horizon/openstack_auth/backend.py
Rob Cresswell e3e5812b19 Add Django OpenStack Auth to Horizon
Moves Django OpenStack Auth content to Horizon, since they are so
tightly coupled. This cleans up the development workflow and should
make keystone / auth related contributions easier.

Implements: blueprint merge-openstack-auth
Change-Id: Ia1cdc47bad1ca6e633073a9f9445b0c7f70d05bc
2017-09-27 12:06:57 +01:00

284 lines
12 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.
""" Module defining the Django auth backend class for the Keystone API. """
import datetime
import logging
import pytz
from django.conf import settings
from django.utils.module_loading import import_string
from django.utils.translation import ugettext_lazy as _
from openstack_auth import exceptions
from openstack_auth import user as auth_user
from openstack_auth import utils
LOG = logging.getLogger(__name__)
KEYSTONE_CLIENT_ATTR = "_keystoneclient"
class KeystoneBackend(object):
"""Django authentication backend for use with ``django.contrib.auth``."""
def __init__(self):
self._auth_plugins = None
@property
def auth_plugins(self):
if self._auth_plugins is None:
plugins = getattr(
settings,
'AUTHENTICATION_PLUGINS',
['openstack_auth.plugin.password.PasswordPlugin',
'openstack_auth.plugin.token.TokenPlugin'])
self._auth_plugins = [import_string(p)() for p in plugins]
return self._auth_plugins
def check_auth_expiry(self, auth_ref, margin=None):
if not utils.is_token_valid(auth_ref, margin):
msg = _("The authentication token issued by the Identity service "
"has expired.")
LOG.warning("The authentication token issued by the Identity "
"service appears to have expired before it was "
"issued. This may indicate a problem with either your "
"server or client configuration.")
raise exceptions.KeystoneAuthException(msg)
return True
def get_user(self, user_id):
"""Returns the current user from the session data.
If authenticated, this return the user object based on the user ID
and session data.
.. note::
This required monkey-patching the ``contrib.auth`` middleware
to make the ``request`` object available to the auth backend class.
"""
if (hasattr(self, 'request') and
user_id == self.request.session["user_id"]):
token = self.request.session['token']
endpoint = self.request.session['region_endpoint']
services_region = self.request.session['services_region']
user = auth_user.create_user_from_token(self.request, token,
endpoint, services_region)
return user
else:
return None
def authenticate(self, auth_url=None, **kwargs):
"""Authenticates a user via the Keystone Identity API."""
LOG.debug('Beginning user authentication')
if not auth_url:
auth_url = settings.OPENSTACK_KEYSTONE_URL
auth_url, url_fixed = utils.fix_auth_url_version_prefix(auth_url)
if url_fixed:
LOG.warning("The OPENSTACK_KEYSTONE_URL setting points to a v2.0 "
"Keystone endpoint, but v3 is specified as the API "
"version to use by Horizon. Using v3 endpoint for "
"authentication.")
for plugin in self.auth_plugins:
unscoped_auth = plugin.get_plugin(auth_url=auth_url, **kwargs)
if unscoped_auth:
break
else:
msg = _('No authentication backend could be determined to '
'handle the provided credentials.')
LOG.warning('No authentication backend could be determined to '
'handle the provided credentials. This is likely a '
'configuration error that should be addressed.')
raise exceptions.KeystoneAuthException(msg)
# the recent project id a user might have set in a cookie
recent_project = None
request = kwargs.get('request')
if request:
# Grab recent_project found in the cookie, try to scope
# to the last project used.
recent_project = request.COOKIES.get('recent_project')
unscoped_auth_ref = plugin.get_access_info(unscoped_auth)
# Check expiry for our unscoped auth ref.
self.check_auth_expiry(unscoped_auth_ref)
domain_name = kwargs.get('user_domain_name', None)
domain_auth, domain_auth_ref = plugin.get_domain_scoped_auth(
unscoped_auth, unscoped_auth_ref, domain_name)
scoped_auth, scoped_auth_ref = plugin.get_project_scoped_auth(
unscoped_auth, unscoped_auth_ref, recent_project=recent_project)
# Abort if there are no projects for this user and a valid domain
# token has not been obtained
#
# The valid use cases for a user login are:
# Keystone v2: user must have a role on a project and be able
# to obtain a project scoped token
# Keystone v3: 1) user can obtain a domain scoped token (user
# has a role on the domain they authenticated to),
# only, no roles on a project
# 2) user can obtain a domain scoped token and has
# a role on a project in the domain they
# authenticated to (and can obtain a project scoped
# token)
# 3) user cannot obtain a domain scoped token, but can
# obtain a project scoped token
if not scoped_auth_ref and domain_auth_ref:
# if the user can't obtain a project scoped token, set the scoped
# token to be the domain token, if valid
scoped_auth = domain_auth
scoped_auth_ref = domain_auth_ref
elif not scoped_auth_ref and not domain_auth_ref:
msg = _('You are not authorized for any projects.')
if utils.get_keystone_version() >= 3:
msg = _('You are not authorized for any projects or domains.')
raise exceptions.KeystoneAuthException(msg)
# Check expiry for our new scoped token.
self.check_auth_expiry(scoped_auth_ref)
# We want to try to use the same region we just logged into
# which may or may not be the default depending upon the order
# keystone uses
region_name = None
id_endpoints = scoped_auth_ref.service_catalog.\
get_endpoints(service_type='identity')
for id_endpoint in [cat for cat in id_endpoints['identity']]:
if auth_url in id_endpoint.values():
region_name = id_endpoint['region']
break
interface = getattr(settings, 'OPENSTACK_ENDPOINT_TYPE', 'public')
endpoint, url_fixed = utils.fix_auth_url_version_prefix(
scoped_auth_ref.service_catalog.url_for(
service_type='identity',
interface=interface,
region_name=region_name))
if url_fixed:
LOG.warning("The Keystone URL in service catalog points to a v2.0 "
"Keystone endpoint, but v3 is specified as the API "
"version to use by Horizon. Using v3 endpoint for "
"authentication.")
# If we made it here we succeeded. Create our User!
unscoped_token = unscoped_auth_ref.auth_token
user = auth_user.create_user_from_token(
request,
auth_user.Token(scoped_auth_ref, unscoped_token=unscoped_token),
endpoint,
services_region=region_name)
if request is not None:
# if no k2k providers exist then the function returns quickly
utils.store_initial_k2k_session(auth_url, request, scoped_auth_ref,
unscoped_auth_ref)
request.session['unscoped_token'] = unscoped_token
if domain_auth_ref:
# check django session engine, if using cookies, this will not
# work, as it will overflow the cookie so don't add domain
# scoped token to the session and put error in the log
if utils.using_cookie_backed_sessions():
LOG.error('Using signed cookies as SESSION_ENGINE with '
'OPENSTACK_KEYSTONE_MULTIDOMAIN_SUPPORT is '
'enabled. This disables the ability to '
'perform identity operations due to cookie size '
'constraints.')
else:
request.session['domain_token'] = domain_auth_ref
request.user = user
timeout = getattr(settings, "SESSION_TIMEOUT", 3600)
token_life = user.token.expires - datetime.datetime.now(pytz.utc)
session_time = min(timeout, int(token_life.total_seconds()))
request.session.set_expiry(session_time)
keystone_client_class = utils.get_keystone_client().Client
session = utils.get_session()
scoped_client = keystone_client_class(session=session,
auth=scoped_auth)
# Support client caching to save on auth calls.
setattr(request, KEYSTONE_CLIENT_ATTR, scoped_client)
LOG.debug('Authentication completed.')
return user
def get_group_permissions(self, user, obj=None):
"""Returns an empty set since Keystone doesn't support "groups"."""
# Keystone V3 added "groups". The Auth token response includes the
# roles from the user's Group assignment. It should be fine just
# returning an empty set here.
return set()
def get_all_permissions(self, user, obj=None):
"""Returns a set of permission strings that the user has.
This permission available to the user is derived from the user's
Keystone "roles".
The permissions are returned as ``"openstack.{{ role.name }}"``.
"""
if user.is_anonymous() or obj is not None:
return set()
# TODO(gabrielhurley): Integrate policy-driven RBAC
# when supported by Keystone.
role_perms = {utils.get_role_permission(role['name'])
for role in user.roles}
services = []
for service in user.service_catalog:
try:
service_type = service['type']
except KeyError:
continue
service_regions = [utils.get_endpoint_region(endpoint) for endpoint
in service.get('endpoints', [])]
if user.services_region in service_regions:
services.append(service_type.lower())
service_perms = {"openstack.services.%s" % service
for service in services}
return role_perms | service_perms
def has_perm(self, user, perm, obj=None):
"""Returns True if the given user has the specified permission."""
if not user.is_active:
return False
return perm in self.get_all_permissions(user, obj)
def has_module_perms(self, user, app_label):
"""Returns True if user has any permissions in the given app_label.
Currently this matches for the app_label ``"openstack"``.
"""
if not user.is_active:
return False
for perm in self.get_all_permissions(user):
if perm[:perm.index('.')] == app_label:
return True
return False