ext/signature: reject an extension size of zero

Signed-off-by: Nikos Mavrogiannopoulos <nmav@redhat.com>

diff --git a/lib/ext/signature.c b/lib/ext/signature.c
index 96b97cef946518a47d69a3e593e68b74c3f9ee7b..795f149182f18a663531d8ae79a514215d99dce6 100644 (file)
--- a/lib/ext/signature.c
+++ b/lib/ext/signature.c
@@ -128,7 +128,7 @@ _gnutls_sign_algorithm_parse_data(gnutls_session_t session,
        sig_ext_st *priv;
        extension_priv_data_t epriv;
 
-       if (data_size % 2 != 0)
+       if (data_size == 0 || data_size % 2 != 0)
                return gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
 
        priv = gnutls_calloc(1, sizeof(*priv));