crypto: shash - Require all algorithms to support export/import
This patch provides a default export/import function for all
shash algorithms. It simply copies the descriptor context as
is done by sha1_generic.
This in essence means that all existing shash algorithms now
support export/import. This is something that will be depended
upon in implementations such as hmac. Therefore all new shash
and ahash implementations must support export/import.
For those that cannot obtain a partial result, padlock-sha's
fallback model should be used so that a partial result is always
available.
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
---
crypto/shash.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)
diff --git a/crypto/shash.c b/crypto/shash.c
index 7713b52..98b7f46 100644
--- a/crypto/shash.c
+++ b/crypto/shash.c
@@ -183,14 +183,16 @@ int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
}
EXPORT_SYMBOL_GPL(crypto_shash_digest);
-static int shash_no_export(struct shash_desc *desc, void *out)
+static int shash_default_export(struct shash_desc *desc, void *out)
{
- return -ENOSYS;
+ memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm));
+ return 0;
}
-static int shash_no_import(struct shash_desc *desc, const void *in)
+static int shash_default_import(struct shash_desc *desc, const void *in)
{
- return -ENOSYS;
+ memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm));
+ return 0;
}
static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
@@ -563,10 +565,11 @@ static int shash_prepare_alg(struct shash_alg *alg)
alg->finup = shash_finup_unaligned;
if (!alg->digest)
alg->digest = shash_digest_unaligned;
- if (!alg->import)
- alg->import = shash_no_import;
- if (!alg->export)
- alg->export = shash_no_export;
+ if (!alg->export) {
+ alg->export = shash_default_export;
+ alg->import = shash_default_import;
+ alg->statesize = alg->descsize;
+ }
if (!alg->setkey)
alg->setkey = shash_no_setkey;
--
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