horizon/openstack_auth/policy.py

302 lines
11 KiB
Python

#
# 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.
"""Policy engine for openstack_auth"""
import logging
import os.path
from django.conf import settings
from oslo_config import cfg
from oslo_policy import opts as policy_opts
from oslo_policy import policy
import yaml
from openstack_auth import user as auth_user
from openstack_auth import utils as auth_utils
LOG = logging.getLogger(__name__)
_ENFORCER = None
_BASE_PATH = settings.POLICY_FILES_PATH
def _get_policy_conf(policy_file, policy_dirs=None):
conf = cfg.ConfigOpts()
# Passing [] is required. Otherwise oslo.config looks up sys.argv.
conf([])
policy_opts.set_defaults(conf)
conf.set_default('policy_file', policy_file, 'oslo_policy')
# Policy Enforcer has been updated to take in a policy directory
# as a config option. However, the default value in is set to
# ['policy.d'] which causes the code to break. Set the default
# value to empty list for now.
if policy_dirs is None:
policy_dirs = []
conf.set_default('policy_dirs', policy_dirs, 'oslo_policy')
return conf
def _get_policy_file_with_full_path(service):
policy_files = settings.POLICY_FILES
policy_file = os.path.join(_BASE_PATH, policy_files[service])
policy_dirs = settings.POLICY_DIRS.get(service, [])
policy_dirs = [os.path.join(_BASE_PATH, policy_dir)
for policy_dir in policy_dirs]
return policy_file, policy_dirs
def _convert_to_ruledefault(p):
deprecated = p.get('deprecated_rule')
if deprecated:
deprecated_rule = policy.DeprecatedRule(deprecated['name'],
deprecated['check_str'])
else:
deprecated_rule = None
return policy.RuleDefault(
p['name'], p['check_str'],
description=p['description'],
scope_types=p['scope_types'],
deprecated_rule=deprecated_rule,
deprecated_for_removal=p.get('deprecated_for_removal', False),
deprecated_reason=p.get('deprecated_reason'),
deprecated_since=p.get('deprecated_since'),
)
def _load_default_rules(service, enforcer):
policy_files = settings.DEFAULT_POLICY_FILES
try:
policy_file = os.path.join(_BASE_PATH, policy_files[service])
except KeyError:
LOG.error('Default policy file for %s is not defined. '
'Check DEFAULT_POLICY_FILES setting.', service)
return
try:
with open(policy_file) as f:
policies = yaml.safe_load(f)
except IOError as e:
LOG.error('Failed to open the policy file for %(service)s %(path)s: '
'%(reason)s',
{'service': service, 'path': policy_file, 'reason': e})
return
except yaml.YAMLError as e:
LOG.error('Failed to load the default policies for %(service)s: '
'%(reason)s', {'service': service, 'reason': e})
return
defaults = [_convert_to_ruledefault(p) for p in policies]
enforcer.register_defaults(defaults)
def _get_enforcer():
global _ENFORCER
if not _ENFORCER:
_ENFORCER = {}
policy_files = settings.POLICY_FILES
for service in policy_files.keys():
policy_file, policy_dirs = _get_policy_file_with_full_path(service)
conf = _get_policy_conf(policy_file, policy_dirs)
enforcer = policy.Enforcer(conf)
enforcer.suppress_default_change_warnings = True
_load_default_rules(service, enforcer)
try:
enforcer.load_rules()
except IOError:
# Just in case if we have permission denied error which is not
# handled by oslo.policy now. It will handled in the code like
# we don't have any policy file: allow action from the Horizon
# side.
LOG.warning("Cannot load a policy file '%s' for service '%s' "
"due to IOError. One possible reason is "
"permission denied.", policy_file, service)
except ValueError:
LOG.warning("Cannot load a policy file '%s' for service '%s' "
"due to ValueError. The file might be wrongly "
"formatted.", policy_file, service)
# Ensure enforcer.rules is populated.
if enforcer.rules:
LOG.debug("adding enforcer for service: %s", service)
_ENFORCER[service] = enforcer
else:
locations = policy_file
if policy_dirs:
locations += ' and files under %s' % policy_dirs
LOG.warning("No policy rules for service '%s' in %s",
service, locations)
return _ENFORCER
def reset():
global _ENFORCER
_ENFORCER = None
def check(actions, request, target=None):
"""Check user permission.
Check if the user has permission to the action according
to policy setting.
:param actions: list of scope and action to do policy checks on,
the composition of which is (scope, action). Multiple actions
are treated as a logical AND.
* scope: service type managing the policy for action
* action: string representing the action to be checked
this should be colon separated for clarity.
i.e.
| compute:create_instance
| compute:attach_volume
| volume:attach_volume
for a policy action that requires a single action, actions
should look like
| "(("compute", "compute:create_instance"),)"
for a multiple action check, actions should look like
| "(("identity", "identity:list_users"),
| ("identity", "identity:list_roles"))"
:param request: django http request object. If not specified, credentials
must be passed.
: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.
{'project_id': object.project_id}
:returns: boolean if the user has permission or not for the actions.
"""
if target is None:
target = {}
user = auth_utils.get_user(request)
# Several service policy engines default to a project id check for
# ownership. Since the user is already scoped to a project, if a
# different project id has not been specified use the currently scoped
# project's id.
#
# The reason is the operator can edit the local copies of the service
# policy file. If a rule is removed, then the default rule is used. We
# don't want to block all actions because the operator did not fully
# understand the implication of editing the policy file. Additionally,
# the service APIs will correct us if we are too permissive.
if target.get('project_id') is None:
target['project_id'] = user.project_id
if target.get('tenant_id') is None:
target['tenant_id'] = target['project_id']
# same for user_id
if target.get('user_id') is None:
target['user_id'] = user.id
domain_id_keys = [
'domain_id',
'project.domain_id',
'user.domain_id',
'group.domain_id'
]
# populates domain id keys with user's current domain id
for key in domain_id_keys:
if target.get(key) is None:
target[key] = user.user_domain_id
credentials = _user_to_credentials(user)
domain_credentials = _domain_to_credentials(request, user)
# if there is a domain token use the domain_id instead of the user's domain
if domain_credentials:
credentials['domain_id'] = domain_credentials.get('domain_id')
enforcer = _get_enforcer()
for action in actions:
scope, action = action[0], action[1]
if scope in enforcer:
# this is for handling the v3 policy file and will only be
# needed when a domain scoped token is present
if scope == 'identity' and domain_credentials:
# use domain credentials
if not _check_credentials(enforcer[scope],
action,
target,
domain_credentials):
return False
# use project credentials
if not _check_credentials(enforcer[scope],
action, target, credentials):
return False
# if no policy for scope, allow action, underlying API will
# ultimately block the action if not permitted, treat as though
# allowed
return True
def _check_credentials(enforcer_scope, action, target, credentials):
is_valid = True
if not enforcer_scope.enforce(action, target, credentials):
# to match service implementations, if a rule is not found,
# use the default rule for that service policy
#
# waiting to make the check because the first call to
# enforce loads the rules
if action not in enforcer_scope.rules:
if not enforcer_scope.enforce('default', target, credentials):
if 'default' in enforcer_scope.rules:
is_valid = False
else:
is_valid = False
return is_valid
def _user_to_credentials(user):
if not hasattr(user, "_credentials"):
roles = [role['name'] for role in user.roles]
user._credentials = {'user_id': user.id,
'username': user.username,
'project_id': user.project_id,
'tenant_id': user.project_id,
'project_name': user.project_name,
'domain_id': user.user_domain_id,
'is_admin': user.is_superuser,
'roles': roles}
return user._credentials
def _domain_to_credentials(request, user):
if not hasattr(user, "_domain_credentials"):
try:
domain_auth_ref = request.session.get('domain_token')
# no domain role or not running on V3
if not domain_auth_ref:
return None
domain_user = auth_user.create_user_from_token(
request, auth_user.Token(domain_auth_ref),
domain_auth_ref.service_catalog.url_for(interface=None))
user._domain_credentials = _user_to_credentials(domain_user)
# uses the domain_id associated with the domain_user
user._domain_credentials['domain_id'] = domain_user.domain_id
except Exception:
LOG.warning("Failed to create user from domain scoped token.")
return None
return user._domain_credentials