Aura's own data path over plain UDP, authenticated solely by the existing Aura
PQ handshake (hybrid X25519+ML-KEM-768 + mutual X.509) — no QUIC, no outer TLS.
- One UDP socket, two phases by type byte: 0x01 HS (reliable handshake), 0x02
DATA (datagram records). HS = DTLS-flight reliability over UDP: per-message
seq, cumulative acks, retransmit (RTO), reorder/dedup, post-handshake linger;
message boundaries parsed from the 5-byte Aura header. DATA = one explicit-
nonce AEAD record per datagram (seq||AEAD), replay-checked, optional padding to
HTTPS size buckets (obfuscation).
- UdpServer/UdpClient/UdpConnection (impl PacketConnection, concurrent send/recv).
v1: single peer per accept (multi-client demux is a follow-up).
- 5 adapter unit tests + udp loopback end-to-end (obfuscation on, 1300B/empty/
duplex) + handshake-survives-30%-loss-and-reorder. No new deps. QUIC tests
preserved. Whole workspace builds; clippy/fmt clean.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
xah30