/* $Id: EasySSLProtocolSocketFactory.java 125 2011-03-09 09:49:51Z ohura $ */
package webdav.ssl;

import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.net.SocketAddress;
import java.net.UnknownHostException;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;

import javax.net.SocketFactory;
import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;

import org.apache.commons.httpclient.ConnectTimeoutException;
import org.apache.commons.httpclient.HttpClientError;
import org.apache.commons.httpclient.params.HttpConnectionParams;
import org.apache.commons.httpclient.protocol.SecureProtocolSocketFactory;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * <p>
 * EasySSLProtocolSocketFactory can be used to creats SSL {@link Socket}s 
 * that accept self-signed certificates. 
 * </p>
 * <p>
 * This socket factory SHOULD NOT be used for productive systems 
 * due to security reasons, unless it is a concious decision and 
 * you are perfectly aware of security implications of accepting 
 * self-signed certificates
 * </p>
 *
 * <p>
 * Example of using custom protocol socket factory for a specific host:
 *     <pre>
 *     Protocol easyhttps = new Protocol("https", new EasySSLProtocolSocketFactory(), 443);
 *
 *     URI uri = new URI("https://localhost/", true);
 *     // use relative url only
 *     GetMethod httpget = new GetMethod(uri.getPathQuery());
 *     HostConfiguration hc = new HostConfiguration();
 *     hc.setHost(uri.getHost(), uri.getPort(), easyhttps);
 *     HttpClient client = new HttpClient();
 *     client.executeMethod(hc, httpget);
 *     </pre>
 * </p>
 * <p>
 * Example of using custom protocol socket factory per default instead of the standard one:
 *     <pre>
 *     Protocol easyhttps = new Protocol("https", new EasySSLProtocolSocketFactory(), 443);
 *     Protocol.registerProtocol("https", easyhttps);
 *
 *     HttpClient client = new HttpClient();
 *     GetMethod httpget = new GetMethod("https://localhost/");
 *     client.executeMethod(httpget);
 *     </pre>
 * </p>
 * 
 * @author <a href="mailto:oleg -at- ural.ru">Oleg Kalnichevski</a>
 * 
 * <p>
 * DISCLAIMER: HttpClient developers DO NOT actively support this component.
 * The component is provided as a reference material, which may be inappropriate
 * for use without additional customization.
 * </p>
 */

public class EasySSLProtocolSocketFactory implements SecureProtocolSocketFactory {

    /** Log object for this class. */
    private static final Log LOG = LogFactory.getLog(EasySSLProtocolSocketFactory.class);

    private SSLContext sslcontext = null;

    /**
     * Constructor for EasySSLProtocolSocketFactory.
     */
    public EasySSLProtocolSocketFactory() {
        super();
    }

    private static SSLContext createEasySSLContext() {
        try {
            SSLContext context = SSLContext.getInstance("SSL");
            context.init(
              null, 
              new TrustManager[] { new X509TrustManager() {
                  public void checkClientTrusted(X509Certificate[] arg0,
                          String arg1) throws CertificateException {
                  }

                  public void checkServerTrusted(X509Certificate[] arg0,
                          String arg1) throws CertificateException {
                  }

                  public X509Certificate[] getAcceptedIssuers() {
                      return null;
                  }
              } }, 
              null);
            return context;
        } catch (Exception e) {
            LOG.error(e.getMessage(), e);
            throw new HttpClientError(e.toString());
        }
    }

    private SSLContext getSSLContext() {
        if (this.sslcontext == null) {
            this.sslcontext = createEasySSLContext();
        }
        return this.sslcontext;
    }

    /**
     * @see SecureProtocolSocketFactory#createSocket(java.lang.String,int,java.net.InetAddress,int)
     */
    public Socket createSocket(
        String host,
        int port,
        InetAddress clientHost,
        int clientPort)
        throws IOException, UnknownHostException {

        return getSSLContext().getSocketFactory().createSocket(
            host,
            port,
            clientHost,
            clientPort
        );
    }

    /**
     * Attempts to get a new socket connection to the given host within the given time limit.
     * <p>
     * To circumvent the limitations of older JREs that do not support connect timeout a 
     * controller thread is executed. The controller thread attempts to create a new socket 
     * within the given limit of time. If socket constructor does not return until the 
     * timeout expires, the controller terminates and throws an {@link ConnectTimeoutException}
     * </p>
     *  
     * @param host the host name/IP
     * @param port the port on the host
     * @param clientHost the local host name/IP to bind the socket to
     * @param clientPort the port on the local machine
     * @param params {@link HttpConnectionParams Http connection parameters}
     * 
     * @return Socket a new socket
     * 
     * @throws IOException if an I/O error occurs while creating the socket
     * @throws UnknownHostException if the IP address of the host cannot be
     * determined
     */
    public Socket createSocket(
        final String host,
        final int port,
        final InetAddress localAddress,
        final int localPort,
        final HttpConnectionParams params
    ) throws IOException, UnknownHostException, ConnectTimeoutException {
        if (params == null) {
            throw new IllegalArgumentException("Parameters may not be null");
        }
        int timeout = params.getConnectionTimeout();
        SocketFactory socketfactory = getSSLContext().getSocketFactory();
        if (timeout == 0) {
            return socketfactory.createSocket(host, port, localAddress, localPort);
        } else {
            Socket socket = socketfactory.createSocket();
            SocketAddress localaddr = new InetSocketAddress(localAddress, localPort);
            SocketAddress remoteaddr = new InetSocketAddress(host, port);
            socket.bind(localaddr);
            socket.connect(remoteaddr, timeout);
            return socket;
        }
    }

    /**
     * @see SecureProtocolSocketFactory#createSocket(java.lang.String,int)
     */
    public Socket createSocket(String host, int port)
        throws IOException, UnknownHostException {
        return getSSLContext().getSocketFactory().createSocket(
            host,
            port
        );
    }

    /**
     * @see SecureProtocolSocketFactory#createSocket(java.net.Socket,java.lang.String,int,boolean)
     */
    public Socket createSocket(
        Socket socket,
        String host,
        int port,
        boolean autoClose)
        throws IOException, UnknownHostException {
        return getSSLContext().getSocketFactory().createSocket(
            socket,
            host,
            port,
            autoClose
        );
    }

    public boolean equals(Object obj) {
        return ((obj != null) && obj.getClass().equals(EasySSLProtocolSocketFactory.class));
    }

    public int hashCode() {
        return EasySSLProtocolSocketFactory.class.hashCode();
    }

}

