def _sign_threshold_signature_fulfillment()

in resdb_driver/transaction.py [0:0]

• 28 lines of code
• 7 McCabe index (conditional complexity)

    def _sign_threshold_signature_fulfillment(cls, input_, message, key_pairs):
        """! Signs a ThresholdSha256.

        @param input_ (:class:`~resdb.transaction.Input`) The Input to be signed.
        @param message (str): The message to be signed
        @param key_pairs (dict): The keys to sign the Transaction with.
        """
        input_ = deepcopy(input_)
        message = sha3_256(message.encode())
        if input_.fulfills:
            message.update(
                "{}{}".format(input_.fulfills.txid,
                              input_.fulfills.output).encode()
            )

        for owner_before in set(input_.owners_before):
            # TODO: CC should throw a KeypairMismatchException, instead of
            #       our manual mapping here

            # TODO FOR CC: Naming wise this is not so smart,
            #              `get_subcondition` in fact doesn't return a
            #              condition but a fulfillment

            # TODO FOR CC: `get_subcondition` is singular. One would not
            #              expect to get a list back.
            ccffill = input_.fulfillment
            subffills = ccffill.get_subcondition_from_vk(
                base58.b58decode(owner_before))
            if not subffills:
                raise KeypairMismatchException(
                    "Public key {} cannot be found "
                    "in the fulfillment".format(owner_before)
                )
            try:
                private_key = key_pairs[owner_before]
            except KeyError:
                raise KeypairMismatchException(
                    "Public key {} is not a pair "
                    "to any of the private keys".format(owner_before)
                )

            # cryptoconditions makes no assumptions of the encoding of the
            # message to sign or verify. It only accepts bytestrings
            for subffill in subffills:
                subffill.sign(message.digest(),
                              base58.b58decode(private_key.encode()))
        return input_