RADIUS server: Place Message-Authenticator attribute as the first one

Move the Message-Authenticator attribute to be the first attribute in
the RADIUS messages. This mitigates certain MD5 attacks against
RADIUS/UDP.

Signed-off-by: Jouni Malinen <j@w1.fi>

diff --git a/src/radius/radius_server.c b/src/radius/radius_server.c
index e02c21540f5dc146c53216670eb59603259b8ab8..fa36915489cbb1306206c09ba25919d29e83d83f 100644 (file)
--- a/src/radius/radius_server.c
+++ b/src/radius/radius_server.c
@@ -920,6 +920,11 @@ radius_server_encapsulate_eap(struct radius_server_data *data,
                return NULL;
        }
 
+       if (!radius_msg_add_msg_auth(msg)) {
+               radius_msg_free(msg);
+               return NULL;
+       }
+
        sess_id = htonl(sess->sess_id);
        if (code == RADIUS_CODE_ACCESS_CHALLENGE &&
            !radius_msg_add_attr(msg, RADIUS_ATTR_STATE,
@@ -1204,6 +1209,11 @@ radius_server_macacl(struct radius_server_data *data,
                return NULL;
        }
 
+       if (!radius_msg_add_msg_auth(msg)) {
+               radius_msg_free(msg);
+               return NULL;
+       }
+
        if (radius_msg_copy_attr(msg, request, RADIUS_ATTR_PROXY_STATE) < 0) {
                RADIUS_DEBUG("Failed to copy Proxy-State attribute(s)");
                radius_msg_free(msg);
@@ -1253,6 +1263,11 @@ static int radius_server_reject(struct radius_server_data *data,
                return -1;
        }
 
+       if (!radius_msg_add_msg_auth(msg)) {
+               radius_msg_free(msg);
+               return -1;
+       }
+
        os_memset(&eapfail, 0, sizeof(eapfail));
        eapfail.code = EAP_CODE_FAILURE;
        eapfail.identifier = 0;