--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/com/sun/security/jgss/ExtendedGSSCredential.java	Wed Nov 07 14:13:01 2012 +0800
@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code 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 General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package com.sun.security.jgss;
+
+import org.ietf.jgss.*;
+
+/**
+ * The extended GSSCredential interface for supporting additional
+ * functionalities not defined by {@code org.ietf.jgss.GSSCredential}.
+ * @since 1.8
+ */
+public interface ExtendedGSSCredential extends GSSCredential {
+    /**
+     * Impersonates a principal. In Kerberos, this can be implemented
+     * using the Microsoft S4U2self extension.
+     * <p>
+     * A {@link GSSException#NO_CRED GSSException.NO_CRED} will be thrown if the
+     * impersonation fails. A {@link GSSException#FAILURE GSSException.FAILURE}
+     * will be  thrown if the impersonation method is not available to this
+     * credential object.
+     * @param name the name of the principal to impersonate
+     * @return a credential for that principal
+     * @throws GSSException  containing the following
+     * major error codes:
+     *   {@link GSSException#NO_CRED GSSException.NO_CRED}
+     *   {@link GSSException#FAILURE GSSException.FAILURE}
+     */
+    public GSSCredential impersonate(GSSName name) throws GSSException;
+}