/*

 * Copyright (c) 1997, 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 javax.net.ssl;

import java.net.*;

import javax.net.SocketFactory;

import java.io.IOException;

import java.io.InputStream;

import java.security.*;

import java.util.Locale;

import sun.security.action.GetPropertyAction;

/**

 * <code>SSLSocketFactory</code>s create <code>SSLSocket</code>s.

 *

 * @since 1.4

 * @see SSLSocket

 * @author David Brownell

 */

public abstract class SSLSocketFactory extends SocketFactory

{

    private static SSLSocketFactory theFactory;

    private static boolean propertyChecked;

    static final boolean DEBUG;

    static {

                .toLowerCase(Locale.ENGLISH);

        DEBUG = s.contains("all") || s.contains("ssl");

    }

    private static void log(String msg) {

        if (DEBUG) {

            System.out.println(msg);

        }

    }

    /**

     * Constructor is used only by subclasses.

     */

    public SSLSocketFactory() {

    }

    /**

     * Returns the default SSL socket factory.

     *

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

     * "ssl.SocketFactory.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 SSLSocketFactory, it is made the default SSL

     * socket factory.

     *

     * <p>Otherwise, this method returns

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

     * call fails, an inoperative factory is returned.

     *

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

     * @see SSLContext#getDefault

     */

    public static synchronized SocketFactory getDefault() {

        if (theFactory != null) {

            return theFactory;

        }

        if (propertyChecked == false) {

            propertyChecked = true;

            String clsName = getSecurityProperty("ssl.SocketFactory.provider");

            if (clsName != null) {

                log("setting up default SSLSocketFactory");

                try {

                    Class<?> cls = null;

                    try {

                        cls = Class.forName(clsName);

                    } catch (ClassNotFoundException e) {

                        ClassLoader cl = ClassLoader.getSystemClassLoader();

                        if (cl != null) {

                            cls = cl.loadClass(clsName);

                        }

                    }

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

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

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

                    theFactory = fac;

                    return fac;

                } catch (Exception e) {

                    log("SSLSocketFactory instantiation failed: " + e.toString());

                    theFactory = new DefaultSSLSocketFactory(e);

                    return theFactory;

                }

            }

        }

        try {

            return SSLContext.getDefault().getSocketFactory();

        } catch (NoSuchAlgorithmException e) {

            return new DefaultSSLSocketFactory(e);

        }

    }

    static String getSecurityProperty(final String name) {

        return AccessController.doPrivileged(new PrivilegedAction<>() {

            @Override

            public String run() {

                String s = java.security.Security.getProperty(name);

                if (s != null) {

                    s = s.trim();

                    if (s.length() == 0) {

                        s = null;

                    }

                }

                return s;

            }

        });

    }

    /**

     * 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.  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.

     *

     * @see #getDefaultCipherSuites()

     * @return an array of cipher suite names

     */

    public abstract String [] getSupportedCipherSuites();

    /**

     * Returns a socket layered over an existing socket connected to the named

     * host, at the given port.  This constructor can be used when tunneling SSL

     * through a proxy or when negotiating the use of SSL over an existing

     * socket. The host and port refer to the logical peer destination.

     * This socket is configured using the socket options established for

     * this factory.

     *

     * @param s the existing socket

     * @param host the server host

     * @param port the server port

     * @param autoClose close the underlying socket when this socket is closed

     * @return a socket connected to the specified host and port

     * @throws IOException if an I/O error occurs when creating the socket

     * @throws NullPointerException if the parameter s is null

     */

    public abstract Socket createSocket(Socket s, String host,

            int port, boolean autoClose) throws IOException;

    /**

     * Creates a server mode {@link Socket} layered over an

     * existing connected socket, and is able to read data which has

     * already been consumed/removed from the {@link Socket}'s

     * underlying {@link InputStream}.

     * <p>

     * This method can be used by a server application that needs to

     * observe the inbound data but still create valid SSL/TLS

     * connections: for example, inspection of Server Name Indication

     * (SNI) extensions (See section 3 of <A

     * HREF="http://www.ietf.org/rfc/rfc6066.txt">TLS Extensions

     * (RFC6066)</A>).  Data that has been already removed from the

     * underlying {@link InputStream} should be loaded into the

     * {@code consumed} stream before this method is called, perhaps

     * using a {@link java.io.ByteArrayInputStream}.  When this

     * {@link Socket} begins handshaking, it will read all of the data in

     * {@code consumed} until it reaches {@code EOF}, then all further

     * data is read from the underlying {@link InputStream} as

     * usual.

     * <p>

     * The returned socket is configured using the socket options

     * established for this factory, and is set to use server mode when

     * handshaking (see {@link SSLSocket#setUseClientMode(boolean)}).

     *

     * @param  s

     *         the existing socket

     * @param  consumed

     *         the consumed inbound network data that has already been

     *         removed from the existing {@link Socket}

     *         {@link InputStream}.  This parameter may be

     *         {@code null} if no data has been removed.

     * @param  autoClose close the underlying socket when this socket is closed.

     *

     * @return the {@link Socket} compliant with the socket options

     *         established for this factory

     *

     * @throws IOException if an I/O error occurs when creating the socket

     * @throws UnsupportedOperationException if the underlying provider

     *         does not implement the operation

     * @throws NullPointerException if {@code s} is {@code null}

     *

     * @since 1.8

     */

    public Socket createSocket(Socket s, InputStream consumed,

            boolean autoClose) throws IOException {

        throw new UnsupportedOperationException();

    }

}

// file private

class DefaultSSLSocketFactory extends SSLSocketFactory

{

    private Exception reason;

    DefaultSSLSocketFactory(Exception reason) {

        this.reason = reason;

    }

    private Socket throwException() throws SocketException {

        throw (SocketException)

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

    }

    @Override

    public Socket createSocket()

    throws IOException

    {

        return throwException();

    }

    @Override

    public Socket createSocket(String host, int port)

    throws IOException

    {

        return throwException();

    }

    @Override

    public Socket createSocket(Socket s, String host,

                                int port, boolean autoClose)

    throws IOException

    {

        return throwException();

    }

    @Override

    public Socket createSocket(InetAddress address, int port)

    throws IOException

    {

        return throwException();

    }

    @Override

    public Socket createSocket(String host, int port,

        InetAddress clientAddress, int clientPort)

    throws IOException

    {

        return throwException();

    }

    @Override

    public Socket createSocket(InetAddress address, int port,

        InetAddress clientAddress, int clientPort)

    throws IOException

    {

        return throwException();

    }

    @Override

    public String [] getDefaultCipherSuites() {

        return new String[0];

    }

    @Override

    public String [] getSupportedCipherSuites() {

        return new String[0];

    }

}