Support EdDSA credential keys

[grzuy]

Depends on cedarcode/cose-ruby#48.

[bdewater]

This will also require ruby/openssl#119 to expose the required OpenSSL APIs in Ruby or an extra gem like https://github.com/RubyCrypto/ed25519

To my knowledge no manufacturer is supporting this at the time of writing.

[bdewater]

I stand corrected, Yubikeys have started shipping with EdDSA support around that time: https://www.yubico.com/blog/whats-new-in-yubikey-firmware-5-2-3/

I started poking at this in cedarcode/cose-ruby#55 but we'll need some work in the OpenSSL gem to have the right APIs.

[grzuy]

I stand corrected, Yubikeys have started shipping with EdDSA support around that time: https://www.yubico.com/blog/whats-new-in-yubikey-firmware-5-2-3/

Nice!
Wasn't aware.

I started poking at this in cedarcode/cose-ruby#55 but we'll need some work in the OpenSSL gem to have the right APIs.

Thank you!

[santiagorodriguez96]

Now that cedarcode/cose-ruby#48 was merged and cose-ruby version 1.3.0 was released, we are in position to add support for EdDSA keys here, right?

@bdewater by any chance are you working on it already (or maybe planning to)? If not I can jump on this if you want, let me know 🙂