diff --git a/os/xsha1.c b/os/xsha1.c
index 24c0aa284..c54e68c83 100644
--- a/os/xsha1.c
+++ b/os/xsha1.c
@@ -1,3 +1,28 @@
+/* Copyright © 2007 Carl Worth
+ * Copyright © 2009 Jeremy Huddleston, Julien Cristau, and Matthieu Herrb
+ * Copyright © 2009-2010 Mikhail Gusarov
+ * Copyright © 2012 Yaakov Selkowitz and Keith Packard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
 #ifdef HAVE_DIX_CONFIG_H
 #include <dix-config.h>
 #endif