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 static int shash_no_setkey(struct crypto_shash *tfm, const u8 *key,
  28                            unsigned int keylen)
  29 {
  30         return -ENOSYS;
  31 }
  32
  33 static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
  34                                   unsigned int keylen)
  35 {
  36         struct shash_alg *shash = crypto_shash_alg(tfm);
  37         unsigned long alignmask = crypto_shash_alignmask(tfm);
  38         unsigned long absize;
  39         u8 *buffer, *alignbuffer;
  40         int err;
  41
  42         absize = keylen + (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
  43         buffer = kmalloc(absize, GFP_KERNEL);
  44         if (!buffer)
  45                 return -ENOMEM;
  46
  47         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  48         memcpy(alignbuffer, key, keylen);
  49         err = shash->setkey(tfm, alignbuffer, keylen);
  50         kzfree(buffer);
  51         return err;
  52 }
  53
  54 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
  55                         unsigned int keylen)
  56 {
  57         struct shash_alg *shash = crypto_shash_alg(tfm);
  58         unsigned long alignmask = crypto_shash_alignmask(tfm);
  59
  60         if ((unsigned long)key & alignmask)
  61                 return shash_setkey_unaligned(tfm, key, keylen);
  62
  63         return shash->setkey(tfm, key, keylen);
  64 }
  65 EXPORT_SYMBOL_GPL(crypto_shash_setkey);
  66
  67 static inline unsigned int shash_align_buffer_size(unsigned len,
  68                                                    unsigned long mask)
  69 {
  70         typedef u8 __attribute__ ((aligned)) u8_aligned;
  71         return len + (mask & ~(__alignof__(u8_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 ubuf[shash_align_buffer_size(unaligned_len, alignmask)]
  83                 __attribute__ ((aligned));
  84         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
  85         int err;
  86
  87         if (unaligned_len > len)
  88                 unaligned_len = len;
  89
  90         memcpy(buf, data, unaligned_len);
  91         err = shash->update(desc, buf, unaligned_len);
  92         memset(buf, 0, unaligned_len);
  93
  94         return err ?:
  95                shash->update(desc, data + unaligned_len, len - unaligned_len);
  96 }
  97
  98 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
  99                         unsigned int len)
 100 {
 101         struct crypto_shash *tfm = desc->tfm;
 102         struct shash_alg *shash = crypto_shash_alg(tfm);
 103         unsigned long alignmask = crypto_shash_alignmask(tfm);
 104
 105         if ((unsigned long)data & alignmask)
 106                 return shash_update_unaligned(desc, data, len);
 107
 108         return shash->update(desc, data, len);
 109 }
 110 EXPORT_SYMBOL_GPL(crypto_shash_update);
 111
 112 static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
 113 {
 114         struct crypto_shash *tfm = desc->tfm;
 115         unsigned long alignmask = crypto_shash_alignmask(tfm);
 116         struct shash_alg *shash = crypto_shash_alg(tfm);
 117         unsigned int ds = crypto_shash_digestsize(tfm);
 118         u8 ubuf[shash_align_buffer_size(ds, alignmask)]
 119                 __attribute__ ((aligned));
 120         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
 121         int err;
 122
 123         err = shash->final(desc, buf);
 124         if (err)
 125                 goto out;
 126
 127         memcpy(out, buf, ds);
 128
 129 out:
 130         memset(buf, 0, ds);
 131         return err;
 132 }
 133
 134 int crypto_shash_final(struct shash_desc *desc, u8 *out)
 135 {
 136         struct crypto_shash *tfm = desc->tfm;
 137         struct shash_alg *shash = crypto_shash_alg(tfm);
 138         unsigned long alignmask = crypto_shash_alignmask(tfm);
 139
 140         if ((unsigned long)out & alignmask)
 141                 return shash_final_unaligned(desc, out);
 142
 143         return shash->final(desc, out);
 144 }
 145 EXPORT_SYMBOL_GPL(crypto_shash_final);
 146
 147 static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
 148                                  unsigned int len, u8 *out)
 149 {
 150         return crypto_shash_update(desc, data, len) ?:
 151                crypto_shash_final(desc, out);
 152 }
 153
 154 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
 155                        unsigned int len, u8 *out)
 156 {
 157         struct crypto_shash *tfm = desc->tfm;
 158         struct shash_alg *shash = crypto_shash_alg(tfm);
 159         unsigned long alignmask = crypto_shash_alignmask(tfm);
 160
 161         if (((unsigned long)data | (unsigned long)out) & alignmask)
 162                 return shash_finup_unaligned(desc, data, len, out);
 163
 164         return shash->finup(desc, data, len, out);
 165 }
 166 EXPORT_SYMBOL_GPL(crypto_shash_finup);
 167
 168 static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
 169                                   unsigned int len, u8 *out)
 170 {
 171         return crypto_shash_init(desc) ?:
 172                crypto_shash_finup(desc, data, len, out);
 173 }
 174
 175 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
 176                         unsigned int len, u8 *out)
 177 {
 178         struct crypto_shash *tfm = desc->tfm;
 179         struct shash_alg *shash = crypto_shash_alg(tfm);
 180         unsigned long alignmask = crypto_shash_alignmask(tfm);
 181
 182         if (((unsigned long)data | (unsigned long)out) & alignmask)
 183                 return shash_digest_unaligned(desc, data, len, out);
 184
 185         return shash->digest(desc, data, len, out);
 186 }
 187 EXPORT_SYMBOL_GPL(crypto_shash_digest);
 188
 189 static int shash_default_export(struct shash_desc *desc, void *out)
 190 {
 191         memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm));
 192         return 0;
 193 }
 194
 195 static int shash_default_import(struct shash_desc *desc, const void *in)
 196 {
 197         memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm));
 198         return 0;
 199 }
 200
 201 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 202                               unsigned int keylen)
 203 {
 204         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
 205
 206         return crypto_shash_setkey(*ctx, key, keylen);
 207 }
 208
 209 static int shash_async_init(struct ahash_request *req)
 210 {
 211         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 212         struct shash_desc *desc = ahash_request_ctx(req);
 213
 214         desc->tfm = *ctx;
 215         desc->flags = req->base.flags;
 216
 217         return crypto_shash_init(desc);
 218 }
 219
 220 int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
 221 {
 222         struct crypto_hash_walk walk;
 223         int nbytes;
 224
 225         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
 226              nbytes = crypto_hash_walk_done(&walk, nbytes))
 227                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 228
 229         return nbytes;
 230 }
 231 EXPORT_SYMBOL_GPL(shash_ahash_update);
 232
 233 static int shash_async_update(struct ahash_request *req)
 234 {
 235         return shash_ahash_update(req, ahash_request_ctx(req));
 236 }
 237
 238 static int shash_async_final(struct ahash_request *req)
 239 {
 240         return crypto_shash_final(ahash_request_ctx(req), req->result);
 241 }
 242
 243 int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
 244 {
 245         struct crypto_hash_walk walk;
 246         int nbytes;
 247
 248         nbytes = crypto_hash_walk_first(req, &walk);
 249         if (!nbytes)
 250                 return crypto_shash_final(desc, req->result);
 251
 252         do {
 253                 nbytes = crypto_hash_walk_last(&walk) ?
 254                          crypto_shash_finup(desc, walk.data, nbytes,
 255                                             req->result) :
 256                          crypto_shash_update(desc, walk.data, nbytes);
 257                 nbytes = crypto_hash_walk_done(&walk, nbytes);
 258         } while (nbytes > 0);
 259
 260         return nbytes;
 261 }
 262 EXPORT_SYMBOL_GPL(shash_ahash_finup);
 263
 264 static int shash_async_finup(struct ahash_request *req)
 265 {
 266         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 267         struct shash_desc *desc = ahash_request_ctx(req);
 268
 269         desc->tfm = *ctx;
 270         desc->flags = req->base.flags;
 271
 272         return shash_ahash_finup(req, desc);
 273 }
 274
 275 int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
 276 {
 277         unsigned int nbytes = req->nbytes;
 278         struct scatterlist *sg;
 279         unsigned int offset;
 280         int err;
 281
 282         if (nbytes &&
 283             (sg = req->src, offset = sg->offset,
 284              nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset))) {
 285                 void *data;
 286
 287                 data = kmap_atomic(sg_page(sg));
 288                 err = crypto_shash_digest(desc, data + offset, nbytes,
 289                                           req->result);
 290                 kunmap_atomic(data);
 291                 crypto_yield(desc->flags);
 292         } else
 293                 err = crypto_shash_init(desc) ?:
 294                       shash_ahash_finup(req, desc);
 295
 296         return err;
 297 }
 298 EXPORT_SYMBOL_GPL(shash_ahash_digest);
 299
 300 static int shash_async_digest(struct ahash_request *req)
 301 {
 302         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 303         struct shash_desc *desc = ahash_request_ctx(req);
 304
 305         desc->tfm = *ctx;
 306         desc->flags = req->base.flags;
 307
 308         return shash_ahash_digest(req, desc);
 309 }
 310
 311 static int shash_async_export(struct ahash_request *req, void *out)
 312 {
 313         return crypto_shash_export(ahash_request_ctx(req), out);
 314 }
 315
 316 static int shash_async_import(struct ahash_request *req, const void *in)
 317 {
 318         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 319         struct shash_desc *desc = ahash_request_ctx(req);
 320
 321         desc->tfm = *ctx;
 322         desc->flags = req->base.flags;
 323
 324         return crypto_shash_import(desc, in);
 325 }
 326
 327 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 328 {
 329         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 330
 331         crypto_free_shash(*ctx);
 332 }
 333
 334 int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 335 {
 336         struct crypto_alg *calg = tfm->__crt_alg;
 337         struct shash_alg *alg = __crypto_shash_alg(calg);
 338         struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
 339         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 340         struct crypto_shash *shash;
 341
 342         if (!crypto_mod_get(calg))
 343                 return -EAGAIN;
 344
 345         shash = crypto_create_tfm(calg, &crypto_shash_type);
 346         if (IS_ERR(shash)) {
 347                 crypto_mod_put(calg);
 348                 return PTR_ERR(shash);
 349         }
 350
 351         *ctx = shash;
 352         tfm->exit = crypto_exit_shash_ops_async;
 353
 354         crt->init = shash_async_init;
 355         crt->update = shash_async_update;
 356         crt->final = shash_async_final;
 357         crt->finup = shash_async_finup;
 358         crt->digest = shash_async_digest;
 359         crt->setkey = shash_async_setkey;
 360
 361         crt->has_setkey = alg->setkey != shash_no_setkey;
 362
 363         if (alg->export)
 364                 crt->export = shash_async_export;
 365         if (alg->import)
 366                 crt->import = shash_async_import;
 367
 368         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 369
 370         return 0;
 371 }
 372
 373 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
 374 {
 375         struct crypto_shash *hash = __crypto_shash_cast(tfm);
 376
 377         hash->descsize = crypto_shash_alg(hash)->descsize;
 378         return 0;
 379 }
 380
 381 #ifdef CONFIG_NET
 382 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 383 {
 384         struct crypto_report_hash rhash;
 385         struct shash_alg *salg = __crypto_shash_alg(alg);
 386
 387         strncpy(rhash.type, "shash", sizeof(rhash.type));
 388
 389         rhash.blocksize = alg->cra_blocksize;
 390         rhash.digestsize = salg->digestsize;
 391
 392         if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
 393                     sizeof(struct crypto_report_hash), &rhash))
 394                 goto nla_put_failure;
 395         return 0;
 396
 397 nla_put_failure:
 398         return -EMSGSIZE;
 399 }
 400 #else
 401 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 402 {
 403         return -ENOSYS;
 404 }
 405 #endif
 406
 407 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 408         __attribute__ ((unused));
 409 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 410 {
 411         struct shash_alg *salg = __crypto_shash_alg(alg);
 412
 413         seq_printf(m, "type         : shash\n");
 414         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 415         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 416 }
 417
 418 static const struct crypto_type crypto_shash_type = {
 419         .extsize = crypto_alg_extsize,
 420         .init_tfm = crypto_shash_init_tfm,
 421 #ifdef CONFIG_PROC_FS
 422         .show = crypto_shash_show,
 423 #endif
 424         .report = crypto_shash_report,
 425         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 426         .maskset = CRYPTO_ALG_TYPE_MASK,
 427         .type = CRYPTO_ALG_TYPE_SHASH,
 428         .tfmsize = offsetof(struct crypto_shash, base),
 429 };
 430
 431 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 432                                         u32 mask)
 433 {
 434         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 435 }
 436 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 437
 438 static int shash_prepare_alg(struct shash_alg *alg)
 439 {
 440         struct crypto_alg *base = &alg->base;
 441
 442         if (alg->digestsize > PAGE_SIZE / 8 ||
 443             alg->descsize > PAGE_SIZE / 8 ||
 444             alg->statesize > PAGE_SIZE / 8)
 445                 return -EINVAL;
 446
 447         base->cra_type = &crypto_shash_type;
 448         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 449         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 450
 451         if (!alg->finup)
 452                 alg->finup = shash_finup_unaligned;
 453         if (!alg->digest)
 454                 alg->digest = shash_digest_unaligned;
 455         if (!alg->export) {
 456                 alg->export = shash_default_export;
 457                 alg->import = shash_default_import;
 458                 alg->statesize = alg->descsize;
 459         }
 460         if (!alg->setkey)
 461                 alg->setkey = shash_no_setkey;
 462
 463         return 0;
 464 }
 465
 466 int crypto_register_shash(struct shash_alg *alg)
 467 {
 468         struct crypto_alg *base = &alg->base;
 469         int err;
 470
 471         err = shash_prepare_alg(alg);
 472         if (err)
 473                 return err;
 474
 475         return crypto_register_alg(base);
 476 }
 477 EXPORT_SYMBOL_GPL(crypto_register_shash);
 478
 479 int crypto_unregister_shash(struct shash_alg *alg)
 480 {
 481         return crypto_unregister_alg(&alg->base);
 482 }
 483 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 484
 485 int crypto_register_shashes(struct shash_alg *algs, int count)
 486 {
 487         int i, ret;
 488
 489         for (i = 0; i < count; i++) {
 490                 ret = crypto_register_shash(&algs[i]);
 491                 if (ret)
 492                         goto err;
 493         }
 494
 495         return 0;
 496
 497 err:
 498         for (--i; i >= 0; --i)
 499                 crypto_unregister_shash(&algs[i]);
 500
 501         return ret;
 502 }
 503 EXPORT_SYMBOL_GPL(crypto_register_shashes);
 504
 505 int crypto_unregister_shashes(struct shash_alg *algs, int count)
 506 {
 507         int i, ret;
 508
 509         for (i = count - 1; i >= 0; --i) {
 510                 ret = crypto_unregister_shash(&algs[i]);
 511                 if (ret)
 512                         pr_err("Failed to unregister %s %s: %d\n",
 513                                algs[i].base.cra_driver_name,
 514                                algs[i].base.cra_name, ret);
 515         }
 516
 517         return 0;
 518 }
 519 EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
 520
 521 int shash_register_instance(struct crypto_template *tmpl,
 522                             struct shash_instance *inst)
 523 {
 524         int err;
 525
 526         err = shash_prepare_alg(&inst->alg);
 527         if (err)
 528                 return err;
 529
 530         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 531 }
 532 EXPORT_SYMBOL_GPL(shash_register_instance);
 533
 534 void shash_free_instance(struct crypto_instance *inst)
 535 {
 536         crypto_drop_spawn(crypto_instance_ctx(inst));
 537         kfree(shash_instance(inst));
 538 }
 539 EXPORT_SYMBOL_GPL(shash_free_instance);
 540
 541 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
 542                             struct shash_alg *alg,
 543                             struct crypto_instance *inst)
 544 {
 545         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 546                                   &crypto_shash_type);
 547 }
 548 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
 549
 550 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 551 {
 552         struct crypto_alg *alg;
 553
 554         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
 555         return IS_ERR(alg) ? ERR_CAST(alg) :
 556                container_of(alg, struct shash_alg, base);
 557 }
 558 EXPORT_SYMBOL_GPL(shash_attr_alg);
 559
 560 MODULE_LICENSE("GPL");
 561 MODULE_DESCRIPTION("Synchronous cryptographic hash type");