rsa.go
func (r RSAMethod) Sign(rand io.Reader, priv *rsa.PrivateKey, hash crypto.Hash, buf []byte) ([]byte, error) {
	return r.SignFunc(rand, priv, hash, buf)
}
func (r RSAMethod) Sign(rand io.Reader, priv *rsa.PrivateKey, hash crypto.Hash, buf []byte) ([]byte, error) {
	return r.SignFunc(rand, priv, hash, buf)
}
func ( r RSAMethod ) Sign ( rand io . Reader , priv * rsa . PrivateKey , hash crypto . Hash , buf [ ] byte ) ( [ ] byte , error ) { return r . SignFunc ( rand , priv , hash , buf ) }
// Sign signs the data in buf using rand, priv and hash.
Sign signs the data in buf using rand priv and hash .