ShadowLink - Secure Local Encrypted Tunnel

ShadowLink is a next-generation local VPN and secure tunnel application that uses AES-256-GCM and X25519 key exchange to encrypt traffic. It features a modern, animated user interface built with Electron and React.

🚀 Features

• Double Encryption: Traffic is encrypted locally using ephemeral keys before leaving your device.
• Strict Mode (Kill Switch): Automatically cuts traffic if the secure tunnel drops.
• System-Wide Proxy: Routes all system traffic through the secure tunnel with one click.
• Modern UI: Polished, cyber-aesthetic interface with real-time stats and animations.
• Cross-Platform: Built on Electron (Frontend) and Python (Backend).

🛠 Architecture

ShadowLink uses a hybrid architecture:

• Frontend: Electron, React, TailwindCSS, Framer Motion.
• Backend: Python (compiled to single-file executable), handling specific encryption and socket operations.
• IPC: The frontend communicates with the backend via standard input/output (stdio) using JSON-RPC.

❓ What Makes It Different?

Feature	Standard SOCKS5 Proxy	ShadowLink
Encryption	None (Usually plaintext)	AES-256-GCM
Key Management	Static Password / None	Ephemeral X25519 (New key per session)
Purpose	IP Masking	Traffic Obfuscation & Layered Security
Dependency	Remote Server	Local-Only (Server runs on your localhost)

Why use this locally? It isolates your application traffic from the rest of the OS until it is fully encrypted. Even if malware on your PC packet-sniffs your network card, they only see the encrypted ShadowLink traffic, not the raw application data.

⚠️ Limitations

1. TCP Only: Currently supports SOCKS5 CONNECT method (TCP). UDP (e.g., for gaming/VoIP) is not yet supported.
2. Performance Overhead: Double encryption (ShadowLink + ProtonVPN) adds a small amount of latency and CPU overhead.
3. Manual Proxy Config: You must configure your browser/app to use the provided SOCKS5 proxy if not using System-Wide mode.

📦 Installation & Build

Prerequisites

• Node.js (v18+)
• Python 3.10+
• pip packages: cryptography

1. Setup

# Install Python dependencies
pip install -r requirements.txt

# Install Node dependencies
cd electron
npm install

2. Development Mode

Run the app locally with hot-reloading:

# In 'electron/' directory
npm run dev

3. Build & Package

To create the Windows installer (.exe):

# In 'electron/' directory
npm run build:css   # Generate Tailwind styles
npm run build:win   # Package app

The installer will be in electron/dist_installer/.

🔐 Verification

To verify the encryption implementation (X25519 + AES-256-GCM), run the included verification script:

python src/verify_encryption.py

This script simulates a full handshake and encryption cycle, printing the keys and ciphertext to the console for inspection.

📄 License

MIT