spki.sign(key, digest) => spki
Instance Public methods
Parameters
key - the private key to be used for signing this instance
digest - the digest to be used for signing this instance
To sign an SPKI, the private key corresponding to
the public key set for this instance should be used, in addition to a
digest algorithm in the form of an OpenSSL::Digest. The private key should be an
instance of OpenSSL::PKey.