From 0ecacfd6123e4026c78d5d61670da0abdcbf7559 Mon Sep 17 00:00:00 2001
From: Ray Strode <rstrode@redhat.com>
Date: Thu, 22 Jan 2015 11:51:18 -0500
Subject: [PATCH] manager: allow the login screen to do reauthentication

At the moment, we only allow the user session to do reauthentication
from its lock screen.  If a user does user switching we instead open
a new session for checking the user's password.

This commit enables reauthentication from the login screen as well.
---
 daemon/gdm-manager.c | 23 ++++++++++++++---------
 1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/daemon/gdm-manager.c b/daemon/gdm-manager.c
index 8c41045..0278512 100644
--- a/daemon/gdm-manager.c
+++ b/daemon/gdm-manager.c
@@ -1161,84 +1161,89 @@ open_temporary_reauthentication_channel (GdmManager            *self,
                           self);
 
         address = gdm_session_get_server_address (session);
 
         return g_strdup (address);
 }
 
 static gboolean
 gdm_manager_handle_open_reauthentication_channel (GdmDBusManager        *manager,
                                                   GDBusMethodInvocation *invocation,
                                                   const char            *username)
 {
         GdmManager       *self = GDM_MANAGER (manager);
         const char       *sender;
         GdmDisplay       *display = NULL;
         GdmSession       *session;
         GDBusConnection  *connection;
         char             *seat_id = NULL;
         char             *session_id = NULL;
         GPid              pid = 0;
         uid_t             uid = (uid_t) -1;
         gboolean          is_login_screen = FALSE;
         gboolean          is_remote = FALSE;
 
         g_debug ("GdmManager: trying to open reauthentication channel for user %s", username);
 
         sender = g_dbus_method_invocation_get_sender (invocation);
         connection = g_dbus_method_invocation_get_connection (invocation);
         get_display_and_details_for_bus_sender (self, connection, sender, &display, &seat_id, &session_id, &pid, &uid, &is_login_screen, &is_remote);
 
-        if (is_login_screen) {
-                g_dbus_method_invocation_return_error_literal (invocation,
-                                                               G_DBUS_ERROR,
-                                                               G_DBUS_ERROR_ACCESS_DENIED,
-                                                               "Login screen not allow to open reauthentication channel");
-                return TRUE;
-        }
-
         if (session_id == NULL || pid == 0 || uid == (uid_t) -1) {
                 g_dbus_method_invocation_return_error_literal (invocation,
                                                                G_DBUS_ERROR,
                                                                G_DBUS_ERROR_ACCESS_DENIED,
                                                                _("No session available"));
 
                 return TRUE;
         }
 
-        session = get_seed_session_for_display (display);
+        if (is_login_screen) {
+                session = find_session_for_user_on_seat (self,
+                                                         username,
+                                                         seat_id,
+                                                         NULL);
+        } else {
+                session = get_seed_session_for_display (display);
+        }
 
         if (session != NULL && gdm_session_is_running (session)) {
                 gdm_session_start_reauthentication (session, pid, uid);
                 g_hash_table_insert (self->priv->open_reauthentication_requests,
                                      GINT_TO_POINTER (pid),
                                      invocation);
+        } else if (is_login_screen) {
+                g_dbus_method_invocation_return_error_literal (invocation,
+                                                               G_DBUS_ERROR,
+                                                               G_DBUS_ERROR_ACCESS_DENIED,
+                                                               "Login screen only allowed to open reauthentication channels for running sessions");
+                return TRUE;
         } else {
                 char *address;
                 address = open_temporary_reauthentication_channel (self,
                                                                    seat_id,
                                                                    session_id,
                                                                    pid,
                                                                    uid,
                                                                    is_remote);
                 gdm_dbus_manager_complete_open_reauthentication_channel (GDM_DBUS_MANAGER (manager),
                                                                          invocation,
                                                                          address);
                 g_free (address);
         }
 
         return TRUE;
 }
 
 static void
 manager_interface_init (GdmDBusManagerIface *interface)
 {
         interface->handle_open_session = gdm_manager_handle_open_session;
         interface->handle_open_reauthentication_channel = gdm_manager_handle_open_reauthentication_channel;
 }
 
 static void
 set_up_greeter_session (GdmManager *manager,
                         GdmDisplay *display)
 {
         char *allowed_user;
         struct passwd *passwd_entry;
-- 
2.2.1