pypeer 0.1.0

A terminal-based P2P messaging application using WebRTC

A Python Terminal-based P2P Messaging Application.

pypeer is a lightweight TUI application that enables direct, encrypted communication between peers. It leverages WebRTC for decentralized data transfer and Firebase RTDB as an ephemeral signaling server.

Start Screen	Host Setup
Join Room	Messaging Screen

Installation & Usage

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$ pip install pypeer

After installation launch the application by simply typing:

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$ pypeer

How to use:

1. Host a Room: Click "Host", set a password, and share the generated 6-character Room ID.
2. Join a Room: Click "Join", enter the Room ID and the password.
3. Chat: Once connected, start messaging.

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How it Works

1. Encrypted Signaling: Before a direct connection is established, peers must exchange handshake metadata (SDP and ICE candidates). pypeer uses Firebase RTDB as an ephemeral signaling server that acts as a temporary bulletin board.

   • Key Derivation: A 32-byte key is derived using SHA-256 from a combination of the Room ID and the User Password.
   • Layered Security: The connection metadata is cryptographically unreadable to anyone even the data provider that do not have the specific Room ID and Password.
     • Compression: Raw SDP strings are compressed using zlib to reduce payload size and obfuscate data structure.
     • Encryption: Compressed data is encrypted via AES-128 (Fernet),ensuring that only the intended peer can decrypt the handshake.

2. The WebRTC Handshake: Once the encrypted metadata is exchanged, the terminals move from "talking to the cloud" to "talking to each other":

   • Firewall Navigation: The app uses Google's STUN servers to navigate through home routers and firewalls and determine the best route between peers.
   • Encrypted DataChannel: A dedicated tunnel is established between peers. Unlike traditional TCP sockets, SCTP over WebRTC provides native encryption, reliability, and ordered delivery without the need for a central server.

3. Secure Direct Messaging: Once connected, the chat enters a serverless state:

   • Zero-Trace Handshake: The signaling data on Firebase RTDB is deleted. The peers remain connected directly, ensuring that no trace of the handshake remains on the cloud.
   • P2P Memory-to-Memory: Messages are sent directly between terminal memories. No history is stored on any server, and no middleman can intercept the traffic once the P2P tunnel is established.
   • Volatile Sessions: Your messages exist only as long as your terminal window is open. Once you quit, the session is wiped from your RAM.

4. Automated Cleanup: To maintain a a clean and secure signaling bridge, pypeer employs a two-tier cleanup strategy:

   • Host-Led Deletion: Under normal conditions, the host cleans up the signaling metadata as soon as the handshake is complete.
   • GitHub Action Janitor: As a failsafe, a scheduled GitHub Action acts as a "Janitor," running every hour to automatically purge any stale or abandoned rooms left behind by interrupted connections.

Tech Stack

Core Components	Implementation	Purpose
TUI Engine	Textual	Powers the modern, responsive terminal interface.
P2P Protocol	aiortc	Handles WebRTC stack, ICE gathering, and DataChannels.
Signaling	Firebase RTDB	Used as a temporary, real-time bridge for handshakes.
Encryption	Fernet (AES)	Encrypts signaling payloads so metadata never leaks.
Async Core	asyncio	Manages concurrent networking and UI updates.

License

This project is licensed under the MIT License.