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         struct scatterlist *sg = req->src;
 279         unsigned int offset = sg->offset;
 280         unsigned int nbytes = req->nbytes;
 281         int err;
 282
 283         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 284                 void *data;
 285
 286                 data = kmap_atomic(sg_page(sg));
 287                 err = crypto_shash_digest(desc, data + offset, nbytes,
 288                                           req->result);
 289                 kunmap_atomic(data);
 290                 crypto_yield(desc->flags);
 291         } else
 292                 err = crypto_shash_init(desc) ?:
 293                       shash_ahash_finup(req, desc);
 294
 295         return err;
 296 }
 297 EXPORT_SYMBOL_GPL(shash_ahash_digest);
 298
 299 static int shash_async_digest(struct ahash_request *req)
 300 {
 301         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 302         struct shash_desc *desc = ahash_request_ctx(req);
 303
 304         desc->tfm = *ctx;
 305         desc->flags = req->base.flags;
 306
 307         return shash_ahash_digest(req, desc);
 308 }
 309
 310 static int shash_async_export(struct ahash_request *req, void *out)
 311 {
 312         return crypto_shash_export(ahash_request_ctx(req), out);
 313 }
 314
 315 static int shash_async_import(struct ahash_request *req, const void *in)
 316 {
 317         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 318         struct shash_desc *desc = ahash_request_ctx(req);
 319
 320         desc->tfm = *ctx;
 321         desc->flags = req->base.flags;
 322
 323         return crypto_shash_import(desc, in);
 324 }
 325
 326 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 327 {
 328         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 329
 330         crypto_free_shash(*ctx);
 331 }
 332
 333 int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 334 {
 335         struct crypto_alg *calg = tfm->__crt_alg;
 336         struct shash_alg *alg = __crypto_shash_alg(calg);
 337         struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
 338         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 339         struct crypto_shash *shash;
 340
 341         if (!crypto_mod_get(calg))
 342                 return -EAGAIN;
 343
 344         shash = crypto_create_tfm(calg, &crypto_shash_type);
 345         if (IS_ERR(shash)) {
 346                 crypto_mod_put(calg);
 347                 return PTR_ERR(shash);
 348         }
 349
 350         *ctx = shash;
 351         tfm->exit = crypto_exit_shash_ops_async;
 352
 353         crt->init = shash_async_init;
 354         crt->update = shash_async_update;
 355         crt->final = shash_async_final;
 356         crt->finup = shash_async_finup;
 357         crt->digest = shash_async_digest;
 358         crt->setkey = shash_async_setkey;
 359
 360         crt->has_setkey = alg->setkey != shash_no_setkey;
 361
 362         if (alg->export)
 363                 crt->export = shash_async_export;
 364         if (alg->import)
 365                 crt->import = shash_async_import;
 366
 367         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 368
 369         return 0;
 370 }
 371
 372 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
 373 {
 374         struct crypto_shash *hash = __crypto_shash_cast(tfm);
 375
 376         hash->descsize = crypto_shash_alg(hash)->descsize;
 377         return 0;
 378 }
 379
 380 #ifdef CONFIG_NET
 381 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 382 {
 383         struct crypto_report_hash rhash;
 384         struct shash_alg *salg = __crypto_shash_alg(alg);
 385
 386         strncpy(rhash.type, "shash", sizeof(rhash.type));
 387
 388         rhash.blocksize = alg->cra_blocksize;
 389         rhash.digestsize = salg->digestsize;
 390
 391         if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
 392                     sizeof(struct crypto_report_hash), &rhash))
 393                 goto nla_put_failure;
 394         return 0;
 395
 396 nla_put_failure:
 397         return -EMSGSIZE;
 398 }
 399 #else
 400 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 401 {
 402         return -ENOSYS;
 403 }
 404 #endif
 405
 406 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 407         __maybe_unused;
 408 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 409 {
 410         struct shash_alg *salg = __crypto_shash_alg(alg);
 411
 412         seq_printf(m, "type         : shash\n");
 413         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 414         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 415 }
 416
 417 static const struct crypto_type crypto_shash_type = {
 418         .extsize = crypto_alg_extsize,
 419         .init_tfm = crypto_shash_init_tfm,
 420 #ifdef CONFIG_PROC_FS
 421         .show = crypto_shash_show,
 422 #endif
 423         .report = crypto_shash_report,
 424         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 425         .maskset = CRYPTO_ALG_TYPE_MASK,
 426         .type = CRYPTO_ALG_TYPE_SHASH,
 427         .tfmsize = offsetof(struct crypto_shash, base),
 428 };
 429
 430 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 431                                         u32 mask)
 432 {
 433         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 434 }
 435 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 436
 437 static int shash_prepare_alg(struct shash_alg *alg)
 438 {
 439         struct crypto_alg *base = &alg->base;
 440
 441         if (alg->digestsize > PAGE_SIZE / 8 ||
 442             alg->descsize > PAGE_SIZE / 8 ||
 443             alg->statesize > PAGE_SIZE / 8)
 444                 return -EINVAL;
 445
 446         base->cra_type = &crypto_shash_type;
 447         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 448         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 449
 450         if (!alg->finup)
 451                 alg->finup = shash_finup_unaligned;
 452         if (!alg->digest)
 453                 alg->digest = shash_digest_unaligned;
 454         if (!alg->export) {
 455                 alg->export = shash_default_export;
 456                 alg->import = shash_default_import;
 457                 alg->statesize = alg->descsize;
 458         }
 459         if (!alg->setkey)
 460                 alg->setkey = shash_no_setkey;
 461
 462         return 0;
 463 }
 464
 465 int crypto_register_shash(struct shash_alg *alg)
 466 {
 467         struct crypto_alg *base = &alg->base;
 468         int err;
 469
 470         err = shash_prepare_alg(alg);
 471         if (err)
 472                 return err;
 473
 474         return crypto_register_alg(base);
 475 }
 476 EXPORT_SYMBOL_GPL(crypto_register_shash);
 477
 478 int crypto_unregister_shash(struct shash_alg *alg)
 479 {
 480         return crypto_unregister_alg(&alg->base);
 481 }
 482 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 483
 484 int crypto_register_shashes(struct shash_alg *algs, int count)
 485 {
 486         int i, ret;
 487
 488         for (i = 0; i < count; i++) {
 489                 ret = crypto_register_shash(&algs[i]);
 490                 if (ret)
 491                         goto err;
 492         }
 493
 494         return 0;
 495
 496 err:
 497         for (--i; i >= 0; --i)
 498                 crypto_unregister_shash(&algs[i]);
 499
 500         return ret;
 501 }
 502 EXPORT_SYMBOL_GPL(crypto_register_shashes);
 503
 504 int crypto_unregister_shashes(struct shash_alg *algs, int count)
 505 {
 506         int i, ret;
 507
 508         for (i = count - 1; i >= 0; --i) {
 509                 ret = crypto_unregister_shash(&algs[i]);
 510                 if (ret)
 511                         pr_err("Failed to unregister %s %s: %d\n",
 512                                algs[i].base.cra_driver_name,
 513                                algs[i].base.cra_name, ret);
 514         }
 515
 516         return 0;
 517 }
 518 EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
 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");