fix: signal key transfer

engine/agent.go

@@ -21,7 +21,7 @@ type PeerAgent struct {
 	// Actual peer-to-peer connection
 	conn *ice.Conn
 	// a signal.Client to negotiate initial connection
-	signal signal.Client
+	signal *signal.Client
 	// a connection to a local Wireguard instance to proxy data
 	wgConn net.Conn
 	// an address of local Wireguard instance
@@ -29,7 +29,7 @@ type PeerAgent struct {
 }
 
 // NewPeerAgent creates a new PeerAgent with give local and remote Wireguard public keys and initializes an ICE Agent
-func NewPeerAgent(localKey string, remoteKey string, stunTurnURLS []*ice.URL, wgAddr string) (*PeerAgent, error) {
+func NewPeerAgent(localKey string, remoteKey string, stunTurnURLS []*ice.URL, wgAddr string, signal *signal.Client) (*PeerAgent, error) {
 
 	// init ICE Agent
 	iceAgent, err := ice.NewAgent(&ice.AgentConfig{
@@ -47,6 +47,7 @@ func NewPeerAgent(localKey string, remoteKey string, stunTurnURLS []*ice.URL, wg
 		wgAddr:    wgAddr,
 		conn:      nil,
 		wgConn:    nil,
+		signal:    signal,
 	}
 
 	err = peerAgent.onConnectionStateChange()
@@ -217,6 +218,24 @@ func (pa *PeerAgent) onConnectionStateChange() error {
 	})
 }
 
+func (pa *PeerAgent) Start() error {
+	localUFrag, localPwd, err := pa.iceAgent.GetLocalUserCredentials()
+	if err != nil {
+		return err
+	}
+
+	offer := signal.MarshalCredential(pa.LocalKey, pa.RemoteKey, &signal.Credential{
+		UFrag: localUFrag,
+		Pwd:   localPwd}, sProto.Message_OFFER)
+
+	err = pa.signal.Send(offer)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
 // authenticate sets the signal.Credential of the remote peer
 // and returns local Credentials
 func (pa *PeerAgent) Authenticate(credential *signal.Credential) (*signal.Credential, error) {

engine/engine.go

@@ -34,12 +34,13 @@ func NewEngine(signal *signal.Client, stunsTurns []*ice.URL, wgIface string, wgA
 	}
 }
 
-func (e *Engine) Start(localKey string, peers []string) error {
+func (e *Engine) Start(privateKey string, peers []string) error {
 
 	// setup wireguard
-	myKey, err := wgtypes.ParseKey(localKey)
+	myKey, err := wgtypes.ParseKey(privateKey)
+	myPubKey := myKey.PublicKey().String()
 	if err != nil {
-		log.Errorf("error parsing Wireguard key %s: [%s]", localKey, err.Error())
+		log.Errorf("error parsing Wireguard key %s: [%s]", privateKey, err.Error())
 		return err
 	}
 
@@ -63,17 +64,23 @@ func (e *Engine) Start(localKey string, peers []string) error {
 
 	// initialize peer agents
 	for _, peer := range peers {
-		peerAgent, err := NewPeerAgent(localKey, peer, e.stunsTurns, fmt.Sprintf("127.0.0.1:%d", *wgPort))
+		peerAgent, err := NewPeerAgent(myPubKey, peer, e.stunsTurns, fmt.Sprintf("127.0.0.1:%d", *wgPort), e.signal)
 		if err != nil {
-			log.Fatalf("failed creating peer agent for pair %s - %s", localKey, peer)
+			log.Fatalf("failed creating peer agent for pair %s - %s", myPubKey, peer)
 			return err
 		}
-		e.agents[localKey] = peerAgent
+		e.agents[myPubKey] = peerAgent
 	}
 
-	e.receiveSignal(localKey)
+	e.receiveSignal(myPubKey)
 
-	// todo send offer to each peer
+	for _, pa := range e.agents {
+		err := pa.Start()
+		if err != nil {
+			log.Fatalf("failed starting agent %s %s", myPubKey, err)
+			return err
+		}
+	}
 
 	return nil
 }