HTTPS over WebSockets tunnel - node.js

Question

I'm trying to build a system in which the backend can send request to the client that will behave as a proxy. I'm constrained in using WebSockets due to the current state of the remote server. I've build a basic version of my idea that works with HTTP request sent from a browser, but as soon as I activate HTTPS it apparently fails on the handshake. I'm adding a request ID to organise and imitate the request/response model. I want to achieve an E2E encryption with this proxy chain.
This is my code for the proxy that catches the requests and sends them over the WebSocket:
const net = require('net');
const WebSocket = require('ws');
const crypto = require("crypto");
const wss = new WebSocket('ws://localhost:8001');
const server = net.createServer();
server.on('connection', (socket) => {
// settings per connection opened
let requests = [];
// Receives data
socket.on('data', data => {
const requestID = crypto.randomBytes(16).toString("hex");
const additionalInfo = JSON.stringify({
"Request": requestID,
});
const header = Buffer.from(`${additionalInfo.length} ${additionalInfo}\n\n`);
wss.send(Buffer.concat([header, data]));
requests.push(requestID);
});
socket.on('error', error => {
console.log(error);
});
socket.on('end', () => {
requests = [];
});
// server response to the request
wss.on('message', (data) => {
// extract basic data
const jsonDataSize = data.toString().split(' ')[0];
const jsonDataOffset = jsonDataSize.length + 1;
const jsonDataText = data.slice(jsonDataOffset, Number(jsonDataSize) + jsonDataOffset).toString();
const jsonData = JSON.parse(jsonDataText);
const message = data.slice(Number(jsonDataSize) + jsonDataOffset + 2);
// check if received response matches the request
if (requests.includes(jsonData.Request)) {
// console.log(data.toString());
socket.write(message);
}
});
wss.on('error', error => {
console.log(error);
});
});
server.on('close', () => {
console.log("Server closed");
})
server.listen({host: "localhost", port: 8000}, () => {
console.log("Server listening on localhost:8000");
});
This is my code for the WebSocket receiver:
const net = require('net');
const WebSocket = require('ws');
const wss = new WebSocket.Server({port: 8001}, () => {
console.log('WebSocket server listening on localhost:8001');
});
wss.on('connection', socket => {
let server;
// trigger for a new message from the same connection
socket.on('message', data => {
// console.log("---------->");
// console.log(data.toString());
const jsonDataSize = data.toString().split(' ')[0];
const jsonDataOffset = jsonDataSize.length + 1;
const jsonDataText = data.slice(jsonDataOffset, Number(jsonDataSize) + jsonDataOffset).toString();
// check if it is a new tls connection request
let isTLSConnection = data.toString().indexOf("CONNECT") !== -1;
// set the new connection's settings
if (isTLSConnection && data.toString().includes('Host: ')) {
const serverPort = 443;
const serverAddress = data
.toString()
.split("CONNECT")[1]
.split(" ")[1]
.split(":")[0];
server = net.createConnection({host: serverAddress, port: serverPort});
// Send back 200 OK to the browser
const header = Buffer.from(`${jsonDataSize} ${jsonDataText}\n\n`);
socket.send(Buffer.concat([header, Buffer.from("HTTP/1.1 200 OK\r\n\r\n")]));
return;
} else if (data.toString().includes('Host: ')) {
const serverPort = 80;
const serverAddress = data.toString().split('Host: ')[1].split("\r\n")[0];
server = net.createConnection({host: serverAddress, port: serverPort});
}
// extract payload
const message = data.slice(Number(jsonDataSize) + jsonDataOffset + 2);
// send payload to server
server.write(message);
server.on('data', (data) => {
// console.log("<----------");
// console.log(data.toString());
const header = Buffer.from(`${jsonDataSize} ${jsonDataText}\n\n`);
socket.send(Buffer.concat([header, data]));
});
server.on('error', error => {
console.log(error);
});
});
socket.on('error', (error) => {
console.log(error);
});
});
I took inspiration from Build your own proxy server from scratch
I tried implementing a request/response model on top of WebSockets since I believe the error relies there, but it didn't work

Answer 1

You should use wss://localhost:8001 when using https