+
+ return true;
+}
+
+bool send_ans_key(node_t *to) {
+ if(to->status.sptps)
+ abort();
+
+#ifdef DISABLE_LEGACY
+ return false;
+#else
+ size_t keylen = myself->incipher ? cipher_keylength(myself->incipher) : 1;
+ char key[keylen * 2 + 1];
+
+ randomize(key, keylen);
+
+ cipher_close(to->incipher);
+ digest_close(to->indigest);
+
+ if(myself->incipher) {
+ to->incipher = cipher_open_by_nid(cipher_get_nid(myself->incipher));
+ if(!to->incipher)
+ abort();
+ if(!cipher_set_key(to->incipher, key, false))
+ abort();
+ }
+
+ if(myself->indigest) {
+ to->indigest = digest_open_by_nid(digest_get_nid(myself->indigest), digest_length(myself->indigest));
+ if(!to->indigest)
+ abort();
+ if(!digest_set_key(to->indigest, key, keylen))
+ abort();
+ }
+
+ to->incompression = myself->incompression;
+
+ bin2hex(key, key, keylen);
+
+ // Reset sequence number and late packet window
+ mykeyused = true;
+ to->received_seqno = 0;
+ to->received = 0;
+ if(replaywin) memset(to->late, 0, replaywin);
+
+ to->status.validkey_in = true;
+
+ return send_request(to->nexthop->connection, "%d %s %s %s %d %d %d %d", ANS_KEY,
+ myself->name, to->name, key,
+ cipher_get_nid(to->incipher),
+ digest_get_nid(to->indigest),
+ (int)digest_length(to->indigest),
+ to->incompression);
+#endif
+}
+
+bool ans_key_h(connection_t *c, const char *request) {
+ char from_name[MAX_STRING_SIZE];
+ char to_name[MAX_STRING_SIZE];
+ char key[MAX_STRING_SIZE];
+ char address[MAX_STRING_SIZE] = "";
+ char port[MAX_STRING_SIZE] = "";
+ int cipher, digest, maclength, compression, keylen;
+ node_t *from, *to;
+
+ if(sscanf(request, "%*d "MAX_STRING" "MAX_STRING" "MAX_STRING" %d %d %d %d "MAX_STRING" "MAX_STRING,
+ from_name, to_name, key, &cipher, &digest, &maclength,
+ &compression, address, port) < 7) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "ANS_KEY", c->name,
+ c->hostname);
+ return false;
+ }
+
+ if(!check_id(from_name) || !check_id(to_name)) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "ANS_KEY", c->name, c->hostname, "invalid name");
+ return false;
+ }
+
+ from = lookup_node(from_name);
+
+ if(!from) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Got %s from %s (%s) origin %s which does not exist in our connection list",
+ "ANS_KEY", c->name, c->hostname, from_name);
+ return true;
+ }
+
+ to = lookup_node(to_name);
+
+ if(!to) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Got %s from %s (%s) destination %s which does not exist in our connection list",
+ "ANS_KEY", c->name, c->hostname, to_name);
+ return true;
+ }
+
+ /* Forward it if necessary */
+
+ if(to != myself) {
+ if(tunnelserver)
+ return true;
+
+ if(!to->status.reachable) {
+ logger(DEBUG_ALWAYS, LOG_WARNING, "Got %s from %s (%s) destination %s which is not reachable",
+ "ANS_KEY", c->name, c->hostname, to_name);
+ return true;
+ }
+
+ if(!*address && from->address.sa.sa_family != AF_UNSPEC) {
+ char *address, *port;
+ logger(DEBUG_PROTOCOL, LOG_DEBUG, "Appending reflexive UDP address to ANS_KEY from %s to %s", from->name, to->name);
+ sockaddr2str(&from->address, &address, &port);
+ send_request(to->nexthop->connection, "%s %s %s", request, address, port);
+ free(address);
+ free(port);
+ return true;
+ }
+
+ return send_request(to->nexthop->connection, "%s", request);
+ }
+
+#ifndef DISABLE_LEGACY
+ /* Don't use key material until every check has passed. */
+ cipher_close(from->outcipher);
+ digest_close(from->outdigest);
+#endif
+ if (!from->status.sptps) from->status.validkey = false;
+
+ if(compression < 0 || compression > 11) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses bogus compression level!", from->name, from->hostname);
+ return true;
+ }
+
+ from->outcompression = compression;
+
+ /* SPTPS or old-style key exchange? */
+
+ if(from->status.sptps) {
+ char buf[strlen(key)];
+ int len = b64decode(key, buf, strlen(key));
+ if(!len || !sptps_receive_data(&from->sptps, buf, len)) {
+ /* Uh-oh. It might be that the tunnel is stuck in some corrupted state,
+ so let's restart SPTPS in case that helps. But don't do that too often
+ to prevent storms.
+ Note that simply relying on handshake timeout is not enough, because
+ that doesn't apply to key regeneration. */
+ if(from->last_req_key < now.tv_sec - 10) {
+ logger(DEBUG_PROTOCOL, LOG_ERR, "Failed to decode handshake TCP packet from %s (%s), restarting SPTPS", from->name, from->hostname);
+ send_req_key(from);
+ }
+ return true;
+ }
+
+ if(from->status.validkey) {
+ if(*address && *port) {
+ logger(DEBUG_PROTOCOL, LOG_DEBUG, "Using reflexive UDP address from %s: %s port %s", from->name, address, port);
+ sockaddr_t sa = str2sockaddr(address, port);
+ update_node_udp(from, &sa);
+ }
+ }
+
+ send_mtu_info(myself, from, MTU);
+
+ return true;
+ }
+
+#ifdef DISABLE_LEGACY
+ logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses legacy protocol!", from->name, from->hostname);
+ return false;
+#else
+ /* Check and lookup cipher and digest algorithms */
+
+ if(cipher) {
+ if(!(from->outcipher = cipher_open_by_nid(cipher))) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses unknown cipher!", from->name, from->hostname);
+ return false;
+ }
+ } else {
+ from->outcipher = NULL;
+ }
+
+ if(digest) {
+ if(!(from->outdigest = digest_open_by_nid(digest, maclength))) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses unknown digest!", from->name, from->hostname);
+ return false;
+ }
+ } else {
+ from->outdigest = NULL;
+ }
+
+ if(maclength != digest_length(from->outdigest)) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses bogus MAC length!", from->name, from->hostname);
+ return false;
+ }
+
+ /* Process key */
+
+ keylen = hex2bin(key, key, sizeof key);
+
+ if(keylen != (from->outcipher ? cipher_keylength(from->outcipher) : 1)) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses wrong keylength!", from->name, from->hostname);
+ return true;
+ }
+
+ /* Update our copy of the origin's packet key */
+
+ if(from->outcipher && !cipher_set_key(from->outcipher, key, true))
+ return false;
+ if(from->outdigest && !digest_set_key(from->outdigest, key, keylen))
+ return false;
+
+ from->status.validkey = true;
+ from->sent_seqno = 0;
+
+ if(*address && *port) {
+ logger(DEBUG_PROTOCOL, LOG_DEBUG, "Using reflexive UDP address from %s: %s port %s", from->name, address, port);
+ sockaddr_t sa = str2sockaddr(address, port);
+ update_node_udp(from, &sa);
+ }
+
+ return true;
+#endif