keystone/keystone/policy/backends/rules.py

97 lines
2.9 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright (c) 2011 OpenStack, LLC.
# 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.
"""Rules-based Policy Engine."""
import os.path
from keystone.common import logging
from keystone.common import policy as common_policy
from keystone.common import utils
from keystone import config
from keystone import exception
from keystone import policy
CONF = config.CONF
LOG = logging.getLogger(__name__)
_POLICY_PATH = None
_POLICY_CACHE = {}
def reset():
global _POLICY_PATH
global _POLICY_CACHE
_POLICY_PATH = None
_POLICY_CACHE = {}
common_policy.reset()
def init():
global _POLICY_PATH
global _POLICY_CACHE
if not _POLICY_PATH:
_POLICY_PATH = CONF.policy_file
if not os.path.exists(_POLICY_PATH):
_POLICY_PATH = CONF.find_file(_POLICY_PATH)
utils.read_cached_file(_POLICY_PATH,
_POLICY_CACHE,
reload_func=_set_brain)
def _set_brain(data):
default_rule = CONF.policy_default_rule
common_policy.set_brain(common_policy.HttpBrain.load_json(data,
default_rule))
def enforce(credentials, action, target):
"""Verifies that the action is valid on the target in this context.
:param credentials: user credentials
:param action: string representing the action to be checked, which
should be colon separated for clarity.
:param target: dictionary representing the object of the action
for object creation this should be a dictionary
representing the location of the object e.g.
{'tenant_id': object.tenant_id}
:raises: `exception.Forbidden` if verification fails.
Actions should be colon separated for clarity. For example:
* compute:create_instance
* compute:attach_volume
* volume:attach_volume
"""
init()
match_list = ('rule:%s' % action,)
try:
common_policy.enforce(match_list, target, credentials)
except common_policy.NotAuthorized:
raise exception.ForbiddenAction(action=action)
class Policy(policy.Driver):
def enforce(self, credentials, action, target):
LOG.debug('enforce %s: %s', action, credentials)
enforce(credentials, action, target)