baalvpn

A hub-and-spoke VPN for IPv6

Features

• Post-quantum security: Uses HPKE(XWingMLKEM768X25519, HKDF-SHA-256) + XChaCha20-Poly1305 for encryption and ML-DSA-44 for signatures.
• NAT-resistant architecture: Any device with Internet access can easily join the network.
• Cross-platform-ish: Tested on Linux and Windows. macOS should probably work too.

Protocol

See proto.go for details

Known limitations

• Compromised server could give out fake pubkeys allowing a MITM attack and decrypting the peer-to-peer traffic
• The keys are rotated only on client and server restart
• The protocol is vulnerable to replay attacks

Third-party dependencies

• github.com/songgao/water - wrapper around TUN interfaces for *nix
• golang.zx2c4.com/wintun - wrapper around wintun.dll
• github.com/cloudflare/circl - used for ML-DSA, hopefully not for long