Web SSH Client using ssh2, socket.io, xterm.js, and express
A bare bones example of an HTML5 web-based terminal emulator and SSH client. We use SSH2 as a client on a host to proxy a Websocket / Socket.io connection to a SSH2 server.
Node v14.x or above. If using <v14.x you should be able to run by replacing the "read-config" package to @1 like this (after a clone):
npm install --save read-config@1
Just keep in mind that there is no intention to ensure compatability with Node < v14
The instructions previously showed cloning directly from main, while normally safe may include "work in progress". It's recommended that after you clone, you switch to a particular tag.
To install:
Clone to a location somewhere
Checkout to the current
tag using git checkout current
or choose a particular release tag
cd app
and npm install --production
. If you want to develop and rebuild javascript and other files utilize npm install
instead.
If desired, edit app/config.json to change the listener to your liking. There are also some default options which may be definied for a few of the variables.
Run npm start
Fire up a browser, navigate to IP/port of your choice and specify a host (https isn't used here because it's assumed it will be off-loaded to some sort of proxy):
http://localhost:2222/ssh/host/127.0.0.1
You will be prompted for credentials to use on the SSH server via HTTP Basic authentcaiton. This is to permit usage with some SSO systems that can replay credentials over HTTP basic.
Alternatively in main for testing, you can send credentials via POST with the variables "username" and "userpassword".
See BUILDING.md for more details.
Docker versions differ from what is in main
and are release dependant.
Meaning billchurch/webssh2:latest is the latest official release. This does NOT sync with what is in main
on this repo. main
is development and will change until it gets a release tag.
On occasion, examples or instructions on main
will drift from what is released. You should refer to the tag of the version you're using to ensure you are following the proper guidance.
That being said the most current release version is 0.4.6, see that tag for details.
Some configuration options are available as Environment Variables. If there is a configuration option you require which does not have an environment variable please open an issue requesting.
webssh2 images are available in docker hub.
the latest
tag will pull the most recent stable release, otherwise you can pull individual tags/releases/versions of this repo by using a particular version in the tag.
For instance:
docker pull billchurch/webssh2:0.4.6
or
docker pull billchurch/webssh2:0.4.7-alpha.2
or
docker pull billchurch/webssh2
for the most recent
If you want to play around localy:
Copy app/config.json.template to app/config.json and modify the latter:
{
// ...
"listen": {
"ip": "0.0.0.0",
"port": 2222
}
// ...
}
Rebuild and run
docker build -t webssh2 .
docker run --name webssh2 -d -p 2222:2222 webssh2
Alternatively if you don't want to rebuild, mount the config at runtime:
docker run --name webssh2 -d -p 2222:2222 -v `pwd`/app/config.json:/usr/src/config.json webssh2
Alternatively if you don't want to build either and mount the config at runtime relying on the community image :
docker run --name webssh2 -d -p 2222:2222 -v `pwd`/app/config.json:/usr/src/config.json billchurch/webssh2
Environment variables introduced in 0.4.7 will override anything specified in config.json
. This is useful for settings that may be per-node, or in a container environment. These are optional and will default to whatever their peer config.json settings are
127.0.0.1
. Peer is listen.ip2222
. Peer is listen.portlocalhost:2222
. Changed in 0.3.1, to enable previous, less secure, default behavior of everything use *:*
(not recommended). Check #240. Peer is socketio.origins/ssh/socket.io
. Peer is socketio.pathfalse
. Peer is socketio.serveClientusername - string - username to log into ssh with
userpassword string password to log into ssh with
port= - integer - port of SSH server (defaults to 22)
header= - string - optional header to display on page
headerBackground= - string - optional background color of header to display on page
sshterm= - string - optional specify terminal emulation to use, defaults to ssh.term
in config.json
or vt100
if that is null
readyTimeout= - integer - How long (in milliseconds) to wait for the SSH handshake to complete. Default: 20000. Enforced Values: Min: 1, Max: 300000
cursorBlink - boolean - Cursor blinks (true), does not (false) Default: true.
scrollback - integer - Lines in the scrollback buffer. Default: 10000. Enforced Values: Min: 1, Max: 200000
tabStopWidth - integer - Tab stops at n characters Default: 8. Enforced Values: Min: 1, Max: 100
bellStyle - string - Style of terminal bell: ("sound"|"none"). Default: "sound". Enforced Values: "sound", "none"
fontSize - number - Size of terminal font. Default: 12
fontFamily - string - Font family
letterSpacing - number - Letter spacing
lineHeight - number - Line height
port= - integer - port of SSH server (defaults to 22)
header= - string - optional header to display on page
headerBackground= - string - optional background color of header to display on page
sshterm= - string - optional specify terminal emulation to use, defaults to ssh.term
in config.json
or vt100
if that is null
readyTimeout= - integer - How long (in milliseconds) to wait for the SSH handshake to complete. Default: 20000. Enforced Values: Min: 1, Max: 300000
cursorBlink - boolean - Cursor blinks (true), does not (false) Default: true.
scrollback - integer - Lines in the scrollback buffer. Default: 10000. Enforced Values: Min: 1, Max: 200000
tabStopWidth - integer - Tab stops at n characters Default: 8. Enforced Values: Min: 1, Max: 100
bellStyle - string - Style of terminal bell: ("sound"|"none"). Default: "sound". Enforced Values: "sound", "none"
fontSize - number - Size of terminal font. Default: "12"
fontFamily - string - Font family
letterSpacing - number - Letter spacing
lineHeight - integer - Line height
allowreplay - boolean - Allow use of password replay feature, example allowreplay: true
mrhsession - string - Can be used to pass APM session for event correlation mrhsession: abc123
config.json
contains several options which may be specified to customize to your needs, vs editing the javascript directly. This is JSON format so mind your spacing, brackets, etc...
listen.ip - string - IP address node should listen on for client connections, defaults to 127.0.0.1
listen.port - integer - Port node should listen on for client connections, defaults to 2222
socketio.serveClient - boolean - serve the socket.io client. This is built into the custom javascript, so you shouldn't need this. Kept as an option just in case. Default: false
socketio.path - string - Path to socket.io client files. Default: /ssh/socket.io
socketio.origins - array - COORS origins to allow connections from to socket.io server, defaults to localhost:2222
. Changed in 0.3.1, to enable previous, less secure, default behavior of everything use *:*
(not recommended). Check #240
user.name - string - Specify user name to authenticate with. In normal cases this should be left to the default null
setting.
user.password - string - Specify password to authenticate with. In normal cases this should be left to the default null
setting.
user.overridebasic - boolean - When set to true
ignores Authorization: Basic
header sent from client and use credentials defined in user.name
and user.password
instead. Defaults to false
. issue 242 for more information.
ssh.host - string - Specify host to connect to. May be either hostname or IP address. Defaults to null
.
ssh.port - integer - Specify SSH port to connect to, defaults to 22
ssh.term - string - Specify terminal emulation to use, defaults to vt100
if null
ssh.readyTimeout - integer - How long (in milliseconds) to wait for the SSH handshake to complete. Default: 20000.
ssh.keepaliveInterval - integer - How often (in milliseconds) to send SSH-level keepalive packets to the server (in a similar way as OpenSSH's ServerAliveInterval config option). Set to 0 to disable. Default: 120000.
ssh.keepaliveCountMax - integer - How many consecutive, unanswered SSH-level keepalive packets that can be sent to the server before disconnection (similar to OpenSSH's ServerAliveCountMax config option). Default: 10.
allowedSubnets - array - A list of subnets that the server is allowed to connect to via SSH. An empty array means all subnets are permitted; no restriction. Default: empty array.
terminal.cursorBlink - boolean - Cursor blinks (true), does not (false) Default: true.
terminal.scrollback - integer - Lines in the scrollback buffer. Default: 10000.
terminal.tabStopWidth - integer - Tab stops at n characters Default: 8.
terminal.bellStyle - string - Style of terminal bell: (sound|none). Default: "sound".
terminal.fontSize - number - Size of terminal font. Default: 14.
terminal.fontFamily - string - Font family
terminal.letterSpacing - number - Letter spacing
terminal.lineHeight - number - Line height
header.text - string - Specify header text, defaults to My Header
but may also be set to null
. When set to null
no header bar will be displayed on the client.
header.background - string - Header background, defaults to green
.
session.name - string - Name of session ID cookie. it's not a horrible idea to make this something unique.
session.secret - string - Secret key for cookie encryption. You should change this in production.
options.challengeButton - boolean - Challenge button. This option, which is still under development, allows the user to resend the password to the server (in cases of step-up authentication for things like sudo
or a router enable
command.
options.allowreauth - boolean - Reauth button. This option creates an option to provide a button to create a new session with new credentials. See issue 51 and pull 85 for more detail.
algorithms - object - This option allows you to explicitly override the default transport layer algorithms used for the connection. Each value must be an array of valid algorithms for that category. The order of the algorithms in the arrays are important, with the most favorable being first. Valid keys:
kex - array - Key exchange algorithms.
Default values:
Supported values:
cipher - array - Ciphers.
Default values:
Supported values:
hmac - array - (H)MAC algorithms.
Default values:
Supported values:
compress - array - Compression algorithms.
Default values:
Supported values:
serverlog.client - boolean - Enables client command logging on server log (console.log). Very simple at this point, buffers data from client until it receives a line-feed then dumps buffer to console.log with session information for tracking. Will capture anything send from client, including passwords, so use for testing only... Default: false. Example:
serverlog.server - boolean - not implemented, default: false.
accesslog - boolean - http style access logging to console.log, default: false
safeShutdownDuration - integer - maximum delay, in seconds, given to users before the server stops when doing a safe shutdown
Clicking Start logging
on the status bar will log all data to the client. A Download log
option will appear after starting the logging. You may download at any time to the client. You may stop logging at any time my pressing the Logging - STOP LOG
. Note that clicking the Start logging
option again will cause the current log to be overwritten, so be sure to download first.
http://localhost:2222/ssh/host/192.168.1.1?port=2244&header=My%20Header&headerBackground=red
As of 0.4.0, we're trying our best to conform to the Airbnb Javascript Style Guide. I'm hoping this will make contributions easier and keep the code readable. I love shortcuts more than anyone but I've found when making changes to code I've not looked at in a while, it can take me a few momements to deconstruct what was being done due to readbility issues. While I don't agree with every decision in the style guide (semi-colons, yuk), it is a good base to keep the code consistent.
If you've not used it before, I recommend installing the vscode extensions for that and Prettier and getting familiar. The autocorrections are great (especially if you hate dealing with semi-colons...)
All contributions are welcome, all may not make it into a release... To increase the chances of your contribution making it into a release, try your best to conform to the style guides and targets of the project.
localStorage.debug = '*';
- Debug Everything (a lot of messages)localStorage.debug = 'WebSSH2';
- Debug potentially interesting WebSSH2 related messages (replaying credentials, resizing data, other control messages)./src/client.html
and add a \<script> element, modify ./src/index.js
directly, or check out webpack.*.js
and add your custom javascript file to a task there (best option).