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   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         memset(alignbuffer, 0, keylen);
  49         kfree(buffer);
  50         return err;
  51 }
  52
  53 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
  54                         unsigned int keylen)
  55 {
  56         struct shash_alg *shash = crypto_shash_alg(tfm);
  57         unsigned long alignmask = crypto_shash_alignmask(tfm);
  58
  59         if ((unsigned long)key & alignmask)
  60                 return shash_setkey_unaligned(tfm, key, keylen);
  61
  62         return shash->setkey(tfm, key, keylen);
  63 }
  64 EXPORT_SYMBOL_GPL(crypto_shash_setkey);
  65
  66 static inline unsigned int shash_align_buffer_size(unsigned len,
  67                                                    unsigned long mask)
  68 {
  69         return len + (mask & ~(__alignof__(u8 __attribute__ ((aligned))) - 1));
  70 }
  71
  72 static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
  73                                   unsigned int len)
  74 {
  75         struct crypto_shash *tfm = desc->tfm;
  76         struct shash_alg *shash = crypto_shash_alg(tfm);
  77         unsigned long alignmask = crypto_shash_alignmask(tfm);
  78         unsigned int unaligned_len = alignmask + 1 -
  79                                      ((unsigned long)data & alignmask);
  80         u8 buf[shash_align_buffer_size(unaligned_len, alignmask)]
  81                 __attribute__ ((aligned));
  82
  83         if (unaligned_len > len)
  84                 unaligned_len = len;
  85
  86         memcpy(buf, data, unaligned_len);
  87
  88         return shash->update(desc, buf, unaligned_len) ?:
  89                shash->update(desc, data + unaligned_len, len - unaligned_len);
  90 }
  91
  92 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
  93                         unsigned int len)
  94 {
  95         struct crypto_shash *tfm = desc->tfm;
  96         struct shash_alg *shash = crypto_shash_alg(tfm);
  97         unsigned long alignmask = crypto_shash_alignmask(tfm);
  98
  99         if ((unsigned long)data & alignmask)
 100                 return shash_update_unaligned(desc, data, len);
 101
 102         return shash->update(desc, data, len);
 103 }
 104 EXPORT_SYMBOL_GPL(crypto_shash_update);
 105
 106 static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
 107 {
 108         struct crypto_shash *tfm = desc->tfm;
 109         unsigned long alignmask = crypto_shash_alignmask(tfm);
 110         struct shash_alg *shash = crypto_shash_alg(tfm);
 111         unsigned int ds = crypto_shash_digestsize(tfm);
 112         u8 buf[shash_align_buffer_size(ds, alignmask)]
 113                 __attribute__ ((aligned));
 114         int err;
 115
 116         err = shash->final(desc, buf);
 117         memcpy(out, buf, ds);
 118         return err;
 119 }
 120
 121 int crypto_shash_final(struct shash_desc *desc, u8 *out)
 122 {
 123         struct crypto_shash *tfm = desc->tfm;
 124         struct shash_alg *shash = crypto_shash_alg(tfm);
 125         unsigned long alignmask = crypto_shash_alignmask(tfm);
 126
 127         if ((unsigned long)out & alignmask)
 128                 return shash_final_unaligned(desc, out);
 129
 130         return shash->final(desc, out);
 131 }
 132 EXPORT_SYMBOL_GPL(crypto_shash_final);
 133
 134 static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
 135                                  unsigned int len, u8 *out)
 136 {
 137         return crypto_shash_update(desc, data, len) ?:
 138                crypto_shash_final(desc, out);
 139 }
 140
 141 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
 142                        unsigned int len, u8 *out)
 143 {
 144         struct crypto_shash *tfm = desc->tfm;
 145         struct shash_alg *shash = crypto_shash_alg(tfm);
 146         unsigned long alignmask = crypto_shash_alignmask(tfm);
 147
 148         if (((unsigned long)data | (unsigned long)out) & alignmask)
 149                 return shash_finup_unaligned(desc, data, len, out);
 150
 151         return shash->finup(desc, data, len, out);
 152 }
 153 EXPORT_SYMBOL_GPL(crypto_shash_finup);
 154
 155 static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
 156                                   unsigned int len, u8 *out)
 157 {
 158         return crypto_shash_init(desc) ?:
 159                crypto_shash_finup(desc, data, len, out);
 160 }
 161
 162 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
 163                         unsigned int len, 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)data | (unsigned long)out) & alignmask)
 170                 return shash_digest_unaligned(desc, data, len, out);
 171
 172         return shash->digest(desc, data, len, out);
 173 }
 174 EXPORT_SYMBOL_GPL(crypto_shash_digest);
 175
 176 static int shash_no_export(struct shash_desc *desc, void *out)
 177 {
 178         return -ENOSYS;
 179 }
 180
 181 static int shash_no_import(struct shash_desc *desc, const void *in)
 182 {
 183         return -ENOSYS;
 184 }
 185
 186 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 187                               unsigned int keylen)
 188 {
 189         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
 190
 191         return crypto_shash_setkey(*ctx, key, keylen);
 192 }
 193
 194 static int shash_async_init(struct ahash_request *req)
 195 {
 196         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 197         struct shash_desc *desc = ahash_request_ctx(req);
 198
 199         desc->tfm = *ctx;
 200         desc->flags = req->base.flags;
 201
 202         return crypto_shash_init(desc);
 203 }
 204
 205 int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
 206 {
 207         struct crypto_hash_walk walk;
 208         int nbytes;
 209
 210         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
 211              nbytes = crypto_hash_walk_done(&walk, nbytes))
 212                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 213
 214         return nbytes;
 215 }
 216 EXPORT_SYMBOL_GPL(shash_ahash_update);
 217
 218 static int shash_async_update(struct ahash_request *req)
 219 {
 220         return shash_ahash_update(req, ahash_request_ctx(req));
 221 }
 222
 223 static int shash_async_final(struct ahash_request *req)
 224 {
 225         return crypto_shash_final(ahash_request_ctx(req), req->result);
 226 }
 227
 228 int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
 229 {
 230         struct scatterlist *sg = req->src;
 231         unsigned int offset = sg->offset;
 232         unsigned int nbytes = req->nbytes;
 233         int err;
 234
 235         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 236                 void *data;
 237
 238                 data = crypto_kmap(sg_page(sg), 0);
 239                 err = crypto_shash_digest(desc, data + offset, nbytes,
 240                                           req->result);
 241                 crypto_kunmap(data, 0);
 242                 crypto_yield(desc->flags);
 243         } else
 244                 err = crypto_shash_init(desc) ?:
 245                       shash_ahash_update(req, desc) ?:
 246                       crypto_shash_final(desc, req->result);
 247
 248         return err;
 249 }
 250 EXPORT_SYMBOL_GPL(shash_ahash_digest);
 251
 252 static int shash_async_digest(struct ahash_request *req)
 253 {
 254         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 255         struct shash_desc *desc = ahash_request_ctx(req);
 256
 257         desc->tfm = *ctx;
 258         desc->flags = req->base.flags;
 259
 260         return shash_ahash_digest(req, desc);
 261 }
 262
 263 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 264 {
 265         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 266
 267         crypto_free_shash(*ctx);
 268 }
 269
 270 static int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 271 {
 272         struct crypto_alg *calg = tfm->__crt_alg;
 273         struct shash_alg *alg = __crypto_shash_alg(calg);
 274         struct ahash_tfm *crt = &tfm->crt_ahash;
 275         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 276         struct crypto_shash *shash;
 277
 278         if (!crypto_mod_get(calg))
 279                 return -EAGAIN;
 280
 281         shash = crypto_create_tfm(calg, &crypto_shash_type);
 282         if (IS_ERR(shash)) {
 283                 crypto_mod_put(calg);
 284                 return PTR_ERR(shash);
 285         }
 286
 287         *ctx = shash;
 288         tfm->exit = crypto_exit_shash_ops_async;
 289
 290         crt->init = shash_async_init;
 291         crt->update = shash_async_update;
 292         crt->final  = shash_async_final;
 293         crt->digest = shash_async_digest;
 294         crt->setkey = shash_async_setkey;
 295
 296         crt->digestsize = alg->digestsize;
 297         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 298
 299         return 0;
 300 }
 301
 302 static int shash_compat_setkey(struct crypto_hash *tfm, const u8 *key,
 303                                unsigned int keylen)
 304 {
 305         struct shash_desc **descp = crypto_hash_ctx(tfm);
 306         struct shash_desc *desc = *descp;
 307
 308         return crypto_shash_setkey(desc->tfm, key, keylen);
 309 }
 310
 311 static int shash_compat_init(struct hash_desc *hdesc)
 312 {
 313         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
 314         struct shash_desc *desc = *descp;
 315
 316         desc->flags = hdesc->flags;
 317
 318         return crypto_shash_init(desc);
 319 }
 320
 321 static int shash_compat_update(struct hash_desc *hdesc, struct scatterlist *sg,
 322                                unsigned int len)
 323 {
 324         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
 325         struct shash_desc *desc = *descp;
 326         struct crypto_hash_walk walk;
 327         int nbytes;
 328
 329         for (nbytes = crypto_hash_walk_first_compat(hdesc, &walk, sg, len);
 330              nbytes > 0; nbytes = crypto_hash_walk_done(&walk, nbytes))
 331                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 332
 333         return nbytes;
 334 }
 335
 336 static int shash_compat_final(struct hash_desc *hdesc, u8 *out)
 337 {
 338         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
 339
 340         return crypto_shash_final(*descp, out);
 341 }
 342
 343 static int shash_compat_digest(struct hash_desc *hdesc, struct scatterlist *sg,
 344                                unsigned int nbytes, u8 *out)
 345 {
 346         unsigned int offset = sg->offset;
 347         int err;
 348
 349         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 350                 struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
 351                 struct shash_desc *desc = *descp;
 352                 void *data;
 353
 354                 desc->flags = hdesc->flags;
 355
 356                 data = crypto_kmap(sg_page(sg), 0);
 357                 err = crypto_shash_digest(desc, data + offset, nbytes, out);
 358                 crypto_kunmap(data, 0);
 359                 crypto_yield(desc->flags);
 360                 goto out;
 361         }
 362
 363         err = shash_compat_init(hdesc);
 364         if (err)
 365                 goto out;
 366
 367         err = shash_compat_update(hdesc, sg, nbytes);
 368         if (err)
 369                 goto out;
 370
 371         err = shash_compat_final(hdesc, out);
 372
 373 out:
 374         return err;
 375 }
 376
 377 static void crypto_exit_shash_ops_compat(struct crypto_tfm *tfm)
 378 {
 379         struct shash_desc **descp = crypto_tfm_ctx(tfm);
 380         struct shash_desc *desc = *descp;
 381
 382         crypto_free_shash(desc->tfm);
 383         kzfree(desc);
 384 }
 385
 386 static int crypto_init_shash_ops_compat(struct crypto_tfm *tfm)
 387 {
 388         struct hash_tfm *crt = &tfm->crt_hash;
 389         struct crypto_alg *calg = tfm->__crt_alg;
 390         struct shash_alg *alg = __crypto_shash_alg(calg);
 391         struct shash_desc **descp = crypto_tfm_ctx(tfm);
 392         struct crypto_shash *shash;
 393         struct shash_desc *desc;
 394
 395         if (!crypto_mod_get(calg))
 396                 return -EAGAIN;
 397
 398         shash = crypto_create_tfm(calg, &crypto_shash_type);
 399         if (IS_ERR(shash)) {
 400                 crypto_mod_put(calg);
 401                 return PTR_ERR(shash);
 402         }
 403
 404         desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(shash),
 405                        GFP_KERNEL);
 406         if (!desc) {
 407                 crypto_free_shash(shash);
 408                 return -ENOMEM;
 409         }
 410
 411         *descp = desc;
 412         desc->tfm = shash;
 413         tfm->exit = crypto_exit_shash_ops_compat;
 414
 415         crt->init = shash_compat_init;
 416         crt->update = shash_compat_update;
 417         crt->final  = shash_compat_final;
 418         crt->digest = shash_compat_digest;
 419         crt->setkey = shash_compat_setkey;
 420
 421         crt->digestsize = alg->digestsize;
 422
 423         return 0;
 424 }
 425
 426 static int crypto_init_shash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 427 {
 428         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 429         case CRYPTO_ALG_TYPE_HASH_MASK:
 430                 return crypto_init_shash_ops_compat(tfm);
 431         case CRYPTO_ALG_TYPE_AHASH_MASK:
 432                 return crypto_init_shash_ops_async(tfm);
 433         }
 434
 435         return -EINVAL;
 436 }
 437
 438 static unsigned int crypto_shash_ctxsize(struct crypto_alg *alg, u32 type,
 439                                          u32 mask)
 440 {
 441         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 442         case CRYPTO_ALG_TYPE_HASH_MASK:
 443                 return sizeof(struct shash_desc *);
 444         case CRYPTO_ALG_TYPE_AHASH_MASK:
 445                 return sizeof(struct crypto_shash *);
 446         }
 447
 448         return 0;
 449 }
 450
 451 static int crypto_shash_init_tfm(struct crypto_tfm *tfm,
 452                                  const struct crypto_type *frontend)
 453 {
 454         struct crypto_shash *hash = __crypto_shash_cast(tfm);
 455
 456         hash->descsize = crypto_shash_alg(hash)->descsize;
 457         return 0;
 458 }
 459
 460 static unsigned int crypto_shash_extsize(struct crypto_alg *alg,
 461                                          const struct crypto_type *frontend)
 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");