SignatureForge.py

    def encodePkcs1Suffix(self, message):
        messageHash = self.hashAlg.digester(message.encode("utf-8")).digest()
        if messageHash[-1] & 0x01 != 0x01:
            print(
                "Hash value must be uneven. Try a different message or a different 
                hash algorithm",
                file=stderr,
            )
            exit(1)
        suffix = bytes([0]) + self.hashAlg.digestInfo + messageHash
        return suffix