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 #include <linux/cryptouser.h>
  21 #include <net/netlink.h>
  22
  23 #include "internal.h"
  24
  25 static const struct crypto_type crypto_shash_type;
  26
  27 int shash_no_setkey(struct crypto_shash *tfm, const u8 *key,
  28                     unsigned int keylen)
  29 {
  30         return -ENOSYS;
  31 }
  32 EXPORT_SYMBOL_GPL(shash_no_setkey);
  33
  34 static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
  35                                   unsigned int keylen)
  36 {
  37         struct shash_alg *shash = crypto_shash_alg(tfm);
  38         unsigned long alignmask = crypto_shash_alignmask(tfm);
  39         unsigned long absize;
  40         u8 *buffer, *alignbuffer;
  41         int err;
  42
  43         absize = keylen + (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
  44         buffer = kmalloc(absize, GFP_KERNEL);
  45         if (!buffer)
  46                 return -ENOMEM;
  47
  48         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  49         memcpy(alignbuffer, key, keylen);
  50         err = shash->setkey(tfm, alignbuffer, keylen);
  51         kzfree(buffer);
  52         return err;
  53 }
  54
  55 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
  56                         unsigned int keylen)
  57 {
  58         struct shash_alg *shash = crypto_shash_alg(tfm);
  59         unsigned long alignmask = crypto_shash_alignmask(tfm);
  60         int err;
  61
  62         if ((unsigned long)key & alignmask)
  63                 err = shash_setkey_unaligned(tfm, key, keylen);
  64         else
  65                 err = shash->setkey(tfm, key, keylen);
  66
  67         if (err)
  68                 return err;
  69
  70         crypto_shash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
  71         return 0;
  72 }
  73 EXPORT_SYMBOL_GPL(crypto_shash_setkey);
  74
  75 static inline unsigned int shash_align_buffer_size(unsigned len,
  76                                                    unsigned long mask)
  77 {
  78         typedef u8 __attribute__ ((aligned)) u8_aligned;
  79         return len + (mask & ~(__alignof__(u8_aligned) - 1));
  80 }
  81
  82 static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
  83                                   unsigned int len)
  84 {
  85         struct crypto_shash *tfm = desc->tfm;
  86         struct shash_alg *shash = crypto_shash_alg(tfm);
  87         unsigned long alignmask = crypto_shash_alignmask(tfm);
  88         unsigned int unaligned_len = alignmask + 1 -
  89                                      ((unsigned long)data & alignmask);
  90         u8 ubuf[shash_align_buffer_size(unaligned_len, alignmask)]
  91                 __attribute__ ((aligned));
  92         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
  93         int err;
  94
  95         if (unaligned_len > len)
  96                 unaligned_len = len;
  97
  98         memcpy(buf, data, unaligned_len);
  99         err = shash->update(desc, buf, unaligned_len);
 100         memset(buf, 0, unaligned_len);
 101
 102         return err ?:
 103                shash->update(desc, data + unaligned_len, len - unaligned_len);
 104 }
 105
 106 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
 107                         unsigned int len)
 108 {
 109         struct crypto_shash *tfm = desc->tfm;
 110         struct shash_alg *shash = crypto_shash_alg(tfm);
 111         unsigned long alignmask = crypto_shash_alignmask(tfm);
 112
 113         if ((unsigned long)data & alignmask)
 114                 return shash_update_unaligned(desc, data, len);
 115
 116         return shash->update(desc, data, len);
 117 }
 118 EXPORT_SYMBOL_GPL(crypto_shash_update);
 119
 120 static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
 121 {
 122         struct crypto_shash *tfm = desc->tfm;
 123         unsigned long alignmask = crypto_shash_alignmask(tfm);
 124         struct shash_alg *shash = crypto_shash_alg(tfm);
 125         unsigned int ds = crypto_shash_digestsize(tfm);
 126         u8 ubuf[shash_align_buffer_size(ds, alignmask)]
 127                 __attribute__ ((aligned));
 128         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
 129         int err;
 130
 131         err = shash->final(desc, buf);
 132         if (err)
 133                 goto out;
 134
 135         memcpy(out, buf, ds);
 136
 137 out:
 138         memset(buf, 0, ds);
 139         return err;
 140 }
 141
 142 int crypto_shash_final(struct shash_desc *desc, 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)out & alignmask)
 149                 return shash_final_unaligned(desc, out);
 150
 151         return shash->final(desc, out);
 152 }
 153 EXPORT_SYMBOL_GPL(crypto_shash_final);
 154
 155 static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
 156                                  unsigned int len, u8 *out)
 157 {
 158         return crypto_shash_update(desc, data, len) ?:
 159                crypto_shash_final(desc, out);
 160 }
 161
 162 int crypto_shash_finup(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_finup_unaligned(desc, data, len, out);
 171
 172         return shash->finup(desc, data, len, out);
 173 }
 174 EXPORT_SYMBOL_GPL(crypto_shash_finup);
 175
 176 static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
 177                                   unsigned int len, u8 *out)
 178 {
 179         return crypto_shash_init(desc) ?:
 180                crypto_shash_finup(desc, data, len, out);
 181 }
 182
 183 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
 184                         unsigned int len, u8 *out)
 185 {
 186         struct crypto_shash *tfm = desc->tfm;
 187         struct shash_alg *shash = crypto_shash_alg(tfm);
 188         unsigned long alignmask = crypto_shash_alignmask(tfm);
 189
 190         if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
 191                 return -ENOKEY;
 192
 193         if (((unsigned long)data | (unsigned long)out) & alignmask)
 194                 return shash_digest_unaligned(desc, data, len, out);
 195
 196         return shash->digest(desc, data, len, out);
 197 }
 198 EXPORT_SYMBOL_GPL(crypto_shash_digest);
 199
 200 static int shash_default_export(struct shash_desc *desc, void *out)
 201 {
 202         memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm));
 203         return 0;
 204 }
 205
 206 static int shash_default_import(struct shash_desc *desc, const void *in)
 207 {
 208         memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm));
 209         return 0;
 210 }
 211
 212 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 213                               unsigned int keylen)
 214 {
 215         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
 216
 217         return crypto_shash_setkey(*ctx, key, keylen);
 218 }
 219
 220 static int shash_async_init(struct ahash_request *req)
 221 {
 222         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 223         struct shash_desc *desc = ahash_request_ctx(req);
 224
 225         desc->tfm = *ctx;
 226         desc->flags = req->base.flags;
 227
 228         return crypto_shash_init(desc);
 229 }
 230
 231 int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
 232 {
 233         struct crypto_hash_walk walk;
 234         int nbytes;
 235
 236         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
 237              nbytes = crypto_hash_walk_done(&walk, nbytes))
 238                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 239
 240         return nbytes;
 241 }
 242 EXPORT_SYMBOL_GPL(shash_ahash_update);
 243
 244 static int shash_async_update(struct ahash_request *req)
 245 {
 246         return shash_ahash_update(req, ahash_request_ctx(req));
 247 }
 248
 249 static int shash_async_final(struct ahash_request *req)
 250 {
 251         return crypto_shash_final(ahash_request_ctx(req), req->result);
 252 }
 253
 254 int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
 255 {
 256         struct crypto_hash_walk walk;
 257         int nbytes;
 258
 259         nbytes = crypto_hash_walk_first(req, &walk);
 260         if (!nbytes)
 261                 return crypto_shash_final(desc, req->result);
 262
 263         do {
 264                 nbytes = crypto_hash_walk_last(&walk) ?
 265                          crypto_shash_finup(desc, walk.data, nbytes,
 266                                             req->result) :
 267                          crypto_shash_update(desc, walk.data, nbytes);
 268                 nbytes = crypto_hash_walk_done(&walk, nbytes);
 269         } while (nbytes > 0);
 270
 271         return nbytes;
 272 }
 273 EXPORT_SYMBOL_GPL(shash_ahash_finup);
 274
 275 static int shash_async_finup(struct ahash_request *req)
 276 {
 277         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 278         struct shash_desc *desc = ahash_request_ctx(req);
 279
 280         desc->tfm = *ctx;
 281         desc->flags = req->base.flags;
 282
 283         return shash_ahash_finup(req, desc);
 284 }
 285
 286 int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
 287 {
 288         unsigned int nbytes = req->nbytes;
 289         struct scatterlist *sg;
 290         unsigned int offset;
 291         int err;
 292
 293         if (nbytes &&
 294             (sg = req->src, offset = sg->offset,
 295              nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset))) {
 296                 void *data;
 297
 298                 data = kmap_atomic(sg_page(sg));
 299                 err = crypto_shash_digest(desc, data + offset, nbytes,
 300                                           req->result);
 301                 kunmap_atomic(data);
 302                 crypto_yield(desc->flags);
 303         } else
 304                 err = crypto_shash_init(desc) ?:
 305                       shash_ahash_finup(req, desc);
 306
 307         return err;
 308 }
 309 EXPORT_SYMBOL_GPL(shash_ahash_digest);
 310
 311 static int shash_async_digest(struct ahash_request *req)
 312 {
 313         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 314         struct shash_desc *desc = ahash_request_ctx(req);
 315
 316         desc->tfm = *ctx;
 317         desc->flags = req->base.flags;
 318
 319         return shash_ahash_digest(req, desc);
 320 }
 321
 322 static int shash_async_export(struct ahash_request *req, void *out)
 323 {
 324         return crypto_shash_export(ahash_request_ctx(req), out);
 325 }
 326
 327 static int shash_async_import(struct ahash_request *req, const void *in)
 328 {
 329         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 330         struct shash_desc *desc = ahash_request_ctx(req);
 331
 332         desc->tfm = *ctx;
 333         desc->flags = req->base.flags;
 334
 335         return crypto_shash_import(desc, in);
 336 }
 337
 338 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 339 {
 340         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 341
 342         crypto_free_shash(*ctx);
 343 }
 344
 345 int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 346 {
 347         struct crypto_alg *calg = tfm->__crt_alg;
 348         struct shash_alg *alg = __crypto_shash_alg(calg);
 349         struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
 350         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 351         struct crypto_shash *shash;
 352
 353         if (!crypto_mod_get(calg))
 354                 return -EAGAIN;
 355
 356         shash = crypto_create_tfm(calg, &crypto_shash_type);
 357         if (IS_ERR(shash)) {
 358                 crypto_mod_put(calg);
 359                 return PTR_ERR(shash);
 360         }
 361
 362         *ctx = shash;
 363         tfm->exit = crypto_exit_shash_ops_async;
 364
 365         crt->init = shash_async_init;
 366         crt->update = shash_async_update;
 367         crt->final = shash_async_final;
 368         crt->finup = shash_async_finup;
 369         crt->digest = shash_async_digest;
 370         crt->setkey = shash_async_setkey;
 371
 372         crypto_ahash_set_flags(crt, crypto_shash_get_flags(shash) &
 373                                     CRYPTO_TFM_NEED_KEY);
 374
 375         if (alg->export)
 376                 crt->export = shash_async_export;
 377         if (alg->import)
 378                 crt->import = shash_async_import;
 379
 380         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 381
 382         return 0;
 383 }
 384
 385 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
 386 {
 387         struct crypto_shash *hash = __crypto_shash_cast(tfm);
 388         struct shash_alg *alg = crypto_shash_alg(hash);
 389
 390         hash->descsize = alg->descsize;
 391
 392         if (crypto_shash_alg_has_setkey(alg) &&
 393             !(alg->base.cra_flags & CRYPTO_ALG_OPTIONAL_KEY))
 394                 crypto_shash_set_flags(hash, CRYPTO_TFM_NEED_KEY);
 395
 396         return 0;
 397 }
 398
 399 #ifdef CONFIG_NET
 400 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 401 {
 402         struct crypto_report_hash rhash;
 403         struct shash_alg *salg = __crypto_shash_alg(alg);
 404
 405         strncpy(rhash.type, "shash", sizeof(rhash.type));
 406
 407         rhash.blocksize = alg->cra_blocksize;
 408         rhash.digestsize = salg->digestsize;
 409
 410         if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
 411                     sizeof(struct crypto_report_hash), &rhash))
 412                 goto nla_put_failure;
 413         return 0;
 414
 415 nla_put_failure:
 416         return -EMSGSIZE;
 417 }
 418 #else
 419 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 420 {
 421         return -ENOSYS;
 422 }
 423 #endif
 424
 425 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 426         __attribute__ ((unused));
 427 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 428 {
 429         struct shash_alg *salg = __crypto_shash_alg(alg);
 430
 431         seq_printf(m, "type         : shash\n");
 432         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 433         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 434 }
 435
 436 static const struct crypto_type crypto_shash_type = {
 437         .extsize = crypto_alg_extsize,
 438         .init_tfm = crypto_shash_init_tfm,
 439 #ifdef CONFIG_PROC_FS
 440         .show = crypto_shash_show,
 441 #endif
 442         .report = crypto_shash_report,
 443         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 444         .maskset = CRYPTO_ALG_TYPE_MASK,
 445         .type = CRYPTO_ALG_TYPE_SHASH,
 446         .tfmsize = offsetof(struct crypto_shash, base),
 447 };
 448
 449 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 450                                         u32 mask)
 451 {
 452         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 453 }
 454 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 455
 456 static int shash_prepare_alg(struct shash_alg *alg)
 457 {
 458         struct crypto_alg *base = &alg->base;
 459
 460         if (alg->digestsize > PAGE_SIZE / 8 ||
 461             alg->descsize > PAGE_SIZE / 8 ||
 462             alg->statesize > PAGE_SIZE / 8)
 463                 return -EINVAL;
 464
 465         base->cra_type = &crypto_shash_type;
 466         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 467         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 468
 469         if (!alg->finup)
 470                 alg->finup = shash_finup_unaligned;
 471         if (!alg->digest)
 472                 alg->digest = shash_digest_unaligned;
 473         if (!alg->export) {
 474                 alg->export = shash_default_export;
 475                 alg->import = shash_default_import;
 476                 alg->statesize = alg->descsize;
 477         }
 478         if (!alg->setkey)
 479                 alg->setkey = shash_no_setkey;
 480
 481         return 0;
 482 }
 483
 484 int crypto_register_shash(struct shash_alg *alg)
 485 {
 486         struct crypto_alg *base = &alg->base;
 487         int err;
 488
 489         err = shash_prepare_alg(alg);
 490         if (err)
 491                 return err;
 492
 493         return crypto_register_alg(base);
 494 }
 495 EXPORT_SYMBOL_GPL(crypto_register_shash);
 496
 497 int crypto_unregister_shash(struct shash_alg *alg)
 498 {
 499         return crypto_unregister_alg(&alg->base);
 500 }
 501 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 502
 503 int crypto_register_shashes(struct shash_alg *algs, int count)
 504 {
 505         int i, ret;
 506
 507         for (i = 0; i < count; i++) {
 508                 ret = crypto_register_shash(&algs[i]);
 509                 if (ret)
 510                         goto err;
 511         }
 512
 513         return 0;
 514
 515 err:
 516         for (--i; i >= 0; --i)
 517                 crypto_unregister_shash(&algs[i]);
 518
 519         return ret;
 520 }
 521 EXPORT_SYMBOL_GPL(crypto_register_shashes);
 522
 523 int crypto_unregister_shashes(struct shash_alg *algs, int count)
 524 {
 525         int i, ret;
 526
 527         for (i = count - 1; i >= 0; --i) {
 528                 ret = crypto_unregister_shash(&algs[i]);
 529                 if (ret)
 530                         pr_err("Failed to unregister %s %s: %d\n",
 531                                algs[i].base.cra_driver_name,
 532                                algs[i].base.cra_name, ret);
 533         }
 534
 535         return 0;
 536 }
 537 EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
 538
 539 int shash_register_instance(struct crypto_template *tmpl,
 540                             struct shash_instance *inst)
 541 {
 542         int err;
 543
 544         err = shash_prepare_alg(&inst->alg);
 545         if (err)
 546                 return err;
 547
 548         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 549 }
 550 EXPORT_SYMBOL_GPL(shash_register_instance);
 551
 552 void shash_free_instance(struct crypto_instance *inst)
 553 {
 554         crypto_drop_spawn(crypto_instance_ctx(inst));
 555         kfree(shash_instance(inst));
 556 }
 557 EXPORT_SYMBOL_GPL(shash_free_instance);
 558
 559 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
 560                             struct shash_alg *alg,
 561                             struct crypto_instance *inst)
 562 {
 563         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 564                                   &crypto_shash_type);
 565 }
 566 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
 567
 568 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 569 {
 570         struct crypto_alg *alg;
 571
 572         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
 573         return IS_ERR(alg) ? ERR_CAST(alg) :
 574                container_of(alg, struct shash_alg, base);
 575 }
 576 EXPORT_SYMBOL_GPL(shash_attr_alg);
 577
 578 MODULE_LICENSE("GPL");
 579 MODULE_DESCRIPTION("Synchronous cryptographic hash type");