[thirdpart] Add shibboleth

thirdpart/shibboleth/backends.py

@@ -0,0 +1,46 @@
+from django.db import connection
+from django.contrib.auth.models import User, Permission
+from django.contrib.auth.backends import RemoteUserBackend
+
+class ShibbolethRemoteUserBackend(RemoteUserBackend):
+    """
+    This backend is to be used in conjunction with the ``RemoteUserMiddleware``
+    found in the middleware module of this package, and is used when the server
+    is handling authentication outside of Django.
+
+    By default, the ``authenticate`` method creates ``User`` objects for
+    usernames that don't already exist in the database.  Subclasses can disable
+    this behavior by setting the ``create_unknown_user`` attribute to
+    ``False``.
+    """
+
+    # Create a User object if not already in the database?
+    create_unknown_user = True
+
+    def authenticate(self, remote_user, shib_meta):
+        """
+        The username passed as ``remote_user`` is considered trusted.  This
+        method simply returns the ``User`` object with the given username,
+        creating a new ``User`` object if ``create_unknown_user`` is ``True``.
+
+        Returns None if ``create_unknown_user`` is ``False`` and a ``User``
+        object with the given username is not found in the database.
+        """
+        if not remote_user:
+            return
+        user = None
+        username = self.clean_username(remote_user)
+        shib_user_params = dict([(k, shib_meta[k]) for k in User._meta.get_all_field_names() if k in shib_meta])
+        # Note that this could be accomplished in one try-except clause, but
+        # instead we use get_or_create when creating unknown users since it has
+        # built-in safeguards for multiple threads.
+        if self.create_unknown_user:
+            user, created = User.objects.get_or_create(username=shib_user_params.get('username'), defaults=shib_user_params)
+            if created:
+                user = self.configure_user(user)
+        else:
+            try:
+                user = User.objects.get(**shib_user_params)
+            except User.DoesNotExist:
+                pass
+        return user