wwhio / webssh

:seedling: Web based ssh client

WebSSH

Introduction

A simple web application to be used as an ssh client to connect to your ssh servers. It is written in Python, base on tornado, paramiko and xterm.js.

Features

• SSH password authentication supported, including empty password.
• SSH public-key authentication supported, including DSA RSA ECDSA Ed25519 keys.
• Encrypted keys supported.
• Two-Factor Authentication (time-based one-time password) supported.
• Fullscreen terminal supported.
• Terminal window resizable.
• Auto detect the ssh server's default encoding.
• Modern browsers including Chrome, Firefox, Safari, Edge, Opera supported.

Preview

How it works

+---------+     http     +--------+    ssh    +-----------+
| browser | <==========> | webssh | <=======> | ssh server|
+---------+   websocket  +--------+    ssh    +-----------+

Requirements

• Python 3.8+

Quickstart

1. Install this app, run command pip install webssh
2. Start a webserver, run command wssh
3. Open your browser, navigate to 127.0.0.1:8888
4. Input your data, submit the form.

Server options

# start a http server with specified listen address and listen port
wssh --address='2.2.2.2' --port=8000

# start a https server, certfile and keyfile must be passed
wssh --certfile='/path/to/cert.crt' --keyfile='/path/to/cert.key'

# missing host key policy
wssh --policy=reject

# logging level
wssh --logging=debug

# log to file
wssh --log-file-prefix=main.log

# more options
wssh --help

Browser console

// connect to your ssh server
wssh.connect(hostname, port, username, password, privatekey, passphrase, totp);

// pass an object to wssh.connect
var opts = {
  hostname: 'hostname',
  port: 'port',
  username: 'username',
  password: 'password',
  privatekey: 'the private key text',
  passphrase: 'passphrase',
  totp: 'totp'
};
wssh.connect(opts);

// without an argument, wssh will use the form data to connect
wssh.connect();

// set a new encoding for client to use
wssh.set_encoding(encoding);

// reset encoding to use the default one
wssh.reset_encoding();

// send a command to the server
wssh.send('ls -l');

Custom Font

To use custom font, put your font file in the directory webssh/static/css/fonts/ and restart the server.

URL Arguments

Support passing arguments by url (query or fragment) like following examples:

Passing form data (password must be encoded in base64, privatekey not supported)

http://localhost:8888/?hostname=xx&username=yy&password=str_base64_encoded

Passing a terminal background color

http://localhost:8888/#bgcolor=green

Passing a terminal font color

http://localhost:8888/#fontcolor=red

Passing a user defined title

http://localhost:8888/?title=my-ssh-server

Passing an encoding

http://localhost:8888/#encoding=gbk

Passing a font size

http://localhost:8888/#fontsize=24

Passing a command executed right after login

http://localhost:8888/?command=pwd

Passing a terminal type

http://localhost:8888/?term=xterm-256color

Use Docker

Start up the app

docker-compose up

Tear down the app

docker-compose down

Tests

Requirements

pip install pytest pytest-cov codecov flake8 mock

Use unittest to run all tests

python -m unittest discover tests

Use pytest to run all tests

python -m pytest tests

Deployment

Running behind an Nginx server

wssh --address='127.0.0.1' --port=8888 --policy=reject

# Nginx config example
location / {
    proxy_pass http://127.0.0.1:8888;
    proxy_http_version 1.1;
    proxy_read_timeout 300;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "upgrade";
    proxy_set_header Host $http_host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Real-PORT $remote_port;
}

Running as a standalone server

wssh --port=8080 --sslport=4433 --certfile='cert.crt' --keyfile='cert.key' --xheaders=False --policy=reject

Tips

• For whatever deployment choice you choose, don't forget to enable SSL.
• By default plain http requests from a public network will be either redirected or blocked and being redirected takes precedence over being blocked.
• Try to use reject policy as the missing host key policy along with your verified known_hosts, this will prevent man-in-the-middle attacks. The idea is that it checks the system host keys file("~/.ssh/known_hosts") and the application host keys file("./known_hosts") in order, if the ssh server's hostname is not found or the key is not matched, the connection will be aborted.