# # 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. import hashlib from oslo.config import cfg import requests import webob from heat.api.aws import exception from heat.api.aws.exception import HeatAPIException from heat.common import wsgi from heat.openstack.common import gettextutils from heat.openstack.common.gettextutils import _ from heat.openstack.common import importutils from heat.openstack.common import jsonutils as json from heat.openstack.common import log as logging gettextutils.install('heat') LOG = logging.getLogger(__name__) opts = [ cfg.StrOpt('auth_uri', help=_("Authentication Endpoint URI.")), cfg.BoolOpt('multi_cloud', default=False, help=_('Allow orchestration of multiple clouds.')), cfg.ListOpt('allowed_auth_uris', default=[], help=_('Allowed keystone endpoints for auth_uri when ' 'multi_cloud is enabled. At least one endpoint needs ' 'to be specified.')) ] cfg.CONF.register_opts(opts, group='ec2authtoken') class EC2Token(wsgi.Middleware): """Authenticate an EC2 request with keystone and convert to token.""" def __init__(self, app, conf): self.conf = conf self.application = app def _conf_get(self, name): # try config from paste-deploy first if name in self.conf: return self.conf[name] else: return cfg.CONF.ec2authtoken[name] def _conf_get_auth_uri(self): auth_uri = self._conf_get('auth_uri') if auth_uri: return auth_uri else: # Import auth_token to have keystone_authtoken settings setup. # We can use the auth_uri from the keystone_authtoken section importutils.import_module('keystoneclient.middleware.auth_token') return cfg.CONF.keystone_authtoken['auth_uri'] @staticmethod def _conf_get_keystone_ec2_uri(auth_uri): if auth_uri.endswith('ec2tokens'): return auth_uri if auth_uri.endswith('/'): return '%sec2tokens' % auth_uri return '%s/ec2tokens' % auth_uri def _get_signature(self, req): """ Extract the signature from the request, this can be a get/post variable or for v4 also in a header called 'Authorization' - params['Signature'] == version 0,1,2,3 - params['X-Amz-Signature'] == version 4 - header 'Authorization' == version 4 """ sig = req.params.get('Signature') or req.params.get('X-Amz-Signature') if sig is None and 'Authorization' in req.headers: auth_str = req.headers['Authorization'] sig = auth_str.partition("Signature=")[2].split(',')[0] return sig def _get_access(self, req): """ Extract the access key identifier, for v 0/1/2/3 this is passed as the AccessKeyId parameter, for version4 it is either and X-Amz-Credential parameter or a Credential= field in the 'Authorization' header string """ access = req.params.get('AWSAccessKeyId') if access is None: cred_param = req.params.get('X-Amz-Credential') if cred_param: access = cred_param.split("/")[0] if access is None and 'Authorization' in req.headers: auth_str = req.headers['Authorization'] cred_str = auth_str.partition("Credential=")[2].split(',')[0] access = cred_str.split("/")[0] return access @webob.dec.wsgify(RequestClass=wsgi.Request) def __call__(self, req): if not self._conf_get('multi_cloud'): return self._authorize(req, self._conf_get_auth_uri()) else: # attempt to authorize for each configured allowed_auth_uris # until one is successful. # This is safe for the following reasons: # 1. AWSAccessKeyId is a randomly generated sequence # 2. No secret is transferred to validate a request last_failure = None for auth_uri in self._conf_get('allowed_auth_uris'): try: LOG.debug("Attempt authorize on %s" % auth_uri) return self._authorize(req, auth_uri) except HeatAPIException as e: LOG.debug("Authorize failed: %s" % e.__class__) last_failure = e raise last_failure or exception.HeatAccessDeniedError() def _authorize(self, req, auth_uri): # Read request signature and access id. # If we find X-Auth-User in the headers we ignore a key error # here so that we can use both authentication methods. # Returning here just means the user didn't supply AWS # authentication and we'll let the app try native keystone next. LOG.info(_("Checking AWS credentials..")) signature = self._get_signature(req) if not signature: if 'X-Auth-User' in req.headers: return self.application else: LOG.info(_("No AWS Signature found.")) raise exception.HeatIncompleteSignatureError() access = self._get_access(req) if not access: if 'X-Auth-User' in req.headers: return self.application else: LOG.info(_("No AWSAccessKeyId/Authorization Credential")) raise exception.HeatMissingAuthenticationTokenError() LOG.info(_("AWS credentials found, checking against keystone.")) if not auth_uri: LOG.error(_("Ec2Token authorization failed, no auth_uri " "specified in config file")) raise exception.HeatInternalFailureError(_('Service ' 'misconfigured')) # Make a copy of args for authentication and signature verification. auth_params = dict(req.params) # 'Signature' param Not part of authentication args auth_params.pop('Signature', None) # Authenticate the request. # AWS v4 authentication requires a hash of the body body_hash = hashlib.sha256(req.body).hexdigest() creds = {'ec2Credentials': {'access': access, 'signature': signature, 'host': req.host, 'verb': req.method, 'path': req.path, 'params': auth_params, 'headers': req.headers, 'body_hash': body_hash }} creds_json = json.dumps(creds) headers = {'Content-Type': 'application/json'} keystone_ec2_uri = self._conf_get_keystone_ec2_uri(auth_uri) LOG.info(_('Authenticating with %s') % keystone_ec2_uri) response = requests.post(keystone_ec2_uri, data=creds_json, headers=headers) result = response.json() try: token_id = result['access']['token']['id'] tenant = result['access']['token']['tenant']['name'] tenant_id = result['access']['token']['tenant']['id'] LOG.info(_("AWS authentication successful.")) except (AttributeError, KeyError): LOG.info(_("AWS authentication failure.")) # Try to extract the reason for failure so we can return the # appropriate AWS error via raising an exception try: reason = result['error']['message'] except KeyError: reason = None if reason == "EC2 access key not found.": raise exception.HeatInvalidClientTokenIdError() elif reason == "EC2 signature not supplied.": raise exception.HeatSignatureError() else: raise exception.HeatAccessDeniedError() # Authenticated! ec2_creds = {'ec2Credentials': {'access': access, 'signature': signature}} req.headers['X-Auth-EC2-Creds'] = json.dumps(ec2_creds) req.headers['X-Auth-Token'] = token_id req.headers['X-Tenant-Name'] = tenant req.headers['X-Tenant-Id'] = tenant_id req.headers['X-Auth-URL'] = auth_uri metadata = result['access'].get('metadata', {}) roles = metadata.get('roles', []) req.headers['X-Roles'] = ','.join(roles) return self.application def EC2Token_filter_factory(global_conf, **local_conf): """ Factory method for paste.deploy """ conf = global_conf.copy() conf.update(local_conf) def filter(app): return EC2Token(app, conf) return filter