Which SSL library?

Projects General Guidance
1

Linux Debian (Bullseye), Arduino 1.8.20 from git.

Working with a WizNet RP2040 EVB board (Pico with a SDI W5100S Ethernet). I have something similar running with a PIC32 and a W5500 and MQTT but no SSL. The new board needs to publish to a cloud service MQTT so I need SSL.

I've been poking around for the last few hours and trying to make heads and tails of the various libraries. A lot of the libraries skip a lot of details making it hard to figure out how to configure. I'm having trouble figuring out the my_cert and my_key configs for:

SSLClientParameters mTLS = SSLClientParameters::fromPEM(my_cert, sizeof my_cert, my_key, sizeof my_key);

I can generate a client cert and key file with openssl but then the codes notes say not to use it.

Does anyone have a suggestion for which SSL library I should use? Also any useful links? I can very easily pub from a PI with mosquitto pub or with curl but I need the RP2040 for this.

Thanks

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SSLClient library

3

But the second part of the problem still exists, how to create the cert and key. The instructions are very vague (or only for AWS).