Log error, if certificate is not found

main.go

@@ -285,6 +285,72 @@ func loop() {
 	for _, element := range portList {
 		log.Printf("\t%v\n", element)
 
+			r.Use(cors.Middleware(cors.Config{
+				Origins:         *origins + ", " + extraOriginStr,
+				Methods:         "GET, PUT, POST, DELETE",
+				RequestHeaders:  "Origin, Authorization, Content-Type",
+				ExposedHeaders:  "",
+				MaxAge:          50 * time.Second,
+				Credentials:     true,
+				ValidateHeaders: false,
+			}))
+
+			r.LoadHTMLFiles("templates/nofirefox.html")
+
+			r.GET("/", homeHandler)
+			r.GET("/certificate.crt", certHandler)
+			r.DELETE("/certificate.crt", deleteCertHandler)
+			r.POST("/upload", uploadHandler)
+			r.GET("/socket.io/", socketHandler)
+			r.POST("/socket.io/", socketHandler)
+			r.Handle("WS", "/socket.io/", socketHandler)
+			r.Handle("WSS", "/socket.io/", socketHandler)
+			r.GET("/info", infoHandler)
+			r.POST("/killbrowser", killBrowserHandler)
+			r.POST("/pause", pauseHandler)
+			r.POST("/update", updateHandler)
+
+			go func() {
+				// check if certificates exist; if not, use plain http
+				if _, err := os.Stat(filepath.Join(dest, "cert.pem")); os.IsNotExist(err) {
+					log.Error("Could not find HTTPS certificate. Using plain HTTP only.")
+					return
+				}
+
+				start := 8990
+				end := 9000
+				i := start
+				for i < end {
+					i = i + 1
+					portSSL = ":" + strconv.Itoa(i)
+					if err := r.RunTLS(*address+portSSL, filepath.Join(dest, "cert.pem"), filepath.Join(dest, "key.pem")); err != nil {
+						log.Printf("Error trying to bind to port: %v, so exiting...", err)
+						continue
+					} else {
+						log.Print("Starting server and websocket (SSL) on " + *address + "" + port)
+						break
+					}
+				}
+			}()
+
+			go func() {
+				start := 8990
+				end := 9000
+				i := start
+				for i < end {
+					i = i + 1
+					port = ":" + strconv.Itoa(i)
+					if err := r.Run(*address + port); err != nil {
+						log.Printf("Error trying to bind to port: %v, so exiting...", err)
+						continue
+					} else {
+						log.Print("Starting server and websocket on " + *address + "" + port)
+						break
+					}
+				}
+			}()
+
+		}()
 	}
 
 	if !*verbose {