git.oblomov.eu Git - linux-2.6/blob - 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_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
  26                                   unsigned int keylen)
  27 {
  28         struct shash_alg *shash = crypto_shash_alg(tfm);
  29         unsigned long alignmask = crypto_shash_alignmask(tfm);
  30         unsigned long absize;
  31         u8 *buffer, *alignbuffer;
  32         int err;
  33
  34         absize = keylen + (alignmask & ~(CRYPTO_MINALIGN - 1));
  35         buffer = kmalloc(absize, GFP_KERNEL);
  36         if (!buffer)
  37                 return -ENOMEM;
  38
  39         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  40         memcpy(alignbuffer, key, keylen);
  41         err = shash->setkey(tfm, alignbuffer, keylen);
  42         memset(alignbuffer, 0, keylen);
  43         kfree(buffer);
  44         return err;
  45 }
  46
  47 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
  48                         unsigned int keylen)
  49 {
  50         struct shash_alg *shash = crypto_shash_alg(tfm);
  51         unsigned long alignmask = crypto_shash_alignmask(tfm);
  52
  53         if (!shash->setkey)
  54                 return -ENOSYS;
  55
  56         if ((unsigned long)key & alignmask)
  57                 return shash_setkey_unaligned(tfm, key, keylen);
  58
  59         return shash->setkey(tfm, key, keylen);
  60 }
  61 EXPORT_SYMBOL_GPL(crypto_shash_setkey);
  62
  63 static inline unsigned int shash_align_buffer_size(unsigned len,
  64                                                    unsigned long mask)
  65 {
  66         return len + (mask & ~(__alignof__(u8 __attribute__ ((aligned))) - 1));
  67 }
  68
  69 static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
  70                                   unsigned int len)
  71 {
  72         struct crypto_shash *tfm = desc->tfm;
  73         struct shash_alg *shash = crypto_shash_alg(tfm);
  74         unsigned long alignmask = crypto_shash_alignmask(tfm);
  75         unsigned int unaligned_len = alignmask + 1 -
  76                                      ((unsigned long)data & alignmask);
  77         u8 buf[shash_align_buffer_size(unaligned_len, alignmask)]
  78                 __attribute__ ((aligned));
  79
  80         if (unaligned_len > len)
  81                 unaligned_len = len;
  82
  83         memcpy(buf, data, unaligned_len);
  84
  85         return shash->update(desc, buf, unaligned_len) ?:
  86                shash->update(desc, data + unaligned_len, len - unaligned_len);
  87 }
  88
  89 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
  90                         unsigned int len)
  91 {
  92         struct crypto_shash *tfm = desc->tfm;
  93         struct shash_alg *shash = crypto_shash_alg(tfm);
  94         unsigned long alignmask = crypto_shash_alignmask(tfm);
  95
  96         if ((unsigned long)data & alignmask)
  97                 return shash_update_unaligned(desc, data, len);
  98
  99         return shash->update(desc, data, len);
 100 }
 101 EXPORT_SYMBOL_GPL(crypto_shash_update);
 102
 103 static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
 104 {
 105         struct crypto_shash *tfm = desc->tfm;
 106         unsigned long alignmask = crypto_shash_alignmask(tfm);
 107         struct shash_alg *shash = crypto_shash_alg(tfm);
 108         unsigned int ds = crypto_shash_digestsize(tfm);
 109         u8 buf[shash_align_buffer_size(ds, alignmask)]
 110                 __attribute__ ((aligned));
 111         int err;
 112
 113         err = shash->final(desc, buf);
 114         memcpy(out, buf, ds);
 115         return err;
 116 }
 117
 118 int crypto_shash_final(struct shash_desc *desc, u8 *out)
 119 {
 120         struct crypto_shash *tfm = desc->tfm;
 121         struct shash_alg *shash = crypto_shash_alg(tfm);
 122         unsigned long alignmask = crypto_shash_alignmask(tfm);
 123
 124         if ((unsigned long)out & alignmask)
 125                 return shash_final_unaligned(desc, out);
 126
 127         return shash->final(desc, out);
 128 }
 129 EXPORT_SYMBOL_GPL(crypto_shash_final);
 130
 131 static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
 132                                  unsigned int len, u8 *out)
 133 {
 134         return crypto_shash_update(desc, data, len) ?:
 135                crypto_shash_final(desc, out);
 136 }
 137
 138 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
 139                        unsigned int len, u8 *out)
 140 {
 141         struct crypto_shash *tfm = desc->tfm;
 142         struct shash_alg *shash = crypto_shash_alg(tfm);
 143         unsigned long alignmask = crypto_shash_alignmask(tfm);
 144
 145         if (((unsigned long)data | (unsigned long)out) & alignmask ||
 146             !shash->finup)
 147                 return shash_finup_unaligned(desc, data, len, out);
 148
 149         return shash->finup(desc, data, len, out);
 150 }
 151 EXPORT_SYMBOL_GPL(crypto_shash_finup);
 152
 153 static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
 154                                   unsigned int len, u8 *out)
 155 {
 156         return crypto_shash_init(desc) ?:
 157                crypto_shash_update(desc, data, len) ?:
 158                crypto_shash_final(desc, out);
 159 }
 160
 161 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
 162                         unsigned int len, u8 *out)
 163 {
 164         struct crypto_shash *tfm = desc->tfm;
 165         struct shash_alg *shash = crypto_shash_alg(tfm);
 166         unsigned long alignmask = crypto_shash_alignmask(tfm);
 167
 168         if (((unsigned long)data | (unsigned long)out) & alignmask ||
 169             !shash->digest)
 170                 return shash_digest_unaligned(desc, data, len, out);
 171
 172         return shash->digest(desc, data, len, out);
 173 }
 174 EXPORT_SYMBOL_GPL(crypto_shash_digest);
 175
 176 int crypto_shash_import(struct shash_desc *desc, const u8 *in)
 177 {
 178         struct crypto_shash *tfm = desc->tfm;
 179         struct shash_alg *alg = crypto_shash_alg(tfm);
 180
 181         memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(tfm));
 182
 183         if (alg->reinit)
 184                 alg->reinit(desc);
 185
 186         return 0;
 187 }
 188 EXPORT_SYMBOL_GPL(crypto_shash_import);
 189
 190 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 191                               unsigned int keylen)
 192 {
 193         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
 194
 195         return crypto_shash_setkey(*ctx, key, keylen);
 196 }
 197
 198 static int shash_async_init(struct ahash_request *req)
 199 {
 200         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 201         struct shash_desc *desc = ahash_request_ctx(req);
 202
 203         desc->tfm = *ctx;
 204         desc->flags = req->base.flags;
 205
 206         return crypto_shash_init(desc);
 207 }
 208
 209 static int shash_async_update(struct ahash_request *req)
 210 {
 211         struct shash_desc *desc = ahash_request_ctx(req);
 212         struct crypto_hash_walk walk;
 213         int nbytes;
 214
 215         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
 216              nbytes = crypto_hash_walk_done(&walk, nbytes))
 217                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 218
 219         return nbytes;
 220 }
 221
 222 static int shash_async_final(struct ahash_request *req)
 223 {
 224         return crypto_shash_final(ahash_request_ctx(req), req->result);
 225 }
 226
 227 static int shash_async_digest(struct ahash_request *req)
 228 {
 229         struct scatterlist *sg = req->src;
 230         unsigned int offset = sg->offset;
 231         unsigned int nbytes = req->nbytes;
 232         int err;
 233
 234         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 235                 struct crypto_shash **ctx =
 236                         crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 237                 struct shash_desc *desc = ahash_request_ctx(req);
 238                 void *data;
 239
 240                 desc->tfm = *ctx;
 241                 desc->flags = req->base.flags;
 242
 243                 data = crypto_kmap(sg_page(sg), 0);
 244                 err = crypto_shash_digest(desc, data + offset, nbytes,
 245                                           req->result);
 246                 crypto_kunmap(data, 0);
 247                 crypto_yield(desc->flags);
 248                 goto out;
 249         }
 250
 251         err = shash_async_init(req);
 252         if (err)
 253                 goto out;
 254
 255         err = shash_async_update(req);
 256         if (err)
 257                 goto out;
 258
 259         err = shash_async_final(req);
 260
 261 out:
 262         return err;
 263 }
 264
 265 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 266 {
 267         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 268
 269         crypto_free_shash(*ctx);
 270 }
 271
 272 static int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 273 {
 274         struct crypto_alg *calg = tfm->__crt_alg;
 275         struct shash_alg *alg = __crypto_shash_alg(calg);
 276         struct ahash_tfm *crt = &tfm->crt_ahash;
 277         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 278         struct crypto_shash *shash;
 279
 280         if (!crypto_mod_get(calg))
 281                 return -EAGAIN;
 282
 283         shash = crypto_create_tfm(calg, &crypto_shash_type);
 284         if (IS_ERR(shash)) {
 285                 crypto_mod_put(calg);
 286                 return PTR_ERR(shash);
 287         }
 288
 289         *ctx = shash;
 290         tfm->exit = crypto_exit_shash_ops_async;
 291
 292         crt->init = shash_async_init;
 293         crt->update = shash_async_update;
 294         crt->final  = shash_async_final;
 295         crt->digest = shash_async_digest;
 296         crt->setkey = shash_async_setkey;
 297
 298         crt->digestsize = alg->digestsize;
 299         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 300
 301         return 0;
 302 }
 303
 304 static int shash_compat_setkey(struct crypto_hash *tfm, const u8 *key,
 305                                unsigned int keylen)
 306 {
 307         struct shash_desc *desc = crypto_hash_ctx(tfm);
 308
 309         return crypto_shash_setkey(desc->tfm, key, keylen);
 310 }
 311
 312 static int shash_compat_init(struct hash_desc *hdesc)
 313 {
 314         struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
 315
 316         desc->flags = hdesc->flags;
 317
 318         return crypto_shash_init(desc);
 319 }
 320
 321 static int shash_compat_update(struct hash_desc *hdesc, struct scatterlist *sg,
 322                                unsigned int len)
 323 {
 324         struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
 325         struct crypto_hash_walk walk;
 326         int nbytes;
 327
 328         for (nbytes = crypto_hash_walk_first_compat(hdesc, &walk, sg, len);
 329              nbytes > 0; nbytes = crypto_hash_walk_done(&walk, nbytes))
 330                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 331
 332         return nbytes;
 333 }
 334
 335 static int shash_compat_final(struct hash_desc *hdesc, u8 *out)
 336 {
 337         return crypto_shash_final(crypto_hash_ctx(hdesc->tfm), out);
 338 }
 339
 340 static int shash_compat_digest(struct hash_desc *hdesc, struct scatterlist *sg,
 341                                unsigned int nbytes, u8 *out)
 342 {
 343         unsigned int offset = sg->offset;
 344         int err;
 345
 346         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 347                 struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
 348                 void *data;
 349
 350                 desc->flags = hdesc->flags;
 351
 352                 data = crypto_kmap(sg_page(sg), 0);
 353                 err = crypto_shash_digest(desc, data + offset, nbytes, out);
 354                 crypto_kunmap(data, 0);
 355                 crypto_yield(desc->flags);
 356                 goto out;
 357         }
 358
 359         err = shash_compat_init(hdesc);
 360         if (err)
 361                 goto out;
 362
 363         err = shash_compat_update(hdesc, sg, nbytes);
 364         if (err)
 365                 goto out;
 366
 367         err = shash_compat_final(hdesc, out);
 368
 369 out:
 370         return err;
 371 }
 372
 373 static void crypto_exit_shash_ops_compat(struct crypto_tfm *tfm)
 374 {
 375         struct shash_desc *desc= crypto_tfm_ctx(tfm);
 376
 377         crypto_free_shash(desc->tfm);
 378 }
 379
 380 static int crypto_init_shash_ops_compat(struct crypto_tfm *tfm)
 381 {
 382         struct hash_tfm *crt = &tfm->crt_hash;
 383         struct crypto_alg *calg = tfm->__crt_alg;
 384         struct shash_alg *alg = __crypto_shash_alg(calg);
 385         struct shash_desc *desc = crypto_tfm_ctx(tfm);
 386         struct crypto_shash *shash;
 387
 388         if (!crypto_mod_get(calg))
 389                 return -EAGAIN;
 390
 391         shash = crypto_create_tfm(calg, &crypto_shash_type);
 392         if (IS_ERR(shash)) {
 393                 crypto_mod_put(calg);
 394                 return PTR_ERR(shash);
 395         }
 396
 397         desc->tfm = shash;
 398         tfm->exit = crypto_exit_shash_ops_compat;
 399
 400         crt->init = shash_compat_init;
 401         crt->update = shash_compat_update;
 402         crt->final  = shash_compat_final;
 403         crt->digest = shash_compat_digest;
 404         crt->setkey = shash_compat_setkey;
 405
 406         crt->digestsize = alg->digestsize;
 407
 408         return 0;
 409 }
 410
 411 static int crypto_init_shash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 412 {
 413         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 414         case CRYPTO_ALG_TYPE_HASH_MASK:
 415                 return crypto_init_shash_ops_compat(tfm);
 416         case CRYPTO_ALG_TYPE_AHASH_MASK:
 417                 return crypto_init_shash_ops_async(tfm);
 418         }
 419
 420         return -EINVAL;
 421 }
 422
 423 static unsigned int crypto_shash_ctxsize(struct crypto_alg *alg, u32 type,
 424                                          u32 mask)
 425 {
 426         struct shash_alg *salg = __crypto_shash_alg(alg);
 427
 428         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 429         case CRYPTO_ALG_TYPE_HASH_MASK:
 430                 return sizeof(struct shash_desc) + salg->descsize;
 431         case CRYPTO_ALG_TYPE_AHASH_MASK:
 432                 return sizeof(struct crypto_shash *);
 433         }
 434
 435         return 0;
 436 }
 437
 438 static int crypto_shash_init_tfm(struct crypto_tfm *tfm,
 439                                  const struct crypto_type *frontend)
 440 {
 441         return 0;
 442 }
 443
 444 static unsigned int crypto_shash_extsize(struct crypto_alg *alg,
 445                                          const struct crypto_type *frontend)
 446 {
 447         return alg->cra_ctxsize;
 448 }
 449
 450 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 451         __attribute__ ((unused));
 452 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 453 {
 454         struct shash_alg *salg = __crypto_shash_alg(alg);
 455
 456         seq_printf(m, "type         : shash\n");
 457         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 458         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 459         seq_printf(m, "descsize     : %u\n", salg->descsize);
 460 }
 461
 462 static const struct crypto_type crypto_shash_type = {
 463         .ctxsize = crypto_shash_ctxsize,
 464         .extsize = crypto_shash_extsize,
 465         .init = crypto_init_shash_ops,
 466         .init_tfm = crypto_shash_init_tfm,
 467 #ifdef CONFIG_PROC_FS
 468         .show = crypto_shash_show,
 469 #endif
 470         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 471         .maskset = CRYPTO_ALG_TYPE_MASK,
 472         .type = CRYPTO_ALG_TYPE_SHASH,
 473         .tfmsize = offsetof(struct crypto_shash, base),
 474 };
 475
 476 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 477                                         u32 mask)
 478 {
 479         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 480 }
 481 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 482
 483 int crypto_register_shash(struct shash_alg *alg)
 484 {
 485         struct crypto_alg *base = &alg->base;
 486
 487         if (alg->digestsize > PAGE_SIZE / 8 ||
 488             alg->descsize > PAGE_SIZE / 8)
 489                 return -EINVAL;
 490
 491         base->cra_type = &crypto_shash_type;
 492         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 493         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 494
 495         return crypto_register_alg(base);
 496 }
 497 EXPORT_SYMBOL_GPL(crypto_register_shash);
 498
 499 int crypto_unregister_shash(struct shash_alg *alg)
 500 {
 501         return crypto_unregister_alg(&alg->base);
 502 }
 503 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 504
 505 MODULE_LICENSE("GPL");
 506 MODULE_DESCRIPTION("Synchronous cryptographic hash type");