--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/app/django/contrib/auth/__init__.py	Fri Jul 18 18:22:23 2008 +0000
@@ -0,0 +1,86 @@
+import datetime
+from django.core.exceptions import ImproperlyConfigured
+
+SESSION_KEY = '_auth_user_id'
+BACKEND_SESSION_KEY = '_auth_user_backend'
+REDIRECT_FIELD_NAME = 'next'
+
+def load_backend(path):
+    i = path.rfind('.')
+    module, attr = path[:i], path[i+1:]
+    try:
+        mod = __import__(module, {}, {}, [attr])
+    except ImportError, e:
+        raise ImproperlyConfigured, 'Error importing authentication backend %s: "%s"' % (module, e)
+    except ValueError, e:
+        raise ImproperlyConfigured, 'Error importing authentication backends. Is AUTHENTICATION_BACKENDS a correctly defined list or tuple?'
+    try:
+        cls = getattr(mod, attr)
+    except AttributeError:
+        raise ImproperlyConfigured, 'Module "%s" does not define a "%s" authentication backend' % (module, attr)
+    return cls()
+
+def get_backends():
+    from django.conf import settings
+    backends = []
+    for backend_path in settings.AUTHENTICATION_BACKENDS:
+        backends.append(load_backend(backend_path))
+    return backends
+
+def authenticate(**credentials):
+    """
+    If the given credentials are valid, return a User object.
+    """
+    for backend in get_backends():
+        try:
+            user = backend.authenticate(**credentials)
+        except TypeError:
+            # This backend doesn't accept these credentials as arguments. Try the next one.
+            continue
+        if user is None:
+            continue
+        # Annotate the user object with the path of the backend.
+        user.backend = "%s.%s" % (backend.__module__, backend.__class__.__name__)
+        return user
+
+def login(request, user):
+    """
+    Persist a user id and a backend in the request. This way a user doesn't
+    have to reauthenticate on every request.
+    """
+    if user is None:
+        user = request.user
+    # TODO: It would be nice to support different login methods, like signed cookies.
+    user.last_login = datetime.datetime.now()
+    user.save()
+    request.session[SESSION_KEY] = user.id
+    request.session[BACKEND_SESSION_KEY] = user.backend
+    if hasattr(request, 'user'):
+        request.user = user
+
+def logout(request):
+    """
+    Remove the authenticated user's ID from the request.
+    """
+    try:
+        del request.session[SESSION_KEY]
+    except KeyError:
+        pass
+    try:
+        del request.session[BACKEND_SESSION_KEY]
+    except KeyError:
+        pass
+    if hasattr(request, 'user'):
+        from django.contrib.auth.models import AnonymousUser
+        request.user = AnonymousUser()
+
+def get_user(request):
+    from django.contrib.auth.models import AnonymousUser
+    try:
+        user_id = request.session[SESSION_KEY]
+        backend_path = request.session[BACKEND_SESSION_KEY]
+        backend = load_backend(backend_path)
+        user = backend.get_user(user_id) or AnonymousUser()
+    except KeyError:
+        user = AnonymousUser()
+    return user