Java

Upgrade an FTP Control Channel to TLS (ConvertToTls)

Demonstrates the Chilkat Ftp2.ConvertToTls method, which upgrades an already-connected clear FTP control channel to explicit TLS. It takes no arguments and is used with a manually staged connection created by ConnectOnly while Ssl is disabled.

Background: This exposes the explicit-FTPS AUTH TLS upgrade as a discrete step for the rare case where you need to do something on the clear connection first — inspect the greeting, apply a workaround — before securing it. In the normal case you simply set AuthTls and let Connect perform the upgrade automatically; this manual path exists for staged control.

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

public class ChilkatExample {

    public static void main(String[] args) {
        // Demonstrates the Ftp2.ConvertToTls method, which upgrades an already-connected clear FTP control
        // channel to explicit TLS.  It takes no arguments.  It is used with a manually staged connection
        // created by ConnectOnly while Ssl is disabled.

        Ftp2 ftp = new Ftp2();

        ftp.setHostname("ftp.example.com");
        ftp.setPort(21);

        // Connect in clear text first (Ssl is false).
        try {
            ftp.connectOnly();

            // Upgrade the control channel to explicit TLS (AUTH TLS).
            ftp.convertToTls();

            // Now authenticate over the encrypted control channel.
            ftp.setUsername("myFtpLogin");
            ftp.setPassword("myPassword");
            ftp.loginAfterConnectOnly();
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("Control channel upgraded to TLS and logged in.");

        try {
            ftp.disconnect();
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }
    }
}