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 inline unsigned int shash_align_buffer_size(unsigned len,
  77                                                    unsigned long mask)
  78 {
  79         typedef u8 __aligned_largest u8_aligned;
  80         return len + (mask & ~(__alignof__(u8_aligned) - 1));
  81 }
  82
  83 static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
  84                                   unsigned int len)
  85 {
  86         struct crypto_shash *tfm = desc->tfm;
  87         struct shash_alg *shash = crypto_shash_alg(tfm);
  88         unsigned long alignmask = crypto_shash_alignmask(tfm);
  89         unsigned int unaligned_len = alignmask + 1 -
  90                                      ((unsigned long)data & alignmask);
  91         u8 ubuf[shash_align_buffer_size(unaligned_len, alignmask)]
  92                 __aligned_largest;
  93         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
  94         int err;
  95
  96         if (unaligned_len > len)
  97                 unaligned_len = len;
  98
  99         memcpy(buf, data, unaligned_len);
 100         err = shash->update(desc, buf, unaligned_len);
 101         memset(buf, 0, unaligned_len);
 102
 103         return err ?:
 104                shash->update(desc, data + unaligned_len, len - unaligned_len);
 105 }
 106
 107 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
 108                         unsigned int len)
 109 {
 110         struct crypto_shash *tfm = desc->tfm;
 111         struct shash_alg *shash = crypto_shash_alg(tfm);
 112         unsigned long alignmask = crypto_shash_alignmask(tfm);
 113
 114         if ((unsigned long)data & alignmask)
 115                 return shash_update_unaligned(desc, data, len);
 116
 117         return shash->update(desc, data, len);
 118 }
 119 EXPORT_SYMBOL_GPL(crypto_shash_update);
 120
 121 static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
 122 {
 123         struct crypto_shash *tfm = desc->tfm;
 124         unsigned long alignmask = crypto_shash_alignmask(tfm);
 125         struct shash_alg *shash = crypto_shash_alg(tfm);
 126         unsigned int ds = crypto_shash_digestsize(tfm);
 127         u8 ubuf[shash_align_buffer_size(ds, alignmask)]
 128                 __aligned_largest;
 129         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
 130         int err;
 131
 132         err = shash->final(desc, buf);
 133         if (err)
 134                 goto out;
 135
 136         memcpy(out, buf, ds);
 137
 138 out:
 139         memset(buf, 0, ds);
 140         return err;
 141 }
 142
 143 int crypto_shash_final(struct shash_desc *desc, u8 *out)
 144 {
 145         struct crypto_shash *tfm = desc->tfm;
 146         struct shash_alg *shash = crypto_shash_alg(tfm);
 147         unsigned long alignmask = crypto_shash_alignmask(tfm);
 148
 149         if ((unsigned long)out & alignmask)
 150                 return shash_final_unaligned(desc, out);
 151
 152         return shash->final(desc, out);
 153 }
 154 EXPORT_SYMBOL_GPL(crypto_shash_final);
 155
 156 static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
 157                                  unsigned int len, u8 *out)
 158 {
 159         return crypto_shash_update(desc, data, len) ?:
 160                crypto_shash_final(desc, out);
 161 }
 162
 163 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
 164                        unsigned int len, u8 *out)
 165 {
 166         struct crypto_shash *tfm = desc->tfm;
 167         struct shash_alg *shash = crypto_shash_alg(tfm);
 168         unsigned long alignmask = crypto_shash_alignmask(tfm);
 169
 170         if (((unsigned long)data | (unsigned long)out) & alignmask)
 171                 return shash_finup_unaligned(desc, data, len, out);
 172
 173         return shash->finup(desc, data, len, out);
 174 }
 175 EXPORT_SYMBOL_GPL(crypto_shash_finup);
 176
 177 static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
 178                                   unsigned int len, u8 *out)
 179 {
 180         return crypto_shash_init(desc) ?:
 181                crypto_shash_finup(desc, data, len, out);
 182 }
 183
 184 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
 185                         unsigned int len, u8 *out)
 186 {
 187         struct crypto_shash *tfm = desc->tfm;
 188         struct shash_alg *shash = crypto_shash_alg(tfm);
 189         unsigned long alignmask = crypto_shash_alignmask(tfm);
 190
 191         if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
 192                 return -ENOKEY;
 193
 194         if (((unsigned long)data | (unsigned long)out) & alignmask)
 195                 return shash_digest_unaligned(desc, data, len, out);
 196
 197         return shash->digest(desc, data, len, out);
 198 }
 199 EXPORT_SYMBOL_GPL(crypto_shash_digest);
 200
 201 static int shash_default_export(struct shash_desc *desc, void *out)
 202 {
 203         memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm));
 204         return 0;
 205 }
 206
 207 static int shash_default_import(struct shash_desc *desc, const void *in)
 208 {
 209         memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm));
 210         return 0;
 211 }
 212
 213 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 214                               unsigned int keylen)
 215 {
 216         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
 217
 218         return crypto_shash_setkey(*ctx, key, keylen);
 219 }
 220
 221 static int shash_async_init(struct ahash_request *req)
 222 {
 223         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 224         struct shash_desc *desc = ahash_request_ctx(req);
 225
 226         desc->tfm = *ctx;
 227         desc->flags = req->base.flags;
 228
 229         return crypto_shash_init(desc);
 230 }
 231
 232 int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
 233 {
 234         struct crypto_hash_walk walk;
 235         int nbytes;
 236
 237         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
 238              nbytes = crypto_hash_walk_done(&walk, nbytes))
 239                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 240
 241         return nbytes;
 242 }
 243 EXPORT_SYMBOL_GPL(shash_ahash_update);
 244
 245 static int shash_async_update(struct ahash_request *req)
 246 {
 247         return shash_ahash_update(req, ahash_request_ctx(req));
 248 }
 249
 250 static int shash_async_final(struct ahash_request *req)
 251 {
 252         return crypto_shash_final(ahash_request_ctx(req), req->result);
 253 }
 254
 255 int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
 256 {
 257         struct crypto_hash_walk walk;
 258         int nbytes;
 259
 260         nbytes = crypto_hash_walk_first(req, &walk);
 261         if (!nbytes)
 262                 return crypto_shash_final(desc, req->result);
 263
 264         do {
 265                 nbytes = crypto_hash_walk_last(&walk) ?
 266                          crypto_shash_finup(desc, walk.data, nbytes,
 267                                             req->result) :
 268                          crypto_shash_update(desc, walk.data, nbytes);
 269                 nbytes = crypto_hash_walk_done(&walk, nbytes);
 270         } while (nbytes > 0);
 271
 272         return nbytes;
 273 }
 274 EXPORT_SYMBOL_GPL(shash_ahash_finup);
 275
 276 static int shash_async_finup(struct ahash_request *req)
 277 {
 278         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 279         struct shash_desc *desc = ahash_request_ctx(req);
 280
 281         desc->tfm = *ctx;
 282         desc->flags = req->base.flags;
 283
 284         return shash_ahash_finup(req, desc);
 285 }
 286
 287 int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
 288 {
 289         unsigned int nbytes = req->nbytes;
 290         struct scatterlist *sg;
 291         unsigned int offset;
 292         int err;
 293
 294         if (nbytes &&
 295             (sg = req->src, offset = sg->offset,
 296              nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset))) {
 297                 void *data;
 298
 299                 data = kmap_atomic(sg_page(sg));
 300                 err = crypto_shash_digest(desc, data + offset, nbytes,
 301                                           req->result);
 302                 kunmap_atomic(data);
 303                 crypto_yield(desc->flags);
 304         } else
 305                 err = crypto_shash_init(desc) ?:
 306                       shash_ahash_finup(req, desc);
 307
 308         return err;
 309 }
 310 EXPORT_SYMBOL_GPL(shash_ahash_digest);
 311
 312 static int shash_async_digest(struct ahash_request *req)
 313 {
 314         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 315         struct shash_desc *desc = ahash_request_ctx(req);
 316
 317         desc->tfm = *ctx;
 318         desc->flags = req->base.flags;
 319
 320         return shash_ahash_digest(req, desc);
 321 }
 322
 323 static int shash_async_export(struct ahash_request *req, void *out)
 324 {
 325         return crypto_shash_export(ahash_request_ctx(req), out);
 326 }
 327
 328 static int shash_async_import(struct ahash_request *req, const void *in)
 329 {
 330         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 331         struct shash_desc *desc = ahash_request_ctx(req);
 332
 333         desc->tfm = *ctx;
 334         desc->flags = req->base.flags;
 335
 336         return crypto_shash_import(desc, in);
 337 }
 338
 339 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 340 {
 341         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 342
 343         crypto_free_shash(*ctx);
 344 }
 345
 346 int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 347 {
 348         struct crypto_alg *calg = tfm->__crt_alg;
 349         struct shash_alg *alg = __crypto_shash_alg(calg);
 350         struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
 351         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 352         struct crypto_shash *shash;
 353
 354         if (!crypto_mod_get(calg))
 355                 return -EAGAIN;
 356
 357         shash = crypto_create_tfm(calg, &crypto_shash_type);
 358         if (IS_ERR(shash)) {
 359                 crypto_mod_put(calg);
 360                 return PTR_ERR(shash);
 361         }
 362
 363         *ctx = shash;
 364         tfm->exit = crypto_exit_shash_ops_async;
 365
 366         crt->init = shash_async_init;
 367         crt->update = shash_async_update;
 368         crt->final = shash_async_final;
 369         crt->finup = shash_async_finup;
 370         crt->digest = shash_async_digest;
 371         crt->setkey = shash_async_setkey;
 372
 373         crypto_ahash_set_flags(crt, crypto_shash_get_flags(shash) &
 374                                     CRYPTO_TFM_NEED_KEY);
 375
 376         if (alg->export)
 377                 crt->export = shash_async_export;
 378         if (alg->import)
 379                 crt->import = shash_async_import;
 380
 381         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 382
 383         return 0;
 384 }
 385
 386 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
 387 {
 388         struct crypto_shash *hash = __crypto_shash_cast(tfm);
 389         struct shash_alg *alg = crypto_shash_alg(hash);
 390
 391         hash->descsize = alg->descsize;
 392
 393         if (crypto_shash_alg_has_setkey(alg) &&
 394             !(alg->base.cra_flags & CRYPTO_ALG_OPTIONAL_KEY))
 395                 crypto_shash_set_flags(hash, CRYPTO_TFM_NEED_KEY);
 396
 397         return 0;
 398 }
 399
 400 #ifdef CONFIG_NET
 401 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 402 {
 403         struct crypto_report_hash rhash;
 404         struct shash_alg *salg = __crypto_shash_alg(alg);
 405
 406         strncpy(rhash.type, "shash", sizeof(rhash.type));
 407
 408         rhash.blocksize = alg->cra_blocksize;
 409         rhash.digestsize = salg->digestsize;
 410
 411         if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
 412                     sizeof(struct crypto_report_hash), &rhash))
 413                 goto nla_put_failure;
 414         return 0;
 415
 416 nla_put_failure:
 417         return -EMSGSIZE;
 418 }
 419 #else
 420 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 421 {
 422         return -ENOSYS;
 423 }
 424 #endif
 425
 426 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 427         __maybe_unused;
 428 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 429 {
 430         struct shash_alg *salg = __crypto_shash_alg(alg);
 431
 432         seq_printf(m, "type         : shash\n");
 433         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 434         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 435 }
 436
 437 static const struct crypto_type crypto_shash_type = {
 438         .extsize = crypto_alg_extsize,
 439         .init_tfm = crypto_shash_init_tfm,
 440 #ifdef CONFIG_PROC_FS
 441         .show = crypto_shash_show,
 442 #endif
 443         .report = crypto_shash_report,
 444         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 445         .maskset = CRYPTO_ALG_TYPE_MASK,
 446         .type = CRYPTO_ALG_TYPE_SHASH,
 447         .tfmsize = offsetof(struct crypto_shash, base),
 448 };
 449
 450 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 451                                         u32 mask)
 452 {
 453         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 454 }
 455 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 456
 457 static int shash_prepare_alg(struct shash_alg *alg)
 458 {
 459         struct crypto_alg *base = &alg->base;
 460
 461         if (alg->digestsize > PAGE_SIZE / 8 ||
 462             alg->descsize > PAGE_SIZE / 8 ||
 463             alg->statesize > PAGE_SIZE / 8)
 464                 return -EINVAL;
 465
 466         base->cra_type = &crypto_shash_type;
 467         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 468         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 469
 470         if (!alg->finup)
 471                 alg->finup = shash_finup_unaligned;
 472         if (!alg->digest)
 473                 alg->digest = shash_digest_unaligned;
 474         if (!alg->export) {
 475                 alg->export = shash_default_export;
 476                 alg->import = shash_default_import;
 477                 alg->statesize = alg->descsize;
 478         }
 479         if (!alg->setkey)
 480                 alg->setkey = shash_no_setkey;
 481
 482         return 0;
 483 }
 484
 485 int crypto_register_shash(struct shash_alg *alg)
 486 {
 487         struct crypto_alg *base = &alg->base;
 488         int err;
 489
 490         err = shash_prepare_alg(alg);
 491         if (err)
 492                 return err;
 493
 494         return crypto_register_alg(base);
 495 }
 496 EXPORT_SYMBOL_GPL(crypto_register_shash);
 497
 498 int crypto_unregister_shash(struct shash_alg *alg)
 499 {
 500         return crypto_unregister_alg(&alg->base);
 501 }
 502 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 503
 504 int crypto_register_shashes(struct shash_alg *algs, int count)
 505 {
 506         int i, ret;
 507
 508         for (i = 0; i < count; i++) {
 509                 ret = crypto_register_shash(&algs[i]);
 510                 if (ret)
 511                         goto err;
 512         }
 513
 514         return 0;
 515
 516 err:
 517         for (--i; i >= 0; --i)
 518                 crypto_unregister_shash(&algs[i]);
 519
 520         return ret;
 521 }
 522 EXPORT_SYMBOL_GPL(crypto_register_shashes);
 523
 524 int crypto_unregister_shashes(struct shash_alg *algs, int count)
 525 {
 526         int i, ret;
 527
 528         for (i = count - 1; i >= 0; --i) {
 529                 ret = crypto_unregister_shash(&algs[i]);
 530                 if (ret)
 531                         pr_err("Failed to unregister %s %s: %d\n",
 532                                algs[i].base.cra_driver_name,
 533                                algs[i].base.cra_name, ret);
 534         }
 535
 536         return 0;
 537 }
 538 EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
 539
 540 int shash_register_instance(struct crypto_template *tmpl,
 541                             struct shash_instance *inst)
 542 {
 543         int err;
 544
 545         err = shash_prepare_alg(&inst->alg);
 546         if (err)
 547                 return err;
 548
 549         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 550 }
 551 EXPORT_SYMBOL_GPL(shash_register_instance);
 552
 553 void shash_free_instance(struct crypto_instance *inst)
 554 {
 555         crypto_drop_spawn(crypto_instance_ctx(inst));
 556         kfree(shash_instance(inst));
 557 }
 558 EXPORT_SYMBOL_GPL(shash_free_instance);
 559
 560 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
 561                             struct shash_alg *alg,
 562                             struct crypto_instance *inst)
 563 {
 564         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 565                                   &crypto_shash_type);
 566 }
 567 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
 568
 569 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 570 {
 571         struct crypto_alg *alg;
 572
 573         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
 574         return IS_ERR(alg) ? ERR_CAST(alg) :
 575                container_of(alg, struct shash_alg, base);
 576 }
 577 EXPORT_SYMBOL_GPL(shash_attr_alg);
 578
 579 MODULE_LICENSE("GPL");
 580 MODULE_DESCRIPTION("Synchronous cryptographic hash type");