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 static int shash_no_setkey(struct crypto_shash *tfm, const u8 *key,
  29                            unsigned int keylen)
  30 {
  31         return -ENOSYS;
  32 }
  33
  34 /*
  35  * Check whether an shash algorithm has a setkey function.
  36  *
  37  * For CFI compatibility, this must not be an inline function.  This is because
  38  * when CFI is enabled, modules won't get the same address for shash_no_setkey
  39  * (if it were exported, which inlining would require) as the core kernel will.
  40  */
  41 bool crypto_shash_alg_has_setkey(struct shash_alg *alg)
  42 {
  43         return alg->setkey != shash_no_setkey;
  44 }
  45 EXPORT_SYMBOL_GPL(crypto_shash_alg_has_setkey);
  46
  47 static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
  48                                   unsigned int keylen)
  49 {
  50         struct shash_alg *shash = crypto_shash_alg(tfm);
  51         unsigned long alignmask = crypto_shash_alignmask(tfm);
  52         unsigned long absize;
  53         u8 *buffer, *alignbuffer;
  54         int err;
  55
  56         absize = keylen + (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
  57         buffer = kmalloc(absize, GFP_ATOMIC);
  58         if (!buffer)
  59                 return -ENOMEM;
  60
  61         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  62         memcpy(alignbuffer, key, keylen);
  63         err = shash->setkey(tfm, alignbuffer, keylen);
  64         kzfree(buffer);
  65         return err;
  66 }
  67
  68 static void shash_set_needkey(struct crypto_shash *tfm, struct shash_alg *alg)
  69 {
  70         if (crypto_shash_alg_has_setkey(alg) &&
  71             !(alg->base.cra_flags & CRYPTO_ALG_OPTIONAL_KEY))
  72                 crypto_shash_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
  73 }
  74
  75 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
  76                         unsigned int keylen)
  77 {
  78         struct shash_alg *shash = crypto_shash_alg(tfm);
  79         unsigned long alignmask = crypto_shash_alignmask(tfm);
  80         int err;
  81
  82         if ((unsigned long)key & alignmask)
  83                 err = shash_setkey_unaligned(tfm, key, keylen);
  84         else
  85                 err = shash->setkey(tfm, key, keylen);
  86
  87         if (unlikely(err)) {
  88                 shash_set_needkey(tfm, shash);
  89                 return err;
  90         }
  91
  92         crypto_shash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
  93         return 0;
  94 }
  95 EXPORT_SYMBOL_GPL(crypto_shash_setkey);
  96
  97 static inline unsigned int shash_align_buffer_size(unsigned len,
  98                                                    unsigned long mask)
  99 {
 100         typedef u8 __aligned_largest u8_aligned;
 101         return len + (mask & ~(__alignof__(u8_aligned) - 1));
 102 }
 103
 104 static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
 105                                   unsigned int len)
 106 {
 107         struct crypto_shash *tfm = desc->tfm;
 108         struct shash_alg *shash = crypto_shash_alg(tfm);
 109         unsigned long alignmask = crypto_shash_alignmask(tfm);
 110         unsigned int unaligned_len = alignmask + 1 -
 111                                      ((unsigned long)data & alignmask);
 112         u8 ubuf[shash_align_buffer_size(unaligned_len, alignmask)]
 113                 __aligned_largest;
 114         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
 115         int err;
 116
 117         if (unaligned_len > len)
 118                 unaligned_len = len;
 119
 120         memcpy(buf, data, unaligned_len);
 121         err = shash->update(desc, buf, unaligned_len);
 122         memset(buf, 0, unaligned_len);
 123
 124         return err ?:
 125                shash->update(desc, data + unaligned_len, len - unaligned_len);
 126 }
 127
 128 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
 129                         unsigned int len)
 130 {
 131         struct crypto_shash *tfm = desc->tfm;
 132         struct shash_alg *shash = crypto_shash_alg(tfm);
 133         unsigned long alignmask = crypto_shash_alignmask(tfm);
 134
 135         if ((unsigned long)data & alignmask)
 136                 return shash_update_unaligned(desc, data, len);
 137
 138         return shash->update(desc, data, len);
 139 }
 140 EXPORT_SYMBOL_GPL(crypto_shash_update);
 141
 142 static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
 143 {
 144         struct crypto_shash *tfm = desc->tfm;
 145         unsigned long alignmask = crypto_shash_alignmask(tfm);
 146         struct shash_alg *shash = crypto_shash_alg(tfm);
 147         unsigned int ds = crypto_shash_digestsize(tfm);
 148         u8 ubuf[shash_align_buffer_size(ds, alignmask)]
 149                 __aligned_largest;
 150         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
 151         int err;
 152
 153         err = shash->final(desc, buf);
 154         if (err)
 155                 goto out;
 156
 157         memcpy(out, buf, ds);
 158
 159 out:
 160         memset(buf, 0, ds);
 161         return err;
 162 }
 163
 164 int crypto_shash_final(struct shash_desc *desc, 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)out & alignmask)
 171                 return shash_final_unaligned(desc, out);
 172
 173         return shash->final(desc, out);
 174 }
 175 EXPORT_SYMBOL_GPL(crypto_shash_final);
 176
 177 static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
 178                                  unsigned int len, u8 *out)
 179 {
 180         return crypto_shash_update(desc, data, len) ?:
 181                crypto_shash_final(desc, out);
 182 }
 183
 184 int crypto_shash_finup(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 (((unsigned long)data | (unsigned long)out) & alignmask)
 192                 return shash_finup_unaligned(desc, data, len, out);
 193
 194         return shash->finup(desc, data, len, out);
 195 }
 196 EXPORT_SYMBOL_GPL(crypto_shash_finup);
 197
 198 static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
 199                                   unsigned int len, u8 *out)
 200 {
 201         return crypto_shash_init(desc) ?:
 202                crypto_shash_finup(desc, data, len, out);
 203 }
 204
 205 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
 206                         unsigned int len, u8 *out)
 207 {
 208         struct crypto_shash *tfm = desc->tfm;
 209         struct shash_alg *shash = crypto_shash_alg(tfm);
 210         unsigned long alignmask = crypto_shash_alignmask(tfm);
 211
 212         if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
 213                 return -ENOKEY;
 214
 215         if (((unsigned long)data | (unsigned long)out) & alignmask)
 216                 return shash_digest_unaligned(desc, data, len, out);
 217
 218         return shash->digest(desc, data, len, out);
 219 }
 220 EXPORT_SYMBOL_GPL(crypto_shash_digest);
 221
 222 static int shash_default_export(struct shash_desc *desc, void *out)
 223 {
 224         memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm));
 225         return 0;
 226 }
 227
 228 static int shash_default_import(struct shash_desc *desc, const void *in)
 229 {
 230         memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm));
 231         return 0;
 232 }
 233
 234 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 235                               unsigned int keylen)
 236 {
 237         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
 238
 239         return crypto_shash_setkey(*ctx, key, keylen);
 240 }
 241
 242 static int shash_async_init(struct ahash_request *req)
 243 {
 244         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 245         struct shash_desc *desc = ahash_request_ctx(req);
 246
 247         desc->tfm = *ctx;
 248         desc->flags = req->base.flags;
 249
 250         return crypto_shash_init(desc);
 251 }
 252
 253 int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
 254 {
 255         struct crypto_hash_walk walk;
 256         int nbytes;
 257
 258         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
 259              nbytes = crypto_hash_walk_done(&walk, nbytes))
 260                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 261
 262         return nbytes;
 263 }
 264 EXPORT_SYMBOL_GPL(shash_ahash_update);
 265
 266 static int shash_async_update(struct ahash_request *req)
 267 {
 268         return shash_ahash_update(req, ahash_request_ctx(req));
 269 }
 270
 271 static int shash_async_final(struct ahash_request *req)
 272 {
 273         return crypto_shash_final(ahash_request_ctx(req), req->result);
 274 }
 275
 276 int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
 277 {
 278         struct crypto_hash_walk walk;
 279         int nbytes;
 280
 281         nbytes = crypto_hash_walk_first(req, &walk);
 282         if (!nbytes)
 283                 return crypto_shash_final(desc, req->result);
 284
 285         do {
 286                 nbytes = crypto_hash_walk_last(&walk) ?
 287                          crypto_shash_finup(desc, walk.data, nbytes,
 288                                             req->result) :
 289                          crypto_shash_update(desc, walk.data, nbytes);
 290                 nbytes = crypto_hash_walk_done(&walk, nbytes);
 291         } while (nbytes > 0);
 292
 293         return nbytes;
 294 }
 295 EXPORT_SYMBOL_GPL(shash_ahash_finup);
 296
 297 static int shash_async_finup(struct ahash_request *req)
 298 {
 299         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 300         struct shash_desc *desc = ahash_request_ctx(req);
 301
 302         desc->tfm = *ctx;
 303         desc->flags = req->base.flags;
 304
 305         return shash_ahash_finup(req, desc);
 306 }
 307
 308 int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
 309 {
 310         unsigned int nbytes = req->nbytes;
 311         struct scatterlist *sg;
 312         unsigned int offset;
 313         int err;
 314
 315         if (nbytes &&
 316             (sg = req->src, offset = sg->offset,
 317              nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset))) {
 318                 void *data;
 319
 320                 data = kmap_atomic(sg_page(sg));
 321                 err = crypto_shash_digest(desc, data + offset, nbytes,
 322                                           req->result);
 323                 kunmap_atomic(data);
 324                 crypto_yield(desc->flags);
 325         } else
 326                 err = crypto_shash_init(desc) ?:
 327                       shash_ahash_finup(req, desc);
 328
 329         return err;
 330 }
 331 EXPORT_SYMBOL_GPL(shash_ahash_digest);
 332
 333 static int shash_async_digest(struct ahash_request *req)
 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 shash_ahash_digest(req, desc);
 342 }
 343
 344 static int shash_async_export(struct ahash_request *req, void *out)
 345 {
 346         return crypto_shash_export(ahash_request_ctx(req), out);
 347 }
 348
 349 static int shash_async_import(struct ahash_request *req, const void *in)
 350 {
 351         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 352         struct shash_desc *desc = ahash_request_ctx(req);
 353
 354         desc->tfm = *ctx;
 355         desc->flags = req->base.flags;
 356
 357         return crypto_shash_import(desc, in);
 358 }
 359
 360 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 361 {
 362         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 363
 364         crypto_free_shash(*ctx);
 365 }
 366
 367 int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 368 {
 369         struct crypto_alg *calg = tfm->__crt_alg;
 370         struct shash_alg *alg = __crypto_shash_alg(calg);
 371         struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
 372         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 373         struct crypto_shash *shash;
 374
 375         if (!crypto_mod_get(calg))
 376                 return -EAGAIN;
 377
 378         shash = crypto_create_tfm(calg, &crypto_shash_type);
 379         if (IS_ERR(shash)) {
 380                 crypto_mod_put(calg);
 381                 return PTR_ERR(shash);
 382         }
 383
 384         *ctx = shash;
 385         tfm->exit = crypto_exit_shash_ops_async;
 386
 387         crt->init = shash_async_init;
 388         crt->update = shash_async_update;
 389         crt->final = shash_async_final;
 390         crt->finup = shash_async_finup;
 391         crt->digest = shash_async_digest;
 392         if (crypto_shash_alg_has_setkey(alg))
 393                 crt->setkey = shash_async_setkey;
 394
 395         crypto_ahash_set_flags(crt, crypto_shash_get_flags(shash) &
 396                                     CRYPTO_TFM_NEED_KEY);
 397
 398         if (alg->export)
 399                 crt->export = shash_async_export;
 400         if (alg->import)
 401                 crt->import = shash_async_import;
 402
 403         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 404
 405         return 0;
 406 }
 407
 408 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
 409 {
 410         struct crypto_shash *hash = __crypto_shash_cast(tfm);
 411         struct shash_alg *alg = crypto_shash_alg(hash);
 412
 413         hash->descsize = alg->descsize;
 414
 415         shash_set_needkey(hash, alg);
 416
 417         return 0;
 418 }
 419
 420 #ifdef CONFIG_NET
 421 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 422 {
 423         struct crypto_report_hash rhash;
 424         struct shash_alg *salg = __crypto_shash_alg(alg);
 425
 426         strncpy(rhash.type, "shash", sizeof(rhash.type));
 427
 428         rhash.blocksize = alg->cra_blocksize;
 429         rhash.digestsize = salg->digestsize;
 430
 431         if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
 432                     sizeof(struct crypto_report_hash), &rhash))
 433                 goto nla_put_failure;
 434         return 0;
 435
 436 nla_put_failure:
 437         return -EMSGSIZE;
 438 }
 439 #else
 440 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 441 {
 442         return -ENOSYS;
 443 }
 444 #endif
 445
 446 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 447         __maybe_unused;
 448 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 449 {
 450         struct shash_alg *salg = __crypto_shash_alg(alg);
 451
 452         seq_printf(m, "type         : shash\n");
 453         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 454         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 455 }
 456
 457 static const struct crypto_type crypto_shash_type = {
 458         .extsize = crypto_alg_extsize,
 459         .init_tfm = crypto_shash_init_tfm,
 460 #ifdef CONFIG_PROC_FS
 461         .show = crypto_shash_show,
 462 #endif
 463         .report = crypto_shash_report,
 464         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 465         .maskset = CRYPTO_ALG_TYPE_MASK,
 466         .type = CRYPTO_ALG_TYPE_SHASH,
 467         .tfmsize = offsetof(struct crypto_shash, base),
 468 };
 469
 470 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 471                                         u32 mask)
 472 {
 473         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 474 }
 475 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 476
 477 static int shash_prepare_alg(struct shash_alg *alg)
 478 {
 479         struct crypto_alg *base = &alg->base;
 480
 481         if (alg->digestsize > PAGE_SIZE / 8 ||
 482             alg->descsize > PAGE_SIZE / 8 ||
 483             alg->statesize > PAGE_SIZE / 8)
 484                 return -EINVAL;
 485
 486         base->cra_type = &crypto_shash_type;
 487         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 488         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 489
 490         if (!alg->finup)
 491                 alg->finup = shash_finup_unaligned;
 492         if (!alg->digest)
 493                 alg->digest = shash_digest_unaligned;
 494         if (!alg->export) {
 495                 alg->export = shash_default_export;
 496                 alg->import = shash_default_import;
 497                 alg->statesize = alg->descsize;
 498         }
 499         if (!alg->setkey)
 500                 alg->setkey = shash_no_setkey;
 501
 502         return 0;
 503 }
 504
 505 int crypto_register_shash(struct shash_alg *alg)
 506 {
 507         struct crypto_alg *base = &alg->base;
 508         int err;
 509
 510         err = shash_prepare_alg(alg);
 511         if (err)
 512                 return err;
 513
 514         return crypto_register_alg(base);
 515 }
 516 EXPORT_SYMBOL_GPL(crypto_register_shash);
 517
 518 int crypto_unregister_shash(struct shash_alg *alg)
 519 {
 520         return crypto_unregister_alg(&alg->base);
 521 }
 522 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 523
 524 int crypto_register_shashes(struct shash_alg *algs, int count)
 525 {
 526         int i, ret;
 527
 528         for (i = 0; i < count; i++) {
 529                 ret = crypto_register_shash(&algs[i]);
 530                 if (ret)
 531                         goto err;
 532         }
 533
 534         return 0;
 535
 536 err:
 537         for (--i; i >= 0; --i)
 538                 crypto_unregister_shash(&algs[i]);
 539
 540         return ret;
 541 }
 542 EXPORT_SYMBOL_GPL(crypto_register_shashes);
 543
 544 int crypto_unregister_shashes(struct shash_alg *algs, int count)
 545 {
 546         int i, ret;
 547
 548         for (i = count - 1; i >= 0; --i) {
 549                 ret = crypto_unregister_shash(&algs[i]);
 550                 if (ret)
 551                         pr_err("Failed to unregister %s %s: %d\n",
 552                                algs[i].base.cra_driver_name,
 553                                algs[i].base.cra_name, ret);
 554         }
 555
 556         return 0;
 557 }
 558 EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
 559
 560 int shash_register_instance(struct crypto_template *tmpl,
 561                             struct shash_instance *inst)
 562 {
 563         int err;
 564
 565         err = shash_prepare_alg(&inst->alg);
 566         if (err)
 567                 return err;
 568
 569         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 570 }
 571 EXPORT_SYMBOL_GPL(shash_register_instance);
 572
 573 void shash_free_instance(struct crypto_instance *inst)
 574 {
 575         crypto_drop_spawn(crypto_instance_ctx(inst));
 576         kfree(shash_instance(inst));
 577 }
 578 EXPORT_SYMBOL_GPL(shash_free_instance);
 579
 580 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
 581                             struct shash_alg *alg,
 582                             struct crypto_instance *inst)
 583 {
 584         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 585                                   &crypto_shash_type);
 586 }
 587 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
 588
 589 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 590 {
 591         struct crypto_alg *alg;
 592
 593         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
 594         return IS_ERR(alg) ? ERR_CAST(alg) :
 595                container_of(alg, struct shash_alg, base);
 596 }
 597 EXPORT_SYMBOL_GPL(shash_attr_alg);
 598
 599 MODULE_LICENSE("GPL");
 600 MODULE_DESCRIPTION("Synchronous cryptographic hash type");