Java

Socket Convert Existing TCP Connection to SSL/TLS

Demonstrates the Chilkat Socket ConvertToSsl method. Chilkat2 Java

import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Socket;

public class ChilkatExample {

    public static void main(String[] args) {
        // This example requires the Chilkat API to have been previously unlocked.
        // See Global Unlock Sample for sample code.

        Socket sock = new Socket();

        // --------------------------------------------------------------------
        // This example uses the public TCP/TLS echo service at https://tcpbin.com/
        // --------------------------------------------------------------------

        // The echo server at tcpbin.com expects to receive TCP connections on port 4242, and TLS connections on port 4243.
        // We could simply connect to port 4243 using TLS like this.
        // However, further below, this example shows how to initially make a TCP connection, and then convert the connection to TLS.
        boolean useTls = true;
        int port = 4243;
        int maxWaitMs = 5000;
        try {
            sock.connect("tcpbin.com", port, useTls, maxWaitMs);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // OK, we have a TLS connection.
        // Note: The server chooses the TLS protocol version.
        // We can see the version of the TLS connection that was established:
        System.out.println("TLS version: " + sock.getTlsVersion());

        sock.closeConnection(maxWaitMs);

        // ---------------------------------------------------------------------
        // Now we'll do the same, except first we connect to port 4243 using TCP,
        // and then convert the connection to TLS.
        //
        // This may seem pointless, and it is for the case w/ this server.  However, there could be situations
        // where you're interacting with a server of some kind where there is a need to convert to/from TLS.
        // (This is common internal to many protocols, such as SMTP, IMAP, FTP, etc., and it is often called "explicit" SSL/TLS)

        // Connect again, except this time useTls is false, so we only have a simple TCP connection after this call.
        useTls = false;
        try {
            sock.connect("tcpbin.com", port, useTls, maxWaitMs);

            // Convert the existing TCP connection to TLS.
            // (The method name uses "SSL" because long ago, at the time of initial development, TLS 1.0 did not yet exist.)
            sock.convertToSsl();
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // OK, we now have a TLS connection.
        // Again, we can see the TLS version:
        System.out.println("TLS version: " + sock.getTlsVersion());

        sock.closeConnection(maxWaitMs);
    }
}