wearvian
Wear OS phone key for Rivian R1 vehicles
- Wear OS app that functions as a Rivian phone key over Bluetooth LE: passive entry and drive enable by proximity, plus lock, frunk, liftgate, window, charge port, and climate commands.
- Reverse engineered the vehicle's phone-key protocol and documented it: the pairing handshake, the authenticated ranging heartbeat that passive entry actually keys on rather than OS-level bonding, AES-GCM command framing, and the status stream that drives live lock, closure, charge, and range display.
- Wrote
core-crypto, a standalone Kotlin/JVM module implementing secp256r1, ECDH, HKDF-SHA256, HMAC, and AES-GCM command frames, verified against known-answer parity tests. - Built for offline operation and key custody: the watch holds no
INTERNETpermission and its private key never leaves the device, with a companion phone app performing the one-time cloud enrollment over the Wear OS Data Layer. - Power-saving passive mode releases the wake lock and tears down the radio when idle, with a hardware-offloaded scan rebuilding the link on approach.