def decrypt_data_key_from_list()

in src/aws_encryption_sdk/key_providers/base.py [0:0]

• 12 lines of code
• 5 McCabe index (conditional complexity)

    def decrypt_data_key_from_list(self, encrypted_data_keys, algorithm, encryption_context):
        """Receives a list of encrypted data keys and returns the first one which this provider is able to decrypt.

        :param encrypted_data_keys: List of encrypted data keys
        :type encrypted_data_keys: list of :class:`aws_encryption_sdk.structures.EncryptedDataKey`
        :param algorithm: Algorithm object which directs how this Master Key will encrypt the data key
        :type algorithm: aws_encryption_sdk.identifiers.Algorithm
        :param dict encryption_context: Encryption context to use in encryption
        :returns: Decrypted data key
        :rtype: aws_encryption_sdk.structures.DataKey
        :raises DecryptKeyError: if unable to decrypt any of the supplied encrypted data keys
        """
        data_key = None
        for encrypted_data_key in encrypted_data_keys:
            try:
                data_key = self.decrypt_data_key(encrypted_data_key, algorithm, encryption_context)
            # MasterKeyProvider.decrypt_data_key throws DecryptKeyError
            # but MasterKey.decrypt_data_key throws IncorrectMasterKeyError and InvalidDataKeyError
            except (DecryptKeyError, IncorrectMasterKeyError, InvalidDataKeyError):
                continue
            else:
                break
        if not data_key:
            raise DecryptKeyError("Unable to decrypt any data key")
        return data_key