Add ChaCha20-Poly1305 AEAD decryption with 4-byte auth tag for peer
messages and group channels, falling back to ECB for backward
compatibility. Sending remains ECB-only in this phase.
- Per-message key derivation: HMAC-SHA256(secret, nonce||dest||src)
- Direction-dependent keys prevent bidirectional keystream reuse
- 12-byte IV from nonce + dest_hash + src_hash
- Advertise AEAD capability via feat1 bit 0 in adverts
- Track peer AEAD support in ContactInfo.flags
- Seed aead_nonce from HW RNG on contact creation and load
Compile fails due to user_btn not declared in board target.
Fixes:
- Add MomentaryButton declaration for user_btn in variants/xiao_nrf52/target.cpp
- Add momentary button helper include in variants/xiao_nrf52/target.h
- Add extern linkage for MomentaryButton -> user_btn in variants/xiao_nrf52/target.h
SerialEthernetInterface.cpp is compiled for every nRF52 target because
PlatformIO builds all .cpp files under src/. It includes
SerialEthernetInterface.h, which unconditionally pulls in
<RAK13800_W5100S.h> -- a library only present in the RAK4631 Ethernet
env's lib_deps. As a result any other nRF52 board (e.g. Heltec T114)
fails to build with 'RAK13800_W5100S.h: No such file or directory'.
Wrap the contents of both files in '#ifdef ETHERNET_ENABLED' so they
compile to empty translation units on non-Ethernet builds. RAK4631
Ethernet envs define ETHERNET_ENABLED and are unaffected.
Fixes#2985
Improvements:
- Add condition to only turn off display if on (avoids wedging the shutdown on some displays)
- Reset LoRa radio before calling radio_driver.powerOff() to ensure it is in a known good state (and will accept the command)
- Ensure SPI is started so LoRa radio commands can be sent (some shutdowns can happen before this)
- Add gate for P_LORA_NSS pin defined before writing to the pin