Add a FederatedBase v3 plugin

With the out of tree federation plugins going on extract the basic
federation workflow and required information that can be reused.

Change-Id: I6fdb3a5c6d9f3e1d6fa3425fd05809155effed1f

2 files changed, 114 insertions, 0 deletions

diff --git a/keystoneclient/auth/identity/v3/__init__.py b/keystoneclient/auth/identity/v3/__init__.py
index 6992c7f..a08f3ec 100644
--- a/keystoneclient/auth/identity/v3/__init__.py
+++ b/keystoneclient/auth/identity/v3/__init__.py
@@ -11,6 +11,7 @@
 # under the License.
 
 from keystoneclient.auth.identity.v3.base import *  # noqa
+from keystoneclient.auth.identity.v3.federated import *  # noqa
 from keystoneclient.auth.identity.v3.password import *  # noqa
 from keystoneclient.auth.identity.v3.token import *  # noqa
 
@@ -20,6 +21,8 @@ __all__ = ['Auth',
            'AuthMethod',
            'BaseAuth',
 
+           'FederatedBaseAuth',
+
            'Password',
            'PasswordMethod',
 
diff --git a/keystoneclient/auth/identity/v3/federated.py b/keystoneclient/auth/identity/v3/federated.py
new file mode 100644
index 0000000..db7ad2b
--- /dev/null
+++ b/keystoneclient/auth/identity/v3/federated.py
@@ -0,0 +1,111 @@
+# 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 abc
+
+from oslo_config import cfg
+import six
+
+from keystoneclient.auth.identity.v3 import base
+from keystoneclient.auth.identity.v3 import token
+
+__all__ = ['FederatedBaseAuth']
+
+
+@six.add_metaclass(abc.ABCMeta)
+class FederatedBaseAuth(base.BaseAuth):
+
+    rescoping_plugin = token.Token
+
+    def __init__(self, auth_url, identity_provider, protocol, **kwargs):
+        """Class constructor accepting following parameters:
+
+        :param auth_url: URL of the Identity Service
+        :type auth_url: string
+        :param identity_provider: name of the Identity Provider the client
+                                  will authenticate against. This parameter
+                                  will be used to build a dynamic URL used to
+                                  obtain unscoped OpenStack token.
+        :type identity_provider: string
+
+        """
+        super(FederatedBaseAuth, self).__init__(auth_url=auth_url, **kwargs)
+        self.identity_provider = identity_provider
+        self.protocol = protocol
+
+    @classmethod
+    def get_options(cls):
+        options = super(FederatedBaseAuth, cls).get_options()
+
+        options.extend([
+            cfg.StrOpt('identity-provider',
+                       help="Identity Provider's name"),
+            cfg.StrOpt('protocol',
+                       help='Protocol for federated plugin'),
+        ])
+
+        return options
+
+    @property
+    def federated_token_url(self):
+        """Full URL where authorization data is sent."""
+        values = {
+            'host': self.auth_url.rstrip('/'),
+            'identity_provider': self.identity_provider,
+            'protocol': self.protocol
+        }
+        url = ("%(host)s/OS-FEDERATION/identity_providers/"
+               "%(identity_provider)s/protocols/%(protocol)s/auth")
+        url = url % values
+
+        return url
+
+    def _get_scoping_data(self):
+        return {'trust_id': self.trust_id,
+                'domain_id': self.domain_id,
+                'domain_name': self.domain_name,
+                'project_id': self.project_id,
+                'project_name': self.project_name,
+                'project_domain_id': self.project_domain_id,
+                'project_domain_name': self.project_domain_name}
+
+    def get_auth_ref(self, session, **kwargs):
+        """Authenticate retrieve token information.
+
+        This is a multi-step process where a client does federated authn
+        receives an unscoped token.
+
+        If an unscoped token is successfully received and scoping information
+        is present then the token is rescoped to that target.
+
+        :param session: a session object to send out HTTP requests.
+        :type session: keystoneclient.session.Session
+
+        :returns: a token data representation
+        :rtype: :py:class:`keystoneclient.access.AccessInfo`
+
+        """
+        auth_ref = self.get_unscoped_auth_ref(session)
+        scoping = self._get_scoping_data()
+
+        if any(scoping.values()):
+            token_plugin = self.rescoping_plugin(self.auth_url,
+                                                 token=auth_ref.auth_token,
+                                                 **scoping)
+
+            auth_ref = token_plugin.get_auth_ref(session)
+
+        return auth_ref
+
+    @abc.abstractmethod
+    def get_unscoped_auth_ref(self, session, **kwargs):
+        """Fetch unscoped federated token."""