Json Web Keys again

[Angus Robertson - Magenta Systems Ltd]

> > It seems the EVP_PKEY_RSA_PSS addition was only committed 28th 
> > October 2019, so need to wait for 1.1.1e, hopefully real soon...
> 
> Ah, that explains it!

Now tested with 1.1.1e-dev and I can generate a JWK from an RSA-PSS key.


Since JWK is for signing, I also tried to support ED25519 private keys,
but get:

error:0D0A40A7:asn1 encoding routines:i2d_PublicKey:unsupported public
key type
 
A binary public key is all I need for JWK, simple format. A search of
master suggests nothing yet.

Angus