Adds permissions support.

Fixes #1.

openstack_auth/backend.py

@@ -121,3 +121,42 @@ class KeystoneBackend(object):
 
         LOG.debug('Authentication completed for user "%s".' % username)
         return user
+
+    def get_group_permissions(self, user, obj=None):
+        """ Returns an empty set since Keystone doesn't support "groups". """
+        return set()
+
+    def get_all_permissions(self, user, obj=None):
+        """
+        Returns a set of permission strings that this user has through his/her
+        Keystone "roles".
+
+        The permissions are returned as ``"openstack.{{ role.name }}"``.
+        """
+        if user.is_anonymous() or obj is not None:
+            return set()
+        # TODO: Integrate policy-driven RBAC when supported by Keystone.
+        role_perms = set(["openstack.roles.%s" % role['name'].lower()
+                          for role in user.roles])
+        service_perms = set(["openstack.services.%s" % service['type'].lower()
+                          for service in user.service_catalog])
+        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

openstack_auth/user.py

@@ -89,6 +89,12 @@ class User(AnonymousUser):
         """ Checks for a valid token that has not yet expired. """
         return self.token is not None and check_token_expiration(self.token)
 
+    def is_anonymous(self):
+        """
+        Returns ``True`` if the user is not authenticated,``False`` otherwise.
+        """
+        return not self.is_authenticated()
+
     @property
     def is_active(self):
         return self.enabled
@@ -99,10 +105,7 @@ class User(AnonymousUser):
         Evaluates whether this user has admin privileges. Returns
         ``True`` or ``False``.
         """
-        for role in self.roles:
+        return 'admin' in [role['name'].lower() for role in self.roles]
-            if role['name'].lower() == 'admin':
-                return True
-        return False
 
     @property
     def authorized_tenants(self):