X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fprotocol_key.c;h=4f1e1b76c2cf374169ab8c91ea00957448f6a251;hp=341d0ac9f86b03a11b10815d7e7b8c22fb5e2851;hb=4a5c12ec97fa1e82aae2d327fdc648e5203eb478;hpb=40d91ff619a6ea24a2a35c9d934bcc6bace27e24

diff --git a/src/protocol_key.c b/src/protocol_key.c
index 341d0ac9..4f1e1b76 100644
--- a/src/protocol_key.c
+++ b/src/protocol_key.c
@@ -1,7 +1,7 @@
 /*
     protocol_key.c -- handle the meta-protocol, key exchange
     Copyright (C) 1999-2005 Ivo Timmermans,
-                  2000-2010 Guus Sliepen <guus@tinc-vpn.org>
+                  2000-2016 Guus Sliepen <guus@tinc-vpn.org>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -34,17 +34,21 @@
 #include "utils.h"
 #include "xalloc.h"
 
-bool mykeyused = false;
+static bool mykeyused = false;
 
-bool send_key_changed() {
-	/* Only send this message if some other daemon requested our key previously.
-	   This reduces unnecessary key_changed broadcasts.
-	 */
+void send_key_changed(void) {
+	avl_node_t *node;
+	connection_t *c;
 
-	if(!mykeyused)
-		return true;
+	send_request(everyone, "%d %x %s", KEY_CHANGED, rand(), myself->name);
+
+	/* Immediately send new keys to directly connected nodes to keep UDP mappings alive */
 
-	return send_request(broadcast, "%d %x %s", KEY_CHANGED, rand(), myself->name);
+	for(node = connection_tree->head; node; node = node->next) {
+		c = node->data;
+		if(c->status.active && c->node && c->node->status.reachable)
+			send_ans_key(c->node);
+	}
 }
 
 bool key_changed_h(connection_t *c) {
@@ -123,7 +127,8 @@ bool req_key_h(connection_t *c) {
 	/* Check if this key request is for us */
 
 	if(to == myself) {			/* Yes, send our own key back */
-		send_ans_key(from);
+		if (!send_ans_key(from))
+			return false;
 	} else {
 		if(tunnelserver)
 			return true;
@@ -141,8 +146,6 @@ bool req_key_h(connection_t *c) {
 }
 
 bool send_ans_key(node_t *to) {
-	char *key;
-
 	// Set key parameters
 	to->incipher = myself->incipher;
 	to->inkeylength = myself->inkeylength;
@@ -154,17 +157,22 @@ bool send_ans_key(node_t *to) {
 	to->inkey = xrealloc(to->inkey, to->inkeylength);
 
 	// Create a new key
-	RAND_pseudo_bytes((unsigned char *)to->inkey, to->inkeylength);
+	if (1 != RAND_bytes((unsigned char *)to->inkey, to->inkeylength)) {
+		int err = ERR_get_error();
+		logger(LOG_ERR, "Failed to generate random for key (%s)", ERR_error_string(err, NULL));
+		return false; // Do not send insecure keys, let connection attempt fail.
+	}
+
 	if(to->incipher)
 		EVP_DecryptInit_ex(&to->inctx, to->incipher, NULL, (unsigned char *)to->inkey, (unsigned char *)to->inkey + to->incipher->key_len);
 
 	// Reset sequence number and late packet window
 	mykeyused = true;
 	to->received_seqno = 0;
-	memset(to->late, 0, sizeof(to->late));
+	if(replaywin) memset(to->late, 0, replaywin);
 
 	// Convert to hexadecimal and send
-	key = alloca(2 * to->inkeylength + 1);
+	char key[2 * to->inkeylength + 1];
 	bin2hex(to->inkey, key, to->inkeylength);
 	key[to->inkeylength * 2] = '\0';
 
@@ -225,7 +233,7 @@ bool ans_key_h(connection_t *c) {
 			return true;
 		}
 
-		if(!*address) {
+		if(!*address && from->address.sa.sa_family != AF_UNSPEC && to->minmtu) {
 			char *address, *port;
 			ifdebug(PROTOCOL) logger(LOG_DEBUG, "Appending reflexive UDP address to ANS_KEY from %s to %s", from->name, to->name);
 			sockaddr2str(&from->address, &address, &port);
@@ -238,12 +246,16 @@ bool ans_key_h(connection_t *c) {
 		return send_request(to->nexthop->connection, "%s", c->buffer);
 	}
 
+	/* Don't use key material until every check has passed. */
+	from->status.validkey = false;
+
 	/* Update our copy of the origin's packet key */
 	from->outkey = xrealloc(from->outkey, strlen(key) / 2);
-
-	from->outkey = xstrdup(key);
 	from->outkeylength = strlen(key) / 2;
-	hex2bin(key, from->outkey, from->outkeylength);
+	if(!hex2bin(key, from->outkey, from->outkeylength)) {
+		logger(LOG_ERR, "Got bad %s from %s(%s): %s", "ANS_KEY", from->name, from->hostname, "invalid key");
+		return true;
+	}
 
 	/* Check and lookup cipher and digest algorithms */
 
@@ -308,7 +320,7 @@ bool ans_key_h(connection_t *c) {
 		update_node_udp(from, &sa);
 	}
 
-	if(from->options & OPTION_PMTU_DISCOVERY && !from->mtuprobes)
+	if(from->options & OPTION_PMTU_DISCOVERY && !from->mtuevent)
 		send_mtu_probe(from);
 
 	return true;