Louie - Stay In Touch for WhatsApp Web
This is the source code of a chrome extension that lets you stay in touch with your friends & family on WhatsApp Web. You can find the published extension in Chrome Web Store.
Installing from GitHub directly
To install the extension off-store, download the latest release as a zip file from the Releases page, extract its content to a directory and add it to Chrome using the 'Load unpacked extension' option when developer mode is turned on.
How it works
This extension works by intercepting the WebSocket frames between chrome and WhatsApp's servers using a modified WebSocket constructor (see wsHook).
Those frames are then decrypted if needed using the local encryption keys (stored in localStorage), and decoded from a binary form using a javascript code from WhatsApp's original implementation.
The resulting "nodes" are being checked to find the chats and check them against the contacts and the "Stay In Touch"
Organization
The main code of the extension is located in core/Main.js and core/UI.js.
Other files inside the core folder deal with the infrastructure that makes the interception and the decoding works. There is also an additional code for parsing messeges (such as MessageTypes.js) that is not used in the extension.
background.js mainly keeps track of the saved prefrences using localStorage.