Checks an account key: its shape, no private members, agreement with alg, a loadable key and an RFC 7638 thumbprint.
alg
the header's jwk
jwk
the header's alg
{ ok, jwk, thumbprint, key }, the JWK rebuilt from its required public members, or a refusal
{ ok, jwk, thumbprint, key }
Checks an account key: its shape, no private members, agreement with
alg, a loadable key and an RFC 7638 thumbprint.