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 #include <linux/compiler.h>
  23
  24 #include "internal.h"
  25
  26 static const struct crypto_type crypto_shash_type;
  27
  28 static int shash_no_setkey(struct crypto_shash *tfm, const u8 *key,
  29                            unsigned int keylen)
  30 {
  31         return -ENOSYS;
  32 }
  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
  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         typedef u8 __aligned_largest u8_aligned;
  72         return len + (mask & ~(__alignof__(u8_aligned) - 1));
  73 }
  74
  75 static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
  76                                   unsigned int len)
  77 {
  78         struct crypto_shash *tfm = desc->tfm;
  79         struct shash_alg *shash = crypto_shash_alg(tfm);
  80         unsigned long alignmask = crypto_shash_alignmask(tfm);
  81         unsigned int unaligned_len = alignmask + 1 -
  82                                      ((unsigned long)data & alignmask);
  83         u8 ubuf[shash_align_buffer_size(unaligned_len, alignmask)]
  84                 __aligned_largest;
  85         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
  86         int err;
  87
  88         if (unaligned_len > len)
  89                 unaligned_len = len;
  90
  91         memcpy(buf, data, unaligned_len);
  92         err = shash->update(desc, buf, unaligned_len);
  93         memset(buf, 0, unaligned_len);
  94
  95         return err ?:
  96                shash->update(desc, data + unaligned_len, len - unaligned_len);
  97 }
  98
  99 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
 100                         unsigned int len)
 101 {
 102         struct crypto_shash *tfm = desc->tfm;
 103         struct shash_alg *shash = crypto_shash_alg(tfm);
 104         unsigned long alignmask = crypto_shash_alignmask(tfm);
 105
 106         if ((unsigned long)data & alignmask)
 107                 return shash_update_unaligned(desc, data, len);
 108
 109         return shash->update(desc, data, len);
 110 }
 111 EXPORT_SYMBOL_GPL(crypto_shash_update);
 112
 113 static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
 114 {
 115         struct crypto_shash *tfm = desc->tfm;
 116         unsigned long alignmask = crypto_shash_alignmask(tfm);
 117         struct shash_alg *shash = crypto_shash_alg(tfm);
 118         unsigned int ds = crypto_shash_digestsize(tfm);
 119         u8 ubuf[shash_align_buffer_size(ds, alignmask)]
 120                 __aligned_largest;
 121         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
 122         int err;
 123
 124         err = shash->final(desc, buf);
 125         if (err)
 126                 goto out;
 127
 128         memcpy(out, buf, ds);
 129
 130 out:
 131         memset(buf, 0, ds);
 132         return err;
 133 }
 134
 135 int crypto_shash_final(struct shash_desc *desc, u8 *out)
 136 {
 137         struct crypto_shash *tfm = desc->tfm;
 138         struct shash_alg *shash = crypto_shash_alg(tfm);
 139         unsigned long alignmask = crypto_shash_alignmask(tfm);
 140
 141         if ((unsigned long)out & alignmask)
 142                 return shash_final_unaligned(desc, out);
 143
 144         return shash->final(desc, out);
 145 }
 146 EXPORT_SYMBOL_GPL(crypto_shash_final);
 147
 148 static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
 149                                  unsigned int len, u8 *out)
 150 {
 151         return crypto_shash_update(desc, data, len) ?:
 152                crypto_shash_final(desc, out);
 153 }
 154
 155 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
 156                        unsigned int len, u8 *out)
 157 {
 158         struct crypto_shash *tfm = desc->tfm;
 159         struct shash_alg *shash = crypto_shash_alg(tfm);
 160         unsigned long alignmask = crypto_shash_alignmask(tfm);
 161
 162         if (((unsigned long)data | (unsigned long)out) & alignmask)
 163                 return shash_finup_unaligned(desc, data, len, out);
 164
 165         return shash->finup(desc, data, len, out);
 166 }
 167 EXPORT_SYMBOL_GPL(crypto_shash_finup);
 168
 169 static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
 170                                   unsigned int len, u8 *out)
 171 {
 172         return crypto_shash_init(desc) ?:
 173                crypto_shash_finup(desc, data, len, out);
 174 }
 175
 176 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
 177                         unsigned int len, u8 *out)
 178 {
 179         struct crypto_shash *tfm = desc->tfm;
 180         struct shash_alg *shash = crypto_shash_alg(tfm);
 181         unsigned long alignmask = crypto_shash_alignmask(tfm);
 182
 183         if (((unsigned long)data | (unsigned long)out) & alignmask)
 184                 return shash_digest_unaligned(desc, data, len, out);
 185
 186         return shash->digest(desc, data, len, out);
 187 }
 188 EXPORT_SYMBOL_GPL(crypto_shash_digest);
 189
 190 static int shash_default_export(struct shash_desc *desc, void *out)
 191 {
 192         memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm));
 193         return 0;
 194 }
 195
 196 static int shash_default_import(struct shash_desc *desc, const void *in)
 197 {
 198         memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm));
 199         return 0;
 200 }
 201
 202 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 203                               unsigned int keylen)
 204 {
 205         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
 206
 207         return crypto_shash_setkey(*ctx, key, keylen);
 208 }
 209
 210 static int shash_async_init(struct ahash_request *req)
 211 {
 212         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 213         struct shash_desc *desc = ahash_request_ctx(req);
 214
 215         desc->tfm = *ctx;
 216         desc->flags = req->base.flags;
 217
 218         return crypto_shash_init(desc);
 219 }
 220
 221 int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
 222 {
 223         struct crypto_hash_walk walk;
 224         int nbytes;
 225
 226         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
 227              nbytes = crypto_hash_walk_done(&walk, nbytes))
 228                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 229
 230         return nbytes;
 231 }
 232 EXPORT_SYMBOL_GPL(shash_ahash_update);
 233
 234 static int shash_async_update(struct ahash_request *req)
 235 {
 236         return shash_ahash_update(req, ahash_request_ctx(req));
 237 }
 238
 239 static int shash_async_final(struct ahash_request *req)
 240 {
 241         return crypto_shash_final(ahash_request_ctx(req), req->result);
 242 }
 243
 244 int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
 245 {
 246         struct crypto_hash_walk walk;
 247         int nbytes;
 248
 249         nbytes = crypto_hash_walk_first(req, &walk);
 250         if (!nbytes)
 251                 return crypto_shash_final(desc, req->result);
 252
 253         do {
 254                 nbytes = crypto_hash_walk_last(&walk) ?
 255                          crypto_shash_finup(desc, walk.data, nbytes,
 256                                             req->result) :
 257                          crypto_shash_update(desc, walk.data, nbytes);
 258                 nbytes = crypto_hash_walk_done(&walk, nbytes);
 259         } while (nbytes > 0);
 260
 261         return nbytes;
 262 }
 263 EXPORT_SYMBOL_GPL(shash_ahash_finup);
 264
 265 static int shash_async_finup(struct ahash_request *req)
 266 {
 267         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 268         struct shash_desc *desc = ahash_request_ctx(req);
 269
 270         desc->tfm = *ctx;
 271         desc->flags = req->base.flags;
 272
 273         return shash_ahash_finup(req, desc);
 274 }
 275
 276 int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
 277 {
 278         unsigned int nbytes = req->nbytes;
 279         struct scatterlist *sg;
 280         unsigned int offset;
 281         int err;
 282
 283         if (nbytes &&
 284             (sg = req->src, offset = sg->offset,
 285              nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset))) {
 286                 void *data;
 287
 288                 data = kmap_atomic(sg_page(sg));
 289                 err = crypto_shash_digest(desc, data + offset, nbytes,
 290                                           req->result);
 291                 kunmap_atomic(data);
 292                 crypto_yield(desc->flags);
 293         } else
 294                 err = crypto_shash_init(desc) ?:
 295                       shash_ahash_finup(req, desc);
 296
 297         return err;
 298 }
 299 EXPORT_SYMBOL_GPL(shash_ahash_digest);
 300
 301 static int shash_async_digest(struct ahash_request *req)
 302 {
 303         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 304         struct shash_desc *desc = ahash_request_ctx(req);
 305
 306         desc->tfm = *ctx;
 307         desc->flags = req->base.flags;
 308
 309         return shash_ahash_digest(req, desc);
 310 }
 311
 312 static int shash_async_export(struct ahash_request *req, void *out)
 313 {
 314         return crypto_shash_export(ahash_request_ctx(req), out);
 315 }
 316
 317 static int shash_async_import(struct ahash_request *req, const void *in)
 318 {
 319         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 320         struct shash_desc *desc = ahash_request_ctx(req);
 321
 322         desc->tfm = *ctx;
 323         desc->flags = req->base.flags;
 324
 325         return crypto_shash_import(desc, in);
 326 }
 327
 328 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 329 {
 330         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 331
 332         crypto_free_shash(*ctx);
 333 }
 334
 335 int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 336 {
 337         struct crypto_alg *calg = tfm->__crt_alg;
 338         struct shash_alg *alg = __crypto_shash_alg(calg);
 339         struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
 340         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 341         struct crypto_shash *shash;
 342
 343         if (!crypto_mod_get(calg))
 344                 return -EAGAIN;
 345
 346         shash = crypto_create_tfm(calg, &crypto_shash_type);
 347         if (IS_ERR(shash)) {
 348                 crypto_mod_put(calg);
 349                 return PTR_ERR(shash);
 350         }
 351
 352         *ctx = shash;
 353         tfm->exit = crypto_exit_shash_ops_async;
 354
 355         crt->init = shash_async_init;
 356         crt->update = shash_async_update;
 357         crt->final = shash_async_final;
 358         crt->finup = shash_async_finup;
 359         crt->digest = shash_async_digest;
 360         crt->setkey = shash_async_setkey;
 361
 362         crt->has_setkey = alg->setkey != shash_no_setkey;
 363
 364         if (alg->export)
 365                 crt->export = shash_async_export;
 366         if (alg->import)
 367                 crt->import = shash_async_import;
 368
 369         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 370
 371         return 0;
 372 }
 373
 374 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
 375 {
 376         struct crypto_shash *hash = __crypto_shash_cast(tfm);
 377
 378         hash->descsize = crypto_shash_alg(hash)->descsize;
 379         return 0;
 380 }
 381
 382 #ifdef CONFIG_NET
 383 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 384 {
 385         struct crypto_report_hash rhash;
 386         struct shash_alg *salg = __crypto_shash_alg(alg);
 387
 388         strncpy(rhash.type, "shash", sizeof(rhash.type));
 389
 390         rhash.blocksize = alg->cra_blocksize;
 391         rhash.digestsize = salg->digestsize;
 392
 393         if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
 394                     sizeof(struct crypto_report_hash), &rhash))
 395                 goto nla_put_failure;
 396         return 0;
 397
 398 nla_put_failure:
 399         return -EMSGSIZE;
 400 }
 401 #else
 402 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 403 {
 404         return -ENOSYS;
 405 }
 406 #endif
 407
 408 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 409         __maybe_unused;
 410 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 411 {
 412         struct shash_alg *salg = __crypto_shash_alg(alg);
 413
 414         seq_printf(m, "type         : shash\n");
 415         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 416         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 417 }
 418
 419 static const struct crypto_type crypto_shash_type = {
 420         .extsize = crypto_alg_extsize,
 421         .init_tfm = crypto_shash_init_tfm,
 422 #ifdef CONFIG_PROC_FS
 423         .show = crypto_shash_show,
 424 #endif
 425         .report = crypto_shash_report,
 426         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 427         .maskset = CRYPTO_ALG_TYPE_MASK,
 428         .type = CRYPTO_ALG_TYPE_SHASH,
 429         .tfmsize = offsetof(struct crypto_shash, base),
 430 };
 431
 432 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 433                                         u32 mask)
 434 {
 435         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 436 }
 437 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 438
 439 static int shash_prepare_alg(struct shash_alg *alg)
 440 {
 441         struct crypto_alg *base = &alg->base;
 442
 443         if (alg->digestsize > PAGE_SIZE / 8 ||
 444             alg->descsize > PAGE_SIZE / 8 ||
 445             alg->statesize > PAGE_SIZE / 8)
 446                 return -EINVAL;
 447
 448         base->cra_type = &crypto_shash_type;
 449         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 450         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 451
 452         if (!alg->finup)
 453                 alg->finup = shash_finup_unaligned;
 454         if (!alg->digest)
 455                 alg->digest = shash_digest_unaligned;
 456         if (!alg->export) {
 457                 alg->export = shash_default_export;
 458                 alg->import = shash_default_import;
 459                 alg->statesize = alg->descsize;
 460         }
 461         if (!alg->setkey)
 462                 alg->setkey = shash_no_setkey;
 463
 464         return 0;
 465 }
 466
 467 int crypto_register_shash(struct shash_alg *alg)
 468 {
 469         struct crypto_alg *base = &alg->base;
 470         int err;
 471
 472         err = shash_prepare_alg(alg);
 473         if (err)
 474                 return err;
 475
 476         return crypto_register_alg(base);
 477 }
 478 EXPORT_SYMBOL_GPL(crypto_register_shash);
 479
 480 int crypto_unregister_shash(struct shash_alg *alg)
 481 {
 482         return crypto_unregister_alg(&alg->base);
 483 }
 484 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 485
 486 int crypto_register_shashes(struct shash_alg *algs, int count)
 487 {
 488         int i, ret;
 489
 490         for (i = 0; i < count; i++) {
 491                 ret = crypto_register_shash(&algs[i]);
 492                 if (ret)
 493                         goto err;
 494         }
 495
 496         return 0;
 497
 498 err:
 499         for (--i; i >= 0; --i)
 500                 crypto_unregister_shash(&algs[i]);
 501
 502         return ret;
 503 }
 504 EXPORT_SYMBOL_GPL(crypto_register_shashes);
 505
 506 int crypto_unregister_shashes(struct shash_alg *algs, int count)
 507 {
 508         int i, ret;
 509
 510         for (i = count - 1; i >= 0; --i) {
 511                 ret = crypto_unregister_shash(&algs[i]);
 512                 if (ret)
 513                         pr_err("Failed to unregister %s %s: %d\n",
 514                                algs[i].base.cra_driver_name,
 515                                algs[i].base.cra_name, ret);
 516         }
 517
 518         return 0;
 519 }
 520 EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
 521
 522 int shash_register_instance(struct crypto_template *tmpl,
 523                             struct shash_instance *inst)
 524 {
 525         int err;
 526
 527         err = shash_prepare_alg(&inst->alg);
 528         if (err)
 529                 return err;
 530
 531         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 532 }
 533 EXPORT_SYMBOL_GPL(shash_register_instance);
 534
 535 void shash_free_instance(struct crypto_instance *inst)
 536 {
 537         crypto_drop_spawn(crypto_instance_ctx(inst));
 538         kfree(shash_instance(inst));
 539 }
 540 EXPORT_SYMBOL_GPL(shash_free_instance);
 541
 542 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
 543                             struct shash_alg *alg,
 544                             struct crypto_instance *inst)
 545 {
 546         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 547                                   &crypto_shash_type);
 548 }
 549 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
 550
 551 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 552 {
 553         struct crypto_alg *alg;
 554
 555         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
 556         return IS_ERR(alg) ? ERR_CAST(alg) :
 557                container_of(alg, struct shash_alg, base);
 558 }
 559 EXPORT_SYMBOL_GPL(shash_attr_alg);
 560
 561 MODULE_LICENSE("GPL");
 562 MODULE_DESCRIPTION("Synchronous cryptographic hash type");