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