# Copyright 2012 OpenStack Foundation # Copyright 2010 United States Government as represented by the # Administrator of the National Aeronautics and Space Administration. # Copyright 2011,2012 Akira YOSHIYAMA # 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. # This source code is based ./auth_token.py and ./ec2_token.py. # See them for their copyright. """ S3 Token Middleware. This WSGI component: * Gets a request from the swift3 middleware with an S3 Authorization access key. * Validates s3 token in Keystone. * Transforms the account name to AUTH_%(tenant_name). """ import webob from oslo_config import cfg from oslo_log import log as logging from oslo_serialization import jsonutils from oslo_utils import strutils import requests s3_opts = [ cfg.IntOpt('timeout', default=60, help='Timeout to obtain token.'), ] CONF = cfg.CONF CONF.register_opts(s3_opts, group='s3_token') PROTOCOL_NAME = 'S3 Token Authentication' class ServiceError(Exception): pass class S3Token(object): """Middleware that handles S3 authentication.""" def __init__(self, app, conf): """Common initialization code.""" self._app = app self._logger = logging.getLogger(conf.get('log_name', __name__)) self._logger.debug('Starting the %s component', PROTOCOL_NAME) self._reseller_prefix = conf.get('reseller_prefix', 'AUTH_') # where to find the auth service (we use this to validate tokens) self._request_uri = conf.get('www_authenticate_uri') auth_uri = conf.get('auth_uri') if not self._request_uri and auth_uri: self._logger.warning( "Use of the auth_uri option was deprecated " "in the Queens release in favor of www_authenticate_uri. This " "option will be removed in the S release.") self._request_uri = auth_uri if not self._request_uri: self._logger.warning( "Use of the auth_host, auth_port, and auth_protocol " "configuration options was deprecated in the Newton release " "in favor of www_authenticate_uri. These options will be " "removed in the S release.") auth_host = conf.get('auth_host') auth_port = int(conf.get('auth_port', 35357)) auth_protocol = conf.get('auth_protocol', 'https') self._request_uri = '%s://%s:%s' % (auth_protocol, auth_host, auth_port) # SSL insecure = strutils.bool_from_string(conf.get('insecure', False)) cert_file = conf.get('certfile') key_file = conf.get('keyfile') if insecure: self._verify = False elif cert_file and key_file: self._verify = (cert_file, key_file) elif cert_file: self._verify = cert_file else: self._verify = None def _deny_request(self, code): error_table = { 'AccessDenied': (401, 'Access denied'), 'InvalidURI': (400, 'Could not parse the specified URI'), } resp = webob.Response(content_type='text/xml') resp.status = error_table[code][0] error_msg = ('\r\n' '\r\n %s\r\n ' '%s\r\n\r\n' % (code, error_table[code][1])) error_msg = error_msg.encode() resp.body = error_msg return resp def _json_request(self, creds_json): headers = {'Content-Type': 'application/json'} try: response = requests.post('%s/v3/s3tokens' % self._request_uri, headers=headers, data=creds_json, verify=self._verify, timeout=CONF.s3_token.timeout) except requests.exceptions.RequestException as e: self._logger.info('HTTP connection exception: %s', e) resp = self._deny_request('InvalidURI') raise ServiceError(resp) if response.status_code < 200 or response.status_code >= 300: self._logger.debug('Keystone reply error: status=%s reason=%s', response.status_code, response.reason) resp = self._deny_request('AccessDenied') raise ServiceError(resp) return response def __call__(self, environ, start_response): """Handle incoming request. authenticate and send downstream.""" req = webob.Request(environ) self._logger.debug('Calling S3Token middleware.') try: parts = strutils.split_path(req.path, 1, 4, True) version, account, container, obj = parts except ValueError: msg = 'Not a path query, skipping.' self._logger.debug(msg) return self._app(environ, start_response) # Read request signature and access id. if 'Authorization' not in req.headers: msg = 'No Authorization header. skipping.' self._logger.debug(msg) return self._app(environ, start_response) token = req.headers.get('X-Auth-Token', req.headers.get('X-Storage-Token')) if not token: msg = 'You did not specify an auth or a storage token. skipping.' self._logger.debug(msg) return self._app(environ, start_response) auth_header = req.headers['Authorization'] try: access, signature = auth_header.split(' ')[-1].rsplit(':', 1) except ValueError: msg = 'You have an invalid Authorization header: %s' self._logger.debug(msg, auth_header) return self._deny_request('InvalidURI')(environ, start_response) # NOTE(chmou): This is to handle the special case with nova # when we have the option s3_affix_tenant. We will force it to # connect to another account than the one # authenticated. Before people start getting worried about # security, I should point that we are connecting with # username/token specified by the user but instead of # connecting to its own account we will force it to go to an # another account. In a normal scenario if that user don't # have the reseller right it will just fail but since the # reseller account can connect to every account it is allowed # by the swift_auth middleware. force_tenant = None if ':' in access: access, force_tenant = access.split(':') # Authenticate request. creds = {'credentials': {'access': access, 'token': token, 'signature': signature}} creds_json = jsonutils.dumps(creds) self._logger.debug('Connecting to Keystone sending this JSON: %s', creds_json) # NOTE(vish): We could save a call to keystone by having # keystone return token, tenant, user, and roles # from this call. # # NOTE(chmou): We still have the same problem we would need to # change token_auth to detect if we already # identified and not doing a second query and just # pass it through to swiftauth in this case. try: resp = self._json_request(creds_json) except ServiceError as e: resp = e.args[0] msg = 'Received error, exiting middleware with error: %s' self._logger.debug(msg, resp.status_code) return resp(environ, start_response) self._logger.debug('Keystone Reply: Status: %d, Output: %s', resp.status_code, resp.content) try: identity_info = resp.json() token_id = str(identity_info['access']['token']['id']) tenant = identity_info['access']['token']['tenant'] except (ValueError, KeyError): error = 'Error on keystone reply: %d %s' self._logger.debug(error, resp.status_code, resp.content) return self._deny_request('InvalidURI')(environ, start_response) req.headers['X-Auth-Token'] = token_id tenant_to_connect = force_tenant or tenant['id'] self._logger.debug('Connecting with tenant: %s', tenant_to_connect) new_tenant_name = '%s%s' % (self._reseller_prefix, tenant_to_connect) environ['PATH_INFO'] = environ['PATH_INFO'].replace(account, new_tenant_name) return self._app(environ, start_response) def filter_factory(global_conf, **local_conf): """Return a WSGI filter app for use with paste.deploy.""" conf = global_conf.copy() conf.update(local_conf) def auth_filter(app): return S3Token(app, conf) return auth_filter