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   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                 return shash_finup_unaligned(desc, data, len, out);
 147
 148         return shash->finup(desc, data, len, out);
 149 }
 150 EXPORT_SYMBOL_GPL(crypto_shash_finup);
 151
 152 static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
 153                                   unsigned int len, u8 *out)
 154 {
 155         return crypto_shash_init(desc) ?:
 156                crypto_shash_finup(desc, data, len, out);
 157 }
 158
 159 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
 160                         unsigned int len, u8 *out)
 161 {
 162         struct crypto_shash *tfm = desc->tfm;
 163         struct shash_alg *shash = crypto_shash_alg(tfm);
 164         unsigned long alignmask = crypto_shash_alignmask(tfm);
 165
 166         if (((unsigned long)data | (unsigned long)out) & alignmask)
 167                 return shash_digest_unaligned(desc, data, len, out);
 168
 169         return shash->digest(desc, data, len, out);
 170 }
 171 EXPORT_SYMBOL_GPL(crypto_shash_digest);
 172
 173 static int shash_no_export(struct shash_desc *desc, void *out)
 174 {
 175         return -ENOSYS;
 176 }
 177
 178 static int shash_no_import(struct shash_desc *desc, const void *in)
 179 {
 180         return -ENOSYS;
 181 }
 182
 183 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 184                               unsigned int keylen)
 185 {
 186         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
 187
 188         return crypto_shash_setkey(*ctx, key, keylen);
 189 }
 190
 191 static int shash_async_init(struct ahash_request *req)
 192 {
 193         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 194         struct shash_desc *desc = ahash_request_ctx(req);
 195
 196         desc->tfm = *ctx;
 197         desc->flags = req->base.flags;
 198
 199         return crypto_shash_init(desc);
 200 }
 201
 202 static int shash_async_update(struct ahash_request *req)
 203 {
 204         struct shash_desc *desc = ahash_request_ctx(req);
 205         struct crypto_hash_walk walk;
 206         int nbytes;
 207
 208         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
 209              nbytes = crypto_hash_walk_done(&walk, nbytes))
 210                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 211
 212         return nbytes;
 213 }
 214
 215 static int shash_async_final(struct ahash_request *req)
 216 {
 217         return crypto_shash_final(ahash_request_ctx(req), req->result);
 218 }
 219
 220 static int shash_async_digest(struct ahash_request *req)
 221 {
 222         struct scatterlist *sg = req->src;
 223         unsigned int offset = sg->offset;
 224         unsigned int nbytes = req->nbytes;
 225         int err;
 226
 227         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 228                 struct crypto_shash **ctx =
 229                         crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 230                 struct shash_desc *desc = ahash_request_ctx(req);
 231                 void *data;
 232
 233                 desc->tfm = *ctx;
 234                 desc->flags = req->base.flags;
 235
 236                 data = crypto_kmap(sg_page(sg), 0);
 237                 err = crypto_shash_digest(desc, data + offset, nbytes,
 238                                           req->result);
 239                 crypto_kunmap(data, 0);
 240                 crypto_yield(desc->flags);
 241                 goto out;
 242         }
 243
 244         err = shash_async_init(req);
 245         if (err)
 246                 goto out;
 247
 248         err = shash_async_update(req);
 249         if (err)
 250                 goto out;
 251
 252         err = shash_async_final(req);
 253
 254 out:
 255         return err;
 256 }
 257
 258 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 259 {
 260         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 261
 262         crypto_free_shash(*ctx);
 263 }
 264
 265 static int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 266 {
 267         struct crypto_alg *calg = tfm->__crt_alg;
 268         struct shash_alg *alg = __crypto_shash_alg(calg);
 269         struct ahash_tfm *crt = &tfm->crt_ahash;
 270         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 271         struct crypto_shash *shash;
 272
 273         if (!crypto_mod_get(calg))
 274                 return -EAGAIN;
 275
 276         shash = crypto_create_tfm(calg, &crypto_shash_type);
 277         if (IS_ERR(shash)) {
 278                 crypto_mod_put(calg);
 279                 return PTR_ERR(shash);
 280         }
 281
 282         *ctx = shash;
 283         tfm->exit = crypto_exit_shash_ops_async;
 284
 285         crt->init = shash_async_init;
 286         crt->update = shash_async_update;
 287         crt->final  = shash_async_final;
 288         crt->digest = shash_async_digest;
 289         crt->setkey = shash_async_setkey;
 290
 291         crt->digestsize = alg->digestsize;
 292         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 293
 294         return 0;
 295 }
 296
 297 static int shash_compat_setkey(struct crypto_hash *tfm, const u8 *key,
 298                                unsigned int keylen)
 299 {
 300         struct shash_desc *desc = crypto_hash_ctx(tfm);
 301
 302         return crypto_shash_setkey(desc->tfm, key, keylen);
 303 }
 304
 305 static int shash_compat_init(struct hash_desc *hdesc)
 306 {
 307         struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
 308
 309         desc->flags = hdesc->flags;
 310
 311         return crypto_shash_init(desc);
 312 }
 313
 314 static int shash_compat_update(struct hash_desc *hdesc, struct scatterlist *sg,
 315                                unsigned int len)
 316 {
 317         struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
 318         struct crypto_hash_walk walk;
 319         int nbytes;
 320
 321         for (nbytes = crypto_hash_walk_first_compat(hdesc, &walk, sg, len);
 322              nbytes > 0; nbytes = crypto_hash_walk_done(&walk, nbytes))
 323                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 324
 325         return nbytes;
 326 }
 327
 328 static int shash_compat_final(struct hash_desc *hdesc, u8 *out)
 329 {
 330         return crypto_shash_final(crypto_hash_ctx(hdesc->tfm), out);
 331 }
 332
 333 static int shash_compat_digest(struct hash_desc *hdesc, struct scatterlist *sg,
 334                                unsigned int nbytes, u8 *out)
 335 {
 336         unsigned int offset = sg->offset;
 337         int err;
 338
 339         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 340                 struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
 341                 void *data;
 342
 343                 desc->flags = hdesc->flags;
 344
 345                 data = crypto_kmap(sg_page(sg), 0);
 346                 err = crypto_shash_digest(desc, data + offset, nbytes, out);
 347                 crypto_kunmap(data, 0);
 348                 crypto_yield(desc->flags);
 349                 goto out;
 350         }
 351
 352         err = shash_compat_init(hdesc);
 353         if (err)
 354                 goto out;
 355
 356         err = shash_compat_update(hdesc, sg, nbytes);
 357         if (err)
 358                 goto out;
 359
 360         err = shash_compat_final(hdesc, out);
 361
 362 out:
 363         return err;
 364 }
 365
 366 static void crypto_exit_shash_ops_compat(struct crypto_tfm *tfm)
 367 {
 368         struct shash_desc *desc= crypto_tfm_ctx(tfm);
 369
 370         crypto_free_shash(desc->tfm);
 371 }
 372
 373 static int crypto_init_shash_ops_compat(struct crypto_tfm *tfm)
 374 {
 375         struct hash_tfm *crt = &tfm->crt_hash;
 376         struct crypto_alg *calg = tfm->__crt_alg;
 377         struct shash_alg *alg = __crypto_shash_alg(calg);
 378         struct shash_desc *desc = crypto_tfm_ctx(tfm);
 379         struct crypto_shash *shash;
 380
 381         if (!crypto_mod_get(calg))
 382                 return -EAGAIN;
 383
 384         shash = crypto_create_tfm(calg, &crypto_shash_type);
 385         if (IS_ERR(shash)) {
 386                 crypto_mod_put(calg);
 387                 return PTR_ERR(shash);
 388         }
 389
 390         desc->tfm = shash;
 391         tfm->exit = crypto_exit_shash_ops_compat;
 392
 393         crt->init = shash_compat_init;
 394         crt->update = shash_compat_update;
 395         crt->final  = shash_compat_final;
 396         crt->digest = shash_compat_digest;
 397         crt->setkey = shash_compat_setkey;
 398
 399         crt->digestsize = alg->digestsize;
 400
 401         return 0;
 402 }
 403
 404 static int crypto_init_shash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 405 {
 406         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 407         case CRYPTO_ALG_TYPE_HASH_MASK:
 408                 return crypto_init_shash_ops_compat(tfm);
 409         case CRYPTO_ALG_TYPE_AHASH_MASK:
 410                 return crypto_init_shash_ops_async(tfm);
 411         }
 412
 413         return -EINVAL;
 414 }
 415
 416 static unsigned int crypto_shash_ctxsize(struct crypto_alg *alg, u32 type,
 417                                          u32 mask)
 418 {
 419         struct shash_alg *salg = __crypto_shash_alg(alg);
 420
 421         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 422         case CRYPTO_ALG_TYPE_HASH_MASK:
 423                 return sizeof(struct shash_desc) + salg->descsize;
 424         case CRYPTO_ALG_TYPE_AHASH_MASK:
 425                 return sizeof(struct crypto_shash *);
 426         }
 427
 428         return 0;
 429 }
 430
 431 static int crypto_shash_init_tfm(struct crypto_tfm *tfm,
 432                                  const struct crypto_type *frontend)
 433 {
 434         return 0;
 435 }
 436
 437 static unsigned int crypto_shash_extsize(struct crypto_alg *alg,
 438                                          const struct crypto_type *frontend)
 439 {
 440         return alg->cra_ctxsize;
 441 }
 442
 443 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 444         __attribute__ ((unused));
 445 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 446 {
 447         struct shash_alg *salg = __crypto_shash_alg(alg);
 448
 449         seq_printf(m, "type         : shash\n");
 450         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 451         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 452         seq_printf(m, "descsize     : %u\n", salg->descsize);
 453 }
 454
 455 static const struct crypto_type crypto_shash_type = {
 456         .ctxsize = crypto_shash_ctxsize,
 457         .extsize = crypto_shash_extsize,
 458         .init = crypto_init_shash_ops,
 459         .init_tfm = crypto_shash_init_tfm,
 460 #ifdef CONFIG_PROC_FS
 461         .show = crypto_shash_show,
 462 #endif
 463         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 464         .maskset = CRYPTO_ALG_TYPE_MASK,
 465         .type = CRYPTO_ALG_TYPE_SHASH,
 466         .tfmsize = offsetof(struct crypto_shash, base),
 467 };
 468
 469 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 470                                         u32 mask)
 471 {
 472         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 473 }
 474 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 475
 476 static int shash_prepare_alg(struct shash_alg *alg)
 477 {
 478         struct crypto_alg *base = &alg->base;
 479
 480         if (alg->digestsize > PAGE_SIZE / 8 ||
 481             alg->descsize > PAGE_SIZE / 8 ||
 482             alg->statesize > PAGE_SIZE / 8)
 483                 return -EINVAL;
 484
 485         base->cra_type = &crypto_shash_type;
 486         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 487         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 488
 489         if (!alg->finup)
 490                 alg->finup = shash_finup_unaligned;
 491         if (!alg->digest)
 492                 alg->digest = shash_digest_unaligned;
 493         if (!alg->import)
 494                 alg->import = shash_no_import;
 495         if (!alg->export)
 496                 alg->export = shash_no_export;
 497
 498         return 0;
 499 }
 500
 501 int crypto_register_shash(struct shash_alg *alg)
 502 {
 503         struct crypto_alg *base = &alg->base;
 504         int err;
 505
 506         err = shash_prepare_alg(alg);
 507         if (err)
 508                 return err;
 509
 510         return crypto_register_alg(base);
 511 }
 512 EXPORT_SYMBOL_GPL(crypto_register_shash);
 513
 514 int crypto_unregister_shash(struct shash_alg *alg)
 515 {
 516         return crypto_unregister_alg(&alg->base);
 517 }
 518 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 519
 520 int shash_register_instance(struct crypto_template *tmpl,
 521                             struct shash_instance *inst)
 522 {
 523         int err;
 524
 525         err = shash_prepare_alg(&inst->alg);
 526         if (err)
 527                 return err;
 528
 529         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 530 }
 531 EXPORT_SYMBOL_GPL(shash_register_instance);
 532
 533 void shash_free_instance(struct crypto_instance *inst)
 534 {
 535         crypto_drop_spawn(crypto_instance_ctx(inst));
 536         kfree(shash_instance(inst));
 537 }
 538 EXPORT_SYMBOL_GPL(shash_free_instance);
 539
 540 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
 541                             struct shash_alg *alg,
 542                             struct crypto_instance *inst)
 543 {
 544         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 545                                   &crypto_shash_type);
 546 }
 547 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
 548
 549 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 550 {
 551         struct crypto_alg *alg;
 552
 553         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
 554         return IS_ERR(alg) ? ERR_CAST(alg) :
 555                container_of(alg, struct shash_alg, base);
 556 }
 557 EXPORT_SYMBOL_GPL(shash_attr_alg);
 558
 559 MODULE_LICENSE("GPL");
 560 MODULE_DESCRIPTION("Synchronous cryptographic hash type");