Returns the HTTP-signature algorithm a key means when the proof is the
string form (section 7.3.1): the algorithm a JOSE library would pick for
that key type.
Parameters
keyObject: any
a node public KeyObject
Returns string
a JWS algorithm name, or null for a key type with none
Returns the HTTP-signature algorithm a key means when the proof is the string form (section 7.3.1): the algorithm a JOSE library would pick for that key type.