/*

 * 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

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package javax.net.ssl;

import java.io.IOException;

import java.net.InetAddress;

import java.net.ServerSocket;

import java.net.SocketException;

import javax.net.ServerSocketFactory;

import java.security.*;

/**

 * <code>SSLServerSocketFactory</code>s create

 * <code>SSLServerSocket</code>s.

 *

 * @since 1.4

 * @see SSLSocket

 * @see SSLServerSocket

 * @author David Brownell

 */

public abstract class SSLServerSocketFactory extends ServerSocketFactory

{

    private static SSLServerSocketFactory theFactory;

    private static boolean propertyChecked;

    private static void log(String msg) {

        if (SSLSocketFactory.DEBUG) {

            System.out.println(msg);

        }

    }

    /**

     * Constructor is used only by subclasses.

     */

    protected SSLServerSocketFactory() { /* NOTHING */ }

    /**

     * Returns the default SSL server socket factory.

     *

     * <p>The first time this method is called, the security property

     * "ssl.ServerSocketFactory.provider" is examined. If it is non-null, a

     * class by that name is loaded and instantiated. If that is successful and

     * the object is an instance of SSLServerSocketFactory, it is made the

     * default SSL server socket factory.

     *

     * <p>Otherwise, this method returns

     * <code>SSLContext.getDefault().getServerSocketFactory()</code>. If that

     * call fails, an inoperative factory is returned.

     *

     * @return the default <code>ServerSocketFactory</code>

     * @see SSLContext#getDefault

     */

    public static synchronized ServerSocketFactory getDefault() {

        if (theFactory != null) {

            return theFactory;

        }

        if (propertyChecked == false) {

            propertyChecked = true;

            String clsName = SSLSocketFactory.getSecurityProperty

                                        ("ssl.ServerSocketFactory.provider");

            if (clsName != null) {

                log("setting up default SSLServerSocketFactory");

                try {

                    try {

                        cls = Class.forName(clsName);

                    } catch (ClassNotFoundException e) {

                        ClassLoader cl = ClassLoader.getSystemClassLoader();

                        if (cl != null) {

                            cls = cl.loadClass(clsName);

                        }

                    }

                    log("class " + clsName + " is loaded");

                    SSLServerSocketFactory fac = (SSLServerSocketFactory)cls.newInstance();

                    log("instantiated an instance of class " + clsName);

                    theFactory = fac;

                    return fac;

                } catch (Exception e) {

                    log("SSLServerSocketFactory instantiation failed: " + e);

                    theFactory = new DefaultSSLServerSocketFactory(e);

                    return theFactory;

                }

            }

        }

        try {

            return SSLContext.getDefault().getServerSocketFactory();

        } catch (NoSuchAlgorithmException e) {

            return new DefaultSSLServerSocketFactory(e);

        }

    }

    /**

     * Returns the list of cipher suites which are enabled by default.

     * Unless a different list is enabled, handshaking on an SSL connection

     * will use one of these cipher suites.  The minimum quality of service

     * for these defaults requires confidentiality protection and server

     * authentication (that is, no anonymous cipher suites).

     *

     * @see #getSupportedCipherSuites()

     * @return array of the cipher suites enabled by default

     */

    public abstract String [] getDefaultCipherSuites();

    /**

     * Returns the names of the cipher suites which could be enabled for use

     * on an SSL connection created by this factory.

     * Normally, only a subset of these will actually

     * be enabled by default, since this list may include cipher suites which

     * do not meet quality of service requirements for those defaults.  Such

     * cipher suites are useful in specialized applications.

     *

     * @return an array of cipher suite names

     * @see #getDefaultCipherSuites()

     */

    public abstract String [] getSupportedCipherSuites();

}

//

// The default factory does NOTHING.

//

class DefaultSSLServerSocketFactory extends SSLServerSocketFactory {

    private final Exception reason;

    DefaultSSLServerSocketFactory(Exception reason) {

        this.reason = reason;

    }

    private ServerSocket throwException() throws SocketException {

        throw (SocketException)

            new SocketException(reason.toString()).initCause(reason);

    }

    public ServerSocket createServerSocket() throws IOException {

        return throwException();

    }

    public ServerSocket createServerSocket(int port)

    throws IOException

    {

        return throwException();

    }

    public ServerSocket createServerSocket(int port, int backlog)

    throws IOException

    {

        return throwException();

    }

    public ServerSocket

    createServerSocket(int port, int backlog, InetAddress ifAddress)

    throws IOException

    {

        return throwException();

    }

    public String [] getDefaultCipherSuites() {

        return new String[0];

    }

    public String [] getSupportedCipherSuites() {

        return new String[0];

    }

}