crypto_unregister_alg(&alg->base);
 513 }
 514 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 515
 516 int crypto_register_shashes(struct shash_alg *algs, int count)
 517 {
 518         int i, ret;
 519
 520         for (i = 0; i < count; i++) {
 521                 ret = crypto_register_shash(&algs[i]);
 522                 if (ret)
 523                         goto err;
 524         }
 525
 526         return 0;
 527
 528 err:
 529         for (--i; i >= 0; --i)
 530                 crypto_unregister_shash(&algs[i]);
 531
 532         return ret;
 533 }
 534 EXPORT_SYMBOL_GPL(crypto_register_shashes);
 535
 536 int crypto_unregister_shashes(struct shash_alg *algs, int count)
 537 {
 538         int i, ret;
 539
 540         for (i = count - 1; i >= 0; --i) {
 541                 ret = crypto_unregister_shash(&algs[i]);
 542                 if (ret)
 543                         pr_err("Failed to unregister %s %s: %d\n",
 544                                algs[i].base.cra_driver_name,
 545                                algs[i].base.cra_name, ret);
 546         }
 547
 548         return 0;
 549 }
 550 EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
 551
 552 int shash_register_instance(struct crypto_template *tmpl,
 553                             struct shash_instance *inst)
 554 {
 555         int err;
 556
 557         err = shash_prepare_alg(&inst->alg);
 558         if (err)
 559                 return err;
 560
 561         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 562 }
 563 EXPORT_SYMBOL_GPL(shash_register_instance);
 564
 565 void shash_free_instance(struct crypto_instance *inst)
 566 {
 567         crypto_drop_spawn(crypto_instance_ctx(inst));
 568         kfree(shash_instance(inst));
 569 }
 570 EXPORT_SYMBOL_GPL(shash_free_instance);
 571
 572 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
 573                             struct shash_alg *alg,
 574                             struct crypto_instance *inst)
 575 {
 576         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 577                                   &crypto_shash_type);
 578 }
 579 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
 580
 581 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 582 {
 583         struct crypto_alg *alg;
 584
 585         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
 586         return IS_ERR(alg) ? ERR_CAST(alg) :
 587                container_of(alg, struct shash_alg, base);
 588 }
 589 EXPORT_SYMBOL_GPL(shash_attr_alg);
 590
 591 MODULE_LICENSE("GPL");
 592 MODULE_DESCRIPTION("Synchronous cryptographic hash type");