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
  62         if ((unsigned long)key & alignmask)
  63                 return shash_setkey_unaligned(tfm, key, keylen);
  64
  65         return shash->setkey(tfm, key, keylen);
  66 }
  67 EXPORT_SYMBOL_GPL(crypto_shash_setkey);
  68
  69 static inline unsigned int shash_align_buffer_size(unsigned len,
  70                                                    unsigned long mask)
  71 {
  72         typedef u8 __aligned_largest u8_aligned;
  73         return len + (mask & ~(__alignof__(u8_aligned) - 1));
  74 }
  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         u8 ubuf[shash_align_buffer_size(unaligned_len, alignmask)]
  85                 __aligned_largest;
  86         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
  87         int err;
  88
  89         if (unaligned_len > len)
  90                 unaligned_len = len;
  91
  92         memcpy(buf, data, unaligned_len);
  93         err = shash->update(desc, buf, unaligned_len);
  94         memset(buf, 0, unaligned_len);
  95
  96         return err ?:
  97                shash->update(desc, data + unaligned_len, len - unaligned_len);
  98 }
  99
 100 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
 101                         unsigned int len)
 102 {
 103         struct crypto_shash *tfm = desc->tfm;
 104         struct shash_alg *shash = crypto_shash_alg(tfm);
 105         unsigned long alignmask = crypto_shash_alignmask(tfm);
 106
 107         if ((unsigned long)data & alignmask)
 108                 return shash_update_unaligned(desc, data, len);
 109
 110         return shash->update(desc, data, len);
 111 }
 112 EXPORT_SYMBOL_GPL(crypto_shash_update);
 113
 114 static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
 115 {
 116         struct crypto_shash *tfm = desc->tfm;
 117         unsigned long alignmask = crypto_shash_alignmask(tfm);
 118         struct shash_alg *shash = crypto_shash_alg(tfm);
 119         unsigned int ds = crypto_shash_digestsize(tfm);
 120         u8 ubuf[shash_align_buffer_size(ds, alignmask)]
 121                 __aligned_largest;
 122         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
 123         int err;
 124
 125         err = shash->final(desc, buf);
 126         if (err)
 127                 goto out;
 128
 129         memcpy(out, buf, ds);
 130
 131 out:
 132         memset(buf, 0, ds);
 133         return err;
 134 }
 135
 136 int crypto_shash_final(struct shash_desc *desc, u8 *out)
 137 {
 138         struct crypto_shash *tfm = desc->tfm;
 139         struct shash_alg *shash = crypto_shash_alg(tfm);
 140         unsigned long alignmask = crypto_shash_alignmask(tfm);
 141
 142         if ((unsigned long)out & alignmask)
 143                 return shash_final_unaligned(desc, out);
 144
 145         return shash->final(desc, out);
 146 }
 147 EXPORT_SYMBOL_GPL(crypto_shash_final);
 148
 149 static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
 150                                  unsigned int len, u8 *out)
 151 {
 152         return crypto_shash_update(desc, data, len) ?:
 153                crypto_shash_final(desc, out);
 154 }
 155
 156 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
 157                        unsigned int len, 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)data | (unsigned long)out) & alignmask)
 164                 return shash_finup_unaligned(desc, data, len, out);
 165
 166         return shash->finup(desc, data, len, out);
 167 }
 168 EXPORT_SYMBOL_GPL(crypto_shash_finup);
 169
 170 static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
 171                                   unsigned int len, u8 *out)
 172 {
 173         return crypto_shash_init(desc) ?:
 174                crypto_shash_finup(desc, data, len, out);
 175 }
 176
 177 int crypto_shash_digest(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_digest_unaligned(desc, data, len, out);
 186
 187         return shash->digest(desc, data, len, out);
 188 }
 189 EXPORT_SYMBOL_GPL(crypto_shash_digest);
 190
 191 static int shash_default_export(struct shash_desc *desc, void *out)
 192 {
 193         memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm));
 194         return 0;
 195 }
 196
 197 static int shash_default_import(struct shash_desc *desc, const void *in)
 198 {
 199         memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm));
 200         return 0;
 201 }
 202
 203 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 204                               unsigned int keylen)
 205 {
 206         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
 207
 208         return crypto_shash_setkey(*ctx, key, keylen);
 209 }
 210
 211 static int shash_async_init(struct ahash_request *req)
 212 {
 213         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 214         struct shash_desc *desc = ahash_request_ctx(req);
 215
 216         desc->tfm = *ctx;
 217         desc->flags = req->base.flags;
 218
 219         return crypto_shash_init(desc);
 220 }
 221
 222 int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
 223 {
 224         struct crypto_hash_walk walk;
 225         int nbytes;
 226
 227         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
 228              nbytes = crypto_hash_walk_done(&walk, nbytes))
 229                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 230
 231         return nbytes;
 232 }
 233 EXPORT_SYMBOL_GPL(shash_ahash_update);
 234
 235 static int shash_async_update(struct ahash_request *req)
 236 {
 237         return shash_ahash_update(req, ahash_request_ctx(req));
 238 }
 239
 240 static int shash_async_final(struct ahash_request *req)
 241 {
 242         return crypto_shash_final(ahash_request_ctx(req), req->result);
 243 }
 244
 245 int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
 246 {
 247         struct crypto_hash_walk walk;
 248         int nbytes;
 249
 250         nbytes = crypto_hash_walk_first(req, &walk);
 251         if (!nbytes)
 252                 return crypto_shash_final(desc, req->result);
 253
 254         do {
 255                 nbytes = crypto_hash_walk_last(&walk) ?
 256                          crypto_shash_finup(desc, walk.data, nbytes,
 257                                             req->result) :
 258                          crypto_shash_update(desc, walk.data, nbytes);
 259                 nbytes = crypto_hash_walk_done(&walk, nbytes);
 260         } while (nbytes > 0);
 261
 262         return nbytes;
 263 }
 264 EXPORT_SYMBOL_GPL(shash_ahash_finup);
 265
 266 static int shash_async_finup(struct ahash_request *req)
 267 {
 268         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 269         struct shash_desc *desc = ahash_request_ctx(req);
 270
 271         desc->tfm = *ctx;
 272         desc->flags = req->base.flags;
 273
 274         return shash_ahash_finup(req, desc);
 275 }
 276
 277 int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
 278 {
 279         unsigned int nbytes = req->nbytes;
 280         struct scatterlist *sg;
 281         unsigned int offset;
 282         int err;
 283
 284         if (nbytes &&
 285             (sg = req->src, offset = sg->offset,
 286              nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset))) {
 287                 void *data;
 288
 289                 data = kmap_atomic(sg_page(sg));
 290                 err = crypto_shash_digest(desc, data + offset, nbytes,
 291                                           req->result);
 292                 kunmap_atomic(data);
 293                 crypto_yield(desc->flags);
 294         } else
 295                 err = crypto_shash_init(desc) ?:
 296                       shash_ahash_finup(req, desc);
 297
 298         return err;
 299 }
 300 EXPORT_SYMBOL_GPL(shash_ahash_digest);
 301
 302 static int shash_async_digest(struct ahash_request *req)
 303 {
 304         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 305         struct shash_desc *desc = ahash_request_ctx(req);
 306
 307         desc->tfm = *ctx;
 308         desc->flags = req->base.flags;
 309
 310         return shash_ahash_digest(req, desc);
 311 }
 312
 313 static int shash_async_export(struct ahash_request *req, void *out)
 314 {
 315         return crypto_shash_export(ahash_request_ctx(req), out);
 316 }
 317
 318 static int shash_async_import(struct ahash_request *req, const void *in)
 319 {
 320         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 321         struct shash_desc *desc = ahash_request_ctx(req);
 322
 323         desc->tfm = *ctx;
 324         desc->flags = req->base.flags;
 325
 326         return crypto_shash_import(desc, in);
 327 }
 328
 329 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 330 {
 331         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 332
 333         crypto_free_shash(*ctx);
 334 }
 335
 336 int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 337 {
 338         struct crypto_alg *calg = tfm->__crt_alg;
 339         struct shash_alg *alg = __crypto_shash_alg(calg);
 340         struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
 341         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 342         struct crypto_shash *shash;
 343
 344         if (!crypto_mod_get(calg))
 345                 return -EAGAIN;
 346
 347         shash = crypto_create_tfm(calg, &crypto_shash_type);
 348         if (IS_ERR(shash)) {
 349                 crypto_mod_put(calg);
 350                 return PTR_ERR(shash);
 351         }
 352
 353         *ctx = shash;
 354         tfm->exit = crypto_exit_shash_ops_async;
 355
 356         crt->init = shash_async_init;
 357         crt->update = shash_async_update;
 358         crt->final = shash_async_final;
 359         crt->finup = shash_async_finup;
 360         crt->digest = shash_async_digest;
 361         crt->setkey = shash_async_setkey;
 362
 363         crt->has_setkey = alg->setkey != shash_no_setkey;
 364
 365         if (alg->export)
 366                 crt->export = shash_async_export;
 367         if (alg->import)
 368                 crt->import = shash_async_import;
 369
 370         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 371
 372         return 0;
 373 }
 374
 375 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
 376 {
 377         struct crypto_shash *hash = __crypto_shash_cast(tfm);
 378
 379         hash->descsize = crypto_shash_alg(hash)->descsize;
 380         return 0;
 381 }
 382
 383 #ifdef CONFIG_NET
 384 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 385 {
 386         struct crypto_report_hash rhash;
 387         struct shash_alg *salg = __crypto_shash_alg(alg);
 388
 389         strncpy(rhash.type, "shash", sizeof(rhash.type));
 390
 391         rhash.blocksize = alg->cra_blocksize;
 392         rhash.digestsize = salg->digestsize;
 393
 394         if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
 395                     sizeof(struct crypto_report_hash), &rhash))
 396                 goto nla_put_failure;
 397         return 0;
 398
 399 nla_put_failure:
 400         return -EMSGSIZE;
 401 }
 402 #else
 403 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 404 {
 405         return -ENOSYS;
 406 }
 407 #endif
 408
 409 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 410         __maybe_unused;
 411 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 412 {
 413         struct shash_alg *salg = __crypto_shash_alg(alg);
 414
 415         seq_printf(m, "type         : shash\n");
 416         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 417         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 418 }
 419
 420 static const struct crypto_type crypto_shash_type = {
 421         .extsize = crypto_alg_extsize,
 422         .init_tfm = crypto_shash_init_tfm,
 423 #ifdef CONFIG_PROC_FS
 424         .show = crypto_shash_show,
 425 #endif
 426         .report = crypto_shash_report,
 427         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 428         .maskset = CRYPTO_ALG_TYPE_MASK,
 429         .type = CRYPTO_ALG_TYPE_SHASH,
 430         .tfmsize = offsetof(struct crypto_shash, base),
 431 };
 432
 433 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 434                                         u32 mask)
 435 {
 436         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 437 }
 438 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 439
 440 static int shash_prepare_alg(struct shash_alg *alg)
 441 {
 442         struct crypto_alg *base = &alg->base;
 443
 444         if (alg->digestsize > PAGE_SIZE / 8 ||
 445             alg->descsize > PAGE_SIZE / 8 ||
 446             alg->statesize > PAGE_SIZE / 8)
 447                 return -EINVAL;
 448
 449         base->cra_type = &crypto_shash_type;
 450         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 451         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 452
 453         if (!alg->finup)
 454                 alg->finup = shash_finup_unaligned;
 455         if (!alg->digest)
 456                 alg->digest = shash_digest_unaligned;
 457         if (!alg->export) {
 458                 alg->export = shash_default_export;
 459                 alg->import = shash_default_import;
 460                 alg->statesize = alg->descsize;
 461         }
 462         if (!alg->setkey)
 463                 alg->setkey = shash_no_setkey;
 464
 465         return 0;
 466 }
 467
 468 int crypto_register_shash(struct shash_alg *alg)
 469 {
 470         struct crypto_alg *base = &alg->base;
 471         int err;
 472
 473         err = shash_prepare_alg(alg);
 474         if (err)
 475                 return err;
 476
 477         return crypto_register_alg(base);
 478 }
 479 EXPORT_SYMBOL_GPL(crypto_register_shash);
 480
 481 int crypto_unregister_shash(struct shash_alg *alg)
 482 {
 483         return crypto_unregister_alg(&alg->base);
 484 }
 485 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 486
 487 int crypto_register_shashes(struct shash_alg *algs, int count)
 488 {
 489         int i, ret;
 490
 491         for (i = 0; i < count; i++) {
 492                 ret = crypto_register_shash(&algs[i]);
 493                 if (ret)
 494                         goto err;
 495         }
 496
 497         return 0;
 498
 499 err:
 500         for (--i; i >= 0; --i)
 501                 crypto_unregister_shash(&algs[i]);
 502
 503         return ret;
 504 }
 505 EXPORT_SYMBOL_GPL(crypto_register_shashes);
 506
 507 int crypto_unregister_shashes(struct shash_alg *algs, int count)
 508 {
 509         int i, ret;
 510
 511         for (i = count - 1; i >= 0; --i) {
 512                 ret = crypto_unregister_shash(&algs[i]);
 513                 if (ret)
 514                         pr_err("Failed to unregister %s %s: %d\n",
 515                                algs[i].base.cra_driver_name,
 516                                algs[i].base.cra_name, ret);
 517         }
 518
 519         return 0;
 520 }
 521 EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
 522
 523 int shash_register_instance(struct crypto_template *tmpl,
 524                             struct shash_instance *inst)
 525 {
 526         int err;
 527
 528         err = shash_prepare_alg(&inst->alg);
 529         if (err)
 530                 return err;
 531
 532         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 533 }
 534 EXPORT_SYMBOL_GPL(shash_register_instance);
 535
 536 void shash_free_instance(struct crypto_instance *inst)
 537 {
 538         crypto_drop_spawn(crypto_instance_ctx(inst));
 539         kfree(shash_instance(inst));
 540 }
 541 EXPORT_SYMBOL_GPL(shash_free_instance);
 542
 543 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
 544                             struct shash_alg *alg,
 545                             struct crypto_instance *inst)
 546 {
 547         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 548                                   &crypto_shash_type);
 549 }
 550 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
 551
 552 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 553 {
 554         struct crypto_alg *alg;
 555
 556         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
 557         return IS_ERR(alg) ? ERR_CAST(alg) :
 558                container_of(alg, struct shash_alg, base);
 559 }
 560 EXPORT_SYMBOL_GPL(shash_attr_alg);
 561
 562 MODULE_LICENSE("GPL");
 563 MODULE_DESCRIPTION("Synchronous cryptographic hash type");