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 static const struct crypto_type crypto_shash_type;
  22
  23 static inline struct crypto_shash *__crypto_shash_cast(struct crypto_tfm *tfm)
  24 {
  25         return container_of(tfm, struct crypto_shash, base);
  26 }
  27
  28 #include "internal.h"
  29
  30 static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
  31                                   unsigned int keylen)
  32 {
  33         struct shash_alg *shash = crypto_shash_alg(tfm);
  34         unsigned long alignmask = crypto_shash_alignmask(tfm);
  35         unsigned long absize;
  36         u8 *buffer, *alignbuffer;
  37         int err;
  38
  39         absize = keylen + (alignmask & ~(CRYPTO_MINALIGN - 1));
  40         buffer = kmalloc(absize, GFP_KERNEL);
  41         if (!buffer)
  42                 return -ENOMEM;
  43
  44         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  45         memcpy(alignbuffer, key, keylen);
  46         err = shash->setkey(tfm, alignbuffer, keylen);
  47         memset(alignbuffer, 0, keylen);
  48         kfree(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 (!shash->setkey)
  59                 return -ENOSYS;
  60
  61         if ((unsigned long)key & alignmask)
  62                 return shash_setkey_unaligned(tfm, key, keylen);
  63
  64         return shash->setkey(tfm, key, keylen);
  65 }
  66 EXPORT_SYMBOL_GPL(crypto_shash_setkey);
  67
  68 static inline unsigned int shash_align_buffer_size(unsigned len,
  69                                                    unsigned long mask)
  70 {
  71         return len + (mask & ~(__alignof__(u8 __attribute__ ((aligned))) - 1));
  72 }
  73
  74 static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
  75                                   unsigned int len)
  76 {
  77         struct crypto_shash *tfm = desc->tfm;
  78         struct shash_alg *shash = crypto_shash_alg(tfm);
  79         unsigned long alignmask = crypto_shash_alignmask(tfm);
  80         unsigned int unaligned_len = alignmask + 1 -
  81                                      ((unsigned long)data & alignmask);
  82         u8 buf[shash_align_buffer_size(unaligned_len, alignmask)]
  83                 __attribute__ ((aligned));
  84
  85         memcpy(buf, data, unaligned_len);
  86
  87         return shash->update(desc, buf, unaligned_len) ?:
  88                shash->update(desc, data + unaligned_len, len - unaligned_len);
  89 }
  90
  91 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
  92                         unsigned int len)
  93 {
  94         struct crypto_shash *tfm = desc->tfm;
  95         struct shash_alg *shash = crypto_shash_alg(tfm);
  96         unsigned long alignmask = crypto_shash_alignmask(tfm);
  97
  98         if ((unsigned long)data & alignmask)
  99                 return shash_update_unaligned(desc, data, len);
 100
 101         return shash->update(desc, data, len);
 102 }
 103 EXPORT_SYMBOL_GPL(crypto_shash_update);
 104
 105 static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
 106 {
 107         struct crypto_shash *tfm = desc->tfm;
 108         unsigned long alignmask = crypto_shash_alignmask(tfm);
 109         struct shash_alg *shash = crypto_shash_alg(tfm);
 110         unsigned int ds = crypto_shash_digestsize(tfm);
 111         u8 buf[shash_align_buffer_size(ds, alignmask)]
 112                 __attribute__ ((aligned));
 113         int err;
 114
 115         err = shash->final(desc, buf);
 116         memcpy(out, buf, ds);
 117         return err;
 118 }
 119
 120 int crypto_shash_final(struct shash_desc *desc, u8 *out)
 121 {
 122         struct crypto_shash *tfm = desc->tfm;
 123         struct shash_alg *shash = crypto_shash_alg(tfm);
 124         unsigned long alignmask = crypto_shash_alignmask(tfm);
 125
 126         if ((unsigned long)out & alignmask)
 127                 return shash_final_unaligned(desc, out);
 128
 129         return shash->final(desc, out);
 130 }
 131 EXPORT_SYMBOL_GPL(crypto_shash_final);
 132
 133 static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
 134                                  unsigned int len, u8 *out)
 135 {
 136         return crypto_shash_update(desc, data, len) ?:
 137                crypto_shash_final(desc, out);
 138 }
 139
 140 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
 141                        unsigned int len, u8 *out)
 142 {
 143         struct crypto_shash *tfm = desc->tfm;
 144         struct shash_alg *shash = crypto_shash_alg(tfm);
 145         unsigned long alignmask = crypto_shash_alignmask(tfm);
 146
 147         if (((unsigned long)data | (unsigned long)out) & alignmask ||
 148             !shash->finup)
 149                 return shash_finup_unaligned(desc, data, len, out);
 150
 151         return shash->finup(desc, data, len, out);
 152 }
 153 EXPORT_SYMBOL_GPL(crypto_shash_finup);
 154
 155 static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
 156                                   unsigned int len, u8 *out)
 157 {
 158         return crypto_shash_init(desc) ?:
 159                crypto_shash_update(desc, data, len) ?:
 160                crypto_shash_final(desc, out);
 161 }
 162
 163 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
 164                         unsigned int len, u8 *out)
 165 {
 166         struct crypto_shash *tfm = desc->tfm;
 167         struct shash_alg *shash = crypto_shash_alg(tfm);
 168         unsigned long alignmask = crypto_shash_alignmask(tfm);
 169
 170         if (((unsigned long)data | (unsigned long)out) & alignmask ||
 171             !shash->digest)
 172                 return shash_digest_unaligned(desc, data, len, out);
 173
 174         return shash->digest(desc, data, len, out);
 175 }
 176 EXPORT_SYMBOL_GPL(crypto_shash_digest);
 177
 178 int crypto_shash_import(struct shash_desc *desc, const u8 *in)
 179 {
 180         struct crypto_shash *tfm = desc->tfm;
 181         struct shash_alg *alg = crypto_shash_alg(tfm);
 182
 183         memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(tfm));
 184
 185         if (alg->reinit)
 186                 alg->reinit(desc);
 187
 188         return 0;
 189 }
 190 EXPORT_SYMBOL_GPL(crypto_shash_import);
 191
 192 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 193                               unsigned int keylen)
 194 {
 195         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
 196
 197         return crypto_shash_setkey(*ctx, key, keylen);
 198 }
 199
 200 static int shash_async_init(struct ahash_request *req)
 201 {
 202         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 203         struct shash_desc *desc = ahash_request_ctx(req);
 204
 205         desc->tfm = *ctx;
 206         desc->flags = req->base.flags;
 207
 208         return crypto_shash_init(desc);
 209 }
 210
 211 static int shash_async_update(struct ahash_request *req)
 212 {
 213         struct shash_desc *desc = ahash_request_ctx(req);
 214         struct crypto_hash_walk walk;
 215         int nbytes;
 216
 217         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
 218              nbytes = crypto_hash_walk_done(&walk, nbytes))
 219                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 220
 221         return nbytes;
 222 }
 223
 224 static int shash_async_final(struct ahash_request *req)
 225 {
 226         return crypto_shash_final(ahash_request_ctx(req), req->result);
 227 }
 228
 229 static int shash_async_digest(struct ahash_request *req)
 230 {
 231         struct scatterlist *sg = req->src;
 232         unsigned int offset = sg->offset;
 233         unsigned int nbytes = req->nbytes;
 234         int err;
 235
 236         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 237                 struct crypto_shash **ctx =
 238                         crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 239                 struct shash_desc *desc = ahash_request_ctx(req);
 240                 void *data;
 241
 242                 desc->tfm = *ctx;
 243                 desc->flags = req->base.flags;
 244
 245                 data = crypto_kmap(sg_page(sg), 0);
 246                 err = crypto_shash_digest(desc, data + offset, nbytes,
 247                                           req->result);
 248                 crypto_kunmap(data, 0);
 249                 crypto_yield(desc->flags);
 250                 goto out;
 251         }
 252
 253         err = shash_async_init(req);
 254         if (err)
 255                 goto out;
 256
 257         err = shash_async_update(req);
 258         if (err)
 259                 goto out;
 260
 261         err = shash_async_final(req);
 262
 263 out:
 264         return err;
 265 }
 266
 267 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 268 {
 269         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 270
 271         crypto_free_shash(*ctx);
 272 }
 273
 274 static int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 275 {
 276         struct crypto_alg *calg = tfm->__crt_alg;
 277         struct shash_alg *alg = __crypto_shash_alg(calg);
 278         struct ahash_tfm *crt = &tfm->crt_ahash;
 279         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 280         struct crypto_shash *shash;
 281
 282         if (!crypto_mod_get(calg))
 283                 return -EAGAIN;
 284
 285         shash = __crypto_shash_cast(crypto_create_tfm(
 286                 calg, &crypto_shash_type));
 287         if (IS_ERR(shash)) {
 288                 crypto_mod_put(calg);
 289                 return PTR_ERR(shash);
 290         }
 291
 292         *ctx = shash;
 293         tfm->exit = crypto_exit_shash_ops_async;
 294
 295         crt->init = shash_async_init;
 296         crt->update = shash_async_update;
 297         crt->final  = shash_async_final;
 298         crt->digest = shash_async_digest;
 299         crt->setkey = shash_async_setkey;
 300
 301         crt->digestsize = alg->digestsize;
 302         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 303
 304         return 0;
 305 }
 306
 307 static int shash_compat_setkey(struct crypto_hash *tfm, const u8 *key,
 308                                unsigned int keylen)
 309 {
 310         struct shash_desc *desc = crypto_hash_ctx(tfm);
 311
 312         return crypto_shash_setkey(desc->tfm, key, keylen);
 313 }
 314
 315 static int shash_compat_init(struct hash_desc *hdesc)
 316 {
 317         struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
 318
 319         desc->flags = hdesc->flags;
 320
 321         return crypto_shash_init(desc);
 322 }
 323
 324 static int shash_compat_update(struct hash_desc *hdesc, struct scatterlist *sg,
 325                                unsigned int len)
 326 {
 327         struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
 328         struct crypto_hash_walk walk;
 329         int nbytes;
 330
 331         for (nbytes = crypto_hash_walk_first_compat(hdesc, &walk, sg, len);
 332              nbytes > 0; nbytes = crypto_hash_walk_done(&walk, nbytes))
 333                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 334
 335         return nbytes;
 336 }
 337
 338 static int shash_compat_final(struct hash_desc *hdesc, u8 *out)
 339 {
 340         return crypto_shash_final(crypto_hash_ctx(hdesc->tfm), out);
 341 }
 342
 343 static int shash_compat_digest(struct hash_desc *hdesc, struct scatterlist *sg,
 344                                unsigned int nbytes, u8 *out)
 345 {
 346         unsigned int offset = sg->offset;
 347         int err;
 348
 349         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 350                 struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
 351                 void *data;
 352
 353                 desc->flags = hdesc->flags;
 354
 355                 data = crypto_kmap(sg_page(sg), 0);
 356                 err = crypto_shash_digest(desc, data + offset, nbytes, out);
 357                 crypto_kunmap(data, 0);
 358                 crypto_yield(desc->flags);
 359                 goto out;
 360         }
 361
 362         err = shash_compat_init(hdesc);
 363         if (err)
 364                 goto out;
 365
 366         err = shash_compat_update(hdesc, sg, nbytes);
 367         if (err)
 368                 goto out;
 369
 370         err = shash_compat_final(hdesc, out);
 371
 372 out:
 373         return err;
 374 }
 375
 376 static void crypto_exit_shash_ops_compat(struct crypto_tfm *tfm)
 377 {
 378         struct shash_desc *desc= crypto_tfm_ctx(tfm);
 379
 380         crypto_free_shash(desc->tfm);
 381 }
 382
 383 static int crypto_init_shash_ops_compat(struct crypto_tfm *tfm)
 384 {
 385         struct hash_tfm *crt = &tfm->crt_hash;
 386         struct crypto_alg *calg = tfm->__crt_alg;
 387         struct shash_alg *alg = __crypto_shash_alg(calg);
 388         struct shash_desc *desc = crypto_tfm_ctx(tfm);
 389         struct crypto_shash *shash;
 390
 391         if (!crypto_mod_get(calg))
 392                 return -EAGAIN;
 393
 394         shash = __crypto_shash_cast(crypto_create_tfm(
 395                 calg, &crypto_shash_type));
 396         if (IS_ERR(shash)) {
 397                 crypto_mod_put(calg);
 398                 return PTR_ERR(shash);
 399         }
 400
 401         desc->tfm = shash;
 402         tfm->exit = crypto_exit_shash_ops_compat;
 403
 404         crt->init = shash_compat_init;
 405         crt->update = shash_compat_update;
 406         crt->final  = shash_compat_final;
 407         crt->digest = shash_compat_digest;
 408         crt->setkey = shash_compat_setkey;
 409
 410         crt->digestsize = alg->digestsize;
 411
 412         return 0;
 413 }
 414
 415 static int crypto_init_shash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 416 {
 417         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 418         case CRYPTO_ALG_TYPE_HASH_MASK:
 419                 return crypto_init_shash_ops_compat(tfm);
 420         case CRYPTO_ALG_TYPE_AHASH_MASK:
 421                 return crypto_init_shash_ops_async(tfm);
 422         }
 423
 424         return -EINVAL;
 425 }
 426
 427 static unsigned int crypto_shash_ctxsize(struct crypto_alg *alg, u32 type,
 428                                          u32 mask)
 429 {
 430         struct shash_alg *salg = __crypto_shash_alg(alg);
 431
 432         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 433         case CRYPTO_ALG_TYPE_HASH_MASK:
 434                 return sizeof(struct shash_desc) + salg->descsize;
 435         case CRYPTO_ALG_TYPE_AHASH_MASK:
 436                 return sizeof(struct crypto_shash *);
 437         }
 438
 439         return 0;
 440 }
 441
 442 static int crypto_shash_init_tfm(struct crypto_tfm *tfm,
 443                                  const struct crypto_type *frontend)
 444 {
 445         if (frontend->type != CRYPTO_ALG_TYPE_SHASH)
 446                 return -EINVAL;
 447         return 0;
 448 }
 449
 450 static unsigned int crypto_shash_extsize(struct crypto_alg *alg,
 451                                          const struct crypto_type *frontend)
 452 {
 453         return alg->cra_ctxsize;
 454 }
 455
 456 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 457         __attribute__ ((unused));
 458 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 459 {
 460         struct shash_alg *salg = __crypto_shash_alg(alg);
 461
 462         seq_printf(m, "type         : shash\n");
 463         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 464         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 465         seq_printf(m, "descsize     : %u\n", salg->descsize);
 466 }
 467
 468 static const struct crypto_type crypto_shash_type = {
 469         .ctxsize = crypto_shash_ctxsize,
 470         .extsize = crypto_shash_extsize,
 471         .init = crypto_init_shash_ops,
 472         .init_tfm = crypto_shash_init_tfm,
 473 #ifdef CONFIG_PROC_FS
 474         .show = crypto_shash_show,
 475 #endif
 476         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 477         .maskset = CRYPTO_ALG_TYPE_MASK,
 478         .type = CRYPTO_ALG_TYPE_SHASH,
 479         .tfmsize = offsetof(struct crypto_shash, base),
 480 };
 481
 482 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 483                                         u32 mask)
 484 {
 485         return __crypto_shash_cast(
 486                 crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask));
 487 }
 488 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 489
 490 int crypto_register_shash(struct shash_alg *alg)
 491 {
 492         struct crypto_alg *base = &alg->base;
 493
 494         if (alg->digestsize > PAGE_SIZE / 8 ||
 495             alg->descsize > PAGE_SIZE / 8)
 496                 return -EINVAL;
 497
 498         base->cra_type = &crypto_shash_type;
 499         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 500         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 501
 502         return crypto_register_alg(base);
 503 }
 504 EXPORT_SYMBOL_GPL(crypto_register_shash);
 505
 506 int crypto_unregister_shash(struct shash_alg *alg)
 507 {
 508         return crypto_unregister_alg(&alg->base);
 509 }
 510 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 511
 512 MODULE_LICENSE("GPL");
 513 MODULE_DESCRIPTION("Synchronous cryptographic hash type");