diff --git a/include/openbsc/auth.h b/include/openbsc/auth.h
new file mode 100644
index 0000000..2364fb3
--- /dev/null
+++ b/include/openbsc/auth.h
@@ -0,0 +1,17 @@
+#ifndef _AUTH_H
+#define _AUTH_H
+
+struct gsm_auth_tuple;
+struct gsm_subscriber;
+
+enum auth_action {
+	AUTH_NOT_AVAIL		= 0,	/* No auth tuple available */
+	AUTH_DO_AUTH_THAN_CIPH	= 1,	/* Firsth authenticate, then cipher */
+	AUTH_DO_CIPH		= 2,	/* Only ciphering */
+	AUTH_DO_AUTH		= 3,	/* Only authentication, no ciphering */
+};
+
+int auth_get_tuple_for_subscr(struct gsm_auth_tuple *atuple,
+                              struct gsm_subscriber *subscr, int key_seq);
+
+#endif /* _AUTH_H */