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         struct scatterlist *sg = req->src;
 278         unsigned int offset = sg->offset;
 279         unsigned int nbytes = req->nbytes;
 280         int err;
 281
 282         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 283                 void *data;
 284
 285                 data = kmap_atomic(sg_page(sg));
 286                 err = crypto_shash_digest(desc, data + offset, nbytes,
 287                                           req->result);
 288                 kunmap_atomic(data);
 289                 crypto_yield(desc->flags);
 290         } else
 291                 err = crypto_shash_init(desc) ?:
 292                       shash_ahash_finup(req, desc);
 293
 294         return err;
 295 }
 296 EXPORT_SYMBOL_GPL(shash_ahash_digest);
 297
 298 static int shash_async_digest(struct ahash_request *req)
 299 {
 300         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 301         struct shash_desc *desc = ahash_request_ctx(req);
 302
 303         desc->tfm = *ctx;
 304         desc->flags = req->base.flags;
 305
 306         return shash_ahash_digest(req, desc);
 307 }
 308
 309 static int shash_async_export(struct ahash_request *req, void *out)
 310 {
 311         return crypto_shash_export(ahash_request_ctx(req), out);
 312 }
 313
 314 static int shash_async_import(struct ahash_request *req, const void *in)
 315 {
 316         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 317         struct shash_desc *desc = ahash_request_ctx(req);
 318
 319         desc->tfm = *ctx;
 320         desc->flags = req->base.flags;
 321
 322         return crypto_shash_import(desc, in);
 323 }
 324
 325 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 326 {
 327         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 328
 329         crypto_free_shash(*ctx);
 330 }
 331
 332 int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 333 {
 334         struct crypto_alg *calg = tfm->__crt_alg;
 335         struct shash_alg *alg = __crypto_shash_alg(calg);
 336         struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
 337         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 338         struct crypto_shash *shash;
 339
 340         if (!crypto_mod_get(calg))
 341                 return -EAGAIN;
 342
 343         shash = crypto_create_tfm(calg, &crypto_shash_type);
 344         if (IS_ERR(shash)) {
 345                 crypto_mod_put(calg);
 346                 return PTR_ERR(shash);
 347         }
 348
 349         *ctx = shash;
 350         tfm->exit = crypto_exit_shash_ops_async;
 351
 352         crt->init = shash_async_init;
 353         crt->update = shash_async_update;
 354         crt->final = shash_async_final;
 355         crt->finup = shash_async_finup;
 356         crt->digest = shash_async_digest;
 357         crt->setkey = shash_async_setkey;
 358
 359         crt->has_setkey = alg->setkey != shash_no_setkey;
 360
 361         if (alg->export)
 362                 crt->export = shash_async_export;
 363         if (alg->import)
 364                 crt->import = shash_async_import;
 365
 366         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 367
 368         return 0;
 369 }
 370
 371 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
 372 {
 373         struct crypto_shash *hash = __crypto_shash_cast(tfm);
 374
 375         hash->descsize = crypto_shash_alg(hash)->descsize;
 376         return 0;
 377 }
 378
 379 #ifdef CONFIG_NET
 380 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 381 {
 382         struct crypto_report_hash rhash;
 383         struct shash_alg *salg = __crypto_shash_alg(alg);
 384
 385         strncpy(rhash.type, "shash", sizeof(rhash.type));
 386
 387         rhash.blocksize = alg->cra_blocksize;
 388         rhash.digestsize = salg->digestsize;
 389
 390         if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
 391                     sizeof(struct crypto_report_hash), &rhash))
 392                 goto nla_put_failure;
 393         return 0;
 394
 395 nla_put_failure:
 396         return -EMSGSIZE;
 397 }
 398 #else
 399 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 400 {
 401         return -ENOSYS;
 402 }
 403 #endif
 404
 405 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 406         __attribute__ ((unused));
 407 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 408 {
 409         struct shash_alg *salg = __crypto_shash_alg(alg);
 410
 411         seq_printf(m, "type         : shash\n");
 412         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 413         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 414 }
 415
 416 static const struct crypto_type crypto_shash_type = {
 417         .extsize = crypto_alg_extsize,
 418         .init_tfm = crypto_shash_init_tfm,
 419 #ifdef CONFIG_PROC_FS
 420         .show = crypto_shash_show,
 421 #endif
 422         .report = crypto_shash_report,
 423         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 424         .maskset = CRYPTO_ALG_TYPE_MASK,
 425         .type = CRYPTO_ALG_TYPE_SHASH,
 426         .tfmsize = offsetof(struct crypto_shash, base),
 427 };
 428
 429 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 430                                         u32 mask)
 431 {
 432         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 433 }
 434 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 435
 436 static int shash_prepare_alg(struct shash_alg *alg)
 437 {
 438         struct crypto_alg *base = &alg->base;
 439
 440         if (alg->digestsize > PAGE_SIZE / 8 ||
 441             alg->descsize > PAGE_SIZE / 8 ||
 442             alg->statesize > PAGE_SIZE / 8)
 443                 return -EINVAL;
 444
 445         base->cra_type = &crypto_shash_type;
 446         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 447         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 448
 449         if (!alg->finup)
 450                 alg->finup = shash_finup_unaligned;
 451         if (!alg->digest)
 452                 alg->digest = shash_digest_unaligned;
 453         if (!alg->export) {
 454                 alg->export = shash_default_export;
 455                 alg->import = shash_default_import;
 456                 alg->statesize = alg->descsize;
 457         }
 458         if (!alg->setkey)
 459                 alg->setkey = shash_no_setkey;
 460
 461         return 0;
 462 }
 463
 464 int crypto_register_shash(struct shash_alg *alg)
 465 {
 466         struct crypto_alg *base = &alg->base;
 467         int err;
 468
 469         err = shash_prepare_alg(alg);
 470         if (err)
 471                 return err;
 472
 473         return crypto_register_alg(base);
 474 }
 475 EXPORT_SYMBOL_GPL(crypto_register_shash);
 476
 477 int crypto_unregister_shash(struct shash_alg *alg)
 478 {
 479         return crypto_unregister_alg(&alg->base);
 480 }
 481 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 482
 483 int crypto_register_shashes(struct shash_alg *algs, int count)
 484 {
 485         int i, ret;
 486
 487         for (i = 0; i < count; i++) {
 488                 ret = crypto_register_shash(&algs[i]);
 489                 if (ret)
 490                         goto err;
 491         }
 492
 493         return 0;
 494
 495 err:
 496         for (--i; i >= 0; --i)
 497                 crypto_unregister_shash(&algs[i]);
 498
 499         return ret;
 500 }
 501 EXPORT_SYMBOL_GPL(crypto_register_shashes);
 502
 503 int crypto_unregister_shashes(struct shash_alg *algs, int count)
 504 {
 505         int i, ret;
 506
 507         for (i = count - 1; i >= 0; --i) {
 508                 ret = crypto_unregister_shash(&algs[i]);
 509                 if (ret)
 510                         pr_err("Failed to unregister %s %s: %d\n",
 511                                algs[i].base.cra_driver_name,
 512                                algs[i].base.cra_name, ret);
 513         }
 514
 515         return 0;
 516 }
 517 EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
 518
 519 int shash_register_instance(struct crypto_template *tmpl,
 520                             struct shash_instance *inst)
 521 {
 522         int err;
 523
 524         err = shash_prepare_alg(&inst->alg);
 525         if (err)
 526                 return err;
 527
 528         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 529 }
 530 EXPORT_SYMBOL_GPL(shash_register_instance);
 531
 532 void shash_free_instance(struct crypto_instance *inst)
 533 {
 534         crypto_drop_spawn(crypto_instance_ctx(inst));
 535         kfree(shash_instance(inst));
 536 }
 537 EXPORT_SYMBOL_GPL(shash_free_instance);
 538
 539 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
 540                             struct shash_alg *alg,
 541                             struct crypto_instance *inst)
 542 {
 543         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 544                                   &crypto_shash_type);
 545 }
 546 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
 547
 548 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 549 {
 550         struct crypto_alg *alg;
 551
 552         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
 553         return IS_ERR(alg) ? ERR_CAST(alg) :
 554                container_of(alg, struct shash_alg, base);
 555 }
 556 EXPORT_SYMBOL_GPL(shash_attr_alg);
 557
 558 MODULE_LICENSE("GPL");
 559 MODULE_DESCRIPTION("Synchronous cryptographic hash type");