crypto: akcipher - default implementations for request callbacks

Because with the introduction of EC-RDSA and change in workings of RSA
in regard to sign/verify, akcipher could have not all callbacks defined,
check the presence of callbacks in crypto_register_akcipher() and
provide default implementation if the callback is not implemented.

This is suggested by Herbert Xu instead of checking the presence of the
callback on every request.

Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 14 insertions, 0 deletions

diff --git a/crypto/akcipher.c b/crypto/akcipher.c
index 0cbeae137e0a..780daa436dac 100644
--- a/crypto/akcipher.c
+++ b/crypto/akcipher.c
@@ -119,10 +119,24 @@ static void akcipher_prepare_alg(struct akcipher_alg *alg)
         base->cra_flags |= CRYPTO_ALG_TYPE_AKCIPHER;
 }
 
+static int akcipher_default_op(struct akcipher_request *req)
+{
+        return -ENOSYS;
+}
+
 int crypto_register_akcipher(struct akcipher_alg *alg)
 {
         struct crypto_alg *base = &alg->base;
 
+        if (!alg->sign)
+                alg->sign = akcipher_default_op;
+        if (!alg->verify)
+                alg->verify = akcipher_default_op;
+        if (!alg->encrypt)
+                alg->encrypt = akcipher_default_op;
+        if (!alg->decrypt)
+                alg->decrypt = akcipher_default_op;
+
         akcipher_prepare_alg(alg);
         return crypto_register_alg(base);
 }