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         crt->export = shash_async_export;
 392         crt->import = shash_async_import;
 393
 394         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 395
 396         return 0;
 397 }
 398
 399 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
 400 {
 401         struct crypto_shash *hash = __crypto_shash_cast(tfm);
 402         struct shash_alg *alg = crypto_shash_alg(hash);
 403
 404         hash->descsize = alg->descsize;
 405
 406         shash_set_needkey(hash, alg);
 407
 408         return 0;
 409 }
 410
 411 #ifdef CONFIG_NET
 412 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 413 {
 414         struct crypto_report_hash rhash;
 415         struct shash_alg *salg = __crypto_shash_alg(alg);
 416
 417         memset(&rhash, 0, sizeof(rhash));
 418
 419         strscpy(rhash.type, "shash", sizeof(rhash.type));
 420
 421         rhash.blocksize = alg->cra_blocksize;
 422         rhash.digestsize = salg->digestsize;
 423
 424         return nla_put(skb, CRYPTOCFGA_REPORT_HASH, sizeof(rhash), &rhash);
 425 }
 426 #else
 427 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 428 {
 429         return -ENOSYS;
 430 }
 431 #endif
 432
 433 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 434         __maybe_unused;
 435 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 436 {
 437         struct shash_alg *salg = __crypto_shash_alg(alg);
 438
 439         seq_printf(m, "type         : shash\n");
 440         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 441         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 442 }
 443
 444 static const struct crypto_type crypto_shash_type = {
 445         .extsize = crypto_alg_extsize,
 446         .init_tfm = crypto_shash_init_tfm,
 447 #ifdef CONFIG_PROC_FS
 448         .show = crypto_shash_show,
 449 #endif
 450         .report = crypto_shash_report,
 451         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 452         .maskset = CRYPTO_ALG_TYPE_MASK,
 453         .type = CRYPTO_ALG_TYPE_SHASH,
 454         .tfmsize = offsetof(struct crypto_shash, base),
 455 };
 456
 457 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 458                                         u32 mask)
 459 {
 460         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 461 }
 462 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 463
 464 static int shash_prepare_alg(struct shash_alg *alg)
 465 {
 466         struct crypto_alg *base = &alg->base;
 467
 468         if (alg->digestsize > HASH_MAX_DIGESTSIZE ||
 469             alg->descsize > HASH_MAX_DESCSIZE ||
 470             alg->statesize > HASH_MAX_STATESIZE)
 471                 return -EINVAL;
 472
 473         if ((alg->export && !alg->import) || (alg->import && !alg->export))
 474                 return -EINVAL;
 475
 476         base->cra_type = &crypto_shash_type;
 477         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 478         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 479
 480         if (!alg->finup)
 481                 alg->finup = shash_finup_unaligned;
 482         if (!alg->digest)
 483                 alg->digest = shash_digest_unaligned;
 484         if (!alg->export) {
 485                 alg->export = shash_default_export;
 486                 alg->import = shash_default_import;
 487                 alg->statesize = alg->descsize;
 488         }
 489         if (!alg->setkey)
 490                 alg->setkey = shash_no_setkey;
 491
 492         return 0;
 493 }
 494
 495 int crypto_register_shash(struct shash_alg *alg)
 496 {
 497         struct crypto_alg *base = &alg->base;
 498         int err;
 499
 500         err = shash_prepare_alg(alg);
 501         if (err)
 502                 return err;
 503
 504         return crypto_register_alg(base);
 505 }
 506 EXPORT_SYMBOL_GPL(crypto_register_shash);
 507
 508 int crypto_unregister_shash(struct shash_alg *alg)
 509 {
 510         return crypto_unregister_alg(&alg->base);
 511 }
 512 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 513
 514 int crypto_register_shashes(struct shash_alg *algs, int count)
 515 {
 516         int i, ret;
 517
 518         for (i = 0; i < count; i++) {
 519                 ret = crypto_register_shash(&algs[i]);
 520                 if (ret)
 521                         goto err;
 522         }
 523
 524         return 0;
 525
 526 err:
 527         for (--i; i >= 0; --i)
 528                 crypto_unregister_shash(&algs[i]);
 529
 530         return ret;
 531 }
 532 EXPORT_SYMBOL_GPL(crypto_register_shashes);
 533
 534 int crypto_unregister_shashes(struct shash_alg *algs, int count)
 535 {
 536         int i, ret;
 537
 538         for (i = count - 1; i >= 0; --i) {
 539                 ret = crypto_unregister_shash(&algs[i]);
 540                 if (ret)
 541                         pr_err("Failed to unregister %s %s: %d\n",
 542                                algs[i].base.cra_driver_name,
 543                                algs[i].base.cra_name, ret);
 544         }
 545
 546         return 0;
 547 }
 548 EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
 549
 550 int shash_register_instance(struct crypto_template *tmpl,
 551                             struct shash_instance *inst)
 552 {
 553         int err;
 554
 555         err = shash_prepare_alg(&inst->alg);
 556         if (err)
 557                 return err;
 558
 559         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 560 }
 561 EXPORT_SYMBOL_GPL(shash_register_instance);
 562
 563 void shash_free_instance(struct crypto_instance *inst)
 564 {
 565         crypto_drop_spawn(crypto_instance_ctx(inst));
 566         kfree(shash_instance(inst));
 567 }
 568 EXPORT_SYMBOL_GPL(shash_free_instance);
 569
 570 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
 571                             struct shash_alg *alg,
 572                             struct crypto_instance *inst)
 573 {
 574         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 575                                   &crypto_shash_type);
 576 }
 577 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
 578
 579 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 580 {
 581         struct crypto_alg *alg;
 582
 583         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
 584         return IS_ERR(alg) ? ERR_CAST(alg) :
 585                container_of(alg, struct shash_alg, base);
 586 }
 587 EXPORT_SYMBOL_GPL(shash_attr_alg);
 588
 589 MODULE_LICENSE("GPL");
 590 MODULE_DESCRIPTION("Synchronous cryptographic hash type");