Handle truncated message authentication codes.

[tinc] / src / net_packet.c

diff --git a/src/net_packet.c b/src/net_packet.c
index 062e0be..af71af9 100644 (file)
--- a/src/net_packet.c
+++ b/src/net_packet.c
@@ -163,7 +163,7 @@ static void receive_packet(node_t *n, vpn_packet_t *packet) {
 
 static bool try_mac(node_t *n, const vpn_packet_t *inpkt)
 {
-       if(!digest_active(&n->indigest) || !n->inmaclength || inpkt->len < sizeof inpkt->seqno + n->inmaclength)
+       if(!digest_active(&n->indigest) || inpkt->len < sizeof inpkt->seqno + digest_length(&n->indigest))
                return false;
 
        return digest_verify(&n->indigest, &inpkt->seqno, inpkt->len, &inpkt->seqno + inpkt->len);