True P2P File Sharing Application (Direct WebRTC)

A true peer-to-peer file sharing system using WebRTC DataChannels for direct communication between browsers. The server only acts as a signaling server to facilitate WebRTC connection establishment, with no file data passing through the server.

🚀 Overview

The True P2P application implements direct peer-to-peer file sharing using WebRTC DataChannels. This approach provides the highest level of privacy and true P2P communication while maintaining the reliability of WebRTC for NAT traversal and connection establishment.

🛠️ Technology Stack

• Backend: Flask, Flask-SocketIO (signaling only)
• Frontend: HTML5, CSS3, JavaScript (ES6+)
• P2P Protocol: WebRTC DataChannels
• Signaling: WebSocket (Socket.IO)
• NAT Traversal: STUN servers
• Styling: Bootstrap 5, Font Awesome icons

📁 Project Structure

.
├── app.py                 # Main Flask application with 
├── templates/
│   ├── upload.html        # File upload interface
│   └── receive.html       # File download interface
├── static/
│   ├── js/
│   │   ├── protocol.js    # True P2P protocol implementation
│   │   ├── upload.js      # Upload page JavaScript
│   │   └── receive.js     # Download page JavaScript
│   └── css/
│       └── style.css      # Application styles
├── requirements.txt       # Python dependencies for this repo
├── .gitignore             # Git ignore rules
└── README.md              # This documentation

🔧 How It Works

Upload Process

1. File Selection: User selects files to share
2. Protocol Initialization: True P2P protocol is initialized
3. File Chunking: Files are split into chunks for transfer
4. WebRTC Setup: RTCPeerConnection is established
5. Data Channel Creation: WebRTC DataChannel is created
6. Signaling: Server facilitates WebRTC connection establishment
7. Direct Transfer: File chunks are sent directly to peer
8. Shareable URL: A shareable URL is generated for distribution

Download Process

1. Magnet URI Access: User accesses the shareable URL
2. Metadata Retrieval: Transfer metadata is retrieved from server
3. Protocol Initialization: True P2P protocol is initialized
4. WebRTC Setup: RTCPeerConnection is established
5. Data Channel Setup: WebRTC DataChannel is configured
6. Signaling: Server facilitates WebRTC connection establishment
7. Direct Download: File chunks are received directly from peer
8. File Reconstruction: Chunks are reassembled into original file
9. Progress Tracking: Real-time progress updates are displayed
10. File Download: Reconstructed file is made available for download

🌐 API Endpoints

Main Routes

• GET / - Upload page interface
• GET /share/<transfer_id> - Download page interface

API Endpoints

• POST /api/create-transfer - Create new transfer
• GET /api/transfer/<transfer_id> - Get transfer information
• POST /api/cleanup - Clean up expired transfers

WebSocket Events

• join_transfer_room - Join transfer room for signaling
• webrtc_offer - WebRTC offer for peer connection
• webrtc_answer - WebRTC answer for peer connection
• webrtc_ice_candidate - ICE candidate for NAT traversal
• request_offer - Request WebRTC offer from sender
• peer_joined - Notify when peer joins room
• offer_requested - Notify when offer is requested

🔄 Data Flow

Uploader                    Server                    Downloader
   |                          |                          |
   |-- Select Files --------->|                          |
   |                          |                          |
   |-- Initialize Protocol -->|                          |
   |                          |                          |
   |-- Chunk Files ---------->|                          |
   |                          |                          |
   |-- Setup WebRTC --------->|                          |
   |                          |                          |
   |-- Create Data Channel -->|                          |
   |                          |                          |
   |-- Join Signaling Room -->|                          |
   |                          |                          |
   |-- Generate Share URL --->|                          |
   |                          |                          |
   |                          |<-- Access Share URL -----|
   |                          |                          |
   |                          |-- Return Metadata ------->|
   |                          |                          |
   |                          |<-- Join Signaling Room --|
   |                          |                          |
   |<-- WebRTC Signaling ------------------------------->|
   |                                                     |
   |<-- Direct P2P Transfer ---------------------------->|
   |                                                     |
   |<-- File Transfer Complete-------------------------->|

🎯 Key Features

Upload Features

• Direct P2P Transfer: Files sent directly between peers
• WebRTC DataChannels: High-performance data transfer
• NAT Traversal: Automatic NAT traversal with STUN servers
• File Chunking: Efficient chunk-based transfer
• Progress Tracking: Real-time transfer progress
• Shareable URLs: Easy sharing via generated URLs

Download Features

• Direct P2P Download: Files received directly from peers
• WebRTC DataChannels: Reliable data channel communication
• File Reconstruction: Automatic file assembly from chunks
• Progress Tracking: Real-time download progress
• Direct Download: Browser-based file download
• Error Handling: Comprehensive error management

Technical Features

• True P2P: No server storage of file data
• WebRTC Signaling: Server only for connection establishment
• STUN Servers: NAT traversal support
• Data Channel Management: Reliable data transfer
• Connection Monitoring: Real-time connection status
• Resource Cleanup: Automatic cleanup of resources

🔧 Configuration

WebRTC Configuration

const iceServers = [
    { urls: 'stun:stun.l.google.com:19302' },
    { urls: 'stun:stun1.l.google.com:19302' },
];

const dataChannelConfig = {
    ordered: true,
    maxRetransmits: 3
};

Server Configuration

# SocketIO configuration
socketio = SocketIO(app, cors_allowed_origins="*")

# Transfer cleanup settings
CLEANUP_INTERVAL = 86400  # 24 hours in seconds
MAX_FILE_SIZE = 100 * 1024 * 1024  # 100MB limit

🚀 Getting Started

Prerequisites

• Python 3.7+
• Flask, Flask-SocketIO
• Modern web browser with WebRTC support

Installation

1. Install Dependencies

   pip install -r requirements.txt

2. Run the Application

   python app.py

3. Access the Application

   • Open http://localhost:5004 in your browser
   • Start uploading and sharing files!

Usage

1. Upload Files

   • Select files using the file input
   • Click "Start Direct P2P Sharing"
   • Wait for WebRTC connection establishment
   • Copy the shareable URL

2. Download Files

   • Open the shareable URL
   • Wait for WebRTC connection establishment
   • Monitor download progress
   • Click "Download File" when complete

📊 Monitoring and Logging

Console Logging

The application provides comprehensive logging for debugging and monitoring:

True P2P Upload: Page initialized
True P2P Upload: Files selected: 1
True P2P Upload: Generated transfer ID: true-p2p-1234567890-abc123
True P2P Upload: Protocol initialized
True P2P Upload: File set for processing: example.jpg (1024000 bytes)
True P2P Upload: File split into 16 chunks
True P2P Upload: WebRTC connection ready
True P2P Upload: Data channel ready for P2P transfer
True P2P Upload: Shareable URL generated

Progress Tracking

• Upload Progress: Direct P2P transfer progress
• Download Progress: Real-time download percentage
• WebRTC Status: Connection and data channel status
• Peer Status: Peer connection monitoring

🔒 Security Considerations

Privacy

• No Server Storage: Files never stored on server
• Direct P2P: Direct communication between peers
• End-to-End: Data encrypted by WebRTC

Network Security

• STUN Servers: Trusted STUN servers for NAT traversal
• WebRTC Security: Built-in WebRTC security features
• HTTPS: Use HTTPS in production

🔗 Resources

• WebRTC Documentation
• Flask-SocketIO Documentation
• STUN Server List Repo I Found
• WebRTC DataChannels