Forwarding proxy with nodeJS proxy

gistfile1.txt

const net = require("net");
const server = net.createServer();

// Listening to connection event
server.on("connection", (ClientToProxySocket) => {
  console.log("Client connected to the proxy");
  ClientToProxySocket.once("data", (data) => {
    //checking if connection is HTTP or HTTPS
    let isTLSConnection = data.toString().indexOf("CONNECT") !== -1;

    //defining variable we will need later on
    let serverPort = 80;
    let serverAddress;

    if (isTLSConnection) {
      //change port to 443
      serverPort = 443;

      //Get address information from the request by splitting and filtering out
      serverAddress = data
        .toString()
        .split("CONNECT")[1]
        .split(" ")[1]
        .split(":")[0];
    } else {
      // if it is not HTTPS, the port is already 80
      // and we only need to filter out the address
      serverAddress = data.toString().split("Host: ")[1].split("\n")[0];
    }

    //Creating a connection from proxy to destination server
    let proxyToServerSocket = net.createConnection(
      {
        host: serverAddress,
        port: serverPort,
      },
      () => {
        console.log("Proxy to server set up");
      }
    );
    if (isTLSConnection) {
      ClientToProxySocket.write("HTTP/1.1 200 OK\r\n\n");
    } else {
      proxyToServerSocket.write(data);
    }

    ClientToProxySocket.pipe(proxyToServerSocket);
    proxyToServerSocket.pipe(ClientToProxySocket);

    proxyToServerSocket.on("error", (err) => {
      console.log("Proxy to server error");
      console.log(err);
    });

    ClientToProxySocket.on("error", (err) => {
      console.log("Client to proxy error");
    });
  });
});

// Listening to error event
server.on("error", (err) => {
  console.log("Some internal server error occured");
  console.log(err);
});

// Listening to close event
server.on("close", (ClientToProxySocket) => {
  console.log("Client disconnected");
});

server.listen(
  {
    host: "0.0.0.0",
    port: 8080,
  },
  () => {
    console.log("Server listening on 0.0.0.0:8080 ");
  }
);