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 static int shash_no_export(struct shash_desc *desc, void *out)
 176 {
 177         return -ENOSYS;
 178 }
 179
 180 static int shash_no_import(struct shash_desc *desc, const void *in)
 181 {
 182         return -ENOSYS;
 183 }
 184
 185 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 186                               unsigned int keylen)
 187 {
 188         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
 189
 190         return crypto_shash_setkey(*ctx, key, keylen);
 191 }
 192
 193 static int shash_async_init(struct ahash_request *req)
 194 {
 195         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 196         struct shash_desc *desc = ahash_request_ctx(req);
 197
 198         desc->tfm = *ctx;
 199         desc->flags = req->base.flags;
 200
 201         return crypto_shash_init(desc);
 202 }
 203
 204 static int shash_async_update(struct ahash_request *req)
 205 {
 206         struct shash_desc *desc = ahash_request_ctx(req);
 207         struct crypto_hash_walk walk;
 208         int nbytes;
 209
 210         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
 211              nbytes = crypto_hash_walk_done(&walk, nbytes))
 212                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 213
 214         return nbytes;
 215 }
 216
 217 static int shash_async_final(struct ahash_request *req)
 218 {
 219         return crypto_shash_final(ahash_request_ctx(req), req->result);
 220 }
 221
 222 static int shash_async_digest(struct ahash_request *req)
 223 {
 224         struct scatterlist *sg = req->src;
 225         unsigned int offset = sg->offset;
 226         unsigned int nbytes = req->nbytes;
 227         int err;
 228
 229         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 230                 struct crypto_shash **ctx =
 231                         crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 232                 struct shash_desc *desc = ahash_request_ctx(req);
 233                 void *data;
 234
 235                 desc->tfm = *ctx;
 236                 desc->flags = req->base.flags;
 237
 238                 data = crypto_kmap(sg_page(sg), 0);
 239                 err = crypto_shash_digest(desc, data + offset, nbytes,
 240                                           req->result);
 241                 crypto_kunmap(data, 0);
 242                 crypto_yield(desc->flags);
 243                 goto out;
 244         }
 245
 246         err = shash_async_init(req);
 247         if (err)
 248                 goto out;
 249
 250         err = shash_async_update(req);
 251         if (err)
 252                 goto out;
 253
 254         err = shash_async_final(req);
 255
 256 out:
 257         return err;
 258 }
 259
 260 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 261 {
 262         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 263
 264         crypto_free_shash(*ctx);
 265 }
 266
 267 static int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 268 {
 269         struct crypto_alg *calg = tfm->__crt_alg;
 270         struct shash_alg *alg = __crypto_shash_alg(calg);
 271         struct ahash_tfm *crt = &tfm->crt_ahash;
 272         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 273         struct crypto_shash *shash;
 274
 275         if (!crypto_mod_get(calg))
 276                 return -EAGAIN;
 277
 278         shash = crypto_create_tfm(calg, &crypto_shash_type);
 279         if (IS_ERR(shash)) {
 280                 crypto_mod_put(calg);
 281                 return PTR_ERR(shash);
 282         }
 283
 284         *ctx = shash;
 285         tfm->exit = crypto_exit_shash_ops_async;
 286
 287         crt->init = shash_async_init;
 288         crt->update = shash_async_update;
 289         crt->final  = shash_async_final;
 290         crt->digest = shash_async_digest;
 291         crt->setkey = shash_async_setkey;
 292
 293         crt->digestsize = alg->digestsize;
 294         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 295
 296         return 0;
 297 }
 298
 299 static int shash_compat_setkey(struct crypto_hash *tfm, const u8 *key,
 300                                unsigned int keylen)
 301 {
 302         struct shash_desc *desc = crypto_hash_ctx(tfm);
 303
 304         return crypto_shash_setkey(desc->tfm, key, keylen);
 305 }
 306
 307 static int shash_compat_init(struct hash_desc *hdesc)
 308 {
 309         struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
 310
 311         desc->flags = hdesc->flags;
 312
 313         return crypto_shash_init(desc);
 314 }
 315
 316 static int shash_compat_update(struct hash_desc *hdesc, struct scatterlist *sg,
 317                                unsigned int len)
 318 {
 319         struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
 320         struct crypto_hash_walk walk;
 321         int nbytes;
 322
 323         for (nbytes = crypto_hash_walk_first_compat(hdesc, &walk, sg, len);
 324              nbytes > 0; nbytes = crypto_hash_walk_done(&walk, nbytes))
 325                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 326
 327         return nbytes;
 328 }
 329
 330 static int shash_compat_final(struct hash_desc *hdesc, u8 *out)
 331 {
 332         return crypto_shash_final(crypto_hash_ctx(hdesc->tfm), out);
 333 }
 334
 335 static int shash_compat_digest(struct hash_desc *hdesc, struct scatterlist *sg,
 336                                unsigned int nbytes, u8 *out)
 337 {
 338         unsigned int offset = sg->offset;
 339         int err;
 340
 341         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 342                 struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
 343                 void *data;
 344
 345                 desc->flags = hdesc->flags;
 346
 347                 data = crypto_kmap(sg_page(sg), 0);
 348                 err = crypto_shash_digest(desc, data + offset, nbytes, out);
 349                 crypto_kunmap(data, 0);
 350                 crypto_yield(desc->flags);
 351                 goto out;
 352         }
 353
 354         err = shash_compat_init(hdesc);
 355         if (err)
 356                 goto out;
 357
 358         err = shash_compat_update(hdesc, sg, nbytes);
 359         if (err)
 360                 goto out;
 361
 362         err = shash_compat_final(hdesc, out);
 363
 364 out:
 365         return err;
 366 }
 367
 368 static void crypto_exit_shash_ops_compat(struct crypto_tfm *tfm)
 369 {
 370         struct shash_desc *desc= crypto_tfm_ctx(tfm);
 371
 372         crypto_free_shash(desc->tfm);
 373 }
 374
 375 static int crypto_init_shash_ops_compat(struct crypto_tfm *tfm)
 376 {
 377         struct hash_tfm *crt = &tfm->crt_hash;
 378         struct crypto_alg *calg = tfm->__crt_alg;
 379         struct shash_alg *alg = __crypto_shash_alg(calg);
 380         struct shash_desc *desc = crypto_tfm_ctx(tfm);
 381         struct crypto_shash *shash;
 382
 383         if (!crypto_mod_get(calg))
 384                 return -EAGAIN;
 385
 386         shash = crypto_create_tfm(calg, &crypto_shash_type);
 387         if (IS_ERR(shash)) {
 388                 crypto_mod_put(calg);
 389                 return PTR_ERR(shash);
 390         }
 391
 392         desc->tfm = shash;
 393         tfm->exit = crypto_exit_shash_ops_compat;
 394
 395         crt->init = shash_compat_init;
 396         crt->update = shash_compat_update;
 397         crt->final  = shash_compat_final;
 398         crt->digest = shash_compat_digest;
 399         crt->setkey = shash_compat_setkey;
 400
 401         crt->digestsize = alg->digestsize;
 402
 403         return 0;
 404 }
 405
 406 static int crypto_init_shash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 407 {
 408         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 409         case CRYPTO_ALG_TYPE_HASH_MASK:
 410                 return crypto_init_shash_ops_compat(tfm);
 411         case CRYPTO_ALG_TYPE_AHASH_MASK:
 412                 return crypto_init_shash_ops_async(tfm);
 413         }
 414
 415         return -EINVAL;
 416 }
 417
 418 static unsigned int crypto_shash_ctxsize(struct crypto_alg *alg, u32 type,
 419                                          u32 mask)
 420 {
 421         struct shash_alg *salg = __crypto_shash_alg(alg);
 422
 423         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 424         case CRYPTO_ALG_TYPE_HASH_MASK:
 425                 return sizeof(struct shash_desc) + salg->descsize;
 426         case CRYPTO_ALG_TYPE_AHASH_MASK:
 427                 return sizeof(struct crypto_shash *);
 428         }
 429
 430         return 0;
 431 }
 432
 433 static int crypto_shash_init_tfm(struct crypto_tfm *tfm,
 434                                  const struct crypto_type *frontend)
 435 {
 436         return 0;
 437 }
 438
 439 static unsigned int crypto_shash_extsize(struct crypto_alg *alg,
 440                                          const struct crypto_type *frontend)
 441 {
 442         return alg->cra_ctxsize;
 443 }
 444
 445 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 446         __attribute__ ((unused));
 447 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 448 {
 449         struct shash_alg *salg = __crypto_shash_alg(alg);
 450
 451         seq_printf(m, "type         : shash\n");
 452         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 453         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 454         seq_printf(m, "descsize     : %u\n", salg->descsize);
 455 }
 456
 457 static const struct crypto_type crypto_shash_type = {
 458         .ctxsize = crypto_shash_ctxsize,
 459         .extsize = crypto_shash_extsize,
 460         .init = crypto_init_shash_ops,
 461         .init_tfm = crypto_shash_init_tfm,
 462 #ifdef CONFIG_PROC_FS
 463         .show = crypto_shash_show,
 464 #endif
 465         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 466         .maskset = CRYPTO_ALG_TYPE_MASK,
 467         .type = CRYPTO_ALG_TYPE_SHASH,
 468         .tfmsize = offsetof(struct crypto_shash, base),
 469 };
 470
 471 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 472                                         u32 mask)
 473 {
 474         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 475 }
 476 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 477
 478 static int shash_prepare_alg(struct shash_alg *alg)
 479 {
 480         struct crypto_alg *base = &alg->base;
 481
 482         if (alg->digestsize > PAGE_SIZE / 8 ||
 483             alg->descsize > PAGE_SIZE / 8 ||
 484             alg->statesize > PAGE_SIZE / 8)
 485                 return -EINVAL;
 486
 487         base->cra_type = &crypto_shash_type;
 488         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 489         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 490
 491         if (!alg->import)
 492                 alg->import = shash_no_import;
 493         if (!alg->export)
 494                 alg->export = shash_no_export;
 495
 496         return 0;
 497 }
 498
 499 int crypto_register_shash(struct shash_alg *alg)
 500 {
 501         struct crypto_alg *base = &alg->base;
 502         int err;
 503
 504         err = shash_prepare_alg(alg);
 505         if (err)
 506                 return err;
 507
 508         return crypto_register_alg(base);
 509 }
 510 EXPORT_SYMBOL_GPL(crypto_register_shash);
 511
 512 int crypto_unregister_shash(struct shash_alg *alg)
 513 {
 514         return crypto_unregister_alg(&alg->base);
 515 }
 516 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 517
 518 int shash_register_instance(struct crypto_template *tmpl,
 519                             struct shash_instance *inst)
 520 {
 521         int err;
 522
 523         err = shash_prepare_alg(&inst->alg);
 524         if (err)
 525                 return err;
 526
 527         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 528 }
 529 EXPORT_SYMBOL_GPL(shash_register_instance);
 530
 531 void shash_free_instance(struct crypto_instance *inst)
 532 {
 533         crypto_drop_spawn(crypto_instance_ctx(inst));
 534         kfree(shash_instance(inst));
 535 }
 536 EXPORT_SYMBOL_GPL(shash_free_instance);
 537
 538 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
 539                             struct shash_alg *alg,
 540                             struct crypto_instance *inst)
 541 {
 542         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 543                                   &crypto_shash_type);
 544 }
 545 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
 546
 547 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 548 {
 549         struct crypto_alg *alg;
 550
 551         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
 552         return IS_ERR(alg) ? ERR_CAST(alg) :
 553                container_of(alg, struct shash_alg, base);
 554 }
 555 EXPORT_SYMBOL_GPL(shash_attr_alg);
 556
 557 MODULE_LICENSE("GPL");
 558 MODULE_DESCRIPTION("Synchronous cryptographic hash type");