crypto/shash.c

   1 /*
   2  * Synchronous Cryptographic Hash operations.
   3  *
   4  * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the Free
   8  * Software Foundation; either version 2 of the License, or (at your option)
   9  * any later version.
  10  *
  11  */
  12
  13 #include <crypto/scatterwalk.h>
  14 #include <crypto/internal/hash.h>
  15 #include <linux/err.h>
  16 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/slab.h>
  19 #include <linux/seq_file.h>
  20 #include <linux/cryptouser.h>
  21 #include <net/netlink.h>
  22 #include <linux/compiler.h>
  23
  24 #include "internal.h"
  25
  26 static const struct crypto_type crypto_shash_type;
  27
  28 int shash_no_setkey(struct crypto_shash *tfm, const u8 *key,
  29                     unsigned int keylen)
  30 {
  31         return -ENOSYS;
  32 }
  33 EXPORT_SYMBOL_GPL(shash_no_setkey);
  34
  35 static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
  36                                   unsigned int keylen)
  37 {
  38         struct shash_alg *shash = crypto_shash_alg(tfm);
  39         unsigned long alignmask = crypto_shash_alignmask(tfm);
  40         unsigned long absize;
  41         u8 *buffer, *alignbuffer;
  42         int err;
  43
  44         absize = keylen + (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
  45         buffer = kmalloc(absize, GFP_ATOMIC);
  46         if (!buffer)
  47                 return -ENOMEM;
  48
  49         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  50         memcpy(alignbuffer, key, keylen);
  51         err = shash->setkey(tfm, alignbuffer, keylen);
  52         kzfree(buffer);
  53         return err;
  54 }
  55
  56 static void shash_set_needkey(struct crypto_shash *tfm, struct shash_alg *alg)
  57 {
  58         if (crypto_shash_alg_has_setkey(alg) &&
  59             !(alg->base.cra_flags & CRYPTO_ALG_OPTIONAL_KEY))
  60                 crypto_shash_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
  61 }
  62
  63 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
  64                         unsigned int keylen)
  65 {
  66         struct shash_alg *shash = crypto_shash_alg(tfm);
  67         unsigned long alignmask = crypto_shash_alignmask(tfm);
  68         int err;
  69
  70         if ((unsigned long)key & alignmask)
  71                 err = shash_setkey_unaligned(tfm, key, keylen);
  72         else
  73                 err = shash->setkey(tfm, key, keylen);
  74
  75         if (unlikely(err)) {
  76                 shash_set_needkey(tfm, shash);
  77                 return err;
  78         }
  79
  80         crypto_shash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
  81         return 0;
  82 }
  83 EXPORT_SYMBOL_GPL(crypto_shash_setkey);
  84
  85 static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
  86                                   unsigned int len)
  87 {
  88         struct crypto_shash *tfm = desc->tfm;
  89         struct shash_alg *shash = crypto_shash_alg(tfm);
  90         unsigned long alignmask = crypto_shash_alignmask(tfm);
  91         unsigned int unaligned_len = alignmask + 1 -
  92                                      ((unsigned long)data & alignmask);
  93         /*
  94          * We cannot count on __aligned() working for large values:
  95          * https://patchwork.kernel.org/patch/9507697/
  96          */
  97         u8 ubuf[MAX_ALGAPI_ALIGNMASK * 2];
  98         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
  99         int err;
 100
 101         if (WARN_ON(buf + unaligned_len > ubuf + sizeof(ubuf)))
 102                 return -EINVAL;
 103
 104         if (unaligned_len > len)
 105                 unaligned_len = len;
 106
 107         memcpy(buf, data, unaligned_len);
 108         err = shash->update(desc, buf, unaligned_len);
 109         memset(buf, 0, unaligned_len);
 110
 111         return err ?:
 112                shash->update(desc, data + unaligned_len, len - unaligned_len);
 113 }
 114
 115 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
 116                         unsigned int len)
 117 {
 118         struct crypto_shash *tfm = desc->tfm;
 119         struct shash_alg *shash = crypto_shash_alg(tfm);
 120         unsigned long alignmask = crypto_shash_alignmask(tfm);
 121
 122         if ((unsigned long)data & alignmask)
 123                 return shash_update_unaligned(desc, data, len);
 124
 125         return shash->update(desc, data, len);
 126 }
 127 EXPORT_SYMBOL_GPL(crypto_shash_update);
 128
 129 static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
 130 {
 131         struct crypto_shash *tfm = desc->tfm;
 132         unsigned long alignmask = crypto_shash_alignmask(tfm);
 133         struct shash_alg *shash = crypto_shash_alg(tfm);
 134         unsigned int ds = crypto_shash_digestsize(tfm);
 135         /*
 136          * We cannot count on __aligned() working for large values:
 137          * https://patchwork.kernel.org/patch/9507697/
 138          */
 139         u8 ubuf[MAX_ALGAPI_ALIGNMASK + HASH_MAX_DIGESTSIZE];
 140         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
 141         int err;
 142
 143         if (WARN_ON(buf + ds > ubuf + sizeof(ubuf)))
 144                 return -EINVAL;
 145
 146         err = shash->final(desc, buf);
 147         if (err)
 148                 goto out;
 149
 150         memcpy(out, buf, ds);
 151
 152 out:
 153         memset(buf, 0, ds);
 154         return err;
 155 }
 156
 157 int crypto_shash_final(struct shash_desc *desc, u8 *out)
 158 {
 159         struct crypto_shash *tfm = desc->tfm;
 160         struct shash_alg *shash = crypto_shash_alg(tfm);
 161         unsigned long alignmask = crypto_shash_alignmask(tfm);
 162
 163         if ((unsigned long)out & alignmask)
 164                 return shash_final_unaligned(desc, out);
 165
 166         return shash->final(desc, out);
 167 }
 168 EXPORT_SYMBOL_GPL(crypto_shash_final);
 169
 170 static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
 171                                  unsigned int len, u8 *out)
 172 {
 173         return crypto_shash_update(desc, data, len) ?:
 174                crypto_shash_final(desc, out);
 175 }
 176
 177 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
 178                        unsigned int len, u8 *out)
 179 {
 180         struct crypto_shash *tfm = desc->tfm;
 181         struct shash_alg *shash = crypto_shash_alg(tfm);
 182         unsigned long alignmask = crypto_shash_alignmask(tfm);
 183
 184         if (((unsigned long)data | (unsigned long)out) & alignmask)
 185                 return shash_finup_unaligned(desc, data, len, out);
 186
 187         return shash->finup(desc, data, len, out);
 188 }
 189 EXPORT_SYMBOL_GPL(crypto_shash_finup);
 190
 191 static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
 192                                   unsigned int len, u8 *out)
 193 {
 194         return crypto_shash_init(desc) ?:
 195                crypto_shash_finup(desc, data, len, out);
 196 }
 197
 198 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
 199                         unsigned int len, u8 *out)
 200 {
 201         struct crypto_shash *tfm = desc->tfm;
 202         struct shash_alg *shash = crypto_shash_alg(tfm);
 203         unsigned long alignmask = crypto_shash_alignmask(tfm);
 204
 205         if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
 206                 return -ENOKEY;
 207
 208         if (((unsigned long)data | (unsigned long)out) & alignmask)
 209                 return shash_digest_unaligned(desc, data, len, out);
 210
 211         return shash->digest(desc, data, len, out);
 212 }
 213 EXPORT_SYMBOL_GPL(crypto_shash_digest);
 214
 215 static int shash_default_export(struct shash_desc *desc, void *out)
 216 {
 217         memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm));
 218         return 0;
 219 }
 220
 221 static int shash_default_import(struct shash_desc *desc, const void *in)
 222 {
 223         memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm));
 224         return 0;
 225 }
 226
 227 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 228                               unsigned int keylen)
 229 {
 230         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
 231
 232         return crypto_shash_setkey(*ctx, key, keylen);
 233 }
 234
 235 static int shash_async_init(struct ahash_request *req)
 236 {
 237         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 238         struct shash_desc *desc = ahash_request_ctx(req);
 239
 240         desc->tfm = *ctx;
 241         desc->flags = req->base.flags;
 242
 243         return crypto_shash_init(desc);
 244 }
 245
 246 int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
 247 {
 248         struct crypto_hash_walk walk;
 249         int nbytes;
 250
 251         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
 252              nbytes = crypto_hash_walk_done(&walk, nbytes))
 253                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 254
 255         return nbytes;
 256 }
 257 EXPORT_SYMBOL_GPL(shash_ahash_update);
 258
 259 static int shash_async_update(struct ahash_request *req)
 260 {
 261         return shash_ahash_update(req, ahash_request_ctx(req));
 262 }
 263
 264 static int shash_async_final(struct ahash_request *req)
 265 {
 266         return crypto_shash_final(ahash_request_ctx(req), req->result);
 267 }
 268
 269 int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
 270 {
 271         struct crypto_hash_walk walk;
 272         int nbytes;
 273
 274         nbytes = crypto_hash_walk_first(req, &walk);
 275         if (!nbytes)
 276                 return crypto_shash_final(desc, req->result);
 277
 278         do {
 279                 nbytes = crypto_hash_walk_last(&walk) ?
 280                          crypto_shash_finup(desc, walk.data, nbytes,
 281                                             req->result) :
 282                          crypto_shash_update(desc, walk.data, nbytes);
 283                 nbytes = crypto_hash_walk_done(&walk, nbytes);
 284         } while (nbytes > 0);
 285
 286         return nbytes;
 287 }
 288 EXPORT_SYMBOL_GPL(shash_ahash_finup);
 289
 290 static int shash_async_finup(struct ahash_request *req)
 291 {
 292         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 293         struct shash_desc *desc = ahash_request_ctx(req);
 294
 295         desc->tfm = *ctx;
 296         desc->flags = req->base.flags;
 297
 298         return shash_ahash_finup(req, desc);
 299 }
 300
 301 int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
 302 {
 303         unsigned int nbytes = req->nbytes;
 304         struct scatterlist *sg;
 305         unsigned int offset;
 306         int err;
 307
 308         if (nbytes &&
 309             (sg = req->src, offset = sg->offset,
 310              nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset))) {
 311                 void *data;
 312
 313                 data = kmap_atomic(sg_page(sg));
 314                 err = crypto_shash_digest(desc, data + offset, nbytes,
 315                                           req->result);
 316                 kunmap_atomic(data);
 317                 crypto_yield(desc->flags);
 318         } else
 319                 err = crypto_shash_init(desc) ?:
 320                       shash_ahash_finup(req, desc);
 321
 322         return err;
 323 }
 324 EXPORT_SYMBOL_GPL(shash_ahash_digest);
 325
 326 static int shash_async_digest(struct ahash_request *req)
 327 {
 328         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 329         struct shash_desc *desc = ahash_request_ctx(req);
 330
 331         desc->tfm = *ctx;
 332         desc->flags = req->base.flags;
 333
 334         return shash_ahash_digest(req, desc);
 335 }
 336
 337 static int shash_async_export(struct ahash_request *req, void *out)
 338 {
 339         return crypto_shash_export(ahash_request_ctx(req), out);
 340 }
 341
 342 static int shash_async_import(struct ahash_request *req, const void *in)
 343 {
 344         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 345         struct shash_desc *desc = ahash_request_ctx(req);
 346
 347         desc->tfm = *ctx;
 348         desc->flags = req->base.flags;
 349
 350         return crypto_shash_import(desc, in);
 351 }
 352
 353 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 354 {
 355         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 356
 357         crypto_free_shash(*ctx);
 358 }
 359
 360 int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 361 {
 362         struct crypto_alg *calg = tfm->__crt_alg;
 363         struct shash_alg *alg = __crypto_shash_alg(calg);
 364         struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
 365         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 366         struct crypto_shash *shash;
 367
 368         if (!crypto_mod_get(calg))
 369                 return -EAGAIN;
 370
 371         shash = crypto_create_tfm(calg, &crypto_shash_type);
 372         if (IS_ERR(shash)) {
 373                 crypto_mod_put(calg);
 374                 return PTR_ERR(shash);
 375         }
 376
 377         *ctx = shash;
 378         tfm->exit = crypto_exit_shash_ops_async;
 379
 380         crt->init = shash_async_init;
 381         crt->update = shash_async_update;
 382         crt->final = shash_async_final;
 383         crt->finup = shash_async_finup;
 384         crt->digest = shash_async_digest;
 385         if (crypto_shash_alg_has_setkey(alg))
 386                 crt->setkey = shash_async_setkey;
 387
 388         crypto_ahash_set_flags(crt, crypto_shash_get_flags(shash) &
 389                                     CRYPTO_TFM_NEED_KEY);
 390
 391         if (alg->export)
 392                 crt->export = shash_async_export;
 393         if (alg->import)
 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         base->cra_type = &crypto_shash_type;
 476         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 477         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 478
 479         if (!alg->finup)
 480                 alg->finup = shash_finup_unaligned;
 481         if (!alg->digest)
 482                 alg->digest = shash_digest_unaligned;
 483         if (!alg->export) {
 484                 alg->export = shash_default_export;
 485                 alg->import = shash_default_import;
 486                 alg->statesize = alg->descsize;
 487         }
 488         if (!alg->setkey)
 489                 alg->setkey = shash_no_setkey;
 490
 491         return 0;
 492 }
 493
 494 int crypto_register_shash(struct shash_alg *alg)
 495 {
 496         struct crypto_alg *base = &alg->base;
 497         int err;
 498
 499         err = shash_prepare_alg(alg);
 500         if (err)
 501                 return err;
 502
 503         return crypto_register_alg(base);
 504 }
 505 EXPORT_SYMBOL_GPL(crypto_register_shash);
 506
 507 int crypto_unregister_shash(struct shash_alg *alg)
 508 {
 509         return crypto_unregister_alg(&alg->base);
 510 }
 511 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 512
 513 int crypto_register_shashes(struct shash_alg *algs, int count)
 514 {
 515         int i, ret;
 516
 517         for (i = 0; i < count; i++) {
 518                 ret = crypto_register_shash(&algs[i]);
 519                 if (ret)
 520                         goto err;
 521         }
 522
 523         return 0;
 524
 525 err:
 526         for (--i; i >= 0; --i)
 527                 crypto_unregister_shash(&algs[i]);
 528
 529         return ret;
 530 }
 531 EXPORT_SYMBOL_GPL(crypto_register_shashes);
 532
 533 int crypto_unregister_shashes(struct shash_alg *algs, int count)
 534 {
 535         int i, ret;
 536
 537         for (i = count - 1; i >= 0; --i) {
 538                 ret = crypto_unregister_shash(&algs[i]);
 539                 if (ret)
 540                         pr_err("Failed to unregister %s %s: %d\n",
 541                                algs[i].base.cra_driver_name,
 542                                algs[i].base.cra_name, ret);
 543         }
 544
 545         return 0;
 546 }
 547 EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
 548
 549 int shash_register_instance(struct crypto_template *tmpl,
 550                             struct shash_instance *inst)
 551 {
 552         int err;
 553
 554         err = shash_prepare_alg(&inst->alg);
 555         if (err)
 556                 return err;
 557
 558         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 559 }
 560 EXPORT_SYMBOL_GPL(shash_register_instance);
 561
 562 void shash_free_instance(struct crypto_instance *inst)
 563 {
 564         crypto_drop_spawn(crypto_instance_ctx(inst));
 565         kfree(shash_instance(inst));
 566 }
 567 EXPORT_SYMBOL_GPL(shash_free_instance);
 568
 569 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
 570                             struct shash_alg *alg,
 571                             struct crypto_instance *inst)
 572 {
 573         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 574                                   &crypto_shash_type);
 575 }
 576 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
 577
 578 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 579 {
 580         struct crypto_alg *alg;
 581
 582         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
 583         return IS_ERR(alg) ? ERR_CAST(alg) :
 584                container_of(alg, struct shash_alg, base);
 585 }
 586 EXPORT_SYMBOL_GPL(shash_attr_alg);
 587
 588 MODULE_LICENSE("GPL");
 589 MODULE_DESCRIPTION("Synchronous cryptographic hash type");