terminal: disable HTTP timeouts except header read

To make sure that long-running calls and indefinitely opened streaming
connections aren't terminated by the internal proxy, we need to disable
all timeouts except the one for reading the HTTP headers.
That timeout shouldn't be removed as we would otherwise be prone to the
slowloris attack where an attacker takes too long to send the headers
and uses up connections that way.
Once the headers are read, we either know it's a static resource and
can deliver that very cheaply or check the authentication for other
calls.

Fixes #140 and #144.

terminal.go

@@ -555,9 +555,20 @@ func (g *LightningTerminal) startMainWebServer() error {
 	// Create and start our HTTPS server now that will handle both gRPC web
 	// and static file requests.
 	g.httpServer = &http.Server{
-		WriteTimeout: defaultServerTimeout,
-		ReadTimeout:  defaultServerTimeout,
-		Handler:      http.HandlerFunc(httpHandler),
+		// To make sure that long-running calls and indefinitely opened
+		// streaming connections aren't terminated by the internal
+		// proxy, we need to disable all timeouts except the one for
+		// reading the HTTP headers. That timeout shouldn't be removed
+		// as we would otherwise be prone to the slowloris attack where
+		// an attacker takes too long to send the headers and uses up
+		// connections that way. Once the headers are read, we either
+		// know it's a static resource and can deliver that very cheaply
+		// or check the authentication for other calls.
+		WriteTimeout:      0,
+		IdleTimeout:       0,
+		ReadTimeout:       0,
+		ReadHeaderTimeout: defaultServerTimeout,
+		Handler:           http.HandlerFunc(httpHandler),
 	}
 	httpListener, err := net.Listen("tcp", g.cfg.HTTPSListen)
 	if err != nil {