Skype Bot webhook - receive nothing

Question

I am developing a bot for Skype in Java. Right now, I only want the bot to authenticate (get bearer token) and to echo received messages. I did last test on 31st July 2017 and it worked fine. But, since August, the strangest thing is happening:

The bot can authenticate correctly, and I got the bearen token and its timeout. After that, the SslSocket starts listening. When I chat the bot, it gets a connection (initiates handshake and all that) but receives nothing. No headers, no payload, nothing.

I tried reading documentation and see if the latest update to Microsoft Bot Framework had anything to do with it, but I couldn't find anything. Anyone can help me about what's going on?

        InputStream inputStream = sslSocket.getInputStream();
        OutputStream outputStream = sslSocket.getOutputStream();

        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
        PrintWriter printWriter = new PrintWriter(new OutputStreamWriter(outputStream));
        String line = null;
        String jsonLine = null;

        String challenge = null;                

        while(((line = bufferedReader.readLine()) != null)){
            System.out.println("iline = "+line);

            if (!line.isEmpty()){
                if(line.substring(0,1).equals("{")){
                    jsonLine = line;
                }
            }
        }

This is the part of the code which reads the incoming message. JsonLine and line are always null.

Answer 1

Certificate was expired. Once renewed, everything started working again.