Birdo VPN

The universal mobile client for Birdo VPN -- built once with Kotlin Multiplatform, running natively on Android and iOS.

Shared Module (shared/)

The KMP shared module contains all platform-agnostic logic:

- WireGuard tunnel management and key exchange - API client (authentication, server list, session management) - Connection state machine - Certificate pinning and transport security - Encryption utilities (ChaCha20-Poly1305 via WireGuard)

Features

- WireGuard Protocol -- ChaCha20-Poly1305 encryption with Curve25519 + Post-Quantum key exchange - Kill Switch -- Blocks all traffic if the tunnel drops - Split Tunneling -- Per-app VPN routing (Android) - Always-On VPN -- System-level persistent connection with auto-reconnect - Biometric Lock -- Fingerprint / Face ID app lock - Quick Settings Tile -- Toggle VPN from the notification shade (Android) - Home Screen Widgets -- Glanceable status with one-tap connect (iOS) - On-Demand Connect -- Rules-based activation on specific networks (iOS) - iCloud Sync -- Sync settings across Apple devices (iOS) - Stealth Mode -- XRAY Reality obfuscation to bypass DPI - Multi-Hop -- Route through multiple servers for extra anonymity

Security

- All network traffic encrypted with WireGuard (ChaCha20-Poly1305) - Certificate pinning on all API connections - Credentials stored in Android Keystore / iOS Keychain - No activity logs, no DNS logs, no traffic inspection - Release artifacts signed with Sigstore for provenance verification - CI uses pinned action SHAs and minimal permissions - ProGuard/R8 obfuscation on release builds (Android)

License

GNU General Public License v3.0