From: Guus Sliepen <guus@meshlink.io>
Date: Tue, 12 Aug 2014 20:03:32 +0000 (+0200)
Subject: Fix segfault when two nodes that just joined a mesh want to autoconnect to each other.
X-Git-Url: http://git.meshlink.io/?p=meshlink;a=commitdiff_plain;h=98b9d73682733072d66d6db3beb15e7309805cf5

Fix segfault when two nodes that just joined a mesh want to autoconnect to each other.

In this case, we have not exchanged public keys yet. That should not be
a problem, but we blindly pass a NULL pointer to sptps_start() in this
case which blindly dereferences it. Fix sptps_start() by making sure no
arguments are NULL, and teach MeshLink to exchange keys between
reachable nodes when it tries to make a meta-connection.
---

diff --git a/src/protocol_auth.c b/src/protocol_auth.c
index d359b9b6..9cb96b65 100644
--- a/src/protocol_auth.c
+++ b/src/protocol_auth.c
@@ -329,11 +329,20 @@ bool id_h(meshlink_handle_t *mesh, connection_t *c, const char *request) {
 			logger(mesh, MESHLINK_ERROR, "Peer %s had unknown identity (%s)", c->hostname, c->name);
 			return false;
 		}
+	}
 
-		read_ecdsa_public_key(mesh, c);
-	} else {
-		if(c->protocol_minor && !ecdsa_active(c->ecdsa))
-			c->protocol_minor = 1;
+	read_ecdsa_public_key(mesh, c);
+
+	if(!ecdsa_active(c->ecdsa)) {
+		logger(mesh, MESHLINK_ERROR, "No key known for peer %s (%s)", c->name, c->hostname);
+
+		node_t *n = lookup_node(mesh, c->name);
+		if(n && !n->status.waitingforkey) {
+			logger(mesh, MESHLINK_INFO, "Requesting key from peer %s (%s)", c->name, c->hostname);
+			send_req_key(mesh, n);
+		}
+
+		return false;
 	}
 
 	/* Forbid version rollback for nodes whose ECDSA key we know */
diff --git a/src/sptps.c b/src/sptps.c
index 49e0a336..2e9ac6fe 100644
--- a/src/sptps.c
+++ b/src/sptps.c
@@ -565,6 +565,9 @@ bool sptps_receive_data(sptps_t *s, const void *data, size_t len) {
 
 // Start a SPTPS session.
 bool sptps_start(sptps_t *s, void *handle, bool initiator, bool datagram, ecdsa_t *mykey, ecdsa_t *hiskey, const char *label, size_t labellen, send_data_t send_data, receive_record_t receive_record) {
+	if(!s || !mykey || !hiskey || !label || !labellen || !send_data || !receive_record)
+		return error(s, EINVAL, "Invalid argument to sptps_start()");
+
 	// Initialise struct sptps
 	memset(s, 0, sizeof *s);