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
 242         return crypto_shash_init(desc);
 243 }
 244
 245 int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
 246 {
 247         struct crypto_hash_walk walk;
 248         int nbytes;
 249
 250         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
 251              nbytes = crypto_hash_walk_done(&walk, nbytes))
 252                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 253
 254         return nbytes;
 255 }
 256 EXPORT_SYMBOL_GPL(shash_ahash_update);
 257
 258 static int shash_async_update(struct ahash_request *req)
 259 {
 260         return shash_ahash_update(req, ahash_request_ctx(req));
 261 }
 262
 263 static int shash_async_final(struct ahash_request *req)
 264 {
 265         return crypto_shash_final(ahash_request_ctx(req), req->result);
 266 }
 267
 268 int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
 269 {
 270         struct crypto_hash_walk walk;
 271         int nbytes;
 272
 273         nbytes = crypto_hash_walk_first(req, &walk);
 274         if (!nbytes)
 275                 return crypto_shash_final(desc, req->result);
 276
 277         do {
 278                 nbytes = crypto_hash_walk_last(&walk) ?
 279                          crypto_shash_finup(desc, walk.data, nbytes,
 280                                             req->result) :
 281                          crypto_shash_update(desc, walk.data, nbytes);
 282                 nbytes = crypto_hash_walk_done(&walk, nbytes);
 283         } while (nbytes > 0);
 284
 285         return nbytes;
 286 }
 287 EXPORT_SYMBOL_GPL(shash_ahash_finup);
 288
 289 static int shash_async_finup(struct ahash_request *req)
 290 {
 291         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 292         struct shash_desc *desc = ahash_request_ctx(req);
 293
 294         desc->tfm = *ctx;
 295
 296         return shash_ahash_finup(req, desc);
 297 }
 298
 299 int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
 300 {
 301         unsigned int nbytes = req->nbytes;
 302         struct scatterlist *sg;
 303         unsigned int offset;
 304         int err;
 305
 306         if (nbytes &&
 307             (sg = req->src, offset = sg->offset,
 308              nbytes <= min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset))) {
 309                 void *data;
 310
 311                 data = kmap_atomic(sg_page(sg));
 312                 err = crypto_shash_digest(desc, data + offset, nbytes,
 313                                           req->result);
 314                 kunmap_atomic(data);
 315         } else
 316                 err = crypto_shash_init(desc) ?:
 317                       shash_ahash_finup(req, desc);
 318
 319         return err;
 320 }
 321 EXPORT_SYMBOL_GPL(shash_ahash_digest);
 322
 323 static int shash_async_digest(struct ahash_request *req)
 324 {
 325         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 326         struct shash_desc *desc = ahash_request_ctx(req);
 327
 328         desc->tfm = *ctx;
 329
 330         return shash_ahash_digest(req, desc);
 331 }
 332
 333 static int shash_async_export(struct ahash_request *req, void *out)
 334 {
 335         return crypto_shash_export(ahash_request_ctx(req), out);
 336 }
 337
 338 static int shash_async_import(struct ahash_request *req, const void *in)
 339 {
 340         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 341         struct shash_desc *desc = ahash_request_ctx(req);
 342
 343         desc->tfm = *ctx;
 344
 345         return crypto_shash_import(desc, in);
 346 }
 347
 348 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 349 {
 350         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 351
 352         crypto_free_shash(*ctx);
 353 }
 354
 355 int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 356 {
 357         struct crypto_alg *calg = tfm->__crt_alg;
 358         struct shash_alg *alg = __crypto_shash_alg(calg);
 359         struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
 360         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 361         struct crypto_shash *shash;
 362
 363         if (!crypto_mod_get(calg))
 364                 return -EAGAIN;
 365
 366         shash = crypto_create_tfm(calg, &crypto_shash_type);
 367         if (IS_ERR(shash)) {
 368                 crypto_mod_put(calg);
 369                 return PTR_ERR(shash);
 370         }
 371
 372         *ctx = shash;
 373         tfm->exit = crypto_exit_shash_ops_async;
 374
 375         crt->init = shash_async_init;
 376         crt->update = shash_async_update;
 377         crt->final = shash_async_final;
 378         crt->finup = shash_async_finup;
 379         crt->digest = shash_async_digest;
 380         if (crypto_shash_alg_has_setkey(alg))
 381                 crt->setkey = shash_async_setkey;
 382
 383         crypto_ahash_set_flags(crt, crypto_shash_get_flags(shash) &
 384                                     CRYPTO_TFM_NEED_KEY);
 385
 386         crt->export = shash_async_export;
 387         crt->import = shash_async_import;
 388
 389         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 390
 391         return 0;
 392 }
 393
 394 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
 395 {
 396         struct crypto_shash *hash = __crypto_shash_cast(tfm);
 397         struct shash_alg *alg = crypto_shash_alg(hash);
 398
 399         hash->descsize = alg->descsize;
 400
 401         shash_set_needkey(hash, alg);
 402
 403         return 0;
 404 }
 405
 406 #ifdef CONFIG_NET
 407 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 408 {
 409         struct crypto_report_hash rhash;
 410         struct shash_alg *salg = __crypto_shash_alg(alg);
 411
 412         memset(&rhash, 0, sizeof(rhash));
 413
 414         strscpy(rhash.type, "shash", sizeof(rhash.type));
 415
 416         rhash.blocksize = alg->cra_blocksize;
 417         rhash.digestsize = salg->digestsize;
 418
 419         return nla_put(skb, CRYPTOCFGA_REPORT_HASH, sizeof(rhash), &rhash);
 420 }
 421 #else
 422 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 423 {
 424         return -ENOSYS;
 425 }
 426 #endif
 427
 428 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 429         __maybe_unused;
 430 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 431 {
 432         struct shash_alg *salg = __crypto_shash_alg(alg);
 433
 434         seq_printf(m, "type         : shash\n");
 435         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 436         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 437 }
 438
 439 static const struct crypto_type crypto_shash_type = {
 440         .extsize = crypto_alg_extsize,
 441         .init_tfm = crypto_shash_init_tfm,
 442 #ifdef CONFIG_PROC_FS
 443         .show = crypto_shash_show,
 444 #endif
 445         .report = crypto_shash_report,
 446         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 447         .maskset = CRYPTO_ALG_TYPE_MASK,
 448         .type = CRYPTO_ALG_TYPE_SHASH,
 449         .tfmsize = offsetof(struct crypto_shash, base),
 450 };
 451
 452 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 453                                         u32 mask)
 454 {
 455         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 456 }
 457 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 458
 459 static int shash_prepare_alg(struct shash_alg *alg)
 460 {
 461         struct crypto_alg *base = &alg->base;
 462
 463         if (alg->digestsize > HASH_MAX_DIGESTSIZE ||
 464             alg->descsize > HASH_MAX_DESCSIZE ||
 465             alg->statesize > HASH_MAX_STATESIZE)
 466                 return -EINVAL;
 467
 468         if ((alg->export && !alg->import) || (alg->import && !alg->export))
 469                 return -EINVAL;
 470
 471         base->cra_type = &crypto_shash_type;
 472         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 473         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 474
 475         if (!alg->finup)
 476                 alg->finup = shash_finup_unaligned;
 477         if (!alg->digest)
 478                 alg->digest = shash_digest_unaligned;
 479         if (!alg->export) {
 480                 alg->export = shash_default_export;
 481                 alg->import = shash_default_import;
 482                 alg->statesize = alg->descsize;
 483         }
 484         if (!alg->setkey)
 485                 alg->setkey = shash_no_setkey;
 486
 487         return 0;
 488 }
 489
 490 int crypto_register_shash(struct shash_alg *alg)
 491 {
 492         struct crypto_alg *base = &alg->base;
 493         int err;
 494
 495         err = shash_prepare_alg(alg);
 496         if (err)
 497                 return err;
 498
 499         return crypto_register_alg(base);
 500 }
 501 EXPORT_SYMBOL_GPL(crypto_register_shash);
 502
 503 int crypto_unregister_shash(struct shash_alg *alg)
 504 {
 505         return crypto_unregister_alg(&alg->base);
 506 }
 507 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 508
 509 int crypto_register_shashes(struct shash_alg *algs, int count)
 510 {
 511         int i, ret;
 512
 513         for (i = 0; i < count; i++) {
 514                 ret = crypto_register_shash(&algs[i]);
 515                 if (ret)
 516                         goto err;
 517         }
 518
 519         return 0;
 520
 521 err:
 522         for (--i; i >= 0; --i)
 523                 crypto_unregister_shash(&algs[i]);
 524
 525         return ret;
 526 }
 527 EXPORT_SYMBOL_GPL(crypto_register_shashes);
 528
 529 int crypto_unregister_shashes(struct shash_alg *algs, int count)
 530 {
 531         int i, ret;
 532
 533         for (i = count - 1; i >= 0; --i) {
 534                 ret = crypto_unregister_shash(&algs[i]);
 535                 if (ret)
 536                         pr_err("Failed to unregister %s %s: %d\n",
 537                                algs[i].base.cra_driver_name,
 538                                algs[i].base.cra_name, ret);
 539         }
 540
 541         return 0;
 542 }
 543 EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
 544
 545 int shash_register_instance(struct crypto_template *tmpl,
 546                             struct shash_instance *inst)
 547 {
 548         int err;
 549
 550         err = shash_prepare_alg(&inst->alg);
 551         if (err)
 552                 return err;
 553
 554         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 555 }
 556 EXPORT_SYMBOL_GPL(shash_register_instance);
 557
 558 void shash_free_instance(struct crypto_instance *inst)
 559 {
 560         crypto_drop_spawn(crypto_instance_ctx(inst));
 561         kfree(shash_instance(inst));
 562 }
 563 EXPORT_SYMBOL_GPL(shash_free_instance);
 564
 565 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
 566                             struct shash_alg *alg,
 567                             struct crypto_instance *inst)
 568 {
 569         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 570                                   &crypto_shash_type);
 571 }
 572 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
 573
 574 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 575 {
 576         struct crypto_alg *alg;
 577
 578         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
 579         return IS_ERR(alg) ? ERR_CAST(alg) :
 580                container_of(alg, struct shash_alg, base);
 581 }
 582 EXPORT_SYMBOL_GPL(shash_attr_alg);
 583
 584 MODULE_LICENSE("GPL");
 585 MODULE_DESCRIPTION("Synchronous cryptographic hash type");