How to enable HTTPS on Node JS

To create an HTTPS server, you need two things: an SSL certificate, and Node's built-in https module.

We need to start out with a word about SSL certificates. Speaking generally, there are two kinds of certificates: those signed by a 'Certificate Authority', or CA, and 'self-signed certificates'. A Certificate Authority is a trusted source for an SSL certificate, and using a certificate from a CA allows your users to be trust the identity of your website. In most cases, you would want to use a CA-signed certificate in a production environment - for testing purposes, however, a self-signed certicate will do just fine.

To generate a self-signed certificate, run the following in your shell:

openssl genrsa -out key.pem
openssl req -new -key key.pem -out csr.pem
openssl x509 -req -days 9999 -in csr.pem -signkey key.pem -out cert.pem
rm csr.pem

This should leave you with two files, cert.pem (the certificate) and key.pem (the private key). Put these files in the same directory as your Node.js server file. This is all you need for a SSL connection. So now you set up a quick hello world example (the biggest difference between https and http is the options parameter):


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

const options = {
  key: fs.readFileSync('key.pem'),
  cert: fs.readFileSync('cert.pem')
};

https.createServer(options, function (req, res) {
  res.writeHead(200);
  res.end("hello world\n");
}).listen(8000);


NODE PRO TIP: Note fs.readFileSync - unlike fs.readFile, fs.readFileSync will block the entire process until it completes. In situations like this - loading vital configuration data - the sync functions are okay. In a busy server, however, using a synchronous function during a request will force the server to deal with the requests one by one!NODE PRO TIP: Note fs.readFileSync - unlike fs.readFile, fs.readFileSync will block the entire process until it completes. In situations like this - loading vital configuration data - the sync functions are okay. In a busy server, however, using a synchronous function during a request will force the server to deal with the requests one by one!

To start your https server, run node app.js (here, app.js is name of the file) on the terminal.

Now that your server is set up and started, you should be able to get the file with curl:
curl -k https://localhost:8000

References:
https://nodejs.org/en/knowledge/HTTP/servers/how-to-create-a-HTTPS-server/