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_finup(desc, data, len, out);
 158 }
 159
 160 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
 161                         unsigned int len, u8 *out)
 162 {
 163         struct crypto_shash *tfm = desc->tfm;
 164         struct shash_alg *shash = crypto_shash_alg(tfm);
 165         unsigned long alignmask = crypto_shash_alignmask(tfm);
 166
 167         if (((unsigned long)data | (unsigned long)out) & alignmask ||
 168             !shash->digest)
 169                 return shash_digest_unaligned(desc, data, len, out);
 170
 171         return shash->digest(desc, data, len, out);
 172 }
 173 EXPORT_SYMBOL_GPL(crypto_shash_digest);
 174
 175 int crypto_shash_import(struct shash_desc *desc, const u8 *in)
 176 {
 177         struct crypto_shash *tfm = desc->tfm;
 178         struct shash_alg *alg = crypto_shash_alg(tfm);
 179
 180         memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(tfm));
 181
 182         if (alg->reinit)
 183                 alg->reinit(desc);
 184
 185         return 0;
 186 }
 187 EXPORT_SYMBOL_GPL(crypto_shash_import);
 188
 189 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 190                               unsigned int keylen)
 191 {
 192         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
 193
 194         return crypto_shash_setkey(*ctx, key, keylen);
 195 }
 196
 197 static int shash_async_init(struct ahash_request *req)
 198 {
 199         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 200         struct shash_desc *desc = ahash_request_ctx(req);
 201
 202         desc->tfm = *ctx;
 203         desc->flags = req->base.flags;
 204
 205         return crypto_shash_init(desc);
 206 }
 207
 208 static int shash_async_update(struct ahash_request *req)
 209 {
 210         struct shash_desc *desc = ahash_request_ctx(req);
 211         struct crypto_hash_walk walk;
 212         int nbytes;
 213
 214         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
 215              nbytes = crypto_hash_walk_done(&walk, nbytes))
 216                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 217
 218         return nbytes;
 219 }
 220
 221 static int shash_async_final(struct ahash_request *req)
 222 {
 223         return crypto_shash_final(ahash_request_ctx(req), req->result);
 224 }
 225
 226 static int shash_async_digest(struct ahash_request *req)
 227 {
 228         struct scatterlist *sg = req->src;
 229         unsigned int offset = sg->offset;
 230         unsigned int nbytes = req->nbytes;
 231         int err;
 232
 233         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 234                 struct crypto_shash **ctx =
 235                         crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 236                 struct shash_desc *desc = ahash_request_ctx(req);
 237                 void *data;
 238
 239                 desc->tfm = *ctx;
 240                 desc->flags = req->base.flags;
 241
 242                 data = crypto_kmap(sg_page(sg), 0);
 243                 err = crypto_shash_digest(desc, data + offset, nbytes,
 244                                           req->result);
 245                 crypto_kunmap(data, 0);
 246                 crypto_yield(desc->flags);
 247                 goto out;
 248         }
 249
 250         err = shash_async_init(req);
 251         if (err)
 252                 goto out;
 253
 254         err = shash_async_update(req);
 255         if (err)
 256                 goto out;
 257
 258         err = shash_async_final(req);
 259
 260 out:
 261         return err;
 262 }
 263
 264 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 265 {
 266         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 267
 268         crypto_free_shash(*ctx);
 269 }
 270
 271 static int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 272 {
 273         struct crypto_alg *calg = tfm->__crt_alg;
 274         struct shash_alg *alg = __crypto_shash_alg(calg);
 275         struct ahash_tfm *crt = &tfm->crt_ahash;
 276         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 277         struct crypto_shash *shash;
 278
 279         if (!crypto_mod_get(calg))
 280                 return -EAGAIN;
 281
 282         shash = crypto_create_tfm(calg, &crypto_shash_type);
 283         if (IS_ERR(shash)) {
 284                 crypto_mod_put(calg);
 285                 return PTR_ERR(shash);
 286         }
 287
 288         *ctx = shash;
 289         tfm->exit = crypto_exit_shash_ops_async;
 290
 291         crt->init = shash_async_init;
 292         crt->update = shash_async_update;
 293         crt->final  = shash_async_final;
 294         crt->digest = shash_async_digest;
 295         crt->setkey = shash_async_setkey;
 296
 297         crt->digestsize = alg->digestsize;
 298         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 299
 300         return 0;
 301 }
 302
 303 static int shash_compat_setkey(struct crypto_hash *tfm, const u8 *key,
 304                                unsigned int keylen)
 305 {
 306         struct shash_desc *desc = crypto_hash_ctx(tfm);
 307
 308         return crypto_shash_setkey(desc->tfm, key, keylen);
 309 }
 310
 311 static int shash_compat_init(struct hash_desc *hdesc)
 312 {
 313         struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
 314
 315         desc->flags = hdesc->flags;
 316
 317         return crypto_shash_init(desc);
 318 }
 319
 320 static int shash_compat_update(struct hash_desc *hdesc, struct scatterlist *sg,
 321                                unsigned int len)
 322 {
 323         struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
 324         struct crypto_hash_walk walk;
 325         int nbytes;
 326
 327         for (nbytes = crypto_hash_walk_first_compat(hdesc, &walk, sg, len);
 328              nbytes > 0; nbytes = crypto_hash_walk_done(&walk, nbytes))
 329                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 330
 331         return nbytes;
 332 }
 333
 334 static int shash_compat_final(struct hash_desc *hdesc, u8 *out)
 335 {
 336         return crypto_shash_final(crypto_hash_ctx(hdesc->tfm), out);
 337 }
 338
 339 static int shash_compat_digest(struct hash_desc *hdesc, struct scatterlist *sg,
 340                                unsigned int nbytes, u8 *out)
 341 {
 342         unsigned int offset = sg->offset;
 343         int err;
 344
 345         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 346                 struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
 347                 void *data;
 348
 349                 desc->flags = hdesc->flags;
 350
 351                 data = crypto_kmap(sg_page(sg), 0);
 352                 err = crypto_shash_digest(desc, data + offset, nbytes, out);
 353                 crypto_kunmap(data, 0);
 354                 crypto_yield(desc->flags);
 355                 goto out;
 356         }
 357
 358         err = shash_compat_init(hdesc);
 359         if (err)
 360                 goto out;
 361
 362         err = shash_compat_update(hdesc, sg, nbytes);
 363         if (err)
 364                 goto out;
 365
 366         err = shash_compat_final(hdesc, out);
 367
 368 out:
 369         return err;
 370 }
 371
 372 static void crypto_exit_shash_ops_compat(struct crypto_tfm *tfm)
 373 {
 374         struct shash_desc *desc= crypto_tfm_ctx(tfm);
 375
 376         crypto_free_shash(desc->tfm);
 377 }
 378
 379 static int crypto_init_shash_ops_compat(struct crypto_tfm *tfm)
 380 {
 381         struct hash_tfm *crt = &tfm->crt_hash;
 382         struct crypto_alg *calg = tfm->__crt_alg;
 383         struct shash_alg *alg = __crypto_shash_alg(calg);
 384         struct shash_desc *desc = crypto_tfm_ctx(tfm);
 385         struct crypto_shash *shash;
 386
 387         if (!crypto_mod_get(calg))
 388                 return -EAGAIN;
 389
 390         shash = crypto_create_tfm(calg, &crypto_shash_type);
 391         if (IS_ERR(shash)) {
 392                 crypto_mod_put(calg);
 393                 return PTR_ERR(shash);
 394         }
 395
 396         desc->tfm = shash;
 397         tfm->exit = crypto_exit_shash_ops_compat;
 398
 399         crt->init = shash_compat_init;
 400         crt->update = shash_compat_update;
 401         crt->final  = shash_compat_final;
 402         crt->digest = shash_compat_digest;
 403         crt->setkey = shash_compat_setkey;
 404
 405         crt->digestsize = alg->digestsize;
 406
 407         return 0;
 408 }
 409
 410 static int crypto_init_shash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 411 {
 412         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 413         case CRYPTO_ALG_TYPE_HASH_MASK:
 414                 return crypto_init_shash_ops_compat(tfm);
 415         case CRYPTO_ALG_TYPE_AHASH_MASK:
 416                 return crypto_init_shash_ops_async(tfm);
 417         }
 418
 419         return -EINVAL;
 420 }
 421
 422 static unsigned int crypto_shash_ctxsize(struct crypto_alg *alg, u32 type,
 423                                          u32 mask)
 424 {
 425         struct shash_alg *salg = __crypto_shash_alg(alg);
 426
 427         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 428         case CRYPTO_ALG_TYPE_HASH_MASK:
 429                 return sizeof(struct shash_desc) + salg->descsize;
 430         case CRYPTO_ALG_TYPE_AHASH_MASK:
 431                 return sizeof(struct crypto_shash *);
 432         }
 433
 434         return 0;
 435 }
 436
 437 static int crypto_shash_init_tfm(struct crypto_tfm *tfm,
 438                                  const struct crypto_type *frontend)
 439 {
 440         return 0;
 441 }
 442
 443 static unsigned int crypto_shash_extsize(struct crypto_alg *alg,
 444                                          const struct crypto_type *frontend)
 445 {
 446         return alg->cra_ctxsize;
 447 }
 448
 449 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 450         __attribute__ ((unused));
 451 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 452 {
 453         struct shash_alg *salg = __crypto_shash_alg(alg);
 454
 455         seq_printf(m, "type         : shash\n");
 456         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 457         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 458         seq_printf(m, "descsize     : %u\n", salg->descsize);
 459 }
 460
 461 static const struct crypto_type crypto_shash_type = {
 462         .ctxsize = crypto_shash_ctxsize,
 463         .extsize = crypto_shash_extsize,
 464         .init = crypto_init_shash_ops,
 465         .init_tfm = crypto_shash_init_tfm,
 466 #ifdef CONFIG_PROC_FS
 467         .show = crypto_shash_show,
 468 #endif
 469         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 470         .maskset = CRYPTO_ALG_TYPE_MASK,
 471         .type = CRYPTO_ALG_TYPE_SHASH,
 472         .tfmsize = offsetof(struct crypto_shash, base),
 473 };
 474
 475 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 476                                         u32 mask)
 477 {
 478         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 479 }
 480 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 481
 482 static int shash_prepare_alg(struct shash_alg *alg)
 483 {
 484         struct crypto_alg *base = &alg->base;
 485
 486         if (alg->digestsize > PAGE_SIZE / 8 ||
 487             alg->descsize > PAGE_SIZE / 8)
 488                 return -EINVAL;
 489
 490         base->cra_type = &crypto_shash_type;
 491         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 492         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 493         return 0;
 494 }
 495
 496 int crypto_register_shash(struct shash_alg *alg)
 497 {
 498         struct crypto_alg *base = &alg->base;
 499         int err;
 500
 501         err = shash_prepare_alg(alg);
 502         if (err)
 503                 return err;
 504
 505         return crypto_register_alg(base);
 506 }
 507 EXPORT_SYMBOL_GPL(crypto_register_shash);
 508
 509 int crypto_unregister_shash(struct shash_alg *alg)
 510 {
 511         return crypto_unregister_alg(&alg->base);
 512 }
 513 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 514
 515 int shash_register_instance(struct crypto_template *tmpl,
 516                             struct shash_instance *inst)
 517 {
 518         int err;
 519
 520         err = shash_prepare_alg(&inst->alg);
 521         if (err)
 522                 return err;
 523
 524         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 525 }
 526 EXPORT_SYMBOL_GPL(shash_register_instance);
 527
 528 void shash_free_instance(struct crypto_instance *inst)
 529 {
 530         crypto_drop_spawn(crypto_instance_ctx(inst));
 531         kfree(shash_instance(inst));
 532 }
 533 EXPORT_SYMBOL_GPL(shash_free_instance);
 534
 535 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
 536                             struct shash_alg *alg,
 537                             struct crypto_instance *inst)
 538 {
 539         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 540                                   &crypto_shash_type);
 541 }
 542 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
 543
 544 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 545 {
 546         struct crypto_alg *alg;
 547
 548         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
 549         return IS_ERR(alg) ? ERR_CAST(alg) :
 550                container_of(alg, struct shash_alg, base);
 551 }
 552 EXPORT_SYMBOL_GPL(shash_attr_alg);
 553
 554 MODULE_LICENSE("GPL");
 555 MODULE_DESCRIPTION("Synchronous cryptographic hash type");