Do you want to enable SSL for your server runnning in port 80 ?

node-ssl-proxy.js

const fs = require('fs');
const tls = require('tls');
const net = require('net');
const server = tls
  .createServer(
    {
      key: fs.readFileSync('/opt/ssl/certs/key.pem'),
      cert: fs.readFileSync('/opt/ssl/certs/cert.pem'),
    },
    clientToProxySocket => {
      const proxyToServerSocket = net.createConnection(
        {host: 'localhost', port: '80'},
        () => {
          clientToProxySocket.pipe(proxyToServerSocket);
          proxyToServerSocket.pipe(clientToProxySocket);
        },
      );
    },
  )
  .listen(443);

start.sh

# start the original server in background
npm start &

# start the node-ssl-proxy
node ./node-ssl-proxy.js