rsa.go
func (r RSAMethod) Verify(pub *rsa.PublicKey, hash crypto.Hash, hashed []byte, sig []byte) error {
	return r.VerifyFunc(pub, hash, hashed, sig)
}
func (r RSAMethod) Verify(pub *rsa.PublicKey, hash crypto.Hash, hashed []byte, sig []byte) error {
	return r.VerifyFunc(pub, hash, hashed, sig)
}
// Verify verifies the signature sig against using pub, hash, and the hashed
// data.