Java

FTP through SSH Tunnel

See more FTP Examples

Demonstrates how to FTP through an SSH tunnel.

The Chilkat SSH tunnel object is used to create a portable SSH tunnel w/ dynamic port forwarding on a background thread that the foreground thread can use for establishing connections through an SSH tunnel.

Chilkat2 Java

import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Ftp2;
import com.chilkatsoft.chilkat2.SshTunnel;

public class ChilkatExample {

    public static void main(String[] args) {
        boolean success = false;

        // This example assumes the Chilkat API to have been previously unlocked.
        // See Global Unlock Sample for sample code.

        success = false;

        SshTunnel tunnel = new SshTunnel();

        String sshHostname = "sftp.example.com";
        int sshPort = 22;

        // Connect to an SSH server and establish the SSH tunnel:
        try {
            tunnel.connect(sshHostname, sshPort);

            // Authenticate with the SSH server via a login/password
            // or with a public key.
            // This example demonstrates SSH password authentication.
            tunnel.authenticatePw("mySshLogin", "mySshPassword");

            // Indicate that the background SSH tunnel thread will behave as a SOCKS proxy server
            // with dynamic port forwarding:
            tunnel.setDynamicPortForwarding(true);

            // We may optionally require that connecting clients authenticate with our SOCKS proxy server.
            // To do this, set an inbound username/password.  Any connecting clients would be required to
            // use SOCKS5 with the correct username/password.
            // If no inbound username/password is set, then our SOCKS proxy server will accept both
            // SOCKS4 and SOCKS5 unauthenticated connections.

            tunnel.setInboundSocksUsername("chilkat123");
            tunnel.setInboundSocksPassword("password123");

            // Start the listen/accept thread to begin accepting SOCKS proxy client connections.
            // Listen on port 1080.
            tunnel.beginAccepting(1080);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Now that a background thread is running a SOCKS proxy server that forwards connections
        // through an SSH tunnel, it is possible to use any Chilkat implemented protocol that is SOCKS capable,
        // such as Socket, HTTP, POP3, SMTP, IMAP, FTP, etc.  The protocol may use SSL/TLS because the SSL/TLS
        // will be passed through the SSH tunnel to the end-destination.  Also, any number of simultaneous
        // connections may be routed through the SSH tunnel.

        // Let's do an FTP upload through the SSH tunnel.  Both the control and data connections
        // go through the tunnel.
        Ftp2 ftp = new Ftp2();

        ftp.setHostname("ftp.example.com");
        ftp.setUsername("login");
        ftp.setPassword("password");

        // Indicate that the FTP2 object is to use our portable SOCKS proxy/SSH tunnel running in our background thread.
        ftp.setSocksHostname("localhost");
        ftp.setSocksPort(1080);
        ftp.setSocksVersion(5);
        ftp.setSocksUsername("chilkat123");
        ftp.setSocksPassword("password123");

        // Connect to the FTP server
        try {
            ftp.connectOnly();

            // Authenticate with the FTP server.
            ftp.loginAfterConnectOnly();

            // Change to the remote directory where the file will be uploaded.
            ftp.changeRemoteDir("junk");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Upload a file.
        String localPath = "/temp/hamlet.xml";
        String remoteFilename = "hamlet.xml";

        try {
            ftp.putFile(localPath, remoteFilename);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // This closes the SSH channel within the SSH tunnel,
        // and thus closes the connection with the FTP server.
        ftp.disconnect();

        System.out.println("File Uploaded!");

        // Stop the background listen/accept thread:
        boolean waitForThreadExit = true;
        try {
            tunnel.stopAccepting(waitForThreadExit);

            // Close the SSH tunnel (would also kick any remaining connected clients).
            tunnel.closeTunnel(waitForThreadExit);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }
    }
}