crypto: af_alg - add extra parameters for DRBG interface
Extend the user-space RNG interface:
1. Add entropy input via ALG_SET_DRBG_ENTROPY setsockopt option;
2. Add additional data input via sendmsg syscall.
This allows DRBG to be tested with test vectors, for example for the
purpose of CAVP testing, which otherwise isn't possible.
To prevent erroneous use of entropy input, it is hidden under
CRYPTO_USER_API_RNG_CAVP config option and requires CAP_SYS_ADMIN to
succeed.
Signed-off-by: Elena Petrova <lenaptr@google.com>
Acked-by: Stephan Müller <smueller@chronox.de>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index a6f581a..8535cb0 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -253,6 +253,14 @@ static int alg_setsockopt(struct socket *sock, int level, int optname,
if (!type->setauthsize)
goto unlock;
err = type->setauthsize(ask->private, optlen);
+ break;
+ case ALG_SET_DRBG_ENTROPY:
+ if (sock->state == SS_CONNECTED)
+ goto unlock;
+ if (!type->setentropy)
+ goto unlock;
+
+ err = type->setentropy(ask->private, optval, optlen);
}
unlock:
@@ -285,6 +293,11 @@ int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern)
security_sock_graft(sk2, newsock);
security_sk_clone(sk, sk2);
+ /*
+ * newsock->ops assigned here to allow type->accept call to override
+ * them when required.
+ */
+ newsock->ops = type->ops;
err = type->accept(ask->private, sk2);
nokey = err == -ENOKEY;
@@ -303,7 +316,6 @@ int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern)
alg_sk(sk2)->parent = sk;
alg_sk(sk2)->type = type;
- newsock->ops = type->ops;
newsock->state = SS_CONNECTED;
if (nokey)
