How to Create Secure(TLS/SSL) Websocket Server

Your question #1

How to Create Secure(TLS/SSL) Websocket Server?

I found your question while searching online for a guide on how to make websockets work over a secured connection. Since this came up in search results, there is a chance I'm not the only one who ended up on this page. To save everyone (including future me) some time, here goes.

The Problem

I had a simple node.js websocket server, powered by einaros/ws, listening on port 80 over an unsecured connection. Had to switch it to secure connection.

The Solution

Basically, the second link you provided covers pretty much everything I needed to know. Here are few things that took me some time to figure out though:

I needed the .pem files for this, but all I got from the cert provider was a simple .crt/.cert file, and I also had a private .key I got after generating the initial .csr request. So here's how to convert (credit to slf):
```
 openssl rsa -in server.key -text > private.pem
 openssl x509 -inform PEM -in server.crt > public.pem
```
It was unclear to me how to make ws use the secured connection. Since I was trying to add SSL to an existing application, I wanted to avoid having to re-do things. Turns out, all I had to do was replace the {port:80} parameter with a reference to the https instance (see the links for more info on how to initialise it).
```
 var ws = require('ws').Server;
 var wss = new ws({
     server: httpsServer
 });
```

References

github.com/websockets/ws/blob/master/examples/ssl.js
chovy.com/web-development/self-signed-certs-with-secure-websockets-in-node-js

Your question #2

What i want to know is if it is enough to just create the self signed certificate and deploy to my production environment, or do I need to buy a certificate as we need to do while creating HTTPS servers?

For a public server, you will need a certificate from a widely trusted CA. Use the free Let's Encrypt, or any paid certificate from a known issuer. This will ensure your users won't be getting any browser security warnings, or just leaving without even knowing what went wrong.

For your local development environment, or where all connecting clients are known and under your control, you can create your own CA, see deliciousbrains.com/ssl-certificate-authority-for-local-https-development.

to use secure web socket in nodejs use this code sample:

const WebSocket = require("ws").Server;
const HttpsServer = require('https').createServer;
const fs = require("fs");

server = HttpsServer({
    cert: fs.readFileSync(config.ssl_cert_path),
    key: fs.readFileSync(config.ssl_key_path)
})
socket = new WebSocket({
    server: server
});

socket.on(...);
server.listen(config.port);

in case you don't have ssl certificate yet - you can get one for free from letsencrypt.org