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