How to use HTTPS on Node.js using Express/Socket.io

Question

It is hard to test your example without your key and cert files instead I am going to provide an example where I am using Express, socket.io, and https.

First I will create the key and cert files, so inside a directory run the following commands from your terminal:

The command below it is going to generate a file containing an RSA key.

$ openssl genrsa 1024 > file.pem

Here you will be asked to input data but you can leave blank pressing enter until the crs.pem is generated.

$ openssl req -new -key file.pem -out csr.pem

Then a file.crt file will be created containing an SSL certificate.

$ openssl x509 -req -days 365 -in csr.pem -signkey file.pem -out file.crt

So in my app.js file where I am setting and starting the server notice that I am using the files file.pem and file.crt generated in the last step:

var fs = require('fs');
var https = require('https');

var express = require('express');
var app = express();

var options = {
  key: fs.readFileSync('./file.pem'),
  cert: fs.readFileSync('./file.crt')
};
var serverPort = 443;

var server = https.createServer(options, app);
var io = require('socket.io')(server);

app.get("https://stackoverflow.com/", function(req, res) {
  res.sendFile(__dirname + '/public/index.html');
});

io.on('connection', function(socket) {
  console.log('new connection');
  socket.emit('message', 'This is a message from the dark side.');
});

server.listen(serverPort, function() {
  console.log('server up and running at %s port', serverPort);
});

and then my public/index.html where I am consuming the server:

<!doctype html>
<html>

  <head>

  </head>
  <body>
    <h1>I am alive!!</h1>

    <script src="https://cdnjs.cloudflare.com/ajax/libs/socket.io/1.3.5/socket.io.js"></script>

    <script>
      var URL_SERVER = 'https://localhost:443';
      var socket = io.connect(URL_SERVER);

      socket.on('message', function(data) {
        alert(data);
      });
    </script>
  </body>

</html>

then finally if you access from the browser at https://localhost, you will see an alert with a message that is coming from the websocket server.

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