Fix pointer arithmetic when creating and verifying message authentication codes.

diff --git a/src/net_packet.c b/src/net_packet.c
index af71af9..8bf41c3 100644 (file)
--- a/src/net_packet.c
+++ b/src/net_packet.c
@@ -166,7 +166,7 @@ static bool try_mac(node_t *n, const vpn_packet_t *inpkt)
        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);
+       return digest_verify(&n->indigest, &inpkt->seqno, inpkt->len, (const char *)&inpkt->seqno + inpkt->len);
 }
 
 static void receive_udppacket(node_t *n, vpn_packet_t *inpkt)
@@ -196,7 +196,7 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt)
 
        /* Check the message authentication code */
 
-       if(digest_active(&n->indigest) && !digest_verify(&n->indigest, &inpkt->seqno, inpkt->len, &inpkt->seqno + inpkt->len)) {
+       if(digest_active(&n->indigest) && !digest_verify(&n->indigest, &inpkt->seqno, inpkt->len, (const char *)&inpkt->seqno + inpkt->len)) {
                ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Got unauthenticated packet from %s (%s)"), n->name, n->hostname);
                return;
        }
@@ -369,7 +369,7 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
        /* Add the message authentication code */
 
        if(digest_active(&n->outdigest)) {
-               digest_create(&n->outdigest, &inpkt->seqno, inpkt->len, &inpkt->seqno + inpkt->len);
+               digest_create(&n->outdigest, &inpkt->seqno, inpkt->len, (char *)&inpkt->seqno + inpkt->len);
                inpkt->len += digest_length(&n->outdigest);
        }