[Little Brosers] That Key

This is an update on the authentication service I’m still working on. Yesterday I managed to parse the user certificate in DER format and extract interesting fields, such as the validity dates, username, public key and signature. However, in trying to bring it together with the rest of the service, in other words using the parsed public key to verify the challenge response, I ran into a bit of a problem. Upon further investigation (and to spare you the unnecessary details) I realized that if I try to compute the public key from a private one with the nRF crypto library, the output is different than the public key obtained with OpenSSL.

I spent all afternoon working on this so it’s a fresh issue right now. I read somewhere that endianness may be causing this, but my first tests didn’t show any promise there. If you have any ideas or suggestions I’m all ears!

Other than that, I still have to include the server’s public key in the code to test the certificate’s signature. I also have to transform the dates that I parsed into a more convenient format that we can use to compare to the date provided in the time certificate (which we still haven’t touched yet).

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