MQTT Forwarder to AWS: No Private Key found

[morgantechngs]

So found that the problem was talked about here:

Upgrade 4.6 to 4.7, SSL Problem with MQTT Integration

To add some context to this, ChirpStack v4.7 migrated from OpenSSL to Rustls. The big advantage is that it is no longer needed to (cross)compile OpenSSL such that ChirpStack can be linked against it. Unfortunately, Rustls is more restrictive in the certificate formats that it accept than OpenSSL. As far as I understand PKCS#8 is in general the preferred method. For RSA private-keys, there is an easy fix and ChirpStack will automatically do the conversion to PKCS#8: Unfortunate for EC keys I…

The PKCS conversion was not taking place in the mqtt-forwarder mqtt.rs, so I manually converted to PKCS and now it sees the private key. I’m getting AWS authentication failures but the mqtt-forwarder is able to communicate and send requests, the authentication error is probably the AWS side of things.

I would recommend that the PKCS conversion from RSA keys takes place in the mqtt-forwarder similar to how it does currently for chirpstack and gateway-bridge.