title: Socket.IO SSL connection error not using express
body: <p>I'm trying to connect to my Socket.IO server, but the connection couldn't be made. It works without HTTPS. I created the pem and crt file with <code>openssl</code> command, I also have opened port <code>3300</code> through Firewall.</p>
  
  <pre><code>var https = require('https');
  var options = {
    key: fs.readFileSync('file.pem'),
    cert: fs.readFileSync('file.crt')
  };
  var app = https.createServer(options);
  io.listen(app); 
  app.listen('3300');
  </code></pre>
  
  <p>Calling the server/url.</p>
  
  <pre><code>io('https://example.com:3300');
  </code></pre>
  
  <p>NodeJS is just as a backend, I'm not using express or anything on there.</p>