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_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         nbytes = crypto_hash_walk_first(req, &walk);
 244         if (!nbytes)
 245                 return crypto_shash_final(desc, req->result);
 246
 247         do {
 248                 nbytes = crypto_hash_walk_last(&walk) ?
 249                          crypto_shash_finup(desc, walk.data, nbytes,
 250                                             req->result) :
 251                          crypto_shash_update(desc, walk.data, nbytes);
 252                 nbytes = crypto_hash_walk_done(&walk, nbytes);
 253         } while (nbytes > 0);
 254
 255         return nbytes;
 256 }
 257 EXPORT_SYMBOL_GPL(shash_ahash_finup);
 258
 259 static int shash_async_finup(struct ahash_request *req)
 260 {
 261         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 262         struct shash_desc *desc = ahash_request_ctx(req);
 263
 264         desc->tfm = *ctx;
 265         desc->flags = req->base.flags;
 266
 267         return shash_ahash_finup(req, desc);
 268 }
 269
 270 int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
 271 {
 272         struct scatterlist *sg = req->src;
 273         unsigned int offset = sg->offset;
 274         unsigned int nbytes = req->nbytes;
 275         int err;
 276
 277         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 278                 void *data;
 279
 280                 data = crypto_kmap(sg_page(sg), 0);
 281                 err = crypto_shash_digest(desc, data + offset, nbytes,
 282                                           req->result);
 283                 crypto_kunmap(data, 0);
 284                 crypto_yield(desc->flags);
 285         } else
 286                 err = crypto_shash_init(desc) ?:
 287                       shash_ahash_finup(req, desc);
 288
 289         return err;
 290 }
 291 EXPORT_SYMBOL_GPL(shash_ahash_digest);
 292
 293 static int shash_async_digest(struct ahash_request *req)
 294 {
 295         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 296         struct shash_desc *desc = ahash_request_ctx(req);
 297
 298         desc->tfm = *ctx;
 299         desc->flags = req->base.flags;
 300
 301         return shash_ahash_digest(req, desc);
 302 }
 303
 304 static int shash_async_export(struct ahash_request *req, void *out)
 305 {
 306         return crypto_shash_export(ahash_request_ctx(req), out);
 307 }
 308
 309 static int shash_async_import(struct ahash_request *req, const void *in)
 310 {
 311         return crypto_shash_import(ahash_request_ctx(req), in);
 312 }
 313
 314 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 315 {
 316         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 317
 318         crypto_free_shash(*ctx);
 319 }
 320
 321 int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 322 {
 323         struct crypto_alg *calg = tfm->__crt_alg;
 324         struct shash_alg *alg = __crypto_shash_alg(calg);
 325         struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
 326         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 327         struct crypto_shash *shash;
 328
 329         if (!crypto_mod_get(calg))
 330                 return -EAGAIN;
 331
 332         shash = crypto_create_tfm(calg, &crypto_shash_type);
 333         if (IS_ERR(shash)) {
 334                 crypto_mod_put(calg);
 335                 return PTR_ERR(shash);
 336         }
 337
 338         *ctx = shash;
 339         tfm->exit = crypto_exit_shash_ops_async;
 340
 341         crt->init = shash_async_init;
 342         crt->update = shash_async_update;
 343         crt->final = shash_async_final;
 344         crt->finup = shash_async_finup;
 345         crt->digest = shash_async_digest;
 346
 347         if (alg->setkey)
 348                 crt->setkey = shash_async_setkey;
 349         if (alg->export)
 350                 crt->export = shash_async_export;
 351         if (alg->setkey)
 352                 crt->import = shash_async_import;
 353
 354         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 355
 356         return 0;
 357 }
 358
 359 static int shash_compat_setkey(struct crypto_hash *tfm, const u8 *key,
 360                                unsigned int keylen)
 361 {
 362         struct shash_desc **descp = crypto_hash_ctx(tfm);
 363         struct shash_desc *desc = *descp;
 364
 365         return crypto_shash_setkey(desc->tfm, key, keylen);
 366 }
 367
 368 static int shash_compat_init(struct hash_desc *hdesc)
 369 {
 370         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
 371         struct shash_desc *desc = *descp;
 372
 373         desc->flags = hdesc->flags;
 374
 375         return crypto_shash_init(desc);
 376 }
 377
 378 static int shash_compat_update(struct hash_desc *hdesc, struct scatterlist *sg,
 379                                unsigned int len)
 380 {
 381         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
 382         struct shash_desc *desc = *descp;
 383         struct crypto_hash_walk walk;
 384         int nbytes;
 385
 386         for (nbytes = crypto_hash_walk_first_compat(hdesc, &walk, sg, len);
 387              nbytes > 0; nbytes = crypto_hash_walk_done(&walk, nbytes))
 388                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 389
 390         return nbytes;
 391 }
 392
 393 static int shash_compat_final(struct hash_desc *hdesc, u8 *out)
 394 {
 395         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
 396
 397         return crypto_shash_final(*descp, out);
 398 }
 399
 400 static int shash_compat_digest(struct hash_desc *hdesc, struct scatterlist *sg,
 401                                unsigned int nbytes, u8 *out)
 402 {
 403         unsigned int offset = sg->offset;
 404         int err;
 405
 406         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 407                 struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
 408                 struct shash_desc *desc = *descp;
 409                 void *data;
 410
 411                 desc->flags = hdesc->flags;
 412
 413                 data = crypto_kmap(sg_page(sg), 0);
 414                 err = crypto_shash_digest(desc, data + offset, nbytes, out);
 415                 crypto_kunmap(data, 0);
 416                 crypto_yield(desc->flags);
 417                 goto out;
 418         }
 419
 420         err = shash_compat_init(hdesc);
 421         if (err)
 422                 goto out;
 423
 424         err = shash_compat_update(hdesc, sg, nbytes);
 425         if (err)
 426                 goto out;
 427
 428         err = shash_compat_final(hdesc, out);
 429
 430 out:
 431         return err;
 432 }
 433
 434 static void crypto_exit_shash_ops_compat(struct crypto_tfm *tfm)
 435 {
 436         struct shash_desc **descp = crypto_tfm_ctx(tfm);
 437         struct shash_desc *desc = *descp;
 438
 439         crypto_free_shash(desc->tfm);
 440         kzfree(desc);
 441 }
 442
 443 static int crypto_init_shash_ops_compat(struct crypto_tfm *tfm)
 444 {
 445         struct hash_tfm *crt = &tfm->crt_hash;
 446         struct crypto_alg *calg = tfm->__crt_alg;
 447         struct shash_alg *alg = __crypto_shash_alg(calg);
 448         struct shash_desc **descp = crypto_tfm_ctx(tfm);
 449         struct crypto_shash *shash;
 450         struct shash_desc *desc;
 451
 452         if (!crypto_mod_get(calg))
 453                 return -EAGAIN;
 454
 455         shash = crypto_create_tfm(calg, &crypto_shash_type);
 456         if (IS_ERR(shash)) {
 457                 crypto_mod_put(calg);
 458                 return PTR_ERR(shash);
 459         }
 460
 461         desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(shash),
 462                        GFP_KERNEL);
 463         if (!desc) {
 464                 crypto_free_shash(shash);
 465                 return -ENOMEM;
 466         }
 467
 468         *descp = desc;
 469         desc->tfm = shash;
 470         tfm->exit = crypto_exit_shash_ops_compat;
 471
 472         crt->init = shash_compat_init;
 473         crt->update = shash_compat_update;
 474         crt->final  = shash_compat_final;
 475         crt->digest = shash_compat_digest;
 476         crt->setkey = shash_compat_setkey;
 477
 478         crt->digestsize = alg->digestsize;
 479
 480         return 0;
 481 }
 482
 483 static int crypto_init_shash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 484 {
 485         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 486         case CRYPTO_ALG_TYPE_HASH_MASK:
 487                 return crypto_init_shash_ops_compat(tfm);
 488         }
 489
 490         return -EINVAL;
 491 }
 492
 493 static unsigned int crypto_shash_ctxsize(struct crypto_alg *alg, u32 type,
 494                                          u32 mask)
 495 {
 496         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 497         case CRYPTO_ALG_TYPE_HASH_MASK:
 498                 return sizeof(struct shash_desc *);
 499         }
 500
 501         return 0;
 502 }
 503
 504 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
 505 {
 506         struct crypto_shash *hash = __crypto_shash_cast(tfm);
 507
 508         hash->descsize = crypto_shash_alg(hash)->descsize;
 509         return 0;
 510 }
 511
 512 static unsigned int crypto_shash_extsize(struct crypto_alg *alg)
 513 {
 514         return alg->cra_ctxsize;
 515 }
 516
 517 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 518         __attribute__ ((unused));
 519 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 520 {
 521         struct shash_alg *salg = __crypto_shash_alg(alg);
 522
 523         seq_printf(m, "type         : shash\n");
 524         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 525         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 526 }
 527
 528 static const struct crypto_type crypto_shash_type = {
 529         .ctxsize = crypto_shash_ctxsize,
 530         .extsize = crypto_shash_extsize,
 531         .init = crypto_init_shash_ops,
 532         .init_tfm = crypto_shash_init_tfm,
 533 #ifdef CONFIG_PROC_FS
 534         .show = crypto_shash_show,
 535 #endif
 536         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 537         .maskset = CRYPTO_ALG_TYPE_MASK,
 538         .type = CRYPTO_ALG_TYPE_SHASH,
 539         .tfmsize = offsetof(struct crypto_shash, base),
 540 };
 541
 542 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 543                                         u32 mask)
 544 {
 545         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 546 }
 547 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 548
 549 static int shash_prepare_alg(struct shash_alg *alg)
 550 {
 551         struct crypto_alg *base = &alg->base;
 552
 553         if (alg->digestsize > PAGE_SIZE / 8 ||
 554             alg->descsize > PAGE_SIZE / 8 ||
 555             alg->statesize > PAGE_SIZE / 8)
 556                 return -EINVAL;
 557
 558         base->cra_type = &crypto_shash_type;
 559         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 560         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 561
 562         if (!alg->finup)
 563                 alg->finup = shash_finup_unaligned;
 564         if (!alg->digest)
 565                 alg->digest = shash_digest_unaligned;
 566         if (!alg->import)
 567                 alg->import = shash_no_import;
 568         if (!alg->export)
 569                 alg->export = shash_no_export;
 570         if (!alg->setkey)
 571                 alg->setkey = shash_no_setkey;
 572
 573         return 0;
 574 }
 575
 576 int crypto_register_shash(struct shash_alg *alg)
 577 {
 578         struct crypto_alg *base = &alg->base;
 579         int err;
 580
 581         err = shash_prepare_alg(alg);
 582         if (err)
 583                 return err;
 584
 585         return crypto_register_alg(base);
 586 }
 587 EXPORT_SYMBOL_GPL(crypto_register_shash);
 588
 589 int crypto_unregister_shash(struct shash_alg *alg)
 590 {
 591         return crypto_unregister_alg(&alg->base);
 592 }
 593 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 594
 595 int shash_register_instance(struct crypto_template *tmpl,
 596                             struct shash_instance *inst)
 597 {
 598         int err;
 599
 600         err = shash_prepare_alg(&inst->alg);
 601         if (err)
 602                 return err;
 603
 604         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 605 }
 606 EXPORT_SYMBOL_GPL(shash_register_instance);
 607
 608 void shash_free_instance(struct crypto_instance *inst)
 609 {
 610         crypto_drop_spawn(crypto_instance_ctx(inst));
 611         kfree(shash_instance(inst));
 612 }
 613 EXPORT_SYMBOL_GPL(shash_free_instance);
 614
 615 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
 616                             struct shash_alg *alg,
 617                             struct crypto_instance *inst)
 618 {
 619         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 620                                   &crypto_shash_type);
 621 }
 622 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
 623
 624 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 625 {
 626         struct crypto_alg *alg;
 627
 628         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
 629         return IS_ERR(alg) ? ERR_CAST(alg) :
 630                container_of(alg, struct shash_alg, base);
 631 }
 632 EXPORT_SYMBOL_GPL(shash_attr_alg);
 633
 634 MODULE_LICENSE("GPL");
 635 MODULE_DESCRIPTION("Synchronous cryptographic hash type");