daemon: allow NULs in X11 cookie

We currently allow the slave access to its X server via two
mechanisms:

1) we set XAUTHORITY to point to the X servers Xauthority file
2) we call XSetAuthorization with the cookie from the Xauthority file

1) may fail if the user's hostname changes at the wrong moment, and
a bug in the code meant that 2 would fail if NULs are encoded in the
auth cookie.

This commit fixes 2) to work with embedded NUL bytes.

https://bugzilla.gnome.org/show_bug.cgi?id=687691

1 files changed, 6 insertions, 1 deletions

diff --git a/daemon/gdm-display.c b/daemon/gdm-display.c
index 42f5990b..435dc1ca 100644
--- a/daemon/gdm-display.c
+++ b/daemon/gdm-display.c
@@ -1106,10 +1106,15 @@ handle_get_x11_cookie (GdmDBusDisplay        *skeleton,
                        GdmDisplay            *display)
 {
         GArray *cookie = NULL;
+        GVariant *variant;
 
         gdm_display_get_x11_cookie (display, &cookie, NULL);
 
-        gdm_dbus_display_complete_get_x11_cookie (skeleton, invocation, cookie->data);
+        variant = g_variant_new_fixed_array (G_VARIANT_TYPE_BYTE,
+                                             cookie->data,
+                                             cookie->len,
+                                             sizeof (char));
+        gdm_dbus_display_complete_get_x11_cookie (skeleton, invocation, variant);
 
         g_array_unref (cookie);
         return TRUE;