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
  21 #include "internal.h"
  22
  23 static const struct crypto_type crypto_shash_type;
  24
  25 static int shash_no_setkey(struct crypto_shash *tfm, const u8 *key,
  26                            unsigned int keylen)
  27 {
  28         return -ENOSYS;
  29 }
  30
  31 static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
  32                                   unsigned int keylen)
  33 {
  34         struct shash_alg *shash = crypto_shash_alg(tfm);
  35         unsigned long alignmask = crypto_shash_alignmask(tfm);
  36         unsigned long absize;
  37         u8 *buffer, *alignbuffer;
  38         int err;
  39
  40         absize = keylen + (alignmask & ~(CRYPTO_MINALIGN - 1));
  41         buffer = kmalloc(absize, GFP_KERNEL);
  42         if (!buffer)
  43                 return -ENOMEM;
  44
  45         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  46         memcpy(alignbuffer, key, keylen);
  47         err = shash->setkey(tfm, alignbuffer, keylen);
  48         kzfree(buffer);
  49         return err;
  50 }
  51
  52 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
  53                         unsigned int keylen)
  54 {
  55         struct shash_alg *shash = crypto_shash_alg(tfm);
  56         unsigned long alignmask = crypto_shash_alignmask(tfm);
  57
  58         if ((unsigned long)key & alignmask)
  59                 return shash_setkey_unaligned(tfm, key, keylen);
  60
  61         return shash->setkey(tfm, key, keylen);
  62 }
  63 EXPORT_SYMBOL_GPL(crypto_shash_setkey);
  64
  65 static inline unsigned int shash_align_buffer_size(unsigned len,
  66                                                    unsigned long mask)
  67 {
  68         return len + (mask & ~(__alignof__(u8 __attribute__ ((aligned))) - 1));
  69 }
  70
  71 static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
  72                                   unsigned int len)
  73 {
  74         struct crypto_shash *tfm = desc->tfm;
  75         struct shash_alg *shash = crypto_shash_alg(tfm);
  76         unsigned long alignmask = crypto_shash_alignmask(tfm);
  77         unsigned int unaligned_len = alignmask + 1 -
  78                                      ((unsigned long)data & alignmask);
  79         u8 buf[shash_align_buffer_size(unaligned_len, alignmask)]
  80                 __attribute__ ((aligned));
  81         int err;
  82
  83         if (unaligned_len > len)
  84                 unaligned_len = len;
  85
  86         memcpy(buf, data, unaligned_len);
  87         err = shash->update(desc, buf, unaligned_len);
  88         memset(buf, 0, unaligned_len);
  89
  90         return err ?:
  91                shash->update(desc, data + unaligned_len, len - unaligned_len);
  92 }
  93
  94 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
  95                         unsigned int len)
  96 {
  97         struct crypto_shash *tfm = desc->tfm;
  98         struct shash_alg *shash = crypto_shash_alg(tfm);
  99         unsigned long alignmask = crypto_shash_alignmask(tfm);
 100
 101         if ((unsigned long)data & alignmask)
 102                 return shash_update_unaligned(desc, data, len);
 103
 104         return shash->update(desc, data, len);
 105 }
 106 EXPORT_SYMBOL_GPL(crypto_shash_update);
 107
 108 static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
 109 {
 110         struct crypto_shash *tfm = desc->tfm;
 111         unsigned long alignmask = crypto_shash_alignmask(tfm);
 112         struct shash_alg *shash = crypto_shash_alg(tfm);
 113         unsigned int ds = crypto_shash_digestsize(tfm);
 114         u8 buf[shash_align_buffer_size(ds, alignmask)]
 115                 __attribute__ ((aligned));
 116         int err;
 117
 118         err = shash->final(desc, buf);
 119         if (err)
 120                 goto out;
 121
 122         memcpy(out, buf, ds);
 123
 124 out:
 125         memset(buf, 0, ds);
 126         return err;
 127 }
 128
 129 int crypto_shash_final(struct shash_desc *desc, u8 *out)
 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)out & alignmask)
 136                 return shash_final_unaligned(desc, out);
 137
 138         return shash->final(desc, out);
 139 }
 140 EXPORT_SYMBOL_GPL(crypto_shash_final);
 141
 142 static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
 143                                  unsigned int len, u8 *out)
 144 {
 145         return crypto_shash_update(desc, data, len) ?:
 146                crypto_shash_final(desc, out);
 147 }
 148
 149 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
 150                        unsigned int len, u8 *out)
 151 {
 152         struct crypto_shash *tfm = desc->tfm;
 153         struct shash_alg *shash = crypto_shash_alg(tfm);
 154         unsigned long alignmask = crypto_shash_alignmask(tfm);
 155
 156         if (((unsigned long)data | (unsigned long)out) & alignmask)
 157                 return shash_finup_unaligned(desc, data, len, out);
 158
 159         return shash->finup(desc, data, len, out);
 160 }
 161 EXPORT_SYMBOL_GPL(crypto_shash_finup);
 162
 163 static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
 164                                   unsigned int len, u8 *out)
 165 {
 166         return crypto_shash_init(desc) ?:
 167                crypto_shash_finup(desc, data, len, out);
 168 }
 169
 170 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
 171                         unsigned int len, u8 *out)
 172 {
 173         struct crypto_shash *tfm = desc->tfm;
 174         struct shash_alg *shash = crypto_shash_alg(tfm);
 175         unsigned long alignmask = crypto_shash_alignmask(tfm);
 176
 177         if (((unsigned long)data | (unsigned long)out) & alignmask)
 178                 return shash_digest_unaligned(desc, data, len, out);
 179
 180         return shash->digest(desc, data, len, out);
 181 }
 182 EXPORT_SYMBOL_GPL(crypto_shash_digest);
 183
 184 static int shash_no_export(struct shash_desc *desc, void *out)
 185 {
 186         return -ENOSYS;
 187 }
 188
 189 static int shash_no_import(struct shash_desc *desc, const void *in)
 190 {
 191         return -ENOSYS;
 192 }
 193
 194 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 195                               unsigned int keylen)
 196 {
 197         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
 198
 199         return crypto_shash_setkey(*ctx, key, keylen);
 200 }
 201
 202 static int shash_async_init(struct ahash_request *req)
 203 {
 204         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 205         struct shash_desc *desc = ahash_request_ctx(req);
 206
 207         desc->tfm = *ctx;
 208         desc->flags = req->base.flags;
 209
 210         return crypto_shash_init(desc);
 211 }
 212
 213 int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
 214 {
 215         struct crypto_hash_walk walk;
 216         int nbytes;
 217
 218         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
 219              nbytes = crypto_hash_walk_done(&walk, nbytes))
 220                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 221
 222         return nbytes;
 223 }
 224 EXPORT_SYMBOL_GPL(shash_ahash_update);
 225
 226 static int shash_async_update(struct ahash_request *req)
 227 {
 228         return shash_ahash_update(req, ahash_request_ctx(req));
 229 }
 230
 231 static int shash_async_final(struct ahash_request *req)
 232 {
 233         return crypto_shash_final(ahash_request_ctx(req), req->result);
 234 }
 235
 236 int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
 237 {
 238         struct scatterlist *sg = req->src;
 239         unsigned int offset = sg->offset;
 240         unsigned int nbytes = req->nbytes;
 241         int err;
 242
 243         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 244                 void *data;
 245
 246                 data = crypto_kmap(sg_page(sg), 0);
 247                 err = crypto_shash_digest(desc, data + offset, nbytes,
 248                                           req->result);
 249                 crypto_kunmap(data, 0);
 250                 crypto_yield(desc->flags);
 251         } else
 252                 err = crypto_shash_init(desc) ?:
 253                       shash_ahash_update(req, desc) ?:
 254                       crypto_shash_final(desc, req->result);
 255
 256         return err;
 257 }
 258 EXPORT_SYMBOL_GPL(shash_ahash_digest);
 259
 260 static int shash_async_digest(struct ahash_request *req)
 261 {
 262         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 263         struct shash_desc *desc = ahash_request_ctx(req);
 264
 265         desc->tfm = *ctx;
 266         desc->flags = req->base.flags;
 267
 268         return shash_ahash_digest(req, desc);
 269 }
 270
 271 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 272 {
 273         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 274
 275         crypto_free_shash(*ctx);
 276 }
 277
 278 int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 279 {
 280         struct crypto_alg *calg = tfm->__crt_alg;
 281         struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
 282         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 283         struct crypto_shash *shash;
 284
 285         if (!crypto_mod_get(calg))
 286                 return -EAGAIN;
 287
 288         shash = crypto_create_tfm(calg, &crypto_shash_type);
 289         if (IS_ERR(shash)) {
 290                 crypto_mod_put(calg);
 291                 return PTR_ERR(shash);
 292         }
 293
 294         *ctx = shash;
 295         tfm->exit = crypto_exit_shash_ops_async;
 296
 297         crt->init = shash_async_init;
 298         crt->update = shash_async_update;
 299         crt->final  = shash_async_final;
 300         crt->digest = shash_async_digest;
 301         crt->setkey = shash_async_setkey;
 302
 303         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 304
 305         return 0;
 306 }
 307
 308 static int shash_compat_setkey(struct crypto_hash *tfm, const u8 *key,
 309                                unsigned int keylen)
 310 {
 311         struct shash_desc **descp = crypto_hash_ctx(tfm);
 312         struct shash_desc *desc = *descp;
 313
 314         return crypto_shash_setkey(desc->tfm, key, keylen);
 315 }
 316
 317 static int shash_compat_init(struct hash_desc *hdesc)
 318 {
 319         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
 320         struct shash_desc *desc = *descp;
 321
 322         desc->flags = hdesc->flags;
 323
 324         return crypto_shash_init(desc);
 325 }
 326
 327 static int shash_compat_update(struct hash_desc *hdesc, struct scatterlist *sg,
 328                                unsigned int len)
 329 {
 330         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
 331         struct shash_desc *desc = *descp;
 332         struct crypto_hash_walk walk;
 333         int nbytes;
 334
 335         for (nbytes = crypto_hash_walk_first_compat(hdesc, &walk, sg, len);
 336              nbytes > 0; nbytes = crypto_hash_walk_done(&walk, nbytes))
 337                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 338
 339         return nbytes;
 340 }
 341
 342 static int shash_compat_final(struct hash_desc *hdesc, u8 *out)
 343 {
 344         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
 345
 346         return crypto_shash_final(*descp, out);
 347 }
 348
 349 static int shash_compat_digest(struct hash_desc *hdesc, struct scatterlist *sg,
 350                                unsigned int nbytes, u8 *out)
 351 {
 352         unsigned int offset = sg->offset;
 353         int err;
 354
 355         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 356                 struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
 357                 struct shash_desc *desc = *descp;
 358                 void *data;
 359
 360                 desc->flags = hdesc->flags;
 361
 362                 data = crypto_kmap(sg_page(sg), 0);
 363                 err = crypto_shash_digest(desc, data + offset, nbytes, out);
 364                 crypto_kunmap(data, 0);
 365                 crypto_yield(desc->flags);
 366                 goto out;
 367         }
 368
 369         err = shash_compat_init(hdesc);
 370         if (err)
 371                 goto out;
 372
 373         err = shash_compat_update(hdesc, sg, nbytes);
 374         if (err)
 375                 goto out;
 376
 377         err = shash_compat_final(hdesc, out);
 378
 379 out:
 380         return err;
 381 }
 382
 383 static void crypto_exit_shash_ops_compat(struct crypto_tfm *tfm)
 384 {
 385         struct shash_desc **descp = crypto_tfm_ctx(tfm);
 386         struct shash_desc *desc = *descp;
 387
 388         crypto_free_shash(desc->tfm);
 389         kzfree(desc);
 390 }
 391
 392 static int crypto_init_shash_ops_compat(struct crypto_tfm *tfm)
 393 {
 394         struct hash_tfm *crt = &tfm->crt_hash;
 395         struct crypto_alg *calg = tfm->__crt_alg;
 396         struct shash_alg *alg = __crypto_shash_alg(calg);
 397         struct shash_desc **descp = crypto_tfm_ctx(tfm);
 398         struct crypto_shash *shash;
 399         struct shash_desc *desc;
 400
 401         if (!crypto_mod_get(calg))
 402                 return -EAGAIN;
 403
 404         shash = crypto_create_tfm(calg, &crypto_shash_type);
 405         if (IS_ERR(shash)) {
 406                 crypto_mod_put(calg);
 407                 return PTR_ERR(shash);
 408         }
 409
 410         desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(shash),
 411                        GFP_KERNEL);
 412         if (!desc) {
 413                 crypto_free_shash(shash);
 414                 return -ENOMEM;
 415         }
 416
 417         *descp = desc;
 418         desc->tfm = shash;
 419         tfm->exit = crypto_exit_shash_ops_compat;
 420
 421         crt->init = shash_compat_init;
 422         crt->update = shash_compat_update;
 423         crt->final  = shash_compat_final;
 424         crt->digest = shash_compat_digest;
 425         crt->setkey = shash_compat_setkey;
 426
 427         crt->digestsize = alg->digestsize;
 428
 429         return 0;
 430 }
 431
 432 static int crypto_init_shash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 433 {
 434         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 435         case CRYPTO_ALG_TYPE_HASH_MASK:
 436                 return crypto_init_shash_ops_compat(tfm);
 437         }
 438
 439         return -EINVAL;
 440 }
 441
 442 static unsigned int crypto_shash_ctxsize(struct crypto_alg *alg, u32 type,
 443                                          u32 mask)
 444 {
 445         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 446         case CRYPTO_ALG_TYPE_HASH_MASK:
 447                 return sizeof(struct shash_desc *);
 448         }
 449
 450         return 0;
 451 }
 452
 453 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
 454 {
 455         struct crypto_shash *hash = __crypto_shash_cast(tfm);
 456
 457         hash->descsize = crypto_shash_alg(hash)->descsize;
 458         return 0;
 459 }
 460
 461 static unsigned int crypto_shash_extsize(struct crypto_alg *alg)
 462 {
 463         return alg->cra_ctxsize;
 464 }
 465
 466 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 467         __attribute__ ((unused));
 468 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 469 {
 470         struct shash_alg *salg = __crypto_shash_alg(alg);
 471
 472         seq_printf(m, "type         : shash\n");
 473         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 474         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 475 }
 476
 477 static const struct crypto_type crypto_shash_type = {
 478         .ctxsize = crypto_shash_ctxsize,
 479         .extsize = crypto_shash_extsize,
 480         .init = crypto_init_shash_ops,
 481         .init_tfm = crypto_shash_init_tfm,
 482 #ifdef CONFIG_PROC_FS
 483         .show = crypto_shash_show,
 484 #endif
 485         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 486         .maskset = CRYPTO_ALG_TYPE_MASK,
 487         .type = CRYPTO_ALG_TYPE_SHASH,
 488         .tfmsize = offsetof(struct crypto_shash, base),
 489 };
 490
 491 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 492                                         u32 mask)
 493 {
 494         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 495 }
 496 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 497
 498 static int shash_prepare_alg(struct shash_alg *alg)
 499 {
 500         struct crypto_alg *base = &alg->base;
 501
 502         if (alg->digestsize > PAGE_SIZE / 8 ||
 503             alg->descsize > PAGE_SIZE / 8 ||
 504             alg->statesize > PAGE_SIZE / 8)
 505                 return -EINVAL;
 506
 507         base->cra_type = &crypto_shash_type;
 508         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 509         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 510
 511         if (!alg->finup)
 512                 alg->finup = shash_finup_unaligned;
 513         if (!alg->digest)
 514                 alg->digest = shash_digest_unaligned;
 515         if (!alg->import)
 516                 alg->import = shash_no_import;
 517         if (!alg->export)
 518                 alg->export = shash_no_export;
 519         if (!alg->setkey)
 520                 alg->setkey = shash_no_setkey;
 521
 522         return 0;
 523 }
 524
 525 int crypto_register_shash(struct shash_alg *alg)
 526 {
 527         struct crypto_alg *base = &alg->base;
 528         int err;
 529
 530         err = shash_prepare_alg(alg);
 531         if (err)
 532                 return err;
 533
 534         return crypto_register_alg(base);
 535 }
 536 EXPORT_SYMBOL_GPL(crypto_register_shash);
 537
 538 int crypto_unregister_shash(struct shash_alg *alg)
 539 {
 540         return crypto_unregister_alg(&alg->base);
 541 }
 542 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 543
 544 int shash_register_instance(struct crypto_template *tmpl,
 545                             struct shash_instance *inst)
 546 {
 547         int err;
 548
 549         err = shash_prepare_alg(&inst->alg);
 550         if (err)
 551                 return err;
 552
 553         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 554 }
 555 EXPORT_SYMBOL_GPL(shash_register_instance);
 556
 557 void shash_free_instance(struct crypto_instance *inst)
 558 {
 559         crypto_drop_spawn(crypto_instance_ctx(inst));
 560         kfree(shash_instance(inst));
 561 }
 562 EXPORT_SYMBOL_GPL(shash_free_instance);
 563
 564 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
 565                             struct shash_alg *alg,
 566                             struct crypto_instance *inst)
 567 {
 568         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 569                                   &crypto_shash_type);
 570 }
 571 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
 572
 573 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 574 {
 575         struct crypto_alg *alg;
 576
 577         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
 578         return IS_ERR(alg) ? ERR_CAST(alg) :
 579                container_of(alg, struct shash_alg, base);
 580 }
 581 EXPORT_SYMBOL_GPL(shash_attr_alg);
 582
 583 MODULE_LICENSE("GPL");
 584 MODULE_DESCRIPTION("Synchronous cryptographic hash type");