# Copyright (c) 2015 The Johns Hopkins University/Applied Physics Laboratory
# All Rights Reserved.
#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.

"""
Base Key Class

This module defines the Key class. The Key class is the base class to
represent all encryption keys. The basis for this class was copied
from Java.
"""

from castellan.common.objects import managed_object

import abc

import six


@six.add_metaclass(abc.ABCMeta)
class Key(managed_object.ManagedObject):
    """Base class to represent all keys."""

    @abc.abstractproperty
    def algorithm(self):
        """Returns the key's algorithm.

        Returns the key's algorithm. For example, "DSA" indicates that this key
        is a DSA key and "AES" indicates that this key is an AES key.
        """
        pass

    @abc.abstractproperty
    def bit_length(self):
        """Returns the key's bit length.

        Returns the key's bit length. For example, for AES symmetric keys,
        this refers to the length of the key, and for RSA keys, this refers to
        the length of the modulus.
        """
        pass