// Makes an outgoing connection using that protocol type to the given node ID.
// Returns a non-nil error if it is unable to connect.
// Panics if it is called with protocol set to CLIENT_PROTOCOL.
func Dial(protocol int, id uint16) (*BaseConn, error) {
log.Print("dialing node ", id)
if protocol == CLIENT_PROTOCOL {
panic("tried to make outgoing client protocol connection")
}
ip := config.NodeIP(id)
ipStr := ip.String()
port := getProtocolPort(protocol)
portStr := strconv.FormatInt(int64(port), 10)
tlsConfig := new(tls.Config)
tlsConfig.Certificates = []tls.Certificate{*config.Certificate()}
tlsConfig.RootCAs = config.NodeCertPool(id)
// We rely on the receiving node to do TLS authentication for now.
// This is safe because it verifies our identity for us.
// Backwards to the usual arrangement but should be secure.
tlsConfig.InsecureSkipVerify = true
tlsConn, err := tls.Dial("tcp", ipStr+":"+portStr, tlsConfig)
if err != nil {
log.Print(err)
return nil, err
}
return newBaseConn(tlsConn), nil
}
// Blocks listening for connections of that given protocol type,
// and calls the specified handler when one is received,
// passing the node ID of the connecting node, or 0 for the Client Protocol.
func Listen(protocol int, handler func(id uint16, b *BaseConn)) {
ip := config.NodeIP(config.Id())
ipStr := ip.String()
port := getProtocolPort(protocol)
portStr := strconv.FormatInt(int64(port), 10)
tlsConfig := new(tls.Config)
tlsConfig.Certificates = []tls.Certificate{*config.Certificate()}
if protocol != CLIENT_PROTOCOL {
tlsConfig.ClientAuth = tls.RequireAnyClientCert
}
listener, err := tls.Listen("tcp", ipStr+":"+portStr, tlsConfig)
if err != nil {
log.Fatal(err)
}
for {
conn, err := listener.Accept()
if err != nil {
log.Fatal(err)
}
tlsConn := conn.(*tls.Conn)
err = tlsConn.Handshake()
if err != nil {
tlsConn.Close()
continue
}
if protocol != CLIENT_PROTOCOL {
// Check this connecting node has authenticated.
state := tlsConn.ConnectionState()
if len(state.PeerCertificates) == 0 {
tlsConn.Close()
continue
}
cert := state.PeerCertificates[0]
// Identify which node they authenticated as.
matched := false
for _, node := range config.Nodes() {
var verifyOpts x509.VerifyOptions
verifyOpts.Intermediates = new(x509.CertPool)
verifyOpts.Roots = config.NodeCertPool(node)
chains, err := cert.Verify(verifyOpts)
if err != nil {
continue
}
// Matched the node. Start the handler.
if len(chains) > 0 {
matched = true
go handler(node, newBaseConn(tlsConn))
break
}
}
// No matching node found. Close the connection.
if !matched {
tlsConn.Close()
}
} else {
// We don't authenticate clients.
// Just run the handler.
handler(0, newBaseConn(tlsConn))
}
}
}