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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 static int shash_async_update(struct ahash_request *req)
 206 {
 207         struct shash_desc *desc = ahash_request_ctx(req);
 208         struct crypto_hash_walk walk;
 209         int nbytes;
 210
 211         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
 212              nbytes = crypto_hash_walk_done(&walk, nbytes))
 213                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 214
 215         return nbytes;
 216 }
 217
 218 static int shash_async_final(struct ahash_request *req)
 219 {
 220         return crypto_shash_final(ahash_request_ctx(req), req->result);
 221 }
 222
 223 static int shash_async_digest(struct ahash_request *req)
 224 {
 225         struct scatterlist *sg = req->src;
 226         unsigned int offset = sg->offset;
 227         unsigned int nbytes = req->nbytes;
 228         int err;
 229
 230         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 231                 struct crypto_shash **ctx =
 232                         crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 233                 struct shash_desc *desc = ahash_request_ctx(req);
 234                 void *data;
 235
 236                 desc->tfm = *ctx;
 237                 desc->flags = req->base.flags;
 238
 239                 data = crypto_kmap(sg_page(sg), 0);
 240                 err = crypto_shash_digest(desc, data + offset, nbytes,
 241                                           req->result);
 242                 crypto_kunmap(data, 0);
 243                 crypto_yield(desc->flags);
 244                 goto out;
 245         }
 246
 247         err = shash_async_init(req);
 248         if (err)
 249                 goto out;
 250
 251         err = shash_async_update(req);
 252         if (err)
 253                 goto out;
 254
 255         err = shash_async_final(req);
 256
 257 out:
 258         return err;
 259 }
 260
 261 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 262 {
 263         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 264
 265         crypto_free_shash(*ctx);
 266 }
 267
 268 static int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 269 {
 270         struct crypto_alg *calg = tfm->__crt_alg;
 271         struct shash_alg *alg = __crypto_shash_alg(calg);
 272         struct ahash_tfm *crt = &tfm->crt_ahash;
 273         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 274         struct crypto_shash *shash;
 275
 276         if (!crypto_mod_get(calg))
 277                 return -EAGAIN;
 278
 279         shash = crypto_create_tfm(calg, &crypto_shash_type);
 280         if (IS_ERR(shash)) {
 281                 crypto_mod_put(calg);
 282                 return PTR_ERR(shash);
 283         }
 284
 285         *ctx = shash;
 286         tfm->exit = crypto_exit_shash_ops_async;
 287
 288         crt->init = shash_async_init;
 289         crt->update = shash_async_update;
 290         crt->final  = shash_async_final;
 291         crt->digest = shash_async_digest;
 292         crt->setkey = shash_async_setkey;
 293
 294         crt->digestsize = alg->digestsize;
 295         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 296
 297         return 0;
 298 }
 299
 300 static int shash_compat_setkey(struct crypto_hash *tfm, const u8 *key,
 301                                unsigned int keylen)
 302 {
 303         struct shash_desc *desc = crypto_hash_ctx(tfm);
 304
 305         return crypto_shash_setkey(desc->tfm, key, keylen);
 306 }
 307
 308 static int shash_compat_init(struct hash_desc *hdesc)
 309 {
 310         struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
 311
 312         desc->flags = hdesc->flags;
 313
 314         return crypto_shash_init(desc);
 315 }
 316
 317 static int shash_compat_update(struct hash_desc *hdesc, struct scatterlist *sg,
 318                                unsigned int len)
 319 {
 320         struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
 321         struct crypto_hash_walk walk;
 322         int nbytes;
 323
 324         for (nbytes = crypto_hash_walk_first_compat(hdesc, &walk, sg, len);
 325              nbytes > 0; nbytes = crypto_hash_walk_done(&walk, nbytes))
 326                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 327
 328         return nbytes;
 329 }
 330
 331 static int shash_compat_final(struct hash_desc *hdesc, u8 *out)
 332 {
 333         return crypto_shash_final(crypto_hash_ctx(hdesc->tfm), out);
 334 }
 335
 336 static int shash_compat_digest(struct hash_desc *hdesc, struct scatterlist *sg,
 337                                unsigned int nbytes, u8 *out)
 338 {
 339         unsigned int offset = sg->offset;
 340         int err;
 341
 342         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 343                 struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
 344                 void *data;
 345
 346                 desc->flags = hdesc->flags;
 347
 348                 data = crypto_kmap(sg_page(sg), 0);
 349                 err = crypto_shash_digest(desc, data + offset, nbytes, out);
 350                 crypto_kunmap(data, 0);
 351                 crypto_yield(desc->flags);
 352                 goto out;
 353         }
 354
 355         err = shash_compat_init(hdesc);
 356         if (err)
 357                 goto out;
 358
 359         err = shash_compat_update(hdesc, sg, nbytes);
 360         if (err)
 361                 goto out;
 362
 363         err = shash_compat_final(hdesc, out);
 364
 365 out:
 366         return err;
 367 }
 368
 369 static void crypto_exit_shash_ops_compat(struct crypto_tfm *tfm)
 370 {
 371         struct shash_desc *desc= crypto_tfm_ctx(tfm);
 372
 373         crypto_free_shash(desc->tfm);
 374 }
 375
 376 static int crypto_init_shash_ops_compat(struct crypto_tfm *tfm)
 377 {
 378         struct hash_tfm *crt = &tfm->crt_hash;
 379         struct crypto_alg *calg = tfm->__crt_alg;
 380         struct shash_alg *alg = __crypto_shash_alg(calg);
 381         struct shash_desc *desc = crypto_tfm_ctx(tfm);
 382         struct crypto_shash *shash;
 383
 384         if (!crypto_mod_get(calg))
 385                 return -EAGAIN;
 386
 387         shash = crypto_create_tfm(calg, &crypto_shash_type);
 388         if (IS_ERR(shash)) {
 389                 crypto_mod_put(calg);
 390                 return PTR_ERR(shash);
 391         }
 392
 393         desc->tfm = shash;
 394         tfm->exit = crypto_exit_shash_ops_compat;
 395
 396         crt->init = shash_compat_init;
 397         crt->update = shash_compat_update;
 398         crt->final  = shash_compat_final;
 399         crt->digest = shash_compat_digest;
 400         crt->setkey = shash_compat_setkey;
 401
 402         crt->digestsize = alg->digestsize;
 403
 404         return 0;
 405 }
 406
 407 static int crypto_init_shash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 408 {
 409         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 410         case CRYPTO_ALG_TYPE_HASH_MASK:
 411                 return crypto_init_shash_ops_compat(tfm);
 412         case CRYPTO_ALG_TYPE_AHASH_MASK:
 413                 return crypto_init_shash_ops_async(tfm);
 414         }
 415
 416         return -EINVAL;
 417 }
 418
 419 static unsigned int crypto_shash_ctxsize(struct crypto_alg *alg, u32 type,
 420                                          u32 mask)
 421 {
 422         struct shash_alg *salg = __crypto_shash_alg(alg);
 423
 424         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 425         case CRYPTO_ALG_TYPE_HASH_MASK:
 426                 return sizeof(struct shash_desc) + salg->descsize;
 427         case CRYPTO_ALG_TYPE_AHASH_MASK:
 428                 return sizeof(struct crypto_shash *);
 429         }
 430
 431         return 0;
 432 }
 433
 434 static int crypto_shash_init_tfm(struct crypto_tfm *tfm,
 435                                  const struct crypto_type *frontend)
 436 {
 437         return 0;
 438 }
 439
 440 static unsigned int crypto_shash_extsize(struct crypto_alg *alg,
 441                                          const struct crypto_type *frontend)
 442 {
 443         return alg->cra_ctxsize;
 444 }
 445
 446 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 447         __attribute__ ((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         seq_printf(m, "descsize     : %u\n", salg->descsize);
 456 }
 457
 458 static const struct crypto_type crypto_shash_type = {
 459         .ctxsize = crypto_shash_ctxsize,
 460         .extsize = crypto_shash_extsize,
 461         .init = crypto_init_shash_ops,
 462         .init_tfm = crypto_shash_init_tfm,
 463 #ifdef CONFIG_PROC_FS
 464         .show = crypto_shash_show,
 465 #endif
 466         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 467         .maskset = CRYPTO_ALG_TYPE_MASK,
 468         .type = CRYPTO_ALG_TYPE_SHASH,
 469         .tfmsize = offsetof(struct crypto_shash, base),
 470 };
 471
 472 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 473                                         u32 mask)
 474 {
 475         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 476 }
 477 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 478
 479 static int shash_prepare_alg(struct shash_alg *alg)
 480 {
 481         struct crypto_alg *base = &alg->base;
 482
 483         if (alg->digestsize > PAGE_SIZE / 8 ||
 484             alg->descsize > PAGE_SIZE / 8 ||
 485             alg->statesize > PAGE_SIZE / 8)
 486                 return -EINVAL;
 487
 488         base->cra_type = &crypto_shash_type;
 489         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 490         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 491
 492         if (!alg->finup)
 493                 alg->finup = shash_finup_unaligned;
 494         if (!alg->digest)
 495                 alg->digest = shash_digest_unaligned;
 496         if (!alg->import)
 497                 alg->import = shash_no_import;
 498         if (!alg->export)
 499                 alg->export = shash_no_export;
 500         if (!alg->setkey)
 501                 alg->setkey = shash_no_setkey;
 502
 503         return 0;
 504 }
 505
 506 int crypto_register_shash(struct shash_alg *alg)
 507 {
 508         struct crypto_alg *base = &alg->base;
 509         int err;
 510
 511         err = shash_prepare_alg(alg);
 512         if (err)
 513                 return err;
 514
 515         return crypto_register_alg(base);
 516 }
 517 EXPORT_SYMBOL_GPL(crypto_register_shash);
 518
 519 int crypto_unregister_shash(struct shash_alg *alg)
 520 {
 521         return crypto_unregister_alg(&alg->base);
 522 }
 523 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 524
 525 int shash_register_instance(struct crypto_template *tmpl,
 526                             struct shash_instance *inst)
 527 {
 528         int err;
 529
 530         err = shash_prepare_alg(&inst->alg);
 531         if (err)
 532                 return err;
 533
 534         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 535 }
 536 EXPORT_SYMBOL_GPL(shash_register_instance);
 537
 538 void shash_free_instance(struct crypto_instance *inst)
 539 {
 540         crypto_drop_spawn(crypto_instance_ctx(inst));
 541         kfree(shash_instance(inst));
 542 }
 543 EXPORT_SYMBOL_GPL(shash_free_instance);
 544
 545 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
 546                             struct shash_alg *alg,
 547                             struct crypto_instance *inst)
 548 {
 549         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 550                                   &crypto_shash_type);
 551 }
 552 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
 553
 554 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 555 {
 556         struct crypto_alg *alg;
 557
 558         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
 559         return IS_ERR(alg) ? ERR_CAST(alg) :
 560                container_of(alg, struct shash_alg, base);
 561 }
 562 EXPORT_SYMBOL_GPL(shash_attr_alg);
 563
 564 MODULE_LICENSE("GPL");
 565 MODULE_DESCRIPTION("Synchronous cryptographic hash type");