WSSiP: A WebSocket Manipulation Proxy

Short for "WebSocket/Socket.io Proxy", this tool, written in Node.js, provides a user interface to capture, intercept, send custom messages and view all WebSocket and Socket.IO communications between the client and server.

Upstream proxy support also means you can forward HTTP/HTTPS traffic to an intercepting proxy of your choice (e.g. Burp Suite or Pappy Proxy) but view WebSocket traffic in WSSiP. More information can be found on the blog post.

There is an outward bridge via HTTP to write a fuzzer in any language you choose to debug and fuzz for security vulnerabilities. See Fuzzing for more details.

Written and maintained by Samantha Chalker (@thekettu). Icon for WSSiP release provided by @dragonfoxing.

Installation

From Packaged Application

See Releases.

From npm/yarn (for CLI commands)

Run the following in your command line:

npm:

# Install Electron globally
npm i -g [email protected]

# Install wssip global for "wssip" command
npm i -g wssip

# Launch!
wssip

yarn: (Make sure the directory in yarn global bin is in your PATH)

yarn global add [email protected]
yarn global add wssip
wssip

You can also run npm install electron (or yarn add electron) inside the installed WSSiP directory if you do not want to install Electron globally, as the app packager requires Electron be added to developer dependencies.

From Source

Using a command line:

# Clone repository locally
git clone https://github.com/nccgroup/wssip

# Change to the directory
cd wssip

# If you are developing for WSSiP:
# npm i

# If not... (as to minimize disk space):
npm i -g [email protected]
npm i --production

# Start application:
npm start

Usage

1. Open the WSSiP application.
2. WSSiP will start listening automatically. This will default to localhost on port 8080.
3. Optionally, use Tools > Use Upstream Proxy to use another intercepting proxy to view web traffic.
4. Configure the browser to point to http://localhost:8080/ as the HTTP Proxy.
5. Navigate to a page using WebSockets. A good example is the WS Echo Demonstration.
6. ???
7. Potato.

Fuzzing

WSSiP provides an HTTP bridge via the man-in-the-middle proxy for custom applications to help fuzz a connection. These are accessed over the proxy server.

A few of the simple CA certificate downloads are:

• http://mitm/ca.pem / http://mitm/ca.der (Download CA Certificate)
• http://mitm/ca_pri.pem / http://mitm/ca_pri.der (Download Private Key)
• http://mitm/ca_pub.pem / http://mitm/ca_pub.der (Download Public Key)

Get WebSocket Connection Info

Returns whether the WebSocket id is connected to a web server, and if so, return information.

• URL

  GET http://mitm/ws/:id

• URL Params

  id=[integer]

• Success Response (Not Connected)

  • Code: 200
    Content: {connected: false}

• Success Response (Connected)

  • Code: 200
    Content: {connected: true, url: 'ws://echo.websocket.org', bytesReceived: 0, extensions: {}, readyState: 3, protocol: '', protocolVersion: 13}

Send WebSocket Data

Send WebSocket data.

• URL

  POST http://mitm/ws/:id/:sender/:mode/:type?log=:log&mask=:mask

• URL Params

  Required:

  id=[integer]

  sender one of client or server

  mode one of message, ping or pong

  type one of ascii or binary (text is an alias of ascii)

  Optional:

  log either true or y to log in the WSSiP application. Errors will be logged in the WSSiP application instead of being returned via the REST API.

  mask either true or y to set WebSocket flag to mask.

• Data Params

  Raw data in the POST field will be sent to the WebSocket server.

• Success Response:

  • Code: 200
    Content: {success: true}

• Error Response:

  • Code: 500
    Content: {success: false, reason: 'Error message'}

Development

Pull requests are welcomed and encouraged. WSSiP supports the debug npm package, and setting the environment variable DEBUG=wssip:* will output debug information to console.

There are two commands depending on how you want to compile the Webpack bundle: for development, that is npm run compile:dev and for production is npm run compile. React will also log errors depending on whether development or production is specified.

Currently working on:

• Exposed API for external scripts for fuzzing (99% complete, it is live but need to test more data)
• Saving/Resuming Connections from File (35% complete, exporting works sans active connections)
• Using WSSiP in browser without Electron (likely 1.1.0)
• Rewrite in TypeScript (likely 1.2.0)
• Using something other than Appbar for Custom/Intercept tabs, and styling the options to center better

For information on using the mitmengine class, see: npm, yarn, or mitmengine/README.md