/*

 * Copyright (c) 2003, 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.security.ssl;

import java.io.IOException;

import java.io.PrintStream;

import java.security.AccessController;

import java.security.AccessControlContext;

import java.security.Principal;

import java.security.PrivilegedAction;

import java.security.SecureRandom;

import javax.crypto.SecretKey;

/**

 * A helper class that calls the KerberosClientKeyExchange implementation.

 */

public class KerberosClientKeyExchange extends HandshakeMessage {

    private static final String IMPL_CLASS =

        "sun.security.ssl.krb5.KerberosClientKeyExchangeImpl";

    private static final Class<?> implClass = AccessController.doPrivileged(

            new PrivilegedAction<Class<?>>() {

                public Class<?> run() {

                    try {

                        return Class.forName(IMPL_CLASS, true, null);

                    } catch (ClassNotFoundException cnf) {

                        return null;

                    }

                }

            }

        );

    private final KerberosClientKeyExchange impl = createImpl();

    private KerberosClientKeyExchange createImpl() {

        if (getClass() == KerberosClientKeyExchange.class) {

            try {

                return (KerberosClientKeyExchange)implClass.newInstance();

            } catch (InstantiationException e) {

                throw new AssertionError(e);

            } catch (IllegalAccessException e) {

                throw new AssertionError(e);

            }

        }

        return null;

    }

    public KerberosClientKeyExchange() {

        // empty

    }

    public KerberosClientKeyExchange(String serverName, boolean isLoopback,

        AccessControlContext acc, ProtocolVersion protocolVersion,

        SecureRandom rand) throws IOException {

        if (impl != null) {

            init(serverName, isLoopback, acc, protocolVersion, rand);

        } else {

            throw new IllegalStateException("Kerberos is unavailable");

        }

    }

    public KerberosClientKeyExchange(ProtocolVersion protocolVersion,

        ProtocolVersion clientVersion, SecureRandom rand,

        HandshakeInStream input, SecretKey[] serverKeys) throws IOException {

        if (impl != null) {

            init(protocolVersion, clientVersion, rand, input, serverKeys);

        } else {

            throw new IllegalStateException("Kerberos is unavailable");

        }

    }

    @Override

    int messageType() {

        return ht_client_key_exchange;

    }

    @Override

    public int  messageLength() {

        return impl.messageLength();

    }

    @Override

    public void send(HandshakeOutStream s) throws IOException {

        impl.send(s);

    }

    @Override

    public void print(PrintStream p) throws IOException {

        impl.print(p);

    }

    public void init(String serverName, boolean isLoopback,

        AccessControlContext acc, ProtocolVersion protocolVersion,

        SecureRandom rand) throws IOException {

        if (impl != null) {

            impl.init(serverName, isLoopback, acc, protocolVersion, rand);

        }

    }

    public void init(ProtocolVersion protocolVersion,

        ProtocolVersion clientVersion, SecureRandom rand,

        HandshakeInStream input, SecretKey[] serverKeys) throws IOException {

        if (impl != null) {

            impl.init(protocolVersion, clientVersion, rand, input, serverKeys);

        }

    }

    public byte[] getUnencryptedPreMasterSecret() {

        return impl.getUnencryptedPreMasterSecret();

    }

    public Principal getPeerPrincipal(){

        return impl.getPeerPrincipal();

    }

    public Principal getLocalPrincipal(){

        return impl.getLocalPrincipal();

    }

}