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         kfree_sensitive(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 int crypto_shash_tfm_digest(struct crypto_shash *tfm, const u8 *data,
 210                             unsigned int len, u8 *out)
 211 {
 212         SHASH_DESC_ON_STACK(desc, tfm);
 213         int err;
 214
 215         desc->tfm = tfm;
 216
 217         err = crypto_shash_digest(desc, data, len, out);
 218
 219         shash_desc_zero(desc);
 220
 221         return err;
 222 }
 223 EXPORT_SYMBOL_GPL(crypto_shash_tfm_digest);
 224
 225 static int shash_default_export(struct shash_desc *desc, void *out)
 226 {
 227         memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm));
 228         return 0;
 229 }
 230
 231 static int shash_default_import(struct shash_desc *desc, const void *in)
 232 {
 233         memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm));
 234         return 0;
 235 }
 236
 237 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 238                               unsigned int keylen)
 239 {
 240         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
 241
 242         return crypto_shash_setkey(*ctx, key, keylen);
 243 }
 244
 245 static int shash_async_init(struct ahash_request *req)
 246 {
 247         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 248         struct shash_desc *desc = ahash_request_ctx(req);
 249
 250         desc->tfm = *ctx;
 251
 252         return crypto_shash_init(desc);
 253 }
 254
 255 int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
 256 {
 257         struct crypto_hash_walk walk;
 258         int nbytes;
 259
 260         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
 261              nbytes = crypto_hash_walk_done(&walk, nbytes))
 262                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 263
 264         return nbytes;
 265 }
 266 EXPORT_SYMBOL_GPL(shash_ahash_update);
 267
 268 static int shash_async_update(struct ahash_request *req)
 269 {
 270         return shash_ahash_update(req, ahash_request_ctx(req));
 271 }
 272
 273 static int shash_async_final(struct ahash_request *req)
 274 {
 275         return crypto_shash_final(ahash_request_ctx(req), req->result);
 276 }
 277
 278 int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
 279 {
 280         struct crypto_hash_walk walk;
 281         int nbytes;
 282
 283         nbytes = crypto_hash_walk_first(req, &walk);
 284         if (!nbytes)
 285                 return crypto_shash_final(desc, req->result);
 286
 287         do {
 288                 nbytes = crypto_hash_walk_last(&walk) ?
 289                          crypto_shash_finup(desc, walk.data, nbytes,
 290                                             req->result) :
 291                          crypto_shash_update(desc, walk.data, nbytes);
 292                 nbytes = crypto_hash_walk_done(&walk, nbytes);
 293         } while (nbytes > 0);
 294
 295         return nbytes;
 296 }
 297 EXPORT_SYMBOL_GPL(shash_ahash_finup);
 298
 299 static int shash_async_finup(struct ahash_request *req)
 300 {
 301         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 302         struct shash_desc *desc = ahash_request_ctx(req);
 303
 304         desc->tfm = *ctx;
 305
 306         return shash_ahash_finup(req, desc);
 307 }
 308
 309 int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
 310 {
 311         unsigned int nbytes = req->nbytes;
 312         struct scatterlist *sg;
 313         unsigned int offset;
 314         int err;
 315
 316         if (nbytes &&
 317             (sg = req->src, offset = sg->offset,
 318              nbytes <= min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset))) {
 319                 void *data;
 320
 321                 data = kmap_atomic(sg_page(sg));
 322                 err = crypto_shash_digest(desc, data + offset, nbytes,
 323                                           req->result);
 324                 kunmap_atomic(data);
 325         } else
 326                 err = crypto_shash_init(desc) ?:
 327                       shash_ahash_finup(req, desc);
 328
 329         return err;
 330 }
 331 EXPORT_SYMBOL_GPL(shash_ahash_digest);
 332
 333 static int shash_async_digest(struct ahash_request *req)
 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 shash_ahash_digest(req, desc);
 341 }
 342
 343 static int shash_async_export(struct ahash_request *req, void *out)
 344 {
 345         return crypto_shash_export(ahash_request_ctx(req), out);
 346 }
 347
 348 static int shash_async_import(struct ahash_request *req, const void *in)
 349 {
 350         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 351         struct shash_desc *desc = ahash_request_ctx(req);
 352
 353         desc->tfm = *ctx;
 354
 355         return crypto_shash_import(desc, in);
 356 }
 357
 358 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 359 {
 360         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 361
 362         crypto_free_shash(*ctx);
 363 }
 364
 365 int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 366 {
 367         struct crypto_alg *calg = tfm->__crt_alg;
 368         struct shash_alg *alg = __crypto_shash_alg(calg);
 369         struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
 370         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 371         struct crypto_shash *shash;
 372
 373         if (!crypto_mod_get(calg))
 374                 return -EAGAIN;
 375
 376         shash = crypto_create_tfm(calg, &crypto_shash_type);
 377         if (IS_ERR(shash)) {
 378                 crypto_mod_put(calg);
 379                 return PTR_ERR(shash);
 380         }
 381
 382         *ctx = shash;
 383         tfm->exit = crypto_exit_shash_ops_async;
 384
 385         crt->init = shash_async_init;
 386         crt->update = shash_async_update;
 387         crt->final = shash_async_final;
 388         crt->finup = shash_async_finup;
 389         crt->digest = shash_async_digest;
 390         if (crypto_shash_alg_has_setkey(alg))
 391                 crt->setkey = shash_async_setkey;
 392
 393         crypto_ahash_set_flags(crt, crypto_shash_get_flags(shash) &
 394                                     CRYPTO_TFM_NEED_KEY);
 395
 396         crt->export = shash_async_export;
 397         crt->import = shash_async_import;
 398
 399         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 400
 401         return 0;
 402 }
 403
 404 static void crypto_shash_exit_tfm(struct crypto_tfm *tfm)
 405 {
 406         struct crypto_shash *hash = __crypto_shash_cast(tfm);
 407         struct shash_alg *alg = crypto_shash_alg(hash);
 408
 409         alg->exit_tfm(hash);
 410 }
 411
 412 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
 413 {
 414         struct crypto_shash *hash = __crypto_shash_cast(tfm);
 415         struct shash_alg *alg = crypto_shash_alg(hash);
 416         int err;
 417
 418         hash->descsize = alg->descsize;
 419
 420         shash_set_needkey(hash, alg);
 421
 422         if (alg->exit_tfm)
 423                 tfm->exit = crypto_shash_exit_tfm;
 424
 425         if (!alg->init_tfm)
 426                 return 0;
 427
 428         err = alg->init_tfm(hash);
 429         if (err)
 430                 return err;
 431
 432         /* ->init_tfm() may have increased the descsize. */
 433         if (WARN_ON_ONCE(hash->descsize > HASH_MAX_DESCSIZE)) {
 434                 if (alg->exit_tfm)
 435                         alg->exit_tfm(hash);
 436                 return -EINVAL;
 437         }
 438
 439         return 0;
 440 }
 441
 442 static void crypto_shash_free_instance(struct crypto_instance *inst)
 443 {
 444         struct shash_instance *shash = shash_instance(inst);
 445
 446         shash->free(shash);
 447 }
 448
 449 #ifdef CONFIG_NET
 450 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 451 {
 452         struct crypto_report_hash rhash;
 453         struct shash_alg *salg = __crypto_shash_alg(alg);
 454
 455         memset(&rhash, 0, sizeof(rhash));
 456
 457         strscpy(rhash.type, "shash", sizeof(rhash.type));
 458
 459         rhash.blocksize = alg->cra_blocksize;
 460         rhash.digestsize = salg->digestsize;
 461
 462         return nla_put(skb, CRYPTOCFGA_REPORT_HASH, sizeof(rhash), &rhash);
 463 }
 464 #else
 465 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 466 {
 467         return -ENOSYS;
 468 }
 469 #endif
 470
 471 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 472         __maybe_unused;
 473 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 474 {
 475         struct shash_alg *salg = __crypto_shash_alg(alg);
 476
 477         seq_printf(m, "type         : shash\n");
 478         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 479         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 480 }
 481
 482 static const struct crypto_type crypto_shash_type = {
 483         .extsize = crypto_alg_extsize,
 484         .init_tfm = crypto_shash_init_tfm,
 485         .free = crypto_shash_free_instance,
 486 #ifdef CONFIG_PROC_FS
 487         .show = crypto_shash_show,
 488 #endif
 489         .report = crypto_shash_report,
 490         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 491         .maskset = CRYPTO_ALG_TYPE_MASK,
 492         .type = CRYPTO_ALG_TYPE_SHASH,
 493         .tfmsize = offsetof(struct crypto_shash, base),
 494 };
 495
 496 int crypto_grab_shash(struct crypto_shash_spawn *spawn,
 497                       struct crypto_instance *inst,
 498                       const char *name, u32 type, u32 mask)
 499 {
 500         spawn->base.frontend = &crypto_shash_type;
 501         return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
 502 }
 503 EXPORT_SYMBOL_GPL(crypto_grab_shash);
 504
 505 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 506                                         u32 mask)
 507 {
 508         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 509 }
 510 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 511
 512 static int shash_prepare_alg(struct shash_alg *alg)
 513 {
 514         struct crypto_alg *base = &alg->base;
 515
 516         if (alg->digestsize > HASH_MAX_DIGESTSIZE ||
 517             alg->descsize > HASH_MAX_DESCSIZE ||
 518             alg->statesize > HASH_MAX_STATESIZE)
 519                 return -EINVAL;
 520
 521         if ((alg->export && !alg->import) || (alg->import && !alg->export))
 522                 return -EINVAL;
 523
 524         base->cra_type = &crypto_shash_type;
 525         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 526         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 527
 528         if (!alg->finup)
 529                 alg->finup = shash_finup_unaligned;
 530         if (!alg->digest)
 531                 alg->digest = shash_digest_unaligned;
 532         if (!alg->export) {
 533                 alg->export = shash_default_export;
 534                 alg->import = shash_default_import;
 535                 alg->statesize = alg->descsize;
 536         }
 537         if (!alg->setkey)
 538                 alg->setkey = shash_no_setkey;
 539
 540         return 0;
 541 }
 542
 543 int crypto_register_shash(struct shash_alg *alg)
 544 {
 545         struct crypto_alg *base = &alg->base;
 546         int err;
 547
 548         err = shash_prepare_alg(alg);
 549         if (err)
 550                 return err;
 551
 552         return crypto_register_alg(base);
 553 }
 554 EXPORT_SYMBOL_GPL(crypto_register_shash);
 555
 556 void crypto_unregister_shash(struct shash_alg *alg)
 557 {
 558         crypto_unregister_alg(&alg->base);
 559 }
 560 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 561
 562 int crypto_register_shashes(struct shash_alg *algs, int count)
 563 {
 564         int i, ret;
 565
 566         for (i = 0; i < count; i++) {
 567                 ret = crypto_register_shash(&algs[i]);
 568                 if (ret)
 569                         goto err;
 570         }
 571
 572         return 0;
 573
 574 err:
 575         for (--i; i >= 0; --i)
 576                 crypto_unregister_shash(&algs[i]);
 577
 578         return ret;
 579 }
 580 EXPORT_SYMBOL_GPL(crypto_register_shashes);
 581
 582 void crypto_unregister_shashes(struct shash_alg *algs, int count)
 583 {
 584         int i;
 585
 586         for (i = count - 1; i >= 0; --i)
 587                 crypto_unregister_shash(&algs[i]);
 588 }
 589 EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
 590
 591 int shash_register_instance(struct crypto_template *tmpl,
 592                             struct shash_instance *inst)
 593 {
 594         int err;
 595
 596         if (WARN_ON(!inst->free))
 597                 return -EINVAL;
 598
 599         err = shash_prepare_alg(&inst->alg);
 600         if (err)
 601                 return err;
 602
 603         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 604 }
 605 EXPORT_SYMBOL_GPL(shash_register_instance);
 606
 607 void shash_free_singlespawn_instance(struct shash_instance *inst)
 608 {
 609         crypto_drop_spawn(shash_instance_ctx(inst));
 610         kfree(inst);
 611 }
 612 EXPORT_SYMBOL_GPL(shash_free_singlespawn_instance);
 613
 614 MODULE_LICENSE("GPL");
 615 MODULE_DESCRIPTION("Synchronous cryptographic hash type");