Connect: Developer Documentation

Introduction

Welcome to Connect, a revolutionary platform that redefines social media by giving users full control over their data. Our goal is to empower users and provide a secure, privacy-centric platform. We prioritize data protection while providing an exceptional digital experience.

The platform is divided into three branches:

1. Personal
2. Professional
3. Educational

Users can customize their experience across these categories and control what content is visible in each branch.

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Table of Contents

1. Introduction
2. Getting Started
   • Client Setup
   • Server Setup
   • Database Setup
3. Version Control
4. Security
   • End-to-End Encryption
5. Content Analysis and Moderation
6. Social Networking Algorithm
7. Messaging

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Getting Started

2.1 Dependencies and Initialization

File Directory Structure

CONNECT
│
├── client
│   ├── build
│   ├── node_modules
│   ├── public
│   ├── src
│   ├── types
│   ├── .gitignore
│   ├── package-lock.json
│   ├── package.json
│   ├── tsconfig.json
│   └── Documentations
│
├── server
│   ├── dist
│   ├── node_modules
│   ├── src
│   ├── types
│   ├── .gitignore
│   ├── package-lock.json
│   ├── package.json
│   └── tsconfig.json
│
├── UML
├── .env
└── connect_documentation.md

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Client Setup

1. Navigate to the client directory:

   cd client

2. Install the required dependencies:

   npm install

3. Start the React server:

   npm start

   You can now view Connect in the browser at http://localhost:3000.

Note: The development build is not optimized. Use npm run build to create a production build.

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Server Setup

1. Navigate to the server directory:

   cd server

2. Install the required dependencies:

   npm install

3. Compile the TypeScript files:

   cd src
   npx tsc

   This creates .js executables inside the dist directory.

4. Start the server:

   cd ..
   node dist/server.js

   The server will run on http://localhost:8000.

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Database Setup

We use MongoDB as the database for Connect.

1. Download MongoDB Compass from here.

2. Connect to the database using the following connection string:

   mongodb+srv://kamrulhassan:fNXADjxipNKubPlP@connect.ny9wvom.mongodb.net/
   

Note: Do not share the connection string with anyone.

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Version Control

Git Commands

Make sure you are in the root directory before running these commands.

1. Add your changes:

   git add .

2. Commit your changes:

   git commit -m "your message"

3. Push to your branch:

   git push origin <your_branch>

4. To check your current branch:

   git branch

Pushing Code

• Always push to your respective branch first. Collaborate with your teammates through pull requests.
• Kamrul and Zoheb are the only ones who can push from the TestBranch to main.

Creating a Pull Request

1. Go to GitHub Pull Requests.
2. Click on New pull request.
3. Choose the branch you want to merge from and into.

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Security

End-to-End Encryption

We use the Signal Protocol to ensure secure messaging and profile content protection in Connect.

Messaging Encryption

• Key Generation: Each user generates a unique identity key pair during registration, which consists of identity keys and pre-keys.
• Double Ratchet Algorithm: Ensures that each message is encrypted with a unique key, offering forward secrecy.

Code Snippets for E2E Encryption in TypeScript

Key Generation:

import { generateIdentityKeyPair, generatePreKeyBundle } from '@signalapp/libsignal-client';

const generateKeys = async () => {
    const identityKeyPair = await generateIdentityKeyPair();
    const preKeyBundle = await generatePreKeyBundle(identityKeyPair);
    return { identityKeyPair, preKeyBundle };
};

Session Setup:

import { SignalProtocolAddress, SessionBuilder, PreKeyBundle } from '@signalapp/libsignal-client';

const setupSession = async (store, address, preKeyBundle: PreKeyBundle) => {
    const sessionBuilder = new SessionBuilder(store, address);
    await sessionBuilder.processPreKey(preKeyBundle);
};

Message Encryption & Decryption:

import { SessionCipher } from '@signalapp/libsignal-client';

const encryptMessage = async (store, address, message) => {
    const sessionCipher = new SessionCipher(store, address);
    const ciphertext = await sessionCipher.encrypt(message);
    return ciphertext;
};

const decryptMessage = async (store, address, ciphertext) => {
    const sessionCipher = new SessionCipher(store, address);
    const plaintext = await sessionCipher.decryptPreKeyWhisperMessage(ciphertext.body, 'binary');
    return plaintext;
};

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Profile Content Encryption

• Profile Content Protection: Each user's profile content (photos, videos, text) is encrypted with a unique symmetric key (AES).
• The symmetric key is then encrypted using the recipient's public key (ECC).

Profile Encryption in TypeScript:

import { randomBytes, createCipheriv } from 'crypto';

// Generate AES key for content encryption
const generateSenderKey = () => {
    return randomBytes(32); // 256-bit AES key
};

// Encrypt content using the sender's key
const encryptContent = (content: Buffer, senderKey: Buffer) => {
    const iv = randomBytes(16); // Random initialization vector (IV) for AES
    const cipher = createCipheriv('aes-256-cbc', senderKey, iv);
    const encryptedContent = Buffer.concat([cipher.update(content), cipher.final()]);
    return { encryptedContent, iv };
};

// Example content to encrypt
const videoContent = Buffer.from('Example video content');

// Generate the key and encrypt the content
const senderKey = generateSenderKey();
const { encryptedContent, iv } = encryptContent(videoContent, senderKey);

Encrypting the Sender Key with Session Keys:

import { SessionCipher } from '@signalapp/libsignal-client';

// Encrypt sender key using session keys
const encryptSenderKey = async (store, address, senderKey) => {
    const sessionCipher = new SessionCipher(store, address);
    const encryptedSenderKey = await sessionCipher.encrypt(senderKey);
    return encryptedSenderKey;
};

// Example usage for encrypting sender keys for multiple recipients
const encryptedSenderKeyForRecipient1 = await encryptSenderKey(store, recipient1Address, senderKey);
const encryptedSenderKeyForRecipient2 = await encryptSenderKey(store, recipient2Address, senderKey);

// Store the encrypted content and keys on the server
await uploadEncryptedContentToServer({
    encryptedContent,
    iv,
    encryptedKeys: {
        recipient1: encryptedSenderKeyForRecipient1,
        recipient2: encryptedSenderKeyForRecipient2,
    },
});

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Content Analysis and Moderation

Content Analysis

We use multi-label classification for tagging content, leveraging models like TensorFlow Lite and PyTorch Mobile.

• Text, Images, Videos: The system supports analyzing text, multiple images, and video posts.
• Pre-trained models are fine-tuned for optimal performance across mobile and web platforms.

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Social Networking Algorithm

We are implementing a social networking algorithm to enhance user interaction and content recommendation.

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Messaging (End-to-End Encrypted)

Messaging on Connect is fully end-to-end encrypted using the Signal Protocol. This ensures private and secure communication between users.

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For more details and further technical documentation, please refer to connect_documentation.md.

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