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 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         return crypto_shash_import(ahash_request_ctx(req), in);
 314 }
 315
 316 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 317 {
 318         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 319
 320         crypto_free_shash(*ctx);
 321 }
 322
 323 int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 324 {
 325         struct crypto_alg *calg = tfm->__crt_alg;
 326         struct shash_alg *alg = __crypto_shash_alg(calg);
 327         struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
 328         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 329         struct crypto_shash *shash;
 330
 331         if (!crypto_mod_get(calg))
 332                 return -EAGAIN;
 333
 334         shash = crypto_create_tfm(calg, &crypto_shash_type);
 335         if (IS_ERR(shash)) {
 336                 crypto_mod_put(calg);
 337                 return PTR_ERR(shash);
 338         }
 339
 340         *ctx = shash;
 341         tfm->exit = crypto_exit_shash_ops_async;
 342
 343         crt->init = shash_async_init;
 344         crt->update = shash_async_update;
 345         crt->final = shash_async_final;
 346         crt->finup = shash_async_finup;
 347         crt->digest = shash_async_digest;
 348
 349         if (alg->setkey)
 350                 crt->setkey = shash_async_setkey;
 351         if (alg->export)
 352                 crt->export = shash_async_export;
 353         if (alg->import)
 354                 crt->import = shash_async_import;
 355
 356         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 357
 358         return 0;
 359 }
 360
 361 static int shash_compat_setkey(struct crypto_hash *tfm, const u8 *key,
 362                                unsigned int keylen)
 363 {
 364         struct shash_desc **descp = crypto_hash_ctx(tfm);
 365         struct shash_desc *desc = *descp;
 366
 367         return crypto_shash_setkey(desc->tfm, key, keylen);
 368 }
 369
 370 static int shash_compat_init(struct hash_desc *hdesc)
 371 {
 372         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
 373         struct shash_desc *desc = *descp;
 374
 375         desc->flags = hdesc->flags;
 376
 377         return crypto_shash_init(desc);
 378 }
 379
 380 static int shash_compat_update(struct hash_desc *hdesc, struct scatterlist *sg,
 381                                unsigned int len)
 382 {
 383         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
 384         struct shash_desc *desc = *descp;
 385         struct crypto_hash_walk walk;
 386         int nbytes;
 387
 388         for (nbytes = crypto_hash_walk_first_compat(hdesc, &walk, sg, len);
 389              nbytes > 0; nbytes = crypto_hash_walk_done(&walk, nbytes))
 390                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 391
 392         return nbytes;
 393 }
 394
 395 static int shash_compat_final(struct hash_desc *hdesc, u8 *out)
 396 {
 397         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
 398
 399         return crypto_shash_final(*descp, out);
 400 }
 401
 402 static int shash_compat_digest(struct hash_desc *hdesc, struct scatterlist *sg,
 403                                unsigned int nbytes, u8 *out)
 404 {
 405         unsigned int offset = sg->offset;
 406         int err;
 407
 408         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 409                 struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
 410                 struct shash_desc *desc = *descp;
 411                 void *data;
 412
 413                 desc->flags = hdesc->flags;
 414
 415                 data = crypto_kmap(sg_page(sg), 0);
 416                 err = crypto_shash_digest(desc, data + offset, nbytes, out);
 417                 crypto_kunmap(data, 0);
 418                 crypto_yield(desc->flags);
 419                 goto out;
 420         }
 421
 422         err = shash_compat_init(hdesc);
 423         if (err)
 424                 goto out;
 425
 426         err = shash_compat_update(hdesc, sg, nbytes);
 427         if (err)
 428                 goto out;
 429
 430         err = shash_compat_final(hdesc, out);
 431
 432 out:
 433         return err;
 434 }
 435
 436 static void crypto_exit_shash_ops_compat(struct crypto_tfm *tfm)
 437 {
 438         struct shash_desc **descp = crypto_tfm_ctx(tfm);
 439         struct shash_desc *desc = *descp;
 440
 441         crypto_free_shash(desc->tfm);
 442         kzfree(desc);
 443 }
 444
 445 static int crypto_init_shash_ops_compat(struct crypto_tfm *tfm)
 446 {
 447         struct hash_tfm *crt = &tfm->crt_hash;
 448         struct crypto_alg *calg = tfm->__crt_alg;
 449         struct shash_alg *alg = __crypto_shash_alg(calg);
 450         struct shash_desc **descp = crypto_tfm_ctx(tfm);
 451         struct crypto_shash *shash;
 452         struct shash_desc *desc;
 453
 454         if (!crypto_mod_get(calg))
 455                 return -EAGAIN;
 456
 457         shash = crypto_create_tfm(calg, &crypto_shash_type);
 458         if (IS_ERR(shash)) {
 459                 crypto_mod_put(calg);
 460                 return PTR_ERR(shash);
 461         }
 462
 463         desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(shash),
 464                        GFP_KERNEL);
 465         if (!desc) {
 466                 crypto_free_shash(shash);
 467                 return -ENOMEM;
 468         }
 469
 470         *descp = desc;
 471         desc->tfm = shash;
 472         tfm->exit = crypto_exit_shash_ops_compat;
 473
 474         crt->init = shash_compat_init;
 475         crt->update = shash_compat_update;
 476         crt->final  = shash_compat_final;
 477         crt->digest = shash_compat_digest;
 478         crt->setkey = shash_compat_setkey;
 479
 480         crt->digestsize = alg->digestsize;
 481
 482         return 0;
 483 }
 484
 485 static int crypto_init_shash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 486 {
 487         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 488         case CRYPTO_ALG_TYPE_HASH_MASK:
 489                 return crypto_init_shash_ops_compat(tfm);
 490         }
 491
 492         return -EINVAL;
 493 }
 494
 495 static unsigned int crypto_shash_ctxsize(struct crypto_alg *alg, u32 type,
 496                                          u32 mask)
 497 {
 498         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 499         case CRYPTO_ALG_TYPE_HASH_MASK:
 500                 return sizeof(struct shash_desc *);
 501         }
 502
 503         return 0;
 504 }
 505
 506 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
 507 {
 508         struct crypto_shash *hash = __crypto_shash_cast(tfm);
 509
 510         hash->descsize = crypto_shash_alg(hash)->descsize;
 511         return 0;
 512 }
 513
 514 static unsigned int crypto_shash_extsize(struct crypto_alg *alg)
 515 {
 516         return alg->cra_ctxsize;
 517 }
 518
 519 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 520         __attribute__ ((unused));
 521 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 522 {
 523         struct shash_alg *salg = __crypto_shash_alg(alg);
 524
 525         seq_printf(m, "type         : shash\n");
 526         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 527         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 528 }
 529
 530 static const struct crypto_type crypto_shash_type = {
 531         .ctxsize = crypto_shash_ctxsize,
 532         .extsize = crypto_shash_extsize,
 533         .init = crypto_init_shash_ops,
 534         .init_tfm = crypto_shash_init_tfm,
 535 #ifdef CONFIG_PROC_FS
 536         .show = crypto_shash_show,
 537 #endif
 538         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 539         .maskset = CRYPTO_ALG_TYPE_MASK,
 540         .type = CRYPTO_ALG_TYPE_SHASH,
 541         .tfmsize = offsetof(struct crypto_shash, base),
 542 };
 543
 544 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 545                                         u32 mask)
 546 {
 547         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 548 }
 549 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 550
 551 static int shash_prepare_alg(struct shash_alg *alg)
 552 {
 553         struct crypto_alg *base = &alg->base;
 554
 555         if (alg->digestsize > PAGE_SIZE / 8 ||
 556             alg->descsize > PAGE_SIZE / 8 ||
 557             alg->statesize > PAGE_SIZE / 8)
 558                 return -EINVAL;
 559
 560         base->cra_type = &crypto_shash_type;
 561         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 562         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 563
 564         if (!alg->finup)
 565                 alg->finup = shash_finup_unaligned;
 566         if (!alg->digest)
 567                 alg->digest = shash_digest_unaligned;
 568         if (!alg->export) {
 569                 alg->export = shash_default_export;
 570                 alg->import = shash_default_import;
 571                 alg->statesize = alg->descsize;
 572         }
 573         if (!alg->setkey)
 574                 alg->setkey = shash_no_setkey;
 575
 576         return 0;
 577 }
 578
 579 int crypto_register_shash(struct shash_alg *alg)
 580 {
 581         struct crypto_alg *base = &alg->base;
 582         int err;
 583
 584         err = shash_prepare_alg(alg);
 585         if (err)
 586                 return err;
 587
 588         return crypto_register_alg(base);
 589 }
 590 EXPORT_SYMBOL_GPL(crypto_register_shash);
 591
 592 int crypto_unregister_shash(struct shash_alg *alg)
 593 {
 594         return crypto_unregister_alg(&alg->base);
 595 }
 596 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 597
 598 int shash_register_instance(struct crypto_template *tmpl,
 599                             struct shash_instance *inst)
 600 {
 601         int err;
 602
 603         err = shash_prepare_alg(&inst->alg);
 604         if (err)
 605                 return err;
 606
 607         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 608 }
 609 EXPORT_SYMBOL_GPL(shash_register_instance);
 610
 611 void shash_free_instance(struct crypto_instance *inst)
 612 {
 613         crypto_drop_spawn(crypto_instance_ctx(inst));
 614         kfree(shash_instance(inst));
 615 }
 616 EXPORT_SYMBOL_GPL(shash_free_instance);
 617
 618 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
 619                             struct shash_alg *alg,
 620                             struct crypto_instance *inst)
 621 {
 622         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 623                                   &crypto_shash_type);
 624 }
 625 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
 626
 627 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 628 {
 629         struct crypto_alg *alg;
 630
 631         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
 632         return IS_ERR(alg) ? ERR_CAST(alg) :
 633                container_of(alg, struct shash_alg, base);
 634 }
 635 EXPORT_SYMBOL_GPL(shash_attr_alg);
 636
 637 MODULE_LICENSE("GPL");
 638 MODULE_DESCRIPTION("Synchronous cryptographic hash type");