cryptography.py 文件源码

def sign(self, data, hash_context):
        if not isinstance(hash_context, hashes.HashContext):
            raise TypeError("hash_context must be an instance of hashes.HashContext.")
        signer = self._key.signer(hashes.SHA256())
        signer._hash_ctx = hash_context
        signer.update(data)
        r, s = decode_dss_signature(signer.finalize())
        # return long_to_bytes(r, 20) + long_to_bytes(s, 20)
        size = self.private_numbers.public_numbers.parameter_numbers.q.bit_length() // 8
        return long_to_bytes(r, size) + long_to_bytes(s, size)