3bc725b5bd
Previously, the service user (which authenticates tokens passes to the engine by the APIs) was paired with the tenant of the end user to do authentication, which worked only when they were in the same tenant. This should not be the case, since the service user should only have an admin role in the "service" tenant. Fixes #269 Change-Id: I99b764fc489429dd6d081485bd89d5dde737c124 Signed-off-by: Zane Bitter <zbitter@redhat.com>
536 lines
18 KiB
Python
536 lines
18 KiB
Python
# vim: tabstop=4 shiftwidth=4 softtabstop=4
|
|
|
|
# Copyright 2010-2012 OpenStack LLC
|
|
#
|
|
# 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.
|
|
|
|
"""
|
|
TOKEN-BASED AUTH MIDDLEWARE
|
|
|
|
This WSGI component:
|
|
|
|
* Verifies that incoming client requests have valid tokens by validating
|
|
tokens with the auth service.
|
|
* Rejects unauthenticated requests UNLESS it is in 'delay_auth_decision'
|
|
mode, which means the final decision is delegated to the downstream WSGI
|
|
component (usually the OpenStack service)
|
|
* Collects and forwards identity information based on a valid token
|
|
such as user name, tenant, etc
|
|
|
|
Refer to: http://keystone.openstack.org/middlewarearchitecture.html
|
|
|
|
HEADERS
|
|
-------
|
|
|
|
* Headers starting with HTTP\_ is a standard http header
|
|
* Headers starting with HTTP_X is an extended http header
|
|
|
|
Coming in from initial call from client or customer
|
|
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
|
|
|
HTTP_X_AUTH_TOKEN
|
|
The client token being passed in.
|
|
|
|
HTTP_X_STORAGE_TOKEN
|
|
The client token being passed in (legacy Rackspace use) to support
|
|
swift/cloud files
|
|
|
|
Used for communication between components
|
|
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
|
|
|
WWW-Authenticate
|
|
HTTP header returned to a user indicating which endpoint to use
|
|
to retrieve a new token
|
|
|
|
What we add to the request for use by the OpenStack service
|
|
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
|
|
|
HTTP_X_IDENTITY_STATUS
|
|
'Confirmed' or 'Invalid'
|
|
The underlying service will only see a value of 'Invalid' if the Middleware
|
|
is configured to run in 'delay_auth_decision' mode
|
|
|
|
HTTP_X_TENANT_ID
|
|
Identity service managed unique identifier, string
|
|
|
|
HTTP_X_TENANT_NAME
|
|
Unique tenant identifier, string
|
|
|
|
HTTP_X_USER_ID
|
|
Identity-service managed unique identifier, string
|
|
|
|
HTTP_X_USER_NAME
|
|
Unique user identifier, string
|
|
|
|
HTTP_X_ROLES
|
|
Comma delimited list of case-sensitive Roles
|
|
|
|
HTTP_X_TENANT
|
|
*Deprecated* in favor of HTTP_X_TENANT_ID and HTTP_X_TENANT_NAME
|
|
Keystone-assigned unique identifier, deprecated
|
|
|
|
HTTP_X_USER
|
|
*Deprecated* in favor of HTTP_X_USER_ID and HTTP_X_USER_NAME
|
|
Unique user name, string
|
|
|
|
HTTP_X_ROLE
|
|
*Deprecated* in favor of HTTP_X_ROLES
|
|
This is being renamed, and the new header contains the same data.
|
|
|
|
"""
|
|
|
|
import httplib
|
|
import json
|
|
import logging
|
|
import time
|
|
|
|
import webob
|
|
import webob.exc
|
|
|
|
|
|
LOG = logging.getLogger(__name__)
|
|
|
|
|
|
class InvalidUserToken(Exception):
|
|
pass
|
|
|
|
|
|
class ServiceError(Exception):
|
|
pass
|
|
|
|
|
|
class AuthProtocol(object):
|
|
"""Auth Middleware that handles authenticating client calls."""
|
|
|
|
def __init__(self, app, conf):
|
|
LOG.info('Starting keystone auth_token middleware')
|
|
self.conf = conf
|
|
self.app = app
|
|
|
|
# delay_auth_decision means we still allow unauthenticated requests
|
|
# through and we let the downstream service make the final decision
|
|
self.delay_auth_decision = int(conf.get('delay_auth_decision', 0))
|
|
|
|
# where to find the auth service (we use this to validate tokens)
|
|
self.auth_host = conf.get('auth_host')
|
|
self.auth_port = int(conf.get('auth_port', 35357))
|
|
auth_protocol = conf.get('auth_protocol', 'https')
|
|
if auth_protocol == 'http':
|
|
self.http_client_class = httplib.HTTPConnection
|
|
else:
|
|
self.http_client_class = httplib.HTTPSConnection
|
|
|
|
default_auth_uri = '%s://%s:%s' % (auth_protocol,
|
|
self.auth_host,
|
|
self.auth_port)
|
|
self.auth_uri = conf.get('auth_uri', default_auth_uri)
|
|
|
|
# Credentials used to verify this component with the Auth service since
|
|
# validating tokens is a privileged call
|
|
self.admin_token = conf.get('admin_token')
|
|
self.admin_user = conf.get('admin_user')
|
|
self.admin_password = conf.get('admin_password')
|
|
self.admin_tenant_name = conf.get('admin_tenant_name', 'admin')
|
|
|
|
# Token caching via memcache
|
|
self._cache = None
|
|
self._iso8601 = None
|
|
memcache_servers = conf.get('memcache_servers')
|
|
# By default the token will be cached for 5 minutes
|
|
self.token_cache_time = conf.get('token_cache_time', 300)
|
|
if memcache_servers:
|
|
try:
|
|
import memcache
|
|
import iso8601
|
|
LOG.info('Using memcache for caching token')
|
|
self._cache = memcache.Client(memcache_servers.split(','))
|
|
self._iso8601 = iso8601
|
|
except NameError as e:
|
|
LOG.warn('disabled caching due to missing libraries %s', e)
|
|
|
|
def __call__(self, env, start_response):
|
|
"""Handle incoming request.
|
|
|
|
Authenticate send downstream on success. Reject request if
|
|
we can't authenticate.
|
|
|
|
"""
|
|
LOG.debug('Authenticating user token')
|
|
try:
|
|
self._remove_auth_headers(env)
|
|
user_token = self._get_user_token_from_header(env)
|
|
token_info = self._validate_user_token(user_token)
|
|
user_headers = self._build_user_headers(token_info)
|
|
self._add_headers(env, user_headers)
|
|
return self.app(env, start_response)
|
|
|
|
except InvalidUserToken:
|
|
if self.delay_auth_decision:
|
|
LOG.info('Invalid user token - deferring reject downstream')
|
|
self._add_headers(env, {'X-Identity-Status': 'Invalid'})
|
|
return self.app(env, start_response)
|
|
else:
|
|
LOG.info('Invalid user token - rejecting request')
|
|
return self._reject_request(env, start_response)
|
|
|
|
except ServiceError, e:
|
|
LOG.critical('Unable to obtain admin token: %s' % e)
|
|
resp = webob.exc.HTTPServiceUnavailable()
|
|
return resp(env, start_response)
|
|
|
|
def _remove_auth_headers(self, env):
|
|
"""Remove headers so a user can't fake authentication.
|
|
|
|
:param env: wsgi request environment
|
|
|
|
"""
|
|
auth_headers = (
|
|
'X-Identity-Status',
|
|
'X-Tenant-Id',
|
|
'X-Tenant-Name',
|
|
'X-User-Id',
|
|
'X-User-Name',
|
|
'X-Roles',
|
|
# Deprecated
|
|
'X-User',
|
|
'X-Tenant',
|
|
'X-Role',
|
|
)
|
|
LOG.debug('Removing headers from request environment: %s' %
|
|
','.join(auth_headers))
|
|
self._remove_headers(env, auth_headers)
|
|
|
|
def _get_user_token_from_header(self, env):
|
|
"""Get token id from request.
|
|
|
|
:param env: wsgi request environment
|
|
:return token id
|
|
:raises InvalidUserToken if no token is provided in request
|
|
|
|
"""
|
|
token = self._get_header(env, 'X-Auth-Token',
|
|
self._get_header(env, 'X-Storage-Token'))
|
|
if token:
|
|
return token
|
|
else:
|
|
LOG.warn("Unable to find authentication token in headers: %s", env)
|
|
raise InvalidUserToken('Unable to find token in headers')
|
|
|
|
def _reject_request(self, env, start_response):
|
|
"""Redirect client to auth server.
|
|
|
|
:param env: wsgi request environment
|
|
:param start_response: wsgi response callback
|
|
:returns HTTPUnauthorized http response
|
|
|
|
"""
|
|
headers = [('WWW-Authenticate', 'Keystone uri=\'%s\'' % self.auth_uri)]
|
|
resp = webob.exc.HTTPUnauthorized('Authentication required', headers)
|
|
return resp(env, start_response)
|
|
|
|
def get_admin_token(self):
|
|
"""Return admin token, possibly fetching a new one.
|
|
|
|
:return admin token id
|
|
:raise ServiceError when unable to retrieve token from keystone
|
|
|
|
"""
|
|
if not self.admin_token:
|
|
self.admin_token = self._request_admin_token()
|
|
|
|
return self.admin_token
|
|
|
|
def _get_http_connection(self):
|
|
return self.http_client_class(self.auth_host, self.auth_port)
|
|
|
|
def _json_request(self, method, path, body=None, additional_headers=None):
|
|
"""HTTP request helper used to make json requests.
|
|
|
|
:param method: http method
|
|
:param path: relative request url
|
|
:param body: dict to encode to json as request body. Optional.
|
|
:param additional_headers: dict of additional headers to send with
|
|
http request. Optional.
|
|
:return (http response object, response body parsed as json)
|
|
:raise ServerError when unable to communicate with keystone
|
|
|
|
"""
|
|
conn = self._get_http_connection()
|
|
|
|
kwargs = {
|
|
'headers': {
|
|
'Content-type': 'application/json',
|
|
'Accept': 'application/json',
|
|
},
|
|
}
|
|
|
|
if additional_headers:
|
|
kwargs['headers'].update(additional_headers)
|
|
|
|
if body:
|
|
kwargs['body'] = json.dumps(body)
|
|
|
|
try:
|
|
conn.request(method, path, **kwargs)
|
|
response = conn.getresponse()
|
|
body = response.read()
|
|
except Exception, e:
|
|
LOG.error('HTTP connection exception: %s' % e)
|
|
raise ServiceError('Unable to communicate with keystone')
|
|
finally:
|
|
conn.close()
|
|
|
|
try:
|
|
data = json.loads(body)
|
|
except ValueError:
|
|
LOG.debug('Keystone did not return json-encoded body')
|
|
data = {}
|
|
|
|
return response, data
|
|
|
|
def _request_admin_token(self):
|
|
"""Retrieve new token as admin user from keystone.
|
|
|
|
:return token id upon success
|
|
:raises ServerError when unable to communicate with keystone
|
|
|
|
"""
|
|
params = {
|
|
'auth': {
|
|
'passwordCredentials': {
|
|
'username': self.admin_user,
|
|
'password': self.admin_password,
|
|
},
|
|
'tenantName': self.admin_tenant_name,
|
|
}
|
|
}
|
|
|
|
response, data = self._json_request('POST',
|
|
'/v2.0/tokens',
|
|
body=params)
|
|
|
|
try:
|
|
token = data['access']['token']['id']
|
|
assert token
|
|
return token
|
|
except (AssertionError, KeyError):
|
|
LOG.warn("Unexpected response from keystone service: %s", data)
|
|
raise ServiceError('invalid json response')
|
|
|
|
def _validate_user_token(self, user_token, retry=True):
|
|
"""Authenticate user token with keystone.
|
|
|
|
:param user_token: user's token id
|
|
:param retry: flag that forces the middleware to retry
|
|
user authentication when an indeterminate
|
|
response is received. Optional.
|
|
:return token object received from keystone on success
|
|
:raise InvalidUserToken if token is rejected
|
|
:raise ServiceError if unable to authenticate token
|
|
|
|
"""
|
|
cached = self._cache_get(user_token)
|
|
if cached:
|
|
return cached
|
|
|
|
headers = {'X-Auth-Token': self.get_admin_token()}
|
|
response, data = self._json_request('GET',
|
|
'/v2.0/tokens/%s' % user_token,
|
|
additional_headers=headers)
|
|
|
|
if response.status == 200:
|
|
self._cache_put(user_token, data)
|
|
return data
|
|
if response.status == 404:
|
|
# FIXME(ja): I'm assuming the 404 status means that user_token is
|
|
# invalid - not that the admin_token is invalid
|
|
self._cache_store_invalid(user_token)
|
|
LOG.warn("Authorization failed for token %s", user_token)
|
|
raise InvalidUserToken('Token authorization failed')
|
|
if response.status == 401:
|
|
LOG.info('Keystone rejected admin token %s, resetting', headers)
|
|
self.admin_token = None
|
|
else:
|
|
LOG.error('Bad response code while validating token: %s' %
|
|
response.status)
|
|
if retry:
|
|
LOG.info('Retrying validation')
|
|
return self._validate_user_token(user_token, False)
|
|
else:
|
|
LOG.warn("Invalid user token: %s. Keystone response: %s.",
|
|
user_token, data)
|
|
|
|
raise InvalidUserToken()
|
|
|
|
def _build_user_headers(self, token_info):
|
|
"""Convert token object into headers.
|
|
|
|
Build headers that represent authenticated user:
|
|
* X_IDENTITY_STATUS: Confirmed or Invalid
|
|
* X_TENANT_ID: id of tenant if tenant is present
|
|
* X_TENANT_NAME: name of tenant if tenant is present
|
|
* X_USER_ID: id of user
|
|
* X_USER_NAME: name of user
|
|
* X_ROLES: list of roles
|
|
|
|
Additional (deprecated) headers include:
|
|
* X_USER: name of user
|
|
* X_TENANT: For legacy compatibility before we had ID and Name
|
|
* X_ROLE: list of roles
|
|
|
|
:param token_info: token object returned by keystone on authentication
|
|
:raise InvalidUserToken when unable to parse token object
|
|
|
|
"""
|
|
user = token_info['access']['user']
|
|
token = token_info['access']['token']
|
|
roles = ','.join([role['name'] for role in user.get('roles', [])])
|
|
|
|
def get_tenant_info():
|
|
"""Returns a (tenant_id, tenant_name) tuple from context."""
|
|
def essex():
|
|
"""Essex puts the tenant ID and name on the token."""
|
|
return (token['tenant']['id'], token['tenant']['name'])
|
|
|
|
def pre_diablo():
|
|
"""Pre-diablo, Keystone only provided tenantId."""
|
|
return (token['tenantId'], token['tenantId'])
|
|
|
|
def default_tenant():
|
|
"""Assume the user's default tenant."""
|
|
return (user['tenantId'], user['tenantName'])
|
|
|
|
for method in [essex, pre_diablo, default_tenant]:
|
|
try:
|
|
return method()
|
|
except KeyError:
|
|
pass
|
|
|
|
raise InvalidUserToken('Unable to determine tenancy.')
|
|
|
|
tenant_id, tenant_name = get_tenant_info()
|
|
|
|
user_id = user['id']
|
|
user_name = user['name']
|
|
|
|
return {
|
|
'X-Identity-Status': 'Confirmed',
|
|
'X-Tenant-Id': tenant_id,
|
|
'X-Tenant-Name': tenant_name,
|
|
'X-User-Id': user_id,
|
|
'X-User-Name': user_name,
|
|
'X-Roles': roles,
|
|
# Deprecated
|
|
'X-User': user_name,
|
|
'X-Tenant': tenant_name,
|
|
'X-Role': roles,
|
|
'X-Admin-User': self.admin_user,
|
|
'X-Admin-Pass': self.admin_password,
|
|
'X-Admin-Tenant-Name': self.admin_tenant_name,
|
|
'X-Auth-Url': self.conf['auth_uri'],
|
|
}
|
|
|
|
def _header_to_env_var(self, key):
|
|
"""Convert header to wsgi env variable.
|
|
|
|
:param key: http header name (ex. 'X-Auth-Token')
|
|
:return wsgi env variable name (ex. 'HTTP_X_AUTH_TOKEN')
|
|
|
|
"""
|
|
return 'HTTP_%s' % (key.replace('-', '_').upper())
|
|
|
|
def _add_headers(self, env, headers):
|
|
"""Add http headers to environment."""
|
|
for (k, v) in headers.iteritems():
|
|
env_key = self._header_to_env_var(k)
|
|
env[env_key] = v
|
|
|
|
def _remove_headers(self, env, keys):
|
|
"""Remove http headers from environment."""
|
|
for k in keys:
|
|
env_key = self._header_to_env_var(k)
|
|
try:
|
|
del env[env_key]
|
|
except KeyError:
|
|
pass
|
|
|
|
def _get_header(self, env, key, default=None):
|
|
"""Get http header from environment."""
|
|
env_key = self._header_to_env_var(key)
|
|
return env.get(env_key, default)
|
|
|
|
def _cache_get(self, token):
|
|
"""Return token information from cache.
|
|
|
|
If token is invalid raise InvalidUserToken
|
|
return token only if fresh (not expired).
|
|
"""
|
|
if self._cache and token:
|
|
key = 'tokens/%s' % token
|
|
cached = self._cache.get(key)
|
|
if cached == 'invalid':
|
|
LOG.debug('Cached Token %s is marked unauthorized', token)
|
|
raise InvalidUserToken('Token authorization failed')
|
|
if cached:
|
|
data, expires = cached
|
|
if time.time() < float(expires):
|
|
LOG.debug('Returning cached token %s', token)
|
|
return data
|
|
else:
|
|
LOG.debug('Cached Token %s seems expired', token)
|
|
|
|
def _cache_put(self, token, data):
|
|
"""Put token data into the cache.
|
|
|
|
Stores the parsed expire date in cache allowing
|
|
quick check of token freshness on retrieval.
|
|
"""
|
|
if self._cache and data:
|
|
key = 'tokens/%s' % token
|
|
if 'token' in data.get('access', {}):
|
|
timestamp = data['access']['token']['expires']
|
|
expires = self._iso8601.parse_date(timestamp).strftime('%s')
|
|
else:
|
|
LOG.error('invalid token format')
|
|
return
|
|
LOG.debug('Storing %s token in memcache', token)
|
|
self._cache.set(key,
|
|
(data, expires),
|
|
time=self.token_cache_time)
|
|
|
|
def _cache_store_invalid(self, token):
|
|
"""Store invalid token in cache."""
|
|
if self._cache:
|
|
key = 'tokens/%s' % token
|
|
LOG.debug('Marking token %s as unauthorized in memcache', token)
|
|
self._cache.set(key,
|
|
'invalid',
|
|
time=self.token_cache_time)
|
|
|
|
|
|
def filter_factory(global_conf, **local_conf):
|
|
"""Returns a WSGI filter app for use with paste.deploy."""
|
|
conf = global_conf.copy()
|
|
conf.update(local_conf)
|
|
|
|
def auth_filter(app):
|
|
return AuthProtocol(app, conf)
|
|
return auth_filter
|
|
|
|
|
|
def app_factory(global_conf, **local_conf):
|
|
conf = global_conf.copy()
|
|
conf.update(local_conf)
|
|
return AuthProtocol(None, conf)
|