# Copyright 2018 AT&T Intellectual Property.  All other 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.


from random import SystemRandom
from rstr import Rstr
import string

__all__ = ['CryptoString']


class CryptoString(object):

    def __init__(self):
        self._pool = string.ascii_letters + string.digits + string.punctuation
        self._rs = Rstr(SystemRandom())

    def get_crypto_string(self, len=24):
        """
        Create and return a random cryptographic string,
        of the ``len`` length.
        """

        if len < 24:
            len = 24
        return self._rs.rstr(self._pool, len)