/* SSLSocketFactory.java -- factory for SSL client sockets.
   Copyright (C) 2004 Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU Classpath 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 for more details.

You should have received a copy of the GNU General Public License
along with GNU Classpath; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
conditions of the GNU General Public License cover the whole
combination.

As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under
terms of your choice, provided that you also meet, for each linked
independent module, the terms and conditions of the license of that
module.  An independent module is a module which is not derived from
or based on this library.  If you modify this library, you may extend
this exception to your version of the library, but you are not
obligated to do so.  If you do not wish to do so, delete this
exception statement from your version. */


package javax.net.ssl;

import java.io.IOException;
import java.net.Socket;
import java.security.KeyStore;
import java.security.Security;

import javax.net.SocketFactory;

/**
 * A socket factory for creating <i>Secure Socket Layer</i> (<b>SSL</b>)
 * sockets.
 */
public abstract class SSLSocketFactory extends SocketFactory
{
  // Constants.
  // -------------------------------------------------------------------------

  private static SSLContext context;

  // Constructor.
  // -------------------------------------------------------------------------

  public SSLSocketFactory()
  {
    super();
  }

  // Class methods.
  // -------------------------------------------------------------------------

  /**
   * Returns a default implementation of a SSL socket factory.
   *
   * <p>To control the class that gets returned by this method, set the
   * security property "ssl.SocketFactory.provider" to the class
   * name of a concrete implementation of this class. If not set, a
   * system-dependent implementation will be used.</p>
   *
   * <p>The implementation returned is created by the first implementation
   * of the {@link SSLContext} class found, which is initialized with
   * default parameters. To control the key and trust manager factory
   * algorithms used as defaults, set the security properties
   * "ssl.keyManagerFactory.algorithm" and "ssl.trustManagerFactory.algorithm"
   * to the appropriate names.</p>
   *
   * <p>Using this method is not recommended. Instead, use the methods of
   * {@link SSLContext}, which provide much better control over the
   * creation of socket factories.</p>
   *
   * @return The default socket factory.
   * @throws RuntimeException If no default can be created.
   */
  public static synchronized SocketFactory getDefault()
  {
    try
      {
        String s = Security.getProperty("ssl.SocketFactory.provider");
        ClassLoader cl = ClassLoader.getSystemClassLoader();
        if (s != null && cl != null)
          {
            return (SocketFactory) cl.loadClass(s).newInstance();
          }
      }
    catch (Exception e)
      {
      }
    if (context == null)
      {
        KeyManager[] km = null;
        TrustManager[] tm = null;

        // 1. Determine which algorithms to use for the key and trust
        // manager factories.
        String kmAlg = KeyManagerFactory.getDefaultAlgorithm();
        String tmAlg = TrustManagerFactory.getDefaultAlgorithm();

        // 2. Try to initialize the factories with default parameters.
        try
          {
            KeyManagerFactory kmf = KeyManagerFactory.getInstance(kmAlg);
            kmf.init(null, null);
            km = kmf.getKeyManagers();
          }
        catch (Exception ex)
          {
          }
        try
          {
            TrustManagerFactory tmf = TrustManagerFactory.getInstance(tmAlg);
            tmf.init((KeyStore) null);
            tm = tmf.getTrustManagers();
          }
        catch (Exception ex)
          {
          }

        // 3. Create and initialize a context.
        try
          {
            context = SSLContext.getInstance("SSLv3");
            context.init(km, tm, null);
          }
        catch (Exception ex)
          {
            throw new RuntimeException("error instantiating default socket factory: "
                                       + ex.toString());
          }
      }
    try
      {
        return context.getSocketFactory();
      }
    catch (Exception e)
      {
      }
    throw new RuntimeException("no SSLSocketFactory implementation available");
  }

  // Abstract methods.
  // -------------------------------------------------------------------------

  /**
   * Creates a SSL socket wrapped around an existing socket.
   *
   * @param socket The socket to wrap.
   * @param host The host the socket is connected to.
   * @param port The port the socket is connected to.
   * @param autoClose Whether or not the wrapped socket should be closed
   *   automatically.
   * @return The new SSL socket.
   * @throws IOException If the socket could not be created.
   */
  public abstract Socket createSocket(Socket socket, String host,
                                      int port, boolean autoClose)
    throws IOException;

  /**
   * Returns the list of cipher suites that will be enabled in sockets
   * created by this factory.
   *
   * @return The default cipher suites.
   */
  public abstract String[] getDefaultCipherSuites();

  /**
   * Returns the list of all cipher suites supported by this factory.
   *
   * @return The list of supported cipher suites.
   */
  public abstract String[] getSupportedCipherSuites();
}