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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_no_setkey(struct crypto_shash *tfm, const u8 *key,
  26                            unsigned int keylen)
  27 {
  28         return -ENOSYS;
  29 }
  30
  31 static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
  32                                   unsigned int keylen)
  33 {
  34         struct shash_alg *shash = crypto_shash_alg(tfm);
  35         unsigned long alignmask = crypto_shash_alignmask(tfm);
  36         unsigned long absize;
  37         u8 *buffer, *alignbuffer;
  38         int err;
  39
  40         absize = keylen + (alignmask & ~(CRYPTO_MINALIGN - 1));
  41         buffer = kmalloc(absize, GFP_KERNEL);
  42         if (!buffer)
  43                 return -ENOMEM;
  44
  45         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  46         memcpy(alignbuffer, key, keylen);
  47         err = shash->setkey(tfm, alignbuffer, keylen);
  48         memset(alignbuffer, 0, keylen);
  49         kfree(buffer);
  50         return err;
  51 }
  52
  53 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
  54                         unsigned int keylen)
  55 {
  56         struct shash_alg *shash = crypto_shash_alg(tfm);
  57         unsigned long alignmask = crypto_shash_alignmask(tfm);
  58
  59         if ((unsigned long)key & alignmask)
  60                 return shash_setkey_unaligned(tfm, key, keylen);
  61
  62         return shash->setkey(tfm, key, keylen);
  63 }
  64 EXPORT_SYMBOL_GPL(crypto_shash_setkey);
  65
  66 static inline unsigned int shash_align_buffer_size(unsigned len,
  67                                                    unsigned long mask)
  68 {
  69         return len + (mask & ~(__alignof__(u8 __attribute__ ((aligned))) - 1));
  70 }
  71
  72 static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
  73                                   unsigned int len)
  74 {
  75         struct crypto_shash *tfm = desc->tfm;
  76         struct shash_alg *shash = crypto_shash_alg(tfm);
  77         unsigned long alignmask = crypto_shash_alignmask(tfm);
  78         unsigned int unaligned_len = alignmask + 1 -
  79                                      ((unsigned long)data & alignmask);
  80         u8 buf[shash_align_buffer_size(unaligned_len, alignmask)]
  81                 __attribute__ ((aligned));
  82
  83         if (unaligned_len > len)
  84                 unaligned_len = len;
  85
  86         memcpy(buf, data, unaligned_len);
  87
  88         return shash->update(desc, buf, unaligned_len) ?:
  89                shash->update(desc, data + unaligned_len, len - unaligned_len);
  90 }
  91
  92 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
  93                         unsigned int len)
  94 {
  95         struct crypto_shash *tfm = desc->tfm;
  96         struct shash_alg *shash = crypto_shash_alg(tfm);
  97         unsigned long alignmask = crypto_shash_alignmask(tfm);
  98
  99         if ((unsigned long)data & alignmask)
 100                 return shash_update_unaligned(desc, data, len);
 101
 102         return shash->update(desc, data, len);
 103 }
 104 EXPORT_SYMBOL_GPL(crypto_shash_update);
 105
 106 static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
 107 {
 108         struct crypto_shash *tfm = desc->tfm;
 109         unsigned long alignmask = crypto_shash_alignmask(tfm);
 110         struct shash_alg *shash = crypto_shash_alg(tfm);
 111         unsigned int ds = crypto_shash_digestsize(tfm);
 112         u8 buf[shash_align_buffer_size(ds, alignmask)]
 113                 __attribute__ ((aligned));
 114         int err;
 115
 116         err = shash->final(desc, buf);
 117         memcpy(out, buf, ds);
 118         return err;
 119 }
 120
 121 int crypto_shash_final(struct shash_desc *desc, u8 *out)
 122 {
 123         struct crypto_shash *tfm = desc->tfm;
 124         struct shash_alg *shash = crypto_shash_alg(tfm);
 125         unsigned long alignmask = crypto_shash_alignmask(tfm);
 126
 127         if ((unsigned long)out & alignmask)
 128                 return shash_final_unaligned(desc, out);
 129
 130         return shash->final(desc, out);
 131 }
 132 EXPORT_SYMBOL_GPL(crypto_shash_final);
 133
 134 static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
 135                                  unsigned int len, u8 *out)
 136 {
 137         return crypto_shash_update(desc, data, len) ?:
 138                crypto_shash_final(desc, out);
 139 }
 140
 141 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
 142                        unsigned int len, u8 *out)
 143 {
 144         struct crypto_shash *tfm = desc->tfm;
 145         struct shash_alg *shash = crypto_shash_alg(tfm);
 146         unsigned long alignmask = crypto_shash_alignmask(tfm);
 147
 148         if (((unsigned long)data | (unsigned long)out) & alignmask)
 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_finup(desc, data, len, out);
 160 }
 161
 162 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
 163                         unsigned int len, u8 *out)
 164 {
 165         struct crypto_shash *tfm = desc->tfm;
 166         struct shash_alg *shash = crypto_shash_alg(tfm);
 167         unsigned long alignmask = crypto_shash_alignmask(tfm);
 168
 169         if (((unsigned long)data | (unsigned long)out) & alignmask)
 170                 return shash_digest_unaligned(desc, data, len, out);
 171
 172         return shash->digest(desc, data, len, out);
 173 }
 174 EXPORT_SYMBOL_GPL(crypto_shash_digest);
 175
 176 static int shash_no_export(struct shash_desc *desc, void *out)
 177 {
 178         return -ENOSYS;
 179 }
 180
 181 static int shash_no_import(struct shash_desc *desc, const void *in)
 182 {
 183         return -ENOSYS;
 184 }
 185
 186 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 187                               unsigned int keylen)
 188 {
 189         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
 190
 191         return crypto_shash_setkey(*ctx, key, keylen);
 192 }
 193
 194 static int shash_async_init(struct ahash_request *req)
 195 {
 196         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 197         struct shash_desc *desc = ahash_request_ctx(req);
 198
 199         desc->tfm = *ctx;
 200         desc->flags = req->base.flags;
 201
 202         return crypto_shash_init(desc);
 203 }
 204
 205 int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
 206 {
 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 EXPORT_SYMBOL_GPL(shash_ahash_update);
 217
 218 static int shash_async_update(struct ahash_request *req)
 219 {
 220         return shash_ahash_update(req, ahash_request_ctx(req));
 221 }
 222
 223 static int shash_async_final(struct ahash_request *req)
 224 {
 225         return crypto_shash_final(ahash_request_ctx(req), req->result);
 226 }
 227
 228 int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
 229 {
 230         struct scatterlist *sg = req->src;
 231         unsigned int offset = sg->offset;
 232         unsigned int nbytes = req->nbytes;
 233         int err;
 234
 235         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 236                 void *data;
 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         } else
 244                 err = crypto_shash_init(desc) ?:
 245                       shash_ahash_update(req, desc) ?:
 246                       crypto_shash_final(desc, req->result);
 247
 248         return err;
 249 }
 250 EXPORT_SYMBOL_GPL(shash_ahash_digest);
 251
 252 static int shash_async_digest(struct ahash_request *req)
 253 {
 254         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 255         struct shash_desc *desc = ahash_request_ctx(req);
 256
 257         desc->tfm = *ctx;
 258         desc->flags = req->base.flags;
 259
 260         return shash_ahash_digest(req, desc);
 261 }
 262
 263 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 264 {
 265         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 266
 267         crypto_free_shash(*ctx);
 268 }
 269
 270 int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 271 {
 272         struct crypto_alg *calg = tfm->__crt_alg;
 273         struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
 274         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 275         struct crypto_shash *shash;
 276
 277         if (!crypto_mod_get(calg))
 278                 return -EAGAIN;
 279
 280         shash = crypto_create_tfm(calg, &crypto_shash_type);
 281         if (IS_ERR(shash)) {
 282                 crypto_mod_put(calg);
 283                 return PTR_ERR(shash);
 284         }
 285
 286         *ctx = shash;
 287         tfm->exit = crypto_exit_shash_ops_async;
 288
 289         crt->init = shash_async_init;
 290         crt->update = shash_async_update;
 291         crt->final  = shash_async_final;
 292         crt->digest = shash_async_digest;
 293         crt->setkey = shash_async_setkey;
 294
 295         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 296
 297         return 0;
 298 }
 299
 300 static int shash_compat_setkey(struct crypto_hash *tfm, const u8 *key,
 301                                unsigned int keylen)
 302 {
 303         struct shash_desc **descp = crypto_hash_ctx(tfm);
 304         struct shash_desc *desc = *descp;
 305
 306         return crypto_shash_setkey(desc->tfm, key, keylen);
 307 }
 308
 309 static int shash_compat_init(struct hash_desc *hdesc)
 310 {
 311         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
 312         struct shash_desc *desc = *descp;
 313
 314         desc->flags = hdesc->flags;
 315
 316         return crypto_shash_init(desc);
 317 }
 318
 319 static int shash_compat_update(struct hash_desc *hdesc, struct scatterlist *sg,
 320                                unsigned int len)
 321 {
 322         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
 323         struct shash_desc *desc = *descp;
 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         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
 337
 338         return crypto_shash_final(*descp, out);
 339 }
 340
 341 static int shash_compat_digest(struct hash_desc *hdesc, struct scatterlist *sg,
 342                                unsigned int nbytes, u8 *out)
 343 {
 344         unsigned int offset = sg->offset;
 345         int err;
 346
 347         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 348                 struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
 349                 struct shash_desc *desc = *descp;
 350                 void *data;
 351
 352                 desc->flags = hdesc->flags;
 353
 354                 data = crypto_kmap(sg_page(sg), 0);
 355                 err = crypto_shash_digest(desc, data + offset, nbytes, out);
 356                 crypto_kunmap(data, 0);
 357                 crypto_yield(desc->flags);
 358                 goto out;
 359         }
 360
 361         err = shash_compat_init(hdesc);
 362         if (err)
 363                 goto out;
 364
 365         err = shash_compat_update(hdesc, sg, nbytes);
 366         if (err)
 367                 goto out;
 368
 369         err = shash_compat_final(hdesc, out);
 370
 371 out:
 372         return err;
 373 }
 374
 375 static void crypto_exit_shash_ops_compat(struct crypto_tfm *tfm)
 376 {
 377         struct shash_desc **descp = crypto_tfm_ctx(tfm);
 378         struct shash_desc *desc = *descp;
 379
 380         crypto_free_shash(desc->tfm);
 381         kzfree(desc);
 382 }
 383
 384 static int crypto_init_shash_ops_compat(struct crypto_tfm *tfm)
 385 {
 386         struct hash_tfm *crt = &tfm->crt_hash;
 387         struct crypto_alg *calg = tfm->__crt_alg;
 388         struct shash_alg *alg = __crypto_shash_alg(calg);
 389         struct shash_desc **descp = crypto_tfm_ctx(tfm);
 390         struct crypto_shash *shash;
 391         struct shash_desc *desc;
 392
 393         if (!crypto_mod_get(calg))
 394                 return -EAGAIN;
 395
 396         shash = crypto_create_tfm(calg, &crypto_shash_type);
 397         if (IS_ERR(shash)) {
 398                 crypto_mod_put(calg);
 399                 return PTR_ERR(shash);
 400         }
 401
 402         desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(shash),
 403                        GFP_KERNEL);
 404         if (!desc) {
 405                 crypto_free_shash(shash);
 406                 return -ENOMEM;
 407         }
 408
 409         *descp = desc;
 410         desc->tfm = shash;
 411         tfm->exit = crypto_exit_shash_ops_compat;
 412
 413         crt->init = shash_compat_init;
 414         crt->update = shash_compat_update;
 415         crt->final  = shash_compat_final;
 416         crt->digest = shash_compat_digest;
 417         crt->setkey = shash_compat_setkey;
 418
 419         crt->digestsize = alg->digestsize;
 420
 421         return 0;
 422 }
 423
 424 static int crypto_init_shash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 425 {
 426         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 427         case CRYPTO_ALG_TYPE_HASH_MASK:
 428                 return crypto_init_shash_ops_compat(tfm);
 429         }
 430
 431         return -EINVAL;
 432 }
 433
 434 static unsigned int crypto_shash_ctxsize(struct crypto_alg *alg, u32 type,
 435                                          u32 mask)
 436 {
 437         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 438         case CRYPTO_ALG_TYPE_HASH_MASK:
 439                 return sizeof(struct shash_desc *);
 440         }
 441
 442         return 0;
 443 }
 444
 445 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
 446 {
 447         struct crypto_shash *hash = __crypto_shash_cast(tfm);
 448
 449         hash->descsize = crypto_shash_alg(hash)->descsize;
 450         return 0;
 451 }
 452
 453 static unsigned int crypto_shash_extsize(struct crypto_alg *alg)
 454 {
 455         return alg->cra_ctxsize;
 456 }
 457
 458 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 459         __attribute__ ((unused));
 460 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 461 {
 462         struct shash_alg *salg = __crypto_shash_alg(alg);
 463
 464         seq_printf(m, "type         : shash\n");
 465         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 466         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 467 }
 468
 469 static const struct crypto_type crypto_shash_type = {
 470         .ctxsize = crypto_shash_ctxsize,
 471         .extsize = crypto_shash_extsize,
 472         .init = crypto_init_shash_ops,
 473         .init_tfm = crypto_shash_init_tfm,
 474 #ifdef CONFIG_PROC_FS
 475         .show = crypto_shash_show,
 476 #endif
 477         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 478         .maskset = CRYPTO_ALG_TYPE_MASK,
 479         .type = CRYPTO_ALG_TYPE_SHASH,
 480         .tfmsize = offsetof(struct crypto_shash, base),
 481 };
 482
 483 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 484                                         u32 mask)
 485 {
 486         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 487 }
 488 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 489
 490 static int shash_prepare_alg(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             alg->statesize > PAGE_SIZE / 8)
 497                 return -EINVAL;
 498
 499         base->cra_type = &crypto_shash_type;
 500         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 501         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 502
 503         if (!alg->finup)
 504                 alg->finup = shash_finup_unaligned;
 505         if (!alg->digest)
 506                 alg->digest = shash_digest_unaligned;
 507         if (!alg->import)
 508                 alg->import = shash_no_import;
 509         if (!alg->export)
 510                 alg->export = shash_no_export;
 511         if (!alg->setkey)
 512                 alg->setkey = shash_no_setkey;
 513
 514         return 0;
 515 }
 516
 517 int crypto_register_shash(struct shash_alg *alg)
 518 {
 519         struct crypto_alg *base = &alg->base;
 520         int err;
 521
 522         err = shash_prepare_alg(alg);
 523         if (err)
 524                 return err;
 525
 526         return crypto_register_alg(base);
 527 }
 528 EXPORT_SYMBOL_GPL(crypto_register_shash);
 529
 530 int crypto_unregister_shash(struct shash_alg *alg)
 531 {
 532         return crypto_unregister_alg(&alg->base);
 533 }
 534 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 535
 536 int shash_register_instance(struct crypto_template *tmpl,
 537                             struct shash_instance *inst)
 538 {
 539         int err;
 540
 541         err = shash_prepare_alg(&inst->alg);
 542         if (err)
 543                 return err;
 544
 545         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 546 }
 547 EXPORT_SYMBOL_GPL(shash_register_instance);
 548
 549 void shash_free_instance(struct crypto_instance *inst)
 550 {
 551         crypto_drop_spawn(crypto_instance_ctx(inst));
 552         kfree(shash_instance(inst));
 553 }
 554 EXPORT_SYMBOL_GPL(shash_free_instance);
 555
 556 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
 557                             struct shash_alg *alg,
 558                             struct crypto_instance *inst)
 559 {
 560         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 561                                   &crypto_shash_type);
 562 }
 563 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
 564
 565 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 566 {
 567         struct crypto_alg *alg;
 568
 569         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
 570         return IS_ERR(alg) ? ERR_CAST(alg) :
 571                container_of(alg, struct shash_alg, base);
 572 }
 573 EXPORT_SYMBOL_GPL(shash_attr_alg);
 574
 575 MODULE_LICENSE("GPL");
 576 MODULE_DESCRIPTION("Synchronous cryptographic hash type");