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_has_setkey(alg) &&
  54             !(alg->base.cra_flags & CRYPTO_ALG_OPTIONAL_KEY))
  55                 crypto_shash_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
  56 }
  57
  58 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
  59                         unsigned int keylen)
  60 {
  61         struct shash_alg *shash = crypto_shash_alg(tfm);
  62         unsigned long alignmask = crypto_shash_alignmask(tfm);
  63         int err;
  64
  65         if ((unsigned long)key & alignmask)
  66                 err = shash_setkey_unaligned(tfm, key, keylen);
  67         else
  68                 err = shash->setkey(tfm, key, keylen);
  69
  70         if (unlikely(err)) {
  71                 shash_set_needkey(tfm, shash);
  72                 return err;
  73         }
  74
  75         crypto_shash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
  76         return 0;
  77 }
  78 EXPORT_SYMBOL_GPL(crypto_shash_setkey);
  79
  80 static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
  81                                   unsigned int len)
  82 {
  83         struct crypto_shash *tfm = desc->tfm;
  84         struct shash_alg *shash = crypto_shash_alg(tfm);
  85         unsigned long alignmask = crypto_shash_alignmask(tfm);
  86         unsigned int unaligned_len = alignmask + 1 -
  87                                      ((unsigned long)data & alignmask);
  88         /*
  89          * We cannot count on __aligned() working for large values:
  90          * https://patchwork.kernel.org/patch/9507697/
  91          */
  92         u8 ubuf[MAX_ALGAPI_ALIGNMASK * 2];
  93         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
  94         int err;
  95
  96         if (WARN_ON(buf + unaligned_len > ubuf + sizeof(ubuf)))
  97                 return -EINVAL;
  98
  99         if (unaligned_len > len)
 100                 unaligned_len = len;
 101
 102         memcpy(buf, data, unaligned_len);
 103         err = shash->update(desc, buf, unaligned_len);
 104         memset(buf, 0, unaligned_len);
 105
 106         return err ?:
 107                shash->update(desc, data + unaligned_len, len - unaligned_len);
 108 }
 109
 110 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
 111                         unsigned int len)
 112 {
 113         struct crypto_shash *tfm = desc->tfm;
 114         struct shash_alg *shash = crypto_shash_alg(tfm);
 115         unsigned long alignmask = crypto_shash_alignmask(tfm);
 116
 117         if ((unsigned long)data & alignmask)
 118                 return shash_update_unaligned(desc, data, len);
 119
 120         return shash->update(desc, data, len);
 121 }
 122 EXPORT_SYMBOL_GPL(crypto_shash_update);
 123
 124 static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
 125 {
 126         struct crypto_shash *tfm = desc->tfm;
 127         unsigned long alignmask = crypto_shash_alignmask(tfm);
 128         struct shash_alg *shash = crypto_shash_alg(tfm);
 129         unsigned int ds = crypto_shash_digestsize(tfm);
 130         /*
 131          * We cannot count on __aligned() working for large values:
 132          * https://patchwork.kernel.org/patch/9507697/
 133          */
 134         u8 ubuf[MAX_ALGAPI_ALIGNMASK + HASH_MAX_DIGESTSIZE];
 135         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
 136         int err;
 137
 138         if (WARN_ON(buf + ds > ubuf + sizeof(ubuf)))
 139                 return -EINVAL;
 140
 141         err = shash->final(desc, buf);
 142         if (err)
 143                 goto out;
 144
 145         memcpy(out, buf, ds);
 146
 147 out:
 148         memset(buf, 0, ds);
 149         return err;
 150 }
 151
 152 int crypto_shash_final(struct shash_desc *desc, u8 *out)
 153 {
 154         struct crypto_shash *tfm = desc->tfm;
 155         struct shash_alg *shash = crypto_shash_alg(tfm);
 156         unsigned long alignmask = crypto_shash_alignmask(tfm);
 157
 158         if ((unsigned long)out & alignmask)
 159                 return shash_final_unaligned(desc, out);
 160
 161         return shash->final(desc, out);
 162 }
 163 EXPORT_SYMBOL_GPL(crypto_shash_final);
 164
 165 static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
 166                                  unsigned int len, u8 *out)
 167 {
 168         return crypto_shash_update(desc, data, len) ?:
 169                crypto_shash_final(desc, out);
 170 }
 171
 172 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
 173                        unsigned int len, u8 *out)
 174 {
 175         struct crypto_shash *tfm = desc->tfm;
 176         struct shash_alg *shash = crypto_shash_alg(tfm);
 177         unsigned long alignmask = crypto_shash_alignmask(tfm);
 178
 179         if (((unsigned long)data | (unsigned long)out) & alignmask)
 180                 return shash_finup_unaligned(desc, data, len, out);
 181
 182         return shash->finup(desc, data, len, out);
 183 }
 184 EXPORT_SYMBOL_GPL(crypto_shash_finup);
 185
 186 static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
 187                                   unsigned int len, u8 *out)
 188 {
 189         return crypto_shash_init(desc) ?:
 190                crypto_shash_finup(desc, data, len, out);
 191 }
 192
 193 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
 194                         unsigned int len, u8 *out)
 195 {
 196         struct crypto_shash *tfm = desc->tfm;
 197         struct shash_alg *shash = crypto_shash_alg(tfm);
 198         unsigned long alignmask = crypto_shash_alignmask(tfm);
 199
 200         if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
 201                 return -ENOKEY;
 202
 203         if (((unsigned long)data | (unsigned long)out) & alignmask)
 204                 return shash_digest_unaligned(desc, data, len, out);
 205
 206         return shash->digest(desc, data, len, out);
 207 }
 208 EXPORT_SYMBOL_GPL(crypto_shash_digest);
 209
 210 static int shash_default_export(struct shash_desc *desc, void *out)
 211 {
 212         memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm));
 213         return 0;
 214 }
 215
 216 static int shash_default_import(struct shash_desc *desc, const void *in)
 217 {
 218         memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm));
 219         return 0;
 220 }
 221
 222 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 223                               unsigned int keylen)
 224 {
 225         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
 226
 227         return crypto_shash_setkey(*ctx, key, keylen);
 228 }
 229
 230 static int shash_async_init(struct ahash_request *req)
 231 {
 232         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 233         struct shash_desc *desc = ahash_request_ctx(req);
 234
 235         desc->tfm = *ctx;
 236
 237         return crypto_shash_init(desc);
 238 }
 239
 240 int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
 241 {
 242         struct crypto_hash_walk walk;
 243         int nbytes;
 244
 245         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
 246              nbytes = crypto_hash_walk_done(&walk, nbytes))
 247                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 248
 249         return nbytes;
 250 }
 251 EXPORT_SYMBOL_GPL(shash_ahash_update);
 252
 253 static int shash_async_update(struct ahash_request *req)
 254 {
 255         return shash_ahash_update(req, ahash_request_ctx(req));
 256 }
 257
 258 static int shash_async_final(struct ahash_request *req)
 259 {
 260         return crypto_shash_final(ahash_request_ctx(req), req->result);
 261 }
 262
 263 int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
 264 {
 265         struct crypto_hash_walk walk;
 266         int nbytes;
 267
 268         nbytes = crypto_hash_walk_first(req, &walk);
 269         if (!nbytes)
 270                 return crypto_shash_final(desc, req->result);
 271
 272         do {
 273                 nbytes = crypto_hash_walk_last(&walk) ?
 274                          crypto_shash_finup(desc, walk.data, nbytes,
 275                                             req->result) :
 276                          crypto_shash_update(desc, walk.data, nbytes);
 277                 nbytes = crypto_hash_walk_done(&walk, nbytes);
 278         } while (nbytes > 0);
 279
 280         return nbytes;
 281 }
 282 EXPORT_SYMBOL_GPL(shash_ahash_finup);
 283
 284 static int shash_async_finup(struct ahash_request *req)
 285 {
 286         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 287         struct shash_desc *desc = ahash_request_ctx(req);
 288
 289         desc->tfm = *ctx;
 290
 291         return shash_ahash_finup(req, desc);
 292 }
 293
 294 int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
 295 {
 296         unsigned int nbytes = req->nbytes;
 297         struct scatterlist *sg;
 298         unsigned int offset;
 299         int err;
 300
 301         if (nbytes &&
 302             (sg = req->src, offset = sg->offset,
 303              nbytes <= min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset))) {
 304                 void *data;
 305
 306                 data = kmap_atomic(sg_page(sg));
 307                 err = crypto_shash_digest(desc, data + offset, nbytes,
 308                                           req->result);
 309                 kunmap_atomic(data);
 310         } else
 311                 err = crypto_shash_init(desc) ?:
 312                       shash_ahash_finup(req, desc);
 313
 314         return err;
 315 }
 316 EXPORT_SYMBOL_GPL(shash_ahash_digest);
 317
 318 static int shash_async_digest(struct ahash_request *req)
 319 {
 320         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 321         struct shash_desc *desc = ahash_request_ctx(req);
 322
 323         desc->tfm = *ctx;
 324
 325         return shash_ahash_digest(req, desc);
 326 }
 327
 328 static int shash_async_export(struct ahash_request *req, void *out)
 329 {
 330         return crypto_shash_export(ahash_request_ctx(req), out);
 331 }
 332
 333 static int shash_async_import(struct ahash_request *req, const void *in)
 334 {
 335         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 336         struct shash_desc *desc = ahash_request_ctx(req);
 337
 338         desc->tfm = *ctx;
 339
 340         return crypto_shash_import(desc, in);
 341 }
 342
 343 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 344 {
 345         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 346
 347         crypto_free_shash(*ctx);
 348 }
 349
 350 int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 351 {
 352         struct crypto_alg *calg = tfm->__crt_alg;
 353         struct shash_alg *alg = __crypto_shash_alg(calg);
 354         struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
 355         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 356         struct crypto_shash *shash;
 357
 358         if (!crypto_mod_get(calg))
 359                 return -EAGAIN;
 360
 361         shash = crypto_create_tfm(calg, &crypto_shash_type);
 362         if (IS_ERR(shash)) {
 363                 crypto_mod_put(calg);
 364                 return PTR_ERR(shash);
 365         }
 366
 367         *ctx = shash;
 368         tfm->exit = crypto_exit_shash_ops_async;
 369
 370         crt->init = shash_async_init;
 371         crt->update = shash_async_update;
 372         crt->final = shash_async_final;
 373         crt->finup = shash_async_finup;
 374         crt->digest = shash_async_digest;
 375         if (crypto_shash_alg_has_setkey(alg))
 376                 crt->setkey = shash_async_setkey;
 377
 378         crypto_ahash_set_flags(crt, crypto_shash_get_flags(shash) &
 379                                     CRYPTO_TFM_NEED_KEY);
 380
 381         crt->export = shash_async_export;
 382         crt->import = shash_async_import;
 383
 384         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 385
 386         return 0;
 387 }
 388
 389 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
 390 {
 391         struct crypto_shash *hash = __crypto_shash_cast(tfm);
 392         struct shash_alg *alg = crypto_shash_alg(hash);
 393
 394         hash->descsize = alg->descsize;
 395
 396         shash_set_needkey(hash, alg);
 397
 398         return 0;
 399 }
 400
 401 #ifdef CONFIG_NET
 402 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 403 {
 404         struct crypto_report_hash rhash;
 405         struct shash_alg *salg = __crypto_shash_alg(alg);
 406
 407         memset(&rhash, 0, sizeof(rhash));
 408
 409         strscpy(rhash.type, "shash", sizeof(rhash.type));
 410
 411         rhash.blocksize = alg->cra_blocksize;
 412         rhash.digestsize = salg->digestsize;
 413
 414         return nla_put(skb, CRYPTOCFGA_REPORT_HASH, sizeof(rhash), &rhash);
 415 }
 416 #else
 417 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 418 {
 419         return -ENOSYS;
 420 }
 421 #endif
 422
 423 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 424         __maybe_unused;
 425 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 426 {
 427         struct shash_alg *salg = __crypto_shash_alg(alg);
 428
 429         seq_printf(m, "type         : shash\n");
 430         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 431         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 432 }
 433
 434 static const struct crypto_type crypto_shash_type = {
 435         .extsize = crypto_alg_extsize,
 436         .init_tfm = crypto_shash_init_tfm,
 437 #ifdef CONFIG_PROC_FS
 438         .show = crypto_shash_show,
 439 #endif
 440         .report = crypto_shash_report,
 441         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 442         .maskset = CRYPTO_ALG_TYPE_MASK,
 443         .type = CRYPTO_ALG_TYPE_SHASH,
 444         .tfmsize = offsetof(struct crypto_shash, base),
 445 };
 446
 447 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 448                                         u32 mask)
 449 {
 450         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 451 }
 452 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 453
 454 static int shash_prepare_alg(struct shash_alg *alg)
 455 {
 456         struct crypto_alg *base = &alg->base;
 457
 458         if (alg->digestsize > HASH_MAX_DIGESTSIZE ||
 459             alg->descsize > HASH_MAX_DESCSIZE ||
 460             alg->statesize > HASH_MAX_STATESIZE)
 461                 return -EINVAL;
 462
 463         if ((alg->export && !alg->import) || (alg->import && !alg->export))
 464                 return -EINVAL;
 465
 466         base->cra_type = &crypto_shash_type;
 467         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 468         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 469
 470         if (!alg->finup)
 471                 alg->finup = shash_finup_unaligned;
 472         if (!alg->digest)
 473                 alg->digest = shash_digest_unaligned;
 474         if (!alg->export) {
 475                 alg->export = shash_default_export;
 476                 alg->import = shash_default_import;
 477                 alg->statesize = alg->descsize;
 478         }
 479         if (!alg->setkey)
 480                 alg->setkey = shash_no_setkey;
 481
 482         return 0;
 483 }
 484
 485 int crypto_register_shash(struct shash_alg *alg)
 486 {
 487         struct crypto_alg *base = &alg->base;
 488         int err;
 489
 490         err = shash_prepare_alg(alg);
 491         if (err)
 492                 return err;
 493
 494         return crypto_register_alg(base);
 495 }
 496 EXPORT_SYMBOL_GPL(crypto_register_shash);
 497
 498 int crypto_unregister_shash(struct shash_alg *alg)
 499 {
 500         return crypto_unregister_alg(&alg->base);
 501 }
 502 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 503
 504 int crypto_register_shashes(struct shash_alg *algs, int count)
 505 {
 506         int i, ret;
 507
 508         for (i = 0; i < count; i++) {
 509                 ret = crypto_register_shash(&algs[i]);
 510                 if (ret)
 511                         goto err;
 512         }
 513
 514         return 0;
 515
 516 err:
 517         for (--i; i >= 0; --i)
 518                 crypto_unregister_shash(&algs[i]);
 519
 520         return ret;
 521 }
 522 EXPORT_SYMBOL_GPL(crypto_register_shashes);
 523
 524 int crypto_unregister_shashes(struct shash_alg *algs, int count)
 525 {
 526         int i, ret;
 527
 528         for (i = count - 1; i >= 0; --i) {
 529                 ret = crypto_unregister_shash(&algs[i]);
 530                 if (ret)
 531                         pr_err("Failed to unregister %s %s: %d\n",
 532                                algs[i].base.cra_driver_name,
 533                                algs[i].base.cra_name, ret);
 534         }
 535
 536         return 0;
 537 }
 538 EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
 539
 540 int shash_register_instance(struct crypto_template *tmpl,
 541                             struct shash_instance *inst)
 542 {
 543         int err;
 544
 545         err = shash_prepare_alg(&inst->alg);
 546         if (err)
 547                 return err;
 548
 549         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 550 }
 551 EXPORT_SYMBOL_GPL(shash_register_instance);
 552
 553 void shash_free_instance(struct crypto_instance *inst)
 554 {
 555         crypto_drop_spawn(crypto_instance_ctx(inst));
 556         kfree(shash_instance(inst));
 557 }
 558 EXPORT_SYMBOL_GPL(shash_free_instance);
 559
 560 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
 561                             struct shash_alg *alg,
 562                             struct crypto_instance *inst)
 563 {
 564         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 565                                   &crypto_shash_type);
 566 }
 567 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
 568
 569 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 570 {
 571         struct crypto_alg *alg;
 572
 573         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
 574         return IS_ERR(alg) ? ERR_CAST(alg) :
 575                container_of(alg, struct shash_alg, base);
 576 }
 577 EXPORT_SYMBOL_GPL(shash_attr_alg);
 578
 579 MODULE_LICENSE("GPL");
 580 MODULE_DESCRIPTION("Synchronous cryptographic hash type");