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