Add EC Support in JWK.php

[bshaffer]

See 0c693a4

[MikeBeas]

Would love to see this added, too. If I knew how I’d do it myself but crypto is a bit beyond me at this point!

[DCdeBrabander]

I need this. Anyone know of an alternative? some simple dropin just for EC key types?

[bshaffer]

Closing in favor of #339

[bshaffer]

This is now available to try out for EC256. Please see #399!