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
  23 #include "internal.h"
  24
  25 static const struct crypto_type crypto_shash_type;
  26
  27 static int shash_no_setkey(struct crypto_shash *tfm, const u8 *key,
  28                            unsigned int keylen)
  29 {
  30         return -ENOSYS;
  31 }
  32
  33 /*
  34  * Check whether an shash algorithm has a setkey function.
  35  *
  36  * For CFI compatibility, this must not be an inline function.  This is because
  37  * when CFI is enabled, modules won't get the same address for shash_no_setkey
  38  * (if it were exported, which inlining would require) as the core kernel will.
  39  */
  40 bool crypto_shash_alg_has_setkey(struct shash_alg *alg)
  41 {
  42         return alg->setkey != shash_no_setkey;
  43 }
  44 EXPORT_SYMBOL_GPL(crypto_shash_alg_has_setkey);
  45
  46 static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
  47                                   unsigned int keylen)
  48 {
  49         struct shash_alg *shash = crypto_shash_alg(tfm);
  50         unsigned long alignmask = crypto_shash_alignmask(tfm);
  51         unsigned long absize;
  52         u8 *buffer, *alignbuffer;
  53         int err;
  54
  55         absize = keylen + (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
  56         buffer = kmalloc(absize, GFP_ATOMIC);
  57         if (!buffer)
  58                 return -ENOMEM;
  59
  60         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  61         memcpy(alignbuffer, key, keylen);
  62         err = shash->setkey(tfm, alignbuffer, keylen);
  63         kzfree(buffer);
  64         return err;
  65 }
  66
  67 static void shash_set_needkey(struct crypto_shash *tfm, struct shash_alg *alg)
  68 {
  69         if (crypto_shash_alg_has_setkey(alg) &&
  70             !(alg->base.cra_flags & CRYPTO_ALG_OPTIONAL_KEY))
  71                 crypto_shash_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
  72 }
  73
  74 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
  75                         unsigned int keylen)
  76 {
  77         struct shash_alg *shash = crypto_shash_alg(tfm);
  78         unsigned long alignmask = crypto_shash_alignmask(tfm);
  79         int err;
  80
  81         if ((unsigned long)key & alignmask)
  82                 err = shash_setkey_unaligned(tfm, key, keylen);
  83         else
  84                 err = shash->setkey(tfm, key, keylen);
  85
  86         if (unlikely(err)) {
  87                 shash_set_needkey(tfm, shash);
  88                 return err;
  89         }
  90
  91         crypto_shash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
  92         return 0;
  93 }
  94 EXPORT_SYMBOL_GPL(crypto_shash_setkey);
  95
  96 static inline unsigned int shash_align_buffer_size(unsigned len,
  97                                                    unsigned long mask)
  98 {
  99         typedef u8 __attribute__ ((aligned)) u8_aligned;
 100         return len + (mask & ~(__alignof__(u8_aligned) - 1));
 101 }
 102
 103 static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
 104                                   unsigned int len)
 105 {
 106         struct crypto_shash *tfm = desc->tfm;
 107         struct shash_alg *shash = crypto_shash_alg(tfm);
 108         unsigned long alignmask = crypto_shash_alignmask(tfm);
 109         unsigned int unaligned_len = alignmask + 1 -
 110                                      ((unsigned long)data & alignmask);
 111         u8 ubuf[shash_align_buffer_size(unaligned_len, alignmask)]
 112                 __attribute__ ((aligned));
 113         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
 114         int err;
 115
 116         if (unaligned_len > len)
 117                 unaligned_len = len;
 118
 119         memcpy(buf, data, unaligned_len);
 120         err = shash->update(desc, buf, unaligned_len);
 121         memset(buf, 0, unaligned_len);
 122
 123         return err ?:
 124                shash->update(desc, data + unaligned_len, len - unaligned_len);
 125 }
 126
 127 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
 128                         unsigned int len)
 129 {
 130         struct crypto_shash *tfm = desc->tfm;
 131         struct shash_alg *shash = crypto_shash_alg(tfm);
 132         unsigned long alignmask = crypto_shash_alignmask(tfm);
 133
 134         if ((unsigned long)data & alignmask)
 135                 return shash_update_unaligned(desc, data, len);
 136
 137         return shash->update(desc, data, len);
 138 }
 139 EXPORT_SYMBOL_GPL(crypto_shash_update);
 140
 141 static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
 142 {
 143         struct crypto_shash *tfm = desc->tfm;
 144         unsigned long alignmask = crypto_shash_alignmask(tfm);
 145         struct shash_alg *shash = crypto_shash_alg(tfm);
 146         unsigned int ds = crypto_shash_digestsize(tfm);
 147         u8 ubuf[shash_align_buffer_size(ds, alignmask)]
 148                 __attribute__ ((aligned));
 149         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
 150         int err;
 151
 152         err = shash->final(desc, buf);
 153         if (err)
 154                 goto out;
 155
 156         memcpy(out, buf, ds);
 157
 158 out:
 159         memset(buf, 0, ds);
 160         return err;
 161 }
 162
 163 int crypto_shash_final(struct shash_desc *desc, u8 *out)
 164 {
 165         struct crypto_shash *tfm = desc->tfm;
 166         struct shash_alg *shash = crypto_shash_alg(tfm);
 167         unsigned long alignmask = crypto_shash_alignmask(tfm);
 168
 169         if ((unsigned long)out & alignmask)
 170                 return shash_final_unaligned(desc, out);
 171
 172         return shash->final(desc, out);
 173 }
 174 EXPORT_SYMBOL_GPL(crypto_shash_final);
 175
 176 static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
 177                                  unsigned int len, u8 *out)
 178 {
 179         return crypto_shash_update(desc, data, len) ?:
 180                crypto_shash_final(desc, out);
 181 }
 182
 183 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
 184                        unsigned int len, u8 *out)
 185 {
 186         struct crypto_shash *tfm = desc->tfm;
 187         struct shash_alg *shash = crypto_shash_alg(tfm);
 188         unsigned long alignmask = crypto_shash_alignmask(tfm);
 189
 190         if (((unsigned long)data | (unsigned long)out) & alignmask)
 191                 return shash_finup_unaligned(desc, data, len, out);
 192
 193         return shash->finup(desc, data, len, out);
 194 }
 195 EXPORT_SYMBOL_GPL(crypto_shash_finup);
 196
 197 static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
 198                                   unsigned int len, u8 *out)
 199 {
 200         return crypto_shash_init(desc) ?:
 201                crypto_shash_finup(desc, data, len, out);
 202 }
 203
 204 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
 205                         unsigned int len, u8 *out)
 206 {
 207         struct crypto_shash *tfm = desc->tfm;
 208         struct shash_alg *shash = crypto_shash_alg(tfm);
 209         unsigned long alignmask = crypto_shash_alignmask(tfm);
 210
 211         if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
 212                 return -ENOKEY;
 213
 214         if (((unsigned long)data | (unsigned long)out) & alignmask)
 215                 return shash_digest_unaligned(desc, data, len, out);
 216
 217         return shash->digest(desc, data, len, out);
 218 }
 219 EXPORT_SYMBOL_GPL(crypto_shash_digest);
 220
 221 static int shash_default_export(struct shash_desc *desc, void *out)
 222 {
 223         memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm));
 224         return 0;
 225 }
 226
 227 static int shash_default_import(struct shash_desc *desc, const void *in)
 228 {
 229         memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm));
 230         return 0;
 231 }
 232
 233 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 234                               unsigned int keylen)
 235 {
 236         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
 237
 238         return crypto_shash_setkey(*ctx, key, keylen);
 239 }
 240
 241 static int shash_async_init(struct ahash_request *req)
 242 {
 243         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 244         struct shash_desc *desc = ahash_request_ctx(req);
 245
 246         desc->tfm = *ctx;
 247         desc->flags = req->base.flags;
 248
 249         return crypto_shash_init(desc);
 250 }
 251
 252 int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
 253 {
 254         struct crypto_hash_walk walk;
 255         int nbytes;
 256
 257         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
 258              nbytes = crypto_hash_walk_done(&walk, nbytes))
 259                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 260
 261         return nbytes;
 262 }
 263 EXPORT_SYMBOL_GPL(shash_ahash_update);
 264
 265 static int shash_async_update(struct ahash_request *req)
 266 {
 267         return shash_ahash_update(req, ahash_request_ctx(req));
 268 }
 269
 270 static int shash_async_final(struct ahash_request *req)
 271 {
 272         return crypto_shash_final(ahash_request_ctx(req), req->result);
 273 }
 274
 275 int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
 276 {
 277         struct crypto_hash_walk walk;
 278         int nbytes;
 279
 280         nbytes = crypto_hash_walk_first(req, &walk);
 281         if (!nbytes)
 282                 return crypto_shash_final(desc, req->result);
 283
 284         do {
 285                 nbytes = crypto_hash_walk_last(&walk) ?
 286                          crypto_shash_finup(desc, walk.data, nbytes,
 287                                             req->result) :
 288                          crypto_shash_update(desc, walk.data, nbytes);
 289                 nbytes = crypto_hash_walk_done(&walk, nbytes);
 290         } while (nbytes > 0);
 291
 292         return nbytes;
 293 }
 294 EXPORT_SYMBOL_GPL(shash_ahash_finup);
 295
 296 static int shash_async_finup(struct ahash_request *req)
 297 {
 298         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 299         struct shash_desc *desc = ahash_request_ctx(req);
 300
 301         desc->tfm = *ctx;
 302         desc->flags = req->base.flags;
 303
 304         return shash_ahash_finup(req, desc);
 305 }
 306
 307 int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
 308 {
 309         unsigned int nbytes = req->nbytes;
 310         struct scatterlist *sg;
 311         unsigned int offset;
 312         int err;
 313
 314         if (nbytes &&
 315             (sg = req->src, offset = sg->offset,
 316              nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset))) {
 317                 void *data;
 318
 319                 data = kmap_atomic(sg_page(sg));
 320                 err = crypto_shash_digest(desc, data + offset, nbytes,
 321                                           req->result);
 322                 kunmap_atomic(data);
 323                 crypto_yield(desc->flags);
 324         } else
 325                 err = crypto_shash_init(desc) ?:
 326                       shash_ahash_finup(req, desc);
 327
 328         return err;
 329 }
 330 EXPORT_SYMBOL_GPL(shash_ahash_digest);
 331
 332 static int shash_async_digest(struct ahash_request *req)
 333 {
 334         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 335         struct shash_desc *desc = ahash_request_ctx(req);
 336
 337         desc->tfm = *ctx;
 338         desc->flags = req->base.flags;
 339
 340         return shash_ahash_digest(req, desc);
 341 }
 342
 343 static int shash_async_export(struct ahash_request *req, void *out)
 344 {
 345         return crypto_shash_export(ahash_request_ctx(req), out);
 346 }
 347
 348 static int shash_async_import(struct ahash_request *req, const void *in)
 349 {
 350         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 351         struct shash_desc *desc = ahash_request_ctx(req);
 352
 353         desc->tfm = *ctx;
 354         desc->flags = req->base.flags;
 355
 356         return crypto_shash_import(desc, in);
 357 }
 358
 359 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 360 {
 361         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 362
 363         crypto_free_shash(*ctx);
 364 }
 365
 366 int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 367 {
 368         struct crypto_alg *calg = tfm->__crt_alg;
 369         struct shash_alg *alg = __crypto_shash_alg(calg);
 370         struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
 371         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 372         struct crypto_shash *shash;
 373
 374         if (!crypto_mod_get(calg))
 375                 return -EAGAIN;
 376
 377         shash = crypto_create_tfm(calg, &crypto_shash_type);
 378         if (IS_ERR(shash)) {
 379                 crypto_mod_put(calg);
 380                 return PTR_ERR(shash);
 381         }
 382
 383         *ctx = shash;
 384         tfm->exit = crypto_exit_shash_ops_async;
 385
 386         crt->init = shash_async_init;
 387         crt->update = shash_async_update;
 388         crt->final = shash_async_final;
 389         crt->finup = shash_async_finup;
 390         crt->digest = shash_async_digest;
 391         if (crypto_shash_alg_has_setkey(alg))
 392                 crt->setkey = shash_async_setkey;
 393
 394         crypto_ahash_set_flags(crt, crypto_shash_get_flags(shash) &
 395                                     CRYPTO_TFM_NEED_KEY);
 396
 397         if (alg->export)
 398                 crt->export = shash_async_export;
 399         if (alg->import)
 400                 crt->import = shash_async_import;
 401
 402         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 403
 404         return 0;
 405 }
 406
 407 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
 408 {
 409         struct crypto_shash *hash = __crypto_shash_cast(tfm);
 410         struct shash_alg *alg = crypto_shash_alg(hash);
 411
 412         hash->descsize = alg->descsize;
 413
 414         shash_set_needkey(hash, alg);
 415
 416         return 0;
 417 }
 418
 419 #ifdef CONFIG_NET
 420 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 421 {
 422         struct crypto_report_hash rhash;
 423         struct shash_alg *salg = __crypto_shash_alg(alg);
 424
 425         strncpy(rhash.type, "shash", sizeof(rhash.type));
 426
 427         rhash.blocksize = alg->cra_blocksize;
 428         rhash.digestsize = salg->digestsize;
 429
 430         if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
 431                     sizeof(struct crypto_report_hash), &rhash))
 432                 goto nla_put_failure;
 433         return 0;
 434
 435 nla_put_failure:
 436         return -EMSGSIZE;
 437 }
 438 #else
 439 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 440 {
 441         return -ENOSYS;
 442 }
 443 #endif
 444
 445 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 446         __attribute__ ((unused));
 447 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 448 {
 449         struct shash_alg *salg = __crypto_shash_alg(alg);
 450
 451         seq_printf(m, "type         : shash\n");
 452         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 453         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 454 }
 455
 456 static const struct crypto_type crypto_shash_type = {
 457         .extsize = crypto_alg_extsize,
 458         .init_tfm = crypto_shash_init_tfm,
 459 #ifdef CONFIG_PROC_FS
 460         .show = crypto_shash_show,
 461 #endif
 462         .report = crypto_shash_report,
 463         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 464         .maskset = CRYPTO_ALG_TYPE_MASK,
 465         .type = CRYPTO_ALG_TYPE_SHASH,
 466         .tfmsize = offsetof(struct crypto_shash, base),
 467 };
 468
 469 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 470                                         u32 mask)
 471 {
 472         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 473 }
 474 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 475
 476 static int shash_prepare_alg(struct shash_alg *alg)
 477 {
 478         struct crypto_alg *base = &alg->base;
 479
 480         if (alg->digestsize > PAGE_SIZE / 8 ||
 481             alg->descsize > PAGE_SIZE / 8 ||
 482             alg->statesize > PAGE_SIZE / 8)
 483                 return -EINVAL;
 484
 485         base->cra_type = &crypto_shash_type;
 486         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 487         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 488
 489         if (!alg->finup)
 490                 alg->finup = shash_finup_unaligned;
 491         if (!alg->digest)
 492                 alg->digest = shash_digest_unaligned;
 493         if (!alg->export) {
 494                 alg->export = shash_default_export;
 495                 alg->import = shash_default_import;
 496                 alg->statesize = alg->descsize;
 497         }
 498         if (!alg->setkey)
 499                 alg->setkey = shash_no_setkey;
 500
 501         return 0;
 502 }
 503
 504 int crypto_register_shash(struct shash_alg *alg)
 505 {
 506         struct crypto_alg *base = &alg->base;
 507         int err;
 508
 509         err = shash_prepare_alg(alg);
 510         if (err)
 511                 return err;
 512
 513         return crypto_register_alg(base);
 514 }
 515 EXPORT_SYMBOL_GPL(crypto_register_shash);
 516
 517 int crypto_unregister_shash(struct shash_alg *alg)
 518 {
 519         return crypto_unregister_alg(&alg->base);
 520 }
 521 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 522
 523 int crypto_register_shashes(struct shash_alg *algs, int count)
 524 {
 525         int i, ret;
 526
 527         for (i = 0; i < count; i++) {
 528                 ret = crypto_register_shash(&algs[i]);
 529                 if (ret)
 530                         goto err;
 531         }
 532
 533         return 0;
 534
 535 err:
 536         for (--i; i >= 0; --i)
 537                 crypto_unregister_shash(&algs[i]);
 538
 539         return ret;
 540 }
 541 EXPORT_SYMBOL_GPL(crypto_register_shashes);
 542
 543 int crypto_unregister_shashes(struct shash_alg *algs, int count)
 544 {
 545         int i, ret;
 546
 547         for (i = count - 1; i >= 0; --i) {
 548                 ret = crypto_unregister_shash(&algs[i]);
 549                 if (ret)
 550                         pr_err("Failed to unregister %s %s: %d\n",
 551                                algs[i].base.cra_driver_name,
 552                                algs[i].base.cra_name, ret);
 553         }
 554
 555         return 0;
 556 }
 557 EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
 558
 559 int shash_register_instance(struct crypto_template *tmpl,
 560                             struct shash_instance *inst)
 561 {
 562         int err;
 563
 564         err = shash_prepare_alg(&inst->alg);
 565         if (err)
 566                 return err;
 567
 568         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 569 }
 570 EXPORT_SYMBOL_GPL(shash_register_instance);
 571
 572 void shash_free_instance(struct crypto_instance *inst)
 573 {
 574         crypto_drop_spawn(crypto_instance_ctx(inst));
 575         kfree(shash_instance(inst));
 576 }
 577 EXPORT_SYMBOL_GPL(shash_free_instance);
 578
 579 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
 580                             struct shash_alg *alg,
 581                             struct crypto_instance *inst)
 582 {
 583         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 584                                   &crypto_shash_type);
 585 }
 586 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
 587
 588 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 589 {
 590         struct crypto_alg *alg;
 591
 592         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
 593         return IS_ERR(alg) ? ERR_CAST(alg) :
 594                container_of(alg, struct shash_alg, base);
 595 }
 596 EXPORT_SYMBOL_GPL(shash_attr_alg);
 597
 598 MODULE_LICENSE("GPL");
 599 MODULE_DESCRIPTION("Synchronous cryptographic hash type");