Enabling HTTPS on express.js

First, you need to create selfsigned.key and selfsigned.crt files. Go to Create a Self-Signed SSL Certificate Or do following steps.

Go to the terminal and run the following command.

sudo openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout ./selfsigned.key -out selfsigned.crt

• After that put the following information
• Country Name (2 letter code) [AU]: US
• State or Province Name (full name) [Some-State]: NY
• Locality Name (eg, city) []:NY
• Organization Name (eg, company) [Internet Widgits Pty Ltd]: xyz (Your - Organization)
• Organizational Unit Name (eg, section) []: xyz (Your Unit Name)
• Common Name (e.g. server FQDN or YOUR name) []: www.xyz.com (Your URL)
• Email Address []: Your email

After creation adds key & cert file in your code, and pass the options to the server.

const express = require('express');
const https = require('https');
const fs = require('fs');
const port = 3000;

var key = fs.readFileSync(__dirname + '/../certs/selfsigned.key');
var cert = fs.readFileSync(__dirname + '/../certs/selfsigned.crt');
var options = {
  key: key,
  cert: cert
};

app = express()
app.get('/', (req, res) => {
   res.send('Now using https..');
});

var server = https.createServer(options, app);

server.listen(port, () => {
  console.log("server starting on port : " + port)
});

• Finally run your application using https.

More information https://github.com/sagardere/set-up-SSL-in-nodejs

In express.js (since version 3) you should use that syntax:

var fs = require('fs');
var http = require('http');
var https = require('https');
var privateKey  = fs.readFileSync('sslcert/server.key', 'utf8');
var certificate = fs.readFileSync('sslcert/server.crt', 'utf8');

var credentials = {key: privateKey, cert: certificate};
var express = require('express');
var app = express();

// your express configuration here

var httpServer = http.createServer(app);
var httpsServer = https.createServer(credentials, app);

httpServer.listen(8080);
httpsServer.listen(8443);

In that way you provide express middleware to the native http/https server

If you want your app running on ports below 1024, you will need to use sudo command (not recommended) or use a reverse proxy (e.g. nginx, haproxy).