meshtastic / firmware

Meshtastic device firmware
https://meshtastic.org
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Avoid assert on receiving undecryptable packet #4059

Closed GUVWAF closed 2 weeks ago

GUVWAF commented 2 weeks ago

Fixes #3959.

It actually was an assert, as I captured it also on an ESP32:

assert failed: CryptoKey Channels::getKey(ChannelIndex) Channels.cpp:108 (ch.has_settings)

Problem was that it tried to send a NAK when decrypting failed. In that case, the channel index is still the hash, so it couldn’t get the channel settings when trying to encrypt the NAK. So now we’ll send the NAK on its primary channel in that case. It’s the best we can do, in the hope the other side understands that.

However, it tried to send the NAK because it thought mp.decoded.want_response was set and no module responded, but decoded is not valid if it’s not decrypted, so I also added additional checks for that.