MeshCentral/mstsc.js
2021-04-28 00:10:26 -07:00

159 lines
7.1 KiB
JavaScript

/**
* @description MeshCentral MSTSC relay
* @author Ylian Saint-Hilaire & Bryan Roe
* @copyright Intel Corporation 2018-2021
* @license Apache-2.0
* @version v0.0.1
*/
/*jslint node: true */
/*jshint node: true */
/*jshint strict:false */
/*jshint -W097 */
/*jshint esversion: 6 */
"use strict";
// Construct a MSTSC Relay object, called upon connection
// This is a bit of a hack as we are going to run the RDP connection thru a loopback connection.
// If the "node-rdpjs-2" module supported passing a socket, we would do something different.
module.exports.CreateMstscRelay = function (parent, db, ws, req, args, domain) {
const Net = require('net');
const WebSocket = require('ws');
var obj = {};
obj.domain = domain;
obj.ws = ws;
obj.wsClient = null;
obj.tcpServer = null;
obj.tcpServerPort = 0;
obj.relaySocket = null;
obj.relayActive = false;
obj.infos = null;
var rdpClient = null;
parent.parent.debug('relay', 'RDP: Request for RDP relay (' + req.clientIp + ')');
// Disconnect
obj.close = function (arg) {
if ((arg == 1) || (arg == null)) { try { ws.close(); } catch (e) { console.log(e); } } // Soft close, close the websocket
if (arg == 2) { try { ws._socket._parent.end(); } catch (e) { console.log(e); } } // Hard close, close the TCP socket
if (obj.wsClient) { obj.wsClient.close(); obj.wsClient = null; }
if (obj.tcpServer) { obj.tcpServer.close(); obj.tcpServer = null; }
if (rdpClient) { rdpClient.close(); rdpClient = null; }
delete obj.domain;
delete obj.ws;
};
// Start the looppback server
function startTcpServer() {
obj.tcpServer = new Net.Server();
obj.tcpServer.listen(0, '127.0.0.1', function () { obj.tcpServerPort = obj.tcpServer.address().port; startRdp(obj.tcpServerPort); });
obj.tcpServer.on('connection', function (socket) {
if (obj.relaySocket != null) {
socket.close();
} else {
obj.relaySocket = socket;
obj.relaySocket.pause();
obj.relaySocket.on('data', function (chunk) { // Make sure to handle flow control.
if (obj.relayActive == true) { obj.relaySocket.pause(); obj.wsClient.send(chunk, function () { obj.relaySocket.resume(); }); }
});
obj.relaySocket.on('end', function () { obj.close(); });
obj.relaySocket.on('error', function (err) { obj.close(); });
// Decode the authentication cookie
var cookie = parent.parent.decodeCookie(obj.infos.ip, parent.parent.loginCookieEncryptionKey);
if (cookie == null) return;
// Setup the correct URL with domain and use TLS only if needed.
var options = { rejectUnauthorized: false };
if (domain.dns != null) { options.servername = domain.dns; }
var protocol = 'wss';
if (args.tlsoffload) { protocol = 'ws'; }
var domainadd = '';
if ((domain.dns == null) && (domain.id != '')) { domainadd = domain.id + '/' }
var url = protocol + '://127.0.0.1:' + args.port + '/' + domainadd + ((cookie.lc == 1)?'local':'mesh') + 'relay.ashx?noping=1&auth=' + obj.infos.ip;
parent.parent.debug('relay', 'RDP: Connection websocket to ' + url);
obj.wsClient = new WebSocket(url, options);
obj.wsClient.on('open', function () { parent.parent.debug('relay', 'RDP: Relay websocket open'); });
obj.wsClient.on('message', function (data) { // Make sure to handle flow control.
if ((obj.relayActive == false) && (data == 'c')) {
obj.relayActive = true; obj.relaySocket.resume();
} else {
obj.wsClient._socket.pause();
obj.relaySocket.write(data, function () { obj.wsClient._socket.resume(); });
}
});
obj.wsClient.on('close', function () { parent.parent.debug('relay', 'RDP: Relay websocket closed'); obj.close(); });
obj.wsClient.on('error', function (err) { parent.parent.debug('relay', 'RDP: Relay websocket error: ' + err); obj.close(); });
obj.tcpServer.close();
obj.tcpServer = null;
}
});
}
// Start the RDP client
function startRdp(port) {
parent.parent.debug('relay', 'RDP: Starting RDP client on loopback port ' + port);
try {
rdpClient = require('node-rdpjs-2').createClient({
logLevel: 'ERROR',
domain: obj.infos.domain,
userName: obj.infos.username,
password: obj.infos.password,
enablePerf: true,
autoLogin: true,
screen: obj.infos.screen,
locale: obj.infos.locale
}).on('connect', function () {
send(['rdp-connect']);
}).on('bitmap', function (bitmap) {
try { ws.send(bitmap.data); } catch (ex) { } // Send the bitmap data as binary
delete bitmap.data;
send(['rdp-bitmap', bitmap]); // Send the bitmap metadata seperately, without bitmap data.
}).on('close', function () {
send(['rdp-close']);
}).on('error', function (err) {
send(['rdp-error', err]);
}).connect('127.0.0.1', obj.tcpServerPort);
} catch (ex) {
console.log('startRdpException', ex);
obj.close();
}
}
// When data is received from the web socket
// RDP default port is 3389
ws.on('message', function (msg) {
try {
msg = JSON.parse(msg);
switch (msg[0]) {
case 'infos': { obj.infos = msg[1]; startTcpServer(); break; }
case 'mouse': { if (rdpClient) { rdpClient.sendPointerEvent(msg[1], msg[2], msg[3], msg[4]); } break; }
case 'wheel': { if (rdpClient) { rdpClient.sendWheelEvent(msg[1], msg[2], msg[3], msg[4]); } break; }
case 'scancode': { if (rdpClient) { rdpClient.sendKeyEventScancode(msg[1], msg[2]); } break; }
case 'unicode': { if (rdpClient) { rdpClient.sendKeyEventUnicode(msg[1], msg[2]); } break; }
case 'disconnect': { obj.close(); break; }
}
} catch (ex) {
console.log('RdpMessageException', msg, ex);
obj.close();
}
});
// If error, do nothing
ws.on('error', function (err) { parent.parent.debug('relay', 'RDP: Browser websocket error: ' + err); obj.close(); });
// If the web socket is closed
ws.on('close', function (req) { parent.parent.debug('relay', 'RDP: Browser websocket closed'); obj.close(); });
// Send an object with flow control
function send(obj) {
try { rdpClient.bufferLayer.socket.pause(); } catch (ex) { }
try { ws.send(JSON.stringify(obj), function () { try { rdpClient.bufferLayer.socket.resume(); } catch (ex) { } }); } catch (ex) { }
}
// We are all set, start receiving data
ws._socket.resume();
return obj;
};