crypto/shash.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Synchronous Cryptographic Hash operations.
   4  *
   5  * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
   6  */
   7
   8 #include <crypto/scatterwalk.h>
   9 #include <linux/cryptouser.h>
  10 #include <linux/err.h>
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/seq_file.h>
  14 #include <linux/string.h>
  15 #include <net/netlink.h>
  16
  17 #include "hash.h"
  18
  19 static inline struct crypto_istat_hash *shash_get_stat(struct shash_alg *alg)
  20 {
  21         return hash_get_stat(&alg->halg);
  22 }
  23
  24 static inline int crypto_shash_errstat(struct shash_alg *alg, int err)
  25 {
  26         if (!IS_ENABLED(CONFIG_CRYPTO_STATS))
  27                 return err;
  28
  29         if (err && err != -EINPROGRESS && err != -EBUSY)
  30                 atomic64_inc(&shash_get_stat(alg)->err_cnt);
  31
  32         return err;
  33 }
  34
  35 int shash_no_setkey(struct crypto_shash *tfm, const u8 *key,
  36                     unsigned int keylen)
  37 {
  38         return -ENOSYS;
  39 }
  40 EXPORT_SYMBOL_GPL(shash_no_setkey);
  41
  42 static void shash_set_needkey(struct crypto_shash *tfm, struct shash_alg *alg)
  43 {
  44         if (crypto_shash_alg_needs_key(alg))
  45                 crypto_shash_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
  46 }
  47
  48 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
  49                         unsigned int keylen)
  50 {
  51         struct shash_alg *shash = crypto_shash_alg(tfm);
  52         int err;
  53
  54         err = shash->setkey(tfm, key, keylen);
  55         if (unlikely(err)) {
  56                 shash_set_needkey(tfm, shash);
  57                 return err;
  58         }
  59
  60         crypto_shash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
  61         return 0;
  62 }
  63 EXPORT_SYMBOL_GPL(crypto_shash_setkey);
  64
  65 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
  66                         unsigned int len)
  67 {
  68         struct shash_alg *shash = crypto_shash_alg(desc->tfm);
  69         int err;
  70
  71         if (IS_ENABLED(CONFIG_CRYPTO_STATS))
  72                 atomic64_add(len, &shash_get_stat(shash)->hash_tlen);
  73
  74         err = shash->update(desc, data, len);
  75
  76         return crypto_shash_errstat(shash, err);
  77 }
  78 EXPORT_SYMBOL_GPL(crypto_shash_update);
  79
  80 int crypto_shash_final(struct shash_desc *desc, u8 *out)
  81 {
  82         struct shash_alg *shash = crypto_shash_alg(desc->tfm);
  83         int err;
  84
  85         if (IS_ENABLED(CONFIG_CRYPTO_STATS))
  86                 atomic64_inc(&shash_get_stat(shash)->hash_cnt);
  87
  88         err = shash->final(desc, out);
  89
  90         return crypto_shash_errstat(shash, err);
  91 }
  92 EXPORT_SYMBOL_GPL(crypto_shash_final);
  93
  94 static int shash_default_finup(struct shash_desc *desc, const u8 *data,
  95                                unsigned int len, u8 *out)
  96 {
  97         struct shash_alg *shash = crypto_shash_alg(desc->tfm);
  98
  99         return shash->update(desc, data, len) ?:
 100                shash->final(desc, out);
 101 }
 102
 103 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
 104                        unsigned int len, u8 *out)
 105 {
 106         struct crypto_shash *tfm = desc->tfm;
 107         struct shash_alg *shash = crypto_shash_alg(tfm);
 108         int err;
 109
 110         if (IS_ENABLED(CONFIG_CRYPTO_STATS)) {
 111                 struct crypto_istat_hash *istat = shash_get_stat(shash);
 112
 113                 atomic64_inc(&istat->hash_cnt);
 114                 atomic64_add(len, &istat->hash_tlen);
 115         }
 116
 117         err = shash->finup(desc, data, len, out);
 118
 119         return crypto_shash_errstat(shash, err);
 120 }
 121 EXPORT_SYMBOL_GPL(crypto_shash_finup);
 122
 123 static int shash_default_digest(struct shash_desc *desc, const u8 *data,
 124                                 unsigned int len, u8 *out)
 125 {
 126         struct shash_alg *shash = crypto_shash_alg(desc->tfm);
 127
 128         return shash->init(desc) ?:
 129                shash->finup(desc, data, len, out);
 130 }
 131
 132 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
 133                         unsigned int len, u8 *out)
 134 {
 135         struct crypto_shash *tfm = desc->tfm;
 136         struct shash_alg *shash = crypto_shash_alg(tfm);
 137         int err;
 138
 139         if (IS_ENABLED(CONFIG_CRYPTO_STATS)) {
 140                 struct crypto_istat_hash *istat = shash_get_stat(shash);
 141
 142                 atomic64_inc(&istat->hash_cnt);
 143                 atomic64_add(len, &istat->hash_tlen);
 144         }
 145
 146         if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
 147                 err = -ENOKEY;
 148         else
 149                 err = shash->digest(desc, data, len, out);
 150
 151         return crypto_shash_errstat(shash, err);
 152 }
 153 EXPORT_SYMBOL_GPL(crypto_shash_digest);
 154
 155 int crypto_shash_tfm_digest(struct crypto_shash *tfm, const u8 *data,
 156                             unsigned int len, u8 *out)
 157 {
 158         SHASH_DESC_ON_STACK(desc, tfm);
 159         int err;
 160
 161         desc->tfm = tfm;
 162
 163         err = crypto_shash_digest(desc, data, len, out);
 164
 165         shash_desc_zero(desc);
 166
 167         return err;
 168 }
 169 EXPORT_SYMBOL_GPL(crypto_shash_tfm_digest);
 170
 171 int crypto_shash_export(struct shash_desc *desc, void *out)
 172 {
 173         struct crypto_shash *tfm = desc->tfm;
 174         struct shash_alg *shash = crypto_shash_alg(tfm);
 175
 176         if (shash->export)
 177                 return shash->export(desc, out);
 178
 179         memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(tfm));
 180         return 0;
 181 }
 182 EXPORT_SYMBOL_GPL(crypto_shash_export);
 183
 184 int crypto_shash_import(struct shash_desc *desc, const void *in)
 185 {
 186         struct crypto_shash *tfm = desc->tfm;
 187         struct shash_alg *shash = crypto_shash_alg(tfm);
 188
 189         if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
 190                 return -ENOKEY;
 191
 192         if (shash->import)
 193                 return shash->import(desc, in);
 194
 195         memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(tfm));
 196         return 0;
 197 }
 198 EXPORT_SYMBOL_GPL(crypto_shash_import);
 199
 200 static void crypto_shash_exit_tfm(struct crypto_tfm *tfm)
 201 {
 202         struct crypto_shash *hash = __crypto_shash_cast(tfm);
 203         struct shash_alg *alg = crypto_shash_alg(hash);
 204
 205         alg->exit_tfm(hash);
 206 }
 207
 208 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
 209 {
 210         struct crypto_shash *hash = __crypto_shash_cast(tfm);
 211         struct shash_alg *alg = crypto_shash_alg(hash);
 212         int err;
 213
 214         hash->descsize = alg->descsize;
 215
 216         shash_set_needkey(hash, alg);
 217
 218         if (alg->exit_tfm)
 219                 tfm->exit = crypto_shash_exit_tfm;
 220
 221         if (!alg->init_tfm)
 222                 return 0;
 223
 224         err = alg->init_tfm(hash);
 225         if (err)
 226                 return err;
 227
 228         /* ->init_tfm() may have increased the descsize. */
 229         if (WARN_ON_ONCE(hash->descsize > HASH_MAX_DESCSIZE)) {
 230                 if (alg->exit_tfm)
 231                         alg->exit_tfm(hash);
 232                 return -EINVAL;
 233         }
 234
 235         return 0;
 236 }
 237
 238 static void crypto_shash_free_instance(struct crypto_instance *inst)
 239 {
 240         struct shash_instance *shash = shash_instance(inst);
 241
 242         shash->free(shash);
 243 }
 244
 245 static int __maybe_unused crypto_shash_report(
 246         struct sk_buff *skb, struct crypto_alg *alg)
 247 {
 248         struct crypto_report_hash rhash;
 249         struct shash_alg *salg = __crypto_shash_alg(alg);
 250
 251         memset(&rhash, 0, sizeof(rhash));
 252
 253         strscpy(rhash.type, "shash", sizeof(rhash.type));
 254
 255         rhash.blocksize = alg->cra_blocksize;
 256         rhash.digestsize = salg->digestsize;
 257
 258         return nla_put(skb, CRYPTOCFGA_REPORT_HASH, sizeof(rhash), &rhash);
 259 }
 260
 261 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 262         __maybe_unused;
 263 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 264 {
 265         struct shash_alg *salg = __crypto_shash_alg(alg);
 266
 267         seq_printf(m, "type         : shash\n");
 268         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 269         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 270 }
 271
 272 static int __maybe_unused crypto_shash_report_stat(
 273         struct sk_buff *skb, struct crypto_alg *alg)
 274 {
 275         return crypto_hash_report_stat(skb, alg, "shash");
 276 }
 277
 278 const struct crypto_type crypto_shash_type = {
 279         .extsize = crypto_alg_extsize,
 280         .init_tfm = crypto_shash_init_tfm,
 281         .free = crypto_shash_free_instance,
 282 #ifdef CONFIG_PROC_FS
 283         .show = crypto_shash_show,
 284 #endif
 285 #if IS_ENABLED(CONFIG_CRYPTO_USER)
 286         .report = crypto_shash_report,
 287 #endif
 288 #ifdef CONFIG_CRYPTO_STATS
 289         .report_stat = crypto_shash_report_stat,
 290 #endif
 291         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 292         .maskset = CRYPTO_ALG_TYPE_MASK,
 293         .type = CRYPTO_ALG_TYPE_SHASH,
 294         .tfmsize = offsetof(struct crypto_shash, base),
 295 };
 296
 297 int crypto_grab_shash(struct crypto_shash_spawn *spawn,
 298                       struct crypto_instance *inst,
 299                       const char *name, u32 type, u32 mask)
 300 {
 301         spawn->base.frontend = &crypto_shash_type;
 302         return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
 303 }
 304 EXPORT_SYMBOL_GPL(crypto_grab_shash);
 305
 306 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 307                                         u32 mask)
 308 {
 309         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 310 }
 311 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 312
 313 int crypto_has_shash(const char *alg_name, u32 type, u32 mask)
 314 {
 315         return crypto_type_has_alg(alg_name, &crypto_shash_type, type, mask);
 316 }
 317 EXPORT_SYMBOL_GPL(crypto_has_shash);
 318
 319 struct crypto_shash *crypto_clone_shash(struct crypto_shash *hash)
 320 {
 321         struct crypto_tfm *tfm = crypto_shash_tfm(hash);
 322         struct shash_alg *alg = crypto_shash_alg(hash);
 323         struct crypto_shash *nhash;
 324         int err;
 325
 326         if (!crypto_shash_alg_has_setkey(alg)) {
 327                 tfm = crypto_tfm_get(tfm);
 328                 if (IS_ERR(tfm))
 329                         return ERR_CAST(tfm);
 330
 331                 return hash;
 332         }
 333
 334         if (!alg->clone_tfm && (alg->init_tfm || alg->base.cra_init))
 335                 return ERR_PTR(-ENOSYS);
 336
 337         nhash = crypto_clone_tfm(&crypto_shash_type, tfm);
 338         if (IS_ERR(nhash))
 339                 return nhash;
 340
 341         nhash->descsize = hash->descsize;
 342
 343         if (alg->clone_tfm) {
 344                 err = alg->clone_tfm(nhash, hash);
 345                 if (err) {
 346                         crypto_free_shash(nhash);
 347                         return ERR_PTR(err);
 348                 }
 349         }
 350
 351         return nhash;
 352 }
 353 EXPORT_SYMBOL_GPL(crypto_clone_shash);
 354
 355 int hash_prepare_alg(struct hash_alg_common *alg)
 356 {
 357         struct crypto_istat_hash *istat = hash_get_stat(alg);
 358         struct crypto_alg *base = &alg->base;
 359
 360         if (alg->digestsize > HASH_MAX_DIGESTSIZE)
 361                 return -EINVAL;
 362
 363         /* alignmask is not useful for hashes, so it is not supported. */
 364         if (base->cra_alignmask)
 365                 return -EINVAL;
 366
 367         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 368
 369         if (IS_ENABLED(CONFIG_CRYPTO_STATS))
 370                 memset(istat, 0, sizeof(*istat));
 371
 372         return 0;
 373 }
 374
 375 static int shash_prepare_alg(struct shash_alg *alg)
 376 {
 377         struct crypto_alg *base = &alg->halg.base;
 378         int err;
 379
 380         if (alg->descsize > HASH_MAX_DESCSIZE)
 381                 return -EINVAL;
 382
 383         if ((alg->export && !alg->import) || (alg->import && !alg->export))
 384                 return -EINVAL;
 385
 386         err = hash_prepare_alg(&alg->halg);
 387         if (err)
 388                 return err;
 389
 390         base->cra_type = &crypto_shash_type;
 391         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 392
 393         /*
 394          * Handle missing optional functions.  For each one we can either
 395          * install a default here, or we can leave the pointer as NULL and check
 396          * the pointer for NULL in crypto_shash_*(), avoiding an indirect call
 397          * when the default behavior is desired.  For ->finup and ->digest we
 398          * install defaults, since for optimal performance algorithms should
 399          * implement these anyway.  On the other hand, for ->import and
 400          * ->export the common case and best performance comes from the simple
 401          * memcpy of the shash_desc_ctx, so when those pointers are NULL we
 402          * leave them NULL and provide the memcpy with no indirect call.
 403          */
 404         if (!alg->finup)
 405                 alg->finup = shash_default_finup;
 406         if (!alg->digest)
 407                 alg->digest = shash_default_digest;
 408         if (!alg->export)
 409                 alg->halg.statesize = alg->descsize;
 410         if (!alg->setkey)
 411                 alg->setkey = shash_no_setkey;
 412
 413         return 0;
 414 }
 415
 416 int crypto_register_shash(struct shash_alg *alg)
 417 {
 418         struct crypto_alg *base = &alg->base;
 419         int err;
 420
 421         err = shash_prepare_alg(alg);
 422         if (err)
 423                 return err;
 424
 425         return crypto_register_alg(base);
 426 }
 427 EXPORT_SYMBOL_GPL(crypto_register_shash);
 428
 429 void crypto_unregister_shash(struct shash_alg *alg)
 430 {
 431         crypto_unregister_alg(&alg->base);
 432 }
 433 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 434
 435 int crypto_register_shashes(struct shash_alg *algs, int count)
 436 {
 437         int i, ret;
 438
 439         for (i = 0; i < count; i++) {
 440                 ret = crypto_register_shash(&algs[i]);
 441                 if (ret)
 442                         goto err;
 443         }
 444
 445         return 0;
 446
 447 err:
 448         for (--i; i >= 0; --i)
 449                 crypto_unregister_shash(&algs[i]);
 450
 451         return ret;
 452 }
 453 EXPORT_SYMBOL_GPL(crypto_register_shashes);
 454
 455 void crypto_unregister_shashes(struct shash_alg *algs, int count)
 456 {
 457         int i;
 458
 459         for (i = count - 1; i >= 0; --i)
 460                 crypto_unregister_shash(&algs[i]);
 461 }
 462 EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
 463
 464 int shash_register_instance(struct crypto_template *tmpl,
 465                             struct shash_instance *inst)
 466 {
 467         int err;
 468
 469         if (WARN_ON(!inst->free))
 470                 return -EINVAL;
 471
 472         err = shash_prepare_alg(&inst->alg);
 473         if (err)
 474                 return err;
 475
 476         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 477 }
 478 EXPORT_SYMBOL_GPL(shash_register_instance);
 479
 480 void shash_free_singlespawn_instance(struct shash_instance *inst)
 481 {
 482         crypto_drop_spawn(shash_instance_ctx(inst));
 483         kfree(inst);
 484 }
 485 EXPORT_SYMBOL_GPL(shash_free_singlespawn_instance);
 486
 487 MODULE_LICENSE("GPL");
 488 MODULE_DESCRIPTION("Synchronous cryptographic hash type");