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