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