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_tfm_ctx_alignment() - 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 ubuf[shash_align_buffer_size(unaligned_len, alignmask)]
  80                 __attribute__ ((aligned));
  81         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
  82         int err;
  83
  84         if (unaligned_len > len)
  85                 unaligned_len = len;
  86
  87         memcpy(buf, data, unaligned_len);
  88         err = shash->update(desc, buf, unaligned_len);
  89         memset(buf, 0, unaligned_len);
  90
  91         return err ?:
  92                shash->update(desc, data + unaligned_len, len - unaligned_len);
  93 }
  94
  95 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
  96                         unsigned int len)
  97 {
  98         struct crypto_shash *tfm = desc->tfm;
  99         struct shash_alg *shash = crypto_shash_alg(tfm);
 100         unsigned long alignmask = crypto_shash_alignmask(tfm);
 101
 102         if ((unsigned long)data & alignmask)
 103                 return shash_update_unaligned(desc, data, len);
 104
 105         return shash->update(desc, data, len);
 106 }
 107 EXPORT_SYMBOL_GPL(crypto_shash_update);
 108
 109 static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
 110 {
 111         struct crypto_shash *tfm = desc->tfm;
 112         unsigned long alignmask = crypto_shash_alignmask(tfm);
 113         struct shash_alg *shash = crypto_shash_alg(tfm);
 114         unsigned int ds = crypto_shash_digestsize(tfm);
 115         u8 ubuf[shash_align_buffer_size(ds, alignmask)]
 116                 __attribute__ ((aligned));
 117         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
 118         int err;
 119
 120         err = shash->final(desc, buf);
 121         if (err)
 122                 goto out;
 123
 124         memcpy(out, buf, ds);
 125
 126 out:
 127         memset(buf, 0, ds);
 128         return err;
 129 }
 130
 131 int crypto_shash_final(struct shash_desc *desc, u8 *out)
 132 {
 133         struct crypto_shash *tfm = desc->tfm;
 134         struct shash_alg *shash = crypto_shash_alg(tfm);
 135         unsigned long alignmask = crypto_shash_alignmask(tfm);
 136
 137         if ((unsigned long)out & alignmask)
 138                 return shash_final_unaligned(desc, out);
 139
 140         return shash->final(desc, out);
 141 }
 142 EXPORT_SYMBOL_GPL(crypto_shash_final);
 143
 144 static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
 145                                  unsigned int len, u8 *out)
 146 {
 147         return crypto_shash_update(desc, data, len) ?:
 148                crypto_shash_final(desc, out);
 149 }
 150
 151 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
 152                        unsigned int len, u8 *out)
 153 {
 154         struct crypto_shash *tfm = desc->tfm;
 155         struct shash_alg *shash = crypto_shash_alg(tfm);
 156         unsigned long alignmask = crypto_shash_alignmask(tfm);
 157
 158         if (((unsigned long)data | (unsigned long)out) & alignmask)
 159                 return shash_finup_unaligned(desc, data, len, out);
 160
 161         return shash->finup(desc, data, len, out);
 162 }
 163 EXPORT_SYMBOL_GPL(crypto_shash_finup);
 164
 165 static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
 166                                   unsigned int len, u8 *out)
 167 {
 168         return crypto_shash_init(desc) ?:
 169                crypto_shash_finup(desc, data, len, out);
 170 }
 171
 172 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
 173                         unsigned int len, u8 *out)
 174 {
 175         struct crypto_shash *tfm = desc->tfm;
 176         struct shash_alg *shash = crypto_shash_alg(tfm);
 177         unsigned long alignmask = crypto_shash_alignmask(tfm);
 178
 179         if (((unsigned long)data | (unsigned long)out) & alignmask)
 180                 return shash_digest_unaligned(desc, data, len, out);
 181
 182         return shash->digest(desc, data, len, out);
 183 }
 184 EXPORT_SYMBOL_GPL(crypto_shash_digest);
 185
 186 static int shash_default_export(struct shash_desc *desc, void *out)
 187 {
 188         memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm));
 189         return 0;
 190 }
 191
 192 static int shash_default_import(struct shash_desc *desc, const void *in)
 193 {
 194         memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm));
 195         return 0;
 196 }
 197
 198 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 199                               unsigned int keylen)
 200 {
 201         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
 202
 203         return crypto_shash_setkey(*ctx, key, keylen);
 204 }
 205
 206 static int shash_async_init(struct ahash_request *req)
 207 {
 208         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 209         struct shash_desc *desc = ahash_request_ctx(req);
 210
 211         desc->tfm = *ctx;
 212         desc->flags = req->base.flags;
 213
 214         return crypto_shash_init(desc);
 215 }
 216
 217 int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
 218 {
 219         struct crypto_hash_walk walk;
 220         int nbytes;
 221
 222         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
 223              nbytes = crypto_hash_walk_done(&walk, nbytes))
 224                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 225
 226         return nbytes;
 227 }
 228 EXPORT_SYMBOL_GPL(shash_ahash_update);
 229
 230 static int shash_async_update(struct ahash_request *req)
 231 {
 232         return shash_ahash_update(req, ahash_request_ctx(req));
 233 }
 234
 235 static int shash_async_final(struct ahash_request *req)
 236 {
 237         return crypto_shash_final(ahash_request_ctx(req), req->result);
 238 }
 239
 240 int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
 241 {
 242         struct crypto_hash_walk walk;
 243         int nbytes;
 244
 245         nbytes = crypto_hash_walk_first(req, &walk);
 246         if (!nbytes)
 247                 return crypto_shash_final(desc, req->result);
 248
 249         do {
 250                 nbytes = crypto_hash_walk_last(&walk) ?
 251                          crypto_shash_finup(desc, walk.data, nbytes,
 252                                             req->result) :
 253                          crypto_shash_update(desc, walk.data, nbytes);
 254                 nbytes = crypto_hash_walk_done(&walk, nbytes);
 255         } while (nbytes > 0);
 256
 257         return nbytes;
 258 }
 259 EXPORT_SYMBOL_GPL(shash_ahash_finup);
 260
 261 static int shash_async_finup(struct ahash_request *req)
 262 {
 263         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 264         struct shash_desc *desc = ahash_request_ctx(req);
 265
 266         desc->tfm = *ctx;
 267         desc->flags = req->base.flags;
 268
 269         return shash_ahash_finup(req, desc);
 270 }
 271
 272 int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
 273 {
 274         struct scatterlist *sg = req->src;
 275         unsigned int offset = sg->offset;
 276         unsigned int nbytes = req->nbytes;
 277         int err;
 278
 279         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 280                 void *data;
 281
 282                 data = crypto_kmap(sg_page(sg), 0);
 283                 err = crypto_shash_digest(desc, data + offset, nbytes,
 284                                           req->result);
 285                 crypto_kunmap(data, 0);
 286                 crypto_yield(desc->flags);
 287         } else
 288                 err = crypto_shash_init(desc) ?:
 289                       shash_ahash_finup(req, desc);
 290
 291         return err;
 292 }
 293 EXPORT_SYMBOL_GPL(shash_ahash_digest);
 294
 295 static int shash_async_digest(struct ahash_request *req)
 296 {
 297         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 298         struct shash_desc *desc = ahash_request_ctx(req);
 299
 300         desc->tfm = *ctx;
 301         desc->flags = req->base.flags;
 302
 303         return shash_ahash_digest(req, desc);
 304 }
 305
 306 static int shash_async_export(struct ahash_request *req, void *out)
 307 {
 308         return crypto_shash_export(ahash_request_ctx(req), out);
 309 }
 310
 311 static int shash_async_import(struct ahash_request *req, const void *in)
 312 {
 313         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 314         struct shash_desc *desc = ahash_request_ctx(req);
 315
 316         desc->tfm = *ctx;
 317         desc->flags = req->base.flags;
 318
 319         return crypto_shash_import(desc, in);
 320 }
 321
 322 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 323 {
 324         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 325
 326         crypto_free_shash(*ctx);
 327 }
 328
 329 int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 330 {
 331         struct crypto_alg *calg = tfm->__crt_alg;
 332         struct shash_alg *alg = __crypto_shash_alg(calg);
 333         struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
 334         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 335         struct crypto_shash *shash;
 336
 337         if (!crypto_mod_get(calg))
 338                 return -EAGAIN;
 339
 340         shash = crypto_create_tfm(calg, &crypto_shash_type);
 341         if (IS_ERR(shash)) {
 342                 crypto_mod_put(calg);
 343                 return PTR_ERR(shash);
 344         }
 345
 346         *ctx = shash;
 347         tfm->exit = crypto_exit_shash_ops_async;
 348
 349         crt->init = shash_async_init;
 350         crt->update = shash_async_update;
 351         crt->final = shash_async_final;
 352         crt->finup = shash_async_finup;
 353         crt->digest = shash_async_digest;
 354
 355         if (alg->setkey)
 356                 crt->setkey = shash_async_setkey;
 357         if (alg->export)
 358                 crt->export = shash_async_export;
 359         if (alg->import)
 360                 crt->import = shash_async_import;
 361
 362         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 363
 364         return 0;
 365 }
 366
 367 static int shash_compat_setkey(struct crypto_hash *tfm, const u8 *key,
 368                                unsigned int keylen)
 369 {
 370         struct shash_desc **descp = crypto_hash_ctx(tfm);
 371         struct shash_desc *desc = *descp;
 372
 373         return crypto_shash_setkey(desc->tfm, key, keylen);
 374 }
 375
 376 static int shash_compat_init(struct hash_desc *hdesc)
 377 {
 378         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
 379         struct shash_desc *desc = *descp;
 380
 381         desc->flags = hdesc->flags;
 382
 383         return crypto_shash_init(desc);
 384 }
 385
 386 static int shash_compat_update(struct hash_desc *hdesc, struct scatterlist *sg,
 387                                unsigned int len)
 388 {
 389         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
 390         struct shash_desc *desc = *descp;
 391         struct crypto_hash_walk walk;
 392         int nbytes;
 393
 394         for (nbytes = crypto_hash_walk_first_compat(hdesc, &walk, sg, len);
 395              nbytes > 0; nbytes = crypto_hash_walk_done(&walk, nbytes))
 396                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 397
 398         return nbytes;
 399 }
 400
 401 static int shash_compat_final(struct hash_desc *hdesc, u8 *out)
 402 {
 403         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
 404
 405         return crypto_shash_final(*descp, out);
 406 }
 407
 408 static int shash_compat_digest(struct hash_desc *hdesc, struct scatterlist *sg,
 409                                unsigned int nbytes, u8 *out)
 410 {
 411         unsigned int offset = sg->offset;
 412         int err;
 413
 414         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 415                 struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
 416                 struct shash_desc *desc = *descp;
 417                 void *data;
 418
 419                 desc->flags = hdesc->flags;
 420
 421                 data = crypto_kmap(sg_page(sg), 0);
 422                 err = crypto_shash_digest(desc, data + offset, nbytes, out);
 423                 crypto_kunmap(data, 0);
 424                 crypto_yield(desc->flags);
 425                 goto out;
 426         }
 427
 428         err = shash_compat_init(hdesc);
 429         if (err)
 430                 goto out;
 431
 432         err = shash_compat_update(hdesc, sg, nbytes);
 433         if (err)
 434                 goto out;
 435
 436         err = shash_compat_final(hdesc, out);
 437
 438 out:
 439         return err;
 440 }
 441
 442 static void crypto_exit_shash_ops_compat(struct crypto_tfm *tfm)
 443 {
 444         struct shash_desc **descp = crypto_tfm_ctx(tfm);
 445         struct shash_desc *desc = *descp;
 446
 447         crypto_free_shash(desc->tfm);
 448         kzfree(desc);
 449 }
 450
 451 static int crypto_init_shash_ops_compat(struct crypto_tfm *tfm)
 452 {
 453         struct hash_tfm *crt = &tfm->crt_hash;
 454         struct crypto_alg *calg = tfm->__crt_alg;
 455         struct shash_alg *alg = __crypto_shash_alg(calg);
 456         struct shash_desc **descp = crypto_tfm_ctx(tfm);
 457         struct crypto_shash *shash;
 458         struct shash_desc *desc;
 459
 460         if (!crypto_mod_get(calg))
 461                 return -EAGAIN;
 462
 463         shash = crypto_create_tfm(calg, &crypto_shash_type);
 464         if (IS_ERR(shash)) {
 465                 crypto_mod_put(calg);
 466                 return PTR_ERR(shash);
 467         }
 468
 469         desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(shash),
 470                        GFP_KERNEL);
 471         if (!desc) {
 472                 crypto_free_shash(shash);
 473                 return -ENOMEM;
 474         }
 475
 476         *descp = desc;
 477         desc->tfm = shash;
 478         tfm->exit = crypto_exit_shash_ops_compat;
 479
 480         crt->init = shash_compat_init;
 481         crt->update = shash_compat_update;
 482         crt->final  = shash_compat_final;
 483         crt->digest = shash_compat_digest;
 484         crt->setkey = shash_compat_setkey;
 485
 486         crt->digestsize = alg->digestsize;
 487
 488         return 0;
 489 }
 490
 491 static int crypto_init_shash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 492 {
 493         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 494         case CRYPTO_ALG_TYPE_HASH_MASK:
 495                 return crypto_init_shash_ops_compat(tfm);
 496         }
 497
 498         return -EINVAL;
 499 }
 500
 501 static unsigned int crypto_shash_ctxsize(struct crypto_alg *alg, u32 type,
 502                                          u32 mask)
 503 {
 504         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 505         case CRYPTO_ALG_TYPE_HASH_MASK:
 506                 return sizeof(struct shash_desc *);
 507         }
 508
 509         return 0;
 510 }
 511
 512 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
 513 {
 514         struct crypto_shash *hash = __crypto_shash_cast(tfm);
 515
 516         hash->descsize = crypto_shash_alg(hash)->descsize;
 517         return 0;
 518 }
 519
 520 static unsigned int crypto_shash_extsize(struct crypto_alg *alg)
 521 {
 522         return alg->cra_ctxsize;
 523 }
 524
 525 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 526         __attribute__ ((unused));
 527 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 528 {
 529         struct shash_alg *salg = __crypto_shash_alg(alg);
 530
 531         seq_printf(m, "type         : shash\n");
 532         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 533         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 534 }
 535
 536 static const struct crypto_type crypto_shash_type = {
 537         .ctxsize = crypto_shash_ctxsize,
 538         .extsize = crypto_shash_extsize,
 539         .init = crypto_init_shash_ops,
 540         .init_tfm = crypto_shash_init_tfm,
 541 #ifdef CONFIG_PROC_FS
 542         .show = crypto_shash_show,
 543 #endif
 544         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 545         .maskset = CRYPTO_ALG_TYPE_MASK,
 546         .type = CRYPTO_ALG_TYPE_SHASH,
 547         .tfmsize = offsetof(struct crypto_shash, base),
 548 };
 549
 550 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 551                                         u32 mask)
 552 {
 553         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 554 }
 555 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 556
 557 static int shash_prepare_alg(struct shash_alg *alg)
 558 {
 559         struct crypto_alg *base = &alg->base;
 560
 561         if (alg->digestsize > PAGE_SIZE / 8 ||
 562             alg->descsize > PAGE_SIZE / 8 ||
 563             alg->statesize > PAGE_SIZE / 8)
 564                 return -EINVAL;
 565
 566         base->cra_type = &crypto_shash_type;
 567         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 568         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 569
 570         if (!alg->finup)
 571                 alg->finup = shash_finup_unaligned;
 572         if (!alg->digest)
 573                 alg->digest = shash_digest_unaligned;
 574         if (!alg->export) {
 575                 alg->export = shash_default_export;
 576                 alg->import = shash_default_import;
 577                 alg->statesize = alg->descsize;
 578         }
 579         if (!alg->setkey)
 580                 alg->setkey = shash_no_setkey;
 581
 582         return 0;
 583 }
 584
 585 int crypto_register_shash(struct shash_alg *alg)
 586 {
 587         struct crypto_alg *base = &alg->base;
 588         int err;
 589
 590         err = shash_prepare_alg(alg);
 591         if (err)
 592                 return err;
 593
 594         return crypto_register_alg(base);
 595 }
 596 EXPORT_SYMBOL_GPL(crypto_register_shash);
 597
 598 int crypto_unregister_shash(struct shash_alg *alg)
 599 {
 600         return crypto_unregister_alg(&alg->base);
 601 }
 602 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 603
 604 int shash_register_instance(struct crypto_template *tmpl,
 605                             struct shash_instance *inst)
 606 {
 607         int err;
 608
 609         err = shash_prepare_alg(&inst->alg);
 610         if (err)
 611                 return err;
 612
 613         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 614 }
 615 EXPORT_SYMBOL_GPL(shash_register_instance);
 616
 617 void shash_free_instance(struct crypto_instance *inst)
 618 {
 619         crypto_drop_spawn(crypto_instance_ctx(inst));
 620         kfree(shash_instance(inst));
 621 }
 622 EXPORT_SYMBOL_GPL(shash_free_instance);
 623
 624 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
 625                             struct shash_alg *alg,
 626                             struct crypto_instance *inst)
 627 {
 628         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 629                                   &crypto_shash_type);
 630 }
 631 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
 632
 633 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 634 {
 635         struct crypto_alg *alg;
 636
 637         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
 638         return IS_ERR(alg) ? ERR_CAST(alg) :
 639                container_of(alg, struct shash_alg, base);
 640 }
 641 EXPORT_SYMBOL_GPL(shash_attr_alg);
 642
 643 MODULE_LICENSE("GPL");
 644 MODULE_DESCRIPTION("Synchronous cryptographic hash type");