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