/* * Copyright (c) 2005, 2010, 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 sun.net.www.protocol.http.spnego; import java.io.IOException;import java.net.Authenticator;import java.net.PasswordAuthentication;import java.util.Arrays;import javax.security.auth.callback.Callback;import javax.security.auth.callback.CallbackHandler;import javax.security.auth.callback.NameCallback;import javax.security.auth.callback.PasswordCallback;import javax.security.auth.callback.UnsupportedCallbackException;import sun.net.www.protocol.http.HttpCallerInfo; /** * @since 1.6 * Special callback handler used in JGSS for the HttpCaller. */public class NegotiateCallbackHandler implements CallbackHandler {     private String username;    private char[] password;     /**     * Authenticator asks for username and password in a single prompt,     * but CallbackHandler checks one by one. So, no matter which callback     * gets handled first, make sure Authenticator is only called once.     */    private boolean answered;     private final HttpCallerInfo hci;     public NegotiateCallbackHandler(HttpCallerInfo hci) {        this.hci = hci;    }     private void getAnswer() {        if (!answered) {            answered = true;            PasswordAuthentication passAuth =                    Authenticator.requestPasswordAuthentication(                    hci.host, hci.addr, hci.port, hci.protocol,                    hci.prompt, hci.scheme, hci.url, hci.authType);            /**             * To be compatible with existing callback handler implementations,             * when the underlying Authenticator is canceled, username and             * password are assigned null. No exception is thrown.             */            if (passAuth != null) {                username = passAuth.getUserName();                password = passAuth.getPassword();            }        }    }     public void handle(Callback[] callbacks) throws            UnsupportedCallbackException, IOException {        for (int i=0; i<callbacks.length; i++) {            Callback callBack = callbacks[i];             if (callBack instanceof NameCallback) {                getAnswer();                ((NameCallback)callBack).setName(username);            } else if (callBack instanceof PasswordCallback) {                getAnswer();                ((PasswordCallback)callBack).setPassword(password);                if (password != null) Arrays.fill(password, ' ');            } else {                throw new UnsupportedCallbackException(callBack,                        "Call back not supported");            }        }    }}