ActiveModeSocketProvider.java

/*
 * ------------------------------------------------------------------------------
 * Hermes FTP Server
 * Copyright (c) 2005-2014 Lars Behnke
 * ------------------------------------------------------------------------------
 * 
 * This file is part of Hermes FTP Server.
 * 
 * Hermes FTP Server 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 of the License, or
 * (at your option) any later version.
 * 
 * Hermes FTP Server 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 Hermes FTP Server; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 * ------------------------------------------------------------------------------
 */

package com.apporiented.hermesftp.cmd;

import java.io.IOException;
import java.net.Socket;

import javax.net.SocketFactory;
import javax.net.ssl.SSLSocket;
import javax.net.ssl.SSLSocketFactory;

import com.apporiented.hermesftp.common.FtpConstants;
import com.apporiented.hermesftp.common.FtpSessionContext;
import com.apporiented.hermesftp.exception.FtpConfigException;
import com.apporiented.hermesftp.utils.IOUtils;

/**
 * Provider for the client socket (active transfer). The creation of the socket is deferred until it
 * is needed.
 * 
 * @author Behnke
 */
public class ActiveModeSocketProvider implements SocketProvider {

    private FtpSessionContext ctx;

    private DataChannelInfo   dataChannelInfo;

    private Socket            socket;

    /**
     * Constructor.
     * 
     * @param ctx Session context.
     * @param info Channel about the data channel to open.
     */
    public ActiveModeSocketProvider(FtpSessionContext ctx, DataChannelInfo info) {
        this.ctx = ctx;
        this.dataChannelInfo = info;
    }

    /**
     * {@inheritDoc}
     */
    public DataChannelInfo init() throws IOException {
        closeSocket();
        return dataChannelInfo;
    }

    /**
     * {@inheritDoc}
     */
    public Socket provideSocket() throws IOException {
        if (socket == null) {
            socket = createClientSocket();
        }
        return socket;
    }

    /**
     * {@inheritDoc}
     */
    public void closeSocket() {
        if (socket != null) {
            IOUtils.closeGracefully(socket);
            socket = null;
        }

    }

    private Socket createClientSocket() throws IOException {
        Socket dataSocket;
        Boolean dataProtection = (Boolean) ctx.getAttribute(FtpConstants.ATTR_DATA_PROT);
        boolean ssl = dataProtection != null && dataProtection;
        if (ssl) {
            SSLSocketFactory factory;
            try {
                factory = ctx.getOptions().getSslContext().getSocketFactory();
            } catch (FtpConfigException e) {
                throw new IOException("Setting up SSL failed.");
            }
            SSLSocket sslSocket = (SSLSocket) factory.createSocket(dataChannelInfo.getAddress(),
                dataChannelInfo.getPort());
            sslSocket.setUseClientMode(false);
            enableCipherSuites(sslSocket);
            dataSocket = sslSocket;
        } else {
            dataSocket = SocketFactory.getDefault().createSocket(dataChannelInfo.getAddress(),
                dataChannelInfo.getPort());
        }
        return dataSocket;
    }

    /**
     * Enables the configured cipher suites in the passed socket.
     * 
     * @param sslSocket The socket.
     */
    private void enableCipherSuites(SSLSocket sslSocket) {
        String[] cipherSuites = ctx.getOptions().getStringArray(FtpConstants.OPT_SSL_CIPHER_SUITES, null);
        if (cipherSuites != null) {
            if (cipherSuites.length == 1 && FtpConstants.WILDCARD.equals(cipherSuites[0])) {
                sslSocket.setEnabledCipherSuites(sslSocket.getSupportedCipherSuites());
            } else {
                sslSocket.setEnabledCipherSuites(cipherSuites);
            }
        }
    }

}