Add starttls for smtp, imap and ftp (#36)

test/tcp.go

@@ -17,7 +17,7 @@ type TCPServer struct {
 	stopCh   chan struct{}
 }
 
-// StartTLS starts a listener that performs a TLS handshake
+// StartTLS starts a listener that performs an immediate TLS handshake
 func (t *TCPServer) StartTLS() {
 	go func() {
 		ln := tls.NewListener(t.Listener, t.TLS)
@@ -39,6 +39,103 @@ func (t *TCPServer) StartTLS() {
 	}()
 }
 
+// StartSMTP starts a listener that negotiates a TLS connection with an smtp
+// client using STARTTLS
+func (t *TCPServer) StartSMTP() {
+	go func() {
+		conn, err := t.Listener.Accept()
+		if err != nil {
+			panic(fmt.Sprintf("Error accepting on socket: %s", err))
+		}
+		defer conn.Close()
+
+		if err := conn.SetDeadline(time.Now().Add(5 * time.Second)); err != nil {
+			panic("Error setting deadline")
+		}
+
+		fmt.Fprintf(conn, "220 ESMTP StartTLS pseudo-server\n")
+		if _, e := fmt.Fscanf(conn, "EHLO prober\n"); e != nil {
+			panic("Error in dialog. No EHLO received.")
+		}
+		fmt.Fprintf(conn, "250-pseudo-server.example.net\n")
+		fmt.Fprintf(conn, "250-STARTTLS\n")
+		fmt.Fprintf(conn, "250 DSN\n")
+
+		if _, e := fmt.Fscanf(conn, "STARTTLS\n"); e != nil {
+			panic("Error in dialog. No (TLS) STARTTLS received.")
+		}
+		fmt.Fprintf(conn, "220 2.0.0 Ready to start TLS\n")
+
+		// Upgrade to TLS.
+		tlsConn := tls.Server(conn, t.TLS)
+		if err := tlsConn.Handshake(); err != nil {
+			log.Errorln(err)
+		}
+		defer tlsConn.Close()
+
+		t.stopCh <- struct{}{}
+	}()
+}
+
+// StartFTP starts a listener that negotiates a TLS connection with an ftp
+// client using AUTH TLS
+func (t *TCPServer) StartFTP() {
+	go func() {
+		conn, err := t.Listener.Accept()
+		if err != nil {
+			panic(fmt.Sprintf("Error accepting on socket: %s", err))
+		}
+		defer conn.Close()
+
+		fmt.Fprintf(conn, "220 Test FTP Service\n")
+		if _, e := fmt.Fscanf(conn, "AUTH TLS\n"); e != nil {
+			panic("Error in dialog. No AUTH TLS received.")
+		}
+		fmt.Fprintf(conn, "234 AUTH command ok. Expecting TLS Negotiation.\n")
+
+		// Upgrade to TLS.
+		tlsConn := tls.Server(conn, t.TLS)
+		if err := tlsConn.Handshake(); err != nil {
+			log.Errorln(err)
+		}
+		defer tlsConn.Close()
+
+		t.stopCh <- struct{}{}
+	}()
+}
+
+// StartIMAP starts a listener that negotiates a TLS connection with an imap
+// client using STARTTLS
+func (t *TCPServer) StartIMAP() {
+	go func() {
+		conn, err := t.Listener.Accept()
+		if err != nil {
+			panic(fmt.Sprintf("Error accepting on socket: %s", err))
+		}
+		defer conn.Close()
+
+		fmt.Fprintf(conn, "* OK XIMAP ready for requests\n")
+		if _, e := fmt.Fscanf(conn, ". CAPABILITY\n"); e != nil {
+			panic("Error in dialog. No . CAPABILITY received.")
+		}
+		fmt.Fprintf(conn, "* CAPABILITY IMAP4 IMAP4rev1 AUTH=PLAIN STARTTLS\n")
+		fmt.Fprintf(conn, ". OK CAPABILITY completed.\n")
+		if _, e := fmt.Fscanf(conn, ". STARTTLS\n"); e != nil {
+			panic("Error in dialog. No . STARTTLS received.")
+		}
+		fmt.Fprintf(conn, ". OK Begin TLS negotiation now.\n")
+
+		// Upgrade to TLS.
+		tlsConn := tls.Server(conn, t.TLS)
+		if err := tlsConn.Handshake(); err != nil {
+			log.Errorln(err)
+		}
+		defer tlsConn.Close()
+
+		t.stopCh <- struct{}{}
+	}()
+}
+
 // Close stops the server and closes the listener
 func (t *TCPServer) Close() {
 	<-t.stopCh