diff options
Diffstat (limited to 'crypto/shash.c')
| -rw-r--r-- | crypto/shash.c | 41 |
1 files changed, 33 insertions, 8 deletions
diff --git a/crypto/shash.c b/crypto/shash.c index 15fee57cca8e..52420c41db44 100644 --- a/crypto/shash.c +++ b/crypto/shash.c @@ -277,17 +277,34 @@ int crypto_shash_tfm_digest(struct crypto_shash *tfm, const u8 *data, } EXPORT_SYMBOL_GPL(crypto_shash_tfm_digest); -static int shash_default_export(struct shash_desc *desc, void *out) +int crypto_shash_export(struct shash_desc *desc, void *out) { - memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm)); + struct crypto_shash *tfm = desc->tfm; + struct shash_alg *shash = crypto_shash_alg(tfm); + + if (shash->export) + return shash->export(desc, out); + + memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(tfm)); return 0; } +EXPORT_SYMBOL_GPL(crypto_shash_export); -static int shash_default_import(struct shash_desc *desc, const void *in) +int crypto_shash_import(struct shash_desc *desc, const void *in) { - memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm)); + struct crypto_shash *tfm = desc->tfm; + struct shash_alg *shash = crypto_shash_alg(tfm); + + if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) + return -ENOKEY; + + if (shash->import) + return shash->import(desc, in); + + memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(tfm)); return 0; } +EXPORT_SYMBOL_GPL(crypto_shash_import); static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key, unsigned int keylen) @@ -666,15 +683,23 @@ static int shash_prepare_alg(struct shash_alg *alg) base->cra_type = &crypto_shash_type; base->cra_flags |= CRYPTO_ALG_TYPE_SHASH; + /* + * Handle missing optional functions. For each one we can either + * install a default here, or we can leave the pointer as NULL and check + * the pointer for NULL in crypto_shash_*(), avoiding an indirect call + * when the default behavior is desired. For ->finup and ->digest we + * install defaults, since for optimal performance algorithms should + * implement these anyway. On the other hand, for ->import and + * ->export the common case and best performance comes from the simple + * memcpy of the shash_desc_ctx, so when those pointers are NULL we + * leave them NULL and provide the memcpy with no indirect call. + */ if (!alg->finup) alg->finup = shash_default_finup; if (!alg->digest) alg->digest = shash_default_digest; - if (!alg->export) { - alg->export = shash_default_export; - alg->import = shash_default_import; + if (!alg->export) alg->halg.statesize = alg->descsize; - } if (!alg->setkey) alg->setkey = shash_no_setkey; |