Fix packet authentication.

[tinc] / src / net_packet.c

diff --git a/src/net_packet.c b/src/net_packet.c
index aaa0c72..df6f482 100644 (file)
--- a/src/net_packet.c
+++ b/src/net_packet.c
@@ -195,7 +195,7 @@ 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, (const char *)&inpkt->seqno + inpkt->len);
+       return digest_verify(&n->indigest, &inpkt->seqno, inpkt->len - n->indigest.maclength, (const char *)&inpkt->seqno + inpkt->len - n->indigest.maclength);
 }
 
 static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
@@ -222,11 +222,13 @@ 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, (const char *)&inpkt->seqno + inpkt->len)) {
-               ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got unauthenticated packet from %s (%s)", n->name, n->hostname);
-               return;
+       if(digest_active(&n->indigest)) {
+               inpkt->len -= n->indigest.maclength;
+               if(!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;
+               }
        }
-
        /* Decrypt the packet */
 
        if(cipher_active(&n->incipher)) {
@@ -501,31 +503,28 @@ void broadcast_packet(const node_t *from, vpn_packet_t *packet) {
 
 static node_t *try_harder(const sockaddr_t *from, const vpn_packet_t *pkt) {
        splay_node_t *node;
-       edge_t *e;
-       node_t *n = NULL;
+       node_t *n, *found = NULL;
        static time_t last_hard_try = 0;
        time_t now = time(NULL);
 
-       for(node = edge_weight_tree->head; node; node = node->next) {
-               e = node->data;
-
-               if(sockaddrcmp_noport(from, &e->address)) {
-                       if(last_hard_try == now)
-                               continue;
-                       last_hard_try = now;
-               }
+       if(last_hard_try == now)
+               return NULL;
+       else
+               last_hard_try = now;
 
-               if(!n)
-                       n = e->to;
+       for(node = node_tree->head; node; node = node->next) {
+               n = node->data;
 
-               if(!try_mac(e->to, pkt))
+               if(n == myself || !digest_active(&n->indigest))
                        continue;
 
-               n = e->to;
-               break;
+               if(try_mac(n, pkt)) {
+                       found = n;
+                       break;
+               }
        }
 
-       return n;
+       return found;
 }
 
 void handle_incoming_vpn_data(int sock, short events, void *data) {