diff --git a/ap/libc/glibc/glibc-2.23/hurd/setauth.c b/ap/libc/glibc/glibc-2.23/hurd/setauth.c
new file mode 100644
index 0000000..d38fddd
--- /dev/null
+++ b/ap/libc/glibc/glibc-2.23/hurd/setauth.c
@@ -0,0 +1,122 @@
+/* Copyright (C) 1991-2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <hurd.h>
+#include <hurd/port.h>
+#include <hurd/id.h>
+#include "set-hooks.h"
+
+/* Things in the library which want to be run when the auth port changes.  */
+DEFINE_HOOK (_hurd_reauth_hook, (auth_t new_auth));
+
+#include <cthreads.h>
+static struct mutex reauth_lock = MUTEX_INITIALIZER;
+
+
+/* Set the auth port to NEW, and reauthenticate
+   everything used by the library.  */
+error_t
+_hurd_setauth (auth_t new)
+{
+  error_t err;
+  unsigned int d;
+  mach_port_t newport, ref;
+
+  /* Give the new send right a user reference.
+     This is a good way to check that it is valid.  */
+  if (err = __mach_port_mod_refs (__mach_task_self (), new,
+				  MACH_PORT_RIGHT_SEND, 1))
+    return err;
+
+  HURD_CRITICAL_BEGIN;
+
+  /* We lock against another thread doing setauth.  Anyone who sets
+     _hurd_ports[INIT_PORT_AUTH] some other way is asking to lose.  */
+  __mutex_lock (&reauth_lock);
+
+  /* Install the new port in the cell.  */
+  __mutex_lock (&_hurd_id.lock);
+  _hurd_port_set (&_hurd_ports[INIT_PORT_AUTH], new);
+  _hurd_id.valid = 0;
+  if (_hurd_id.rid_auth)
+    {
+      __mach_port_deallocate (__mach_task_self (), _hurd_id.rid_auth);
+      _hurd_id.rid_auth = MACH_PORT_NULL;
+    }
+  __mutex_unlock (&_hurd_id.lock);
+
+  if (_hurd_init_dtable != NULL)
+    /* We just have the simple table we got at startup.
+       Otherwise, a reauth_hook in dtable.c takes care of this.  */
+    for (d = 0; d < _hurd_init_dtablesize; ++d)
+      if (_hurd_init_dtable[d] != MACH_PORT_NULL)
+	{
+	  mach_port_t new;
+	  ref = __mach_reply_port ();
+	  if (! __io_reauthenticate (_hurd_init_dtable[d],
+				     ref, MACH_MSG_TYPE_MAKE_SEND) &&
+	      ! HURD_PORT_USE (&_hurd_ports[INIT_PORT_AUTH],
+			       __auth_user_authenticate
+			       (port,
+				ref, MACH_MSG_TYPE_MAKE_SEND,
+				&new)))
+	    {
+	      __mach_port_deallocate (__mach_task_self (),
+				      _hurd_init_dtable[d]);
+	      _hurd_init_dtable[d] = new;
+	    }
+	  __mach_port_destroy (__mach_task_self (), ref);
+	}
+
+  ref = __mach_reply_port ();
+  if (__USEPORT (CRDIR,
+		 ! __io_reauthenticate (port,
+					ref, MACH_MSG_TYPE_MAKE_SEND) &&
+		 ! __auth_user_authenticate (new,
+					     ref, MACH_MSG_TYPE_MAKE_SEND,
+					     &newport)))
+    _hurd_port_set (&_hurd_ports[INIT_PORT_CRDIR], newport);
+  __mach_port_destroy (__mach_task_self (), ref);
+
+  ref = __mach_reply_port ();
+  if (__USEPORT (CWDIR,
+		 ! __io_reauthenticate (port,
+					ref, MACH_MSG_TYPE_MAKE_SEND) &&
+		 ! __auth_user_authenticate (new,
+					     ref, MACH_MSG_TYPE_MAKE_SEND,
+					     &newport)))
+    _hurd_port_set (&_hurd_ports[INIT_PORT_CWDIR], newport);
+  __mach_port_destroy (__mach_task_self (), ref);
+
+  /* Run things which want to do reauthorization stuff.  */
+  RUN_HOOK (_hurd_reauth_hook, (new));
+
+  __mutex_unlock (&reauth_lock);
+
+  HURD_CRITICAL_END;
+
+  return 0;
+}
+
+int
+__setauth (auth_t new)
+{
+  error_t err = _hurd_setauth (new);
+  return err ? __hurd_fail (err) : 0;
+}
+
+weak_alias (__setauth, setauth)