Source code for keystone.credential.providers.fernet.core

# 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 cryptography import fernet
from oslo_log import log

from keystone.common import fernet_utils
import keystone.conf
from keystone.credential.providers import core
from keystone import exception
from keystone.i18n import _


CONF = keystone.conf.CONF
LOG = log.getLogger(__name__)

# NOTE(lbragstad): Credential key rotation operates slightly different than
# Fernet key rotation. Each credential holds a hash of the key that encrypted
# it. This is important for credential key rotation because it helps us make
# sure we don't over-rotate credential keys. During a rotation of credential
# keys, if any credential has not been re-encrypted with the current primary
# key, we can abandon the key rotation until all credentials have been migrated
# to the new primary key. If we don't take this step, it is possible that we
# could remove a key used to encrypt credentials, leaving them recoverable.
# This also means that we don't need to expose a `[credential] max_active_keys`
# option through configuration. Instead we will use a global configuration and
# share that across all places that need to use FernetUtils for credential
# encryption.
MAX_ACTIVE_KEYS = 3


[docs]class Provider(core.Provider): @property
[docs] def crypto(self): keys = [fernet.Fernet(key) for key in self._get_encryption_keys()] return fernet.MultiFernet(keys)
def _get_encryption_keys(self): self.key_utils = fernet_utils.FernetUtils( CONF.credential.key_repository, MAX_ACTIVE_KEYS ) return self.key_utils.load_keys()
[docs] def encrypt(self, credential): """Attempt to encrypt a plaintext credential. :param credential: a plaintext representation of a credential :returns: an encrypted credential """ try: return self.crypto.encrypt(credential.encode('utf-8')) except (TypeError, ValueError): msg = _('Credential could not be encrypted. Please contact the' ' administrator') LOG.error(msg) raise exception.CredentialEncryptionError(msg)
[docs] def decrypt(self, credential): """Attempt to decrypt a credential. :param credential: an encrypted credential string :returns: a decrypted credential """ try: return self.crypto.decrypt(bytes(credential)).decode('utf-8') except (fernet.InvalidToken, TypeError, ValueError): msg = _('Credential could not be decrypted. Please contact the' ' administrator') LOG.error(msg) raise exception.CredentialEncryptionError(msg)