Connecting to remote SSH server (via Node.js/html5 console)

Question

I have been scouring the face of the web looking to answer a question which I had thought would be simple. My goal is straight forward. I want to build out a simple web-based SSH client using Node.js module(s). I have found several options if I want to connect to the node server itself, but can't seem to find any examples of connecting to a REMOTE server.

Essentially the outcome I am looking for is a workflow like this : Connect to webserver -> Click on a server name in a list of servers -> Enter SSH session to the server I clicked on

The only thing I have found that's even remotely close to what I am looking for is guacamole. I do not want to use guacamole, however, as I want this application to be OS independent. Currently I am building it on a windows 10 platform, and will port it over to fedora when I am done.

I found this tutorial for creating an SSH terminal. However, all this does is creates (or attempts to create) an SSH connection to the local system.

Another options that looked absolutely fantastic was tty.js. Alas, the bottom-line is the same as the above tutorial. The module only allows you to connect to the node.js server, NOT to remote servers.

Anyone have information on a possible path to this goal?

mscdex · Accepted Answer · 2017-09-26 22:43:55Z

58

This is easily doable with modules like ssh2, xterm, and socket.io.

Here's an example:

npm install ssh2 xterm socket.io
Create index.html:

<html>
  <head>
    <title>SSH Terminal</title>
    <link rel="stylesheet" href="/src/xterm.css" />
    <script src="/src/xterm.js"></script>
    <script src="/addons/fit/fit.js"></script>
    <script src="/socket.io/socket.io.js"></script>
    <script>
      window.addEventListener('load', function() {
        var terminalContainer = document.getElementById('terminal-container');
        var term = new Terminal({ cursorBlink: true });
        term.open(terminalContainer);
        term.fit();

        var socket = io.connect();
        socket.on('connect', function() {
          term.write('\r\n*** Connected to backend***\r\n');

          // Browser -> Backend
          term.on('data', function(data) {
            socket.emit('data', data);
          });

          // Backend -> Browser
          socket.on('data', function(data) {
            term.write(data);
          });

          socket.on('disconnect', function() {
            term.write('\r\n*** Disconnected from backend***\r\n');
          });
        });
      }, false);
    </script>
    <style>
      body {
        font-family: helvetica, sans-serif, arial;
        font-size: 1em;
        color: #111;
      }
      h1 {
        text-align: center;
      }
      #terminal-container {
        width: 960px;
        height: 600px;
        margin: 0 auto;
        padding: 2px;
      }
      #terminal-container .terminal {
        background-color: #111;
        color: #fafafa;
        padding: 2px;
      }
      #terminal-container .terminal:focus .terminal-cursor {
        background-color: #fafafa;
      }
    </style>
  </head>
  <body>
    <div id="terminal-container"></div>
  </body>
</html>

Create server.js:

var fs = require('fs');
var path = require('path');
var server = require('http').createServer(onRequest);

var io = require('socket.io')(server);
var SSHClient = require('ssh2').Client;

// Load static files into memory
var staticFiles = {};
var basePath = path.join(require.resolve('xterm'), '..');
[ 'addons/fit/fit.js',
  'src/xterm.css',
  'src/xterm.js'
].forEach(function(f) {
  staticFiles['/' + f] = fs.readFileSync(path.join(basePath, f));
});
staticFiles['/'] = fs.readFileSync('index.html');

// Handle static file serving
function onRequest(req, res) {
  var file;
  if (req.method === 'GET' && (file = staticFiles[req.url])) {
    res.writeHead(200, {
      'Content-Type': 'text/'
                      + (/css$/.test(req.url)
                         ? 'css'
                         : (/js$/.test(req.url) ? 'javascript' : 'html'))
    });
    return res.end(file);
  }
  res.writeHead(404);
  res.end();
}

io.on('connection', function(socket) {
  var conn = new SSHClient();
  conn.on('ready', function() {
    socket.emit('data', '\r\n*** SSH CONNECTION ESTABLISHED ***\r\n');
    conn.shell(function(err, stream) {
      if (err)
        return socket.emit('data', '\r\n*** SSH SHELL ERROR: ' + err.message + ' ***\r\n');
      socket.on('data', function(data) {
        stream.write(data);
      });
      stream.on('data', function(d) {
        socket.emit('data', d.toString('binary'));
      }).on('close', function() {
        conn.end();
      });
    });
  }).on('close', function() {
    socket.emit('data', '\r\n*** SSH CONNECTION CLOSED ***\r\n');
  }).on('error', function(err) {
    socket.emit('data', '\r\n*** SSH CONNECTION ERROR: ' + err.message + ' ***\r\n');
  }).connect({
    host: '192.168.100.105',
    username: 'foo',
    password: 'barbaz'
  });
});

server.listen(8000);

Edit the SSH server configuration passed to .connect() in server.js
node server.js
Visit http://localhost:8000 in your browser

edited Sep 26, 2017 at 22:43

answered Aug 1, 2016 at 2:32

mscdex

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16 Comments

Ethan Over a year ago

Dude, you absolutely rock! :)

Ethan Over a year ago

Don't happen to have something similar for RDP & VNC do ya? :)

mscdex Over a year ago

A quick search for vnc turns up this. It's a bit old and could stand to be optimized a bit, but it might still work. As far as RDP goes, I have not seen an RDP implementation/binding for node yet.

Ethan Over a year ago

Yep, that's the same thing I found for VNC. I'll mess with that eventually. For RDP, I think this'll work github.com/citronneur/node-rdpjs but I'm going to have to find some better documentation than what's on the GIT page.

mscdex Over a year ago

@user2058037 You'd have to parse req.url like url.parse(req.url, true). Then use .pathname from the resulting object instead of req.url for the staticFiles[] lookup.

|

bluepuma77 · Accepted Answer · 2021-02-11 22:23:30Z

Just adding updated code to @mscdex great answer because the libraries have changed over the years.

Libraries:

npm install express socket.io ssh2 xterm xterm-addon-fit

index.html:

<html>
  <head>
    <title>SSH Terminal</title>
    <link rel="stylesheet" href="/xterm.css" />
    <script src="/xterm.js"></script>
    <script src="/xterm-addon-fit.js"></script>
    <script src="/socket.io/socket.io.js"></script>
    <script>
      window.addEventListener('load', function() {
        var terminalContainer = document.getElementById('terminal-container');
        const term = new Terminal({ cursorBlink: true });        
        const fitAddon = new FitAddon.FitAddon();
        term.loadAddon(fitAddon);
        term.open(terminalContainer);
        fitAddon.fit();

        var socket = io() //.connect();
        socket.on('connect', function() {
          term.write('\r\n*** Connected to backend ***\r\n');
        });

        // Browser -> Backend
        term.onKey(function (ev) {
          socket.emit('data', ev.key);
        });

        // Backend -> Browser
        socket.on('data', function(data) {
          term.write(data);
        });

        socket.on('disconnect', function() {
          term.write('\r\n*** Disconnected from backend ***\r\n');
        });
      }, false);
    </script>
    <style>
      body {
        font-family: helvetica, sans-serif, arial;
        font-size: 1em;
        color: #111;
      }
      h1 {
        text-align: center;
      }
      #terminal-container {
        width: 960px;
        height: 600px;
        margin: 0 auto;
        padding: 2px;
      }
      #terminal-container .terminal {
        background-color: #111;
        color: #fafafa;
        padding: 2px;
      }
      #terminal-container .terminal:focus .terminal-cursor {
        background-color: #fafafa;
      }
    </style>
  </head>
  <body>
    <h3>WebSSH</h3>
    <div id="terminal-container"></div>
  </body>
</html>

server.js:

var fs = require('fs');
var path = require('path');
var server = require('http').createServer(onRequest);

var io = require('socket.io')(server);
var SSHClient = require('ssh2').Client;

// Load static files into memory
var staticFiles = {};
var basePath = path.join(require.resolve('xterm'), '..');
staticFiles['/xterm.css'] = fs.readFileSync(path.join(basePath, '../css/xterm.css'));
staticFiles['/xterm.js'] = fs.readFileSync(path.join(basePath, 'xterm.js'));
basePath = path.join(require.resolve('xterm-addon-fit'), '..');
staticFiles['/xterm-addon-fit.js'] = fs.readFileSync(path.join(basePath, 'xterm-addon-fit.js'));
staticFiles['/'] = fs.readFileSync('index.html');

// Handle static file serving
function onRequest(req, res) {
  var file;
  if (req.method === 'GET' && (file = staticFiles[req.url])) {
    res.writeHead(200, {
      'Content-Type': 'text/'
        + (/css$/.test(req.url)
        ? 'css'
        : (/js$/.test(req.url) ? 'javascript' : 'html'))
    });
    return res.end(file);
  }
  res.writeHead(404);
  res.end();
}

io.on('connection', function(socket) {
  var conn = new SSHClient();
  conn.on('ready', function() {
    socket.emit('data', '\r\n*** SSH CONNECTION ESTABLISHED ***\r\n');
    conn.shell(function(err, stream) {
      if (err)
        return socket.emit('data', '\r\n*** SSH SHELL ERROR: ' + err.message + ' ***\r\n');
      socket.on('data', function(data) {
        stream.write(data);
      });
      stream.on('data', function(d) {
        socket.emit('data', d.toString('binary'));
      }).on('close', function() {
        conn.end();
      });
    });
  }).on('close', function() {
    socket.emit('data', '\r\n*** SSH CONNECTION CLOSED ***\r\n');
  }).on('error', function(err) {
    socket.emit('data', '\r\n*** SSH CONNECTION ERROR: ' + err.message + ' ***\r\n');
  }).connect({
    host: 'domain.tld',
    port: 22,
    username: 'root',
    privateKey: require('fs').readFileSync('path/to/keyfile')
  });
});

let port = 8000;
console.log('Listening on port', port)
server.listen(port);

You should not use the onKey event, it is only there for low level event access and rarely needed. Instead use onData and onBinary, these will nicely wrap everything into bytes meant for the IO sink (incl. mouse reports).

Elliot404 · Accepted Answer · 2021-03-07 19:56:05Z

Same as the above answer but actually using express and modern syntax and libraries

const express = require('express');
const app = express();
const http = require('http').Server(app);
const io = require('socket.io')(http, {
  cors: {
    origin: "*"
  }
});
app.set('view engine', 'ejs');
app.use(express.urlencoded({
  extended: false,
  limit: '150mb'
}));
app.use(express.static(__dirname + '/public'));
app.use('/xterm.css', express.static(require.resolve('xterm/css/xterm.css')));
app.use('/xterm.js', express.static(require.resolve('xterm')));
app.use('/xterm-addon-fit.js', express.static(require.resolve('xterm-addon-fit')));

const SSHClient = require('ssh2').Client;

app.get('/', (req, res) => {
  // res.sendFile(__dirname + '/index.html');
  res.render('index');
  // I am using ejs as my templating engine but HTML file work just fine.
});

io.on('connection', function(socket) {
  var conn = new SSHClient();
  conn.on('ready', function() {
    socket.emit('data', '\r\n*** SSH CONNECTION ESTABLISHED ***\r\n');
    conn.shell(function(err, stream) {
      if (err)
        return socket.emit('data', '\r\n*** SSH SHELL ERROR: ' + err.message + ' ***\r\n');
      socket.on('data', function(data) {
        stream.write(data);
      });
      stream.on('data', function(d) {
        socket.emit('data', d.toString('binary'));
      }).on('close', function() {
        conn.end();
      });
    });
  }).on('close', function() {
    socket.emit('data', '\r\n*** SSH CONNECTION CLOSED ***\r\n');
  }).on('error', function(err) {
    socket.emit('data', '\r\n*** SSH CONNECTION ERROR: ' + err.message + ' ***\r\n');
  }).connect({
    host: '192.168.0.103',
    port: 22,
    username: 'kali',
    password: 'kali'
  });
});

http.listen(3000, () => {
  console.log('Listening on http://localhost:3000');
});

* {
  padding: 0%;
  margin: 0%;
  box-sizing: border-box;
}

body {
  font-family: Helvetica, sans-serif, arial;
  font-size: 1em;
  color: #111;
}

h1 {
  text-align: center;
}

#terminal-container {
  width: 960px;
  height: 600px;
  margin: 0 auto;
  padding: 2px;
}

#terminal-container .terminal {
  background-color: #111;
  color: #fafafa;
  padding: 2px;
}

#terminal-container .terminal:focus .terminal-cursor {
  background-color: #fafafa;
}

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>SSH SERVER</title>
  <link rel="stylesheet" href="/xterm.css" />
  <script defer src="/xterm.js"></script>
  <script defer src="/xterm-addon-fit.js"></script>
  <script defer src="/socket.io/socket.io.js"></script>
  <script defer src='/js/app.js'></script>
  <link rel='stylesheet' href='/css/main.css'>
</head>

<body>
  <h3>WebSSH</h3>
  <div id="terminal-container"></div>
  <script>
  // PLEASE USE A SEPERATE FILE FOR THE JS and defer it
  // like the above app.js file 
    window.addEventListener('load', function() {
      const terminalContainer = document.getElementById('terminal-container');
      const term = new Terminal({
        cursorBlink: true
      });
      const fitAddon = new FitAddon.FitAddon();
      term.loadAddon(fitAddon);
      term.open(terminalContainer);
      fitAddon.fit();

      const socket = io() //.connect();
      socket.on('connect', function() {
        term.write('\r\n*** Connected to backend ***\r\n');
      });

      // Browser -> Backend
      term.onKey(function(ev) {
        socket.emit('data', ev.key);
      });

      // Backend -> Browser
      socket.on('data', function(data) {
        term.write(data);
      });

      socket.on('disconnect', function() {
        term.write('\r\n*** Disconnected from backend ***\r\n');
      });
    }, false);
  </script>
</body>

</html>

@ShabbirDhangot use privateKey instead of password in the SSHClient connect arguments.

gdm · Accepted Answer · 2017-06-18 13:10:59Z

2

Try also noVnc. However, a little dig within the page of xterm.js reveals other solutions, like

WebSSH2

edited Jun 18, 2017 at 13:10

answered Jun 6, 2017 at 11:10

gdm

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