A Secure Chat Application using React and the Signal Protocol

Technology Stack

1. ReactJS library for UI
2. Signal Protocol Implementation for E2EE
3. Axios for AJAX calls
4. LocalStorage to store/fetch Pre-key bundle and Chats/Conversations
5. Web Sockets Implementation for Instant Messaging

To Initialize the Frontend of this Project use the command -

nodemon start

Components

1. Login
2. Chat Window
   1. Contact List
   2. Message Box

Axios Calls

1. GET - api/users/login/userName - Returns User Object of the given User
2. GET - api/users/users/userId/role - Returns Users Array other than the given User with given role

Web Sockets

1. Establishing WS Connection: let webSocket = new WebSocket("ws://localhost:3000/chat")
2. Event Listeners of the webSocket Object:

    webSocket.onopen = () => {
        console.log(‘WebSocket Client Connected’);
        webSocket.send('Hi this is web client.');
    };
    webSocket.onmessage = (e) => {
        console.log(‘Received: ’ + e.data);
    };
    webSocket.close = () => {
        console.log('WebSocket Client Closed.’);
    };

Signal Protocol Implementation

1. InMemorySignalProtocolStore.js (and helpers.js) are taken for storage purpose from Signal Github (link mentioned in resources)
2. libsignal-protocol.js (also from Signal Github) implements the protocol
3. Signal Gateway - Created by me to integrate React with Signal. It performs the Initialization, Encryption and Decryption functionality when required on Frontend. Check the file in src/signal/SignalGateway.js for detailed code.

Note: If you do not clear local storage, then you can recover your old conversations post re-login since these are saved in their respective decrypted form. No data is stored on the server. Kindly view the tutorial for more details.

Resources

1. Complete YouTube Tutorial for this project
2. Complete Blog for this project
3. Backend - NodeJS
4. Signal Protocol in JavaScript Github
5. Why Axios
6. ReactJS
7. Web Sockets API