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