Java

TCP or TLS over Multiple Hop SSH to Remote Server

See more Socket/SSL/TLS Examples

Demonstrates how to use the Chilkat Socket API to connect to a remote server (using TCP or TLS) tunneled through mulitple-hop SSH. The scheme looks like this:

Application => ServerSSH1 => ServerSSH2 => DestinationServer

The ConnectThroughSsh and UseSsh methods are added in Chilkat version 9.5.0.55 to accomplish this task.

Chilkat2 Java

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

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.

        Ssh ssh1 = new Ssh();

        // Connect directly to the 1st SSH server.
        try {
            ssh1.connect("serverssh1.com", 22);

            // Authenticate using login/password:
            ssh1.authenticatePw("ssh1Login", "ssh1Password");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Connect through the 1st SSH connection to reach a 2nd SSH server.
        // Note: Any number of SSH connections may be simultaneously tunneled through a single
        // existing SSH connection.
        Ssh ssh2 = new Ssh();
        try {
            ssh2.connectThroughSsh(ssh1, "serverssh2.com", 22);

            // Authenticate with ssh2...
            ssh2.authenticatePw("ssh2Login", "ssh2Password");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        Socket socket = new Socket();

        // Tell the socket object to connect to our destination server though the ssh2 tunnel (which itself is routed through ssh1).
        // The connection looks like this:  ApplicationSocket(TLS) => ServerSSH1 => ServerSSH2 => DestinationServer
        try {
            socket.useSsh(ssh2);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Connect using TLS to www.chilkatsoft.com
        // We could also tunnel a bare TCP connection by specifying port 80 with useTls = false.
        boolean useTls = true;
        int maxWaitMillisec = 20000;
        String responseStatusLine;
        try {
            socket.connect("www.chilkatsoft.com", 443, useTls, maxWaitMillisec);

            // Once the multiple hop SSH tunneled connection is setup,  the socket programming
            // is identical to the normal case where we have a direct connection.

            // Tell the socket object that all text is to be sent in the utf-8 encoding,
            // and the text received is assumed to be utf-8.
            socket.setStringCharset("utf-8");

            // Send an HTTP HEAD request:
            socket.sendString("HEAD / HTTP/1.1\r\nHost: www.chilkatsoft.com\r\n\r\n");

            // Wait a maximum of 4 seconds while no data is forthcoming:
            socket.setMaxReadIdleMs(4000);

            // Get the 1st response line, which should be "HTTP/1.1 200 OK"
            responseStatusLine = socket.receiveToCRLF();
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("StatusLine: " + responseStatusLine);

        // Now get the 1st line of the response header:
        String responseHeaderLine;
        try {
            responseHeaderLine = socket.receiveToCRLF();
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("HeaderLine: " + responseHeaderLine);

        // Now read the remainder of the response header by reading until a double CRLF is seen:
        String remainderOfHeader;
        try {
            remainderOfHeader = socket.receiveUntilMatch("\r\n\r\n");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("Remainder: " + remainderOfHeader);

        // Close the connection with the server.  This closes the tunnel through ssh2.
        // Wait a max of 20 seconds (20000 millsec)
        socket.closeConnection(20000);

        // Close the connection with ssh2.  (This closes the the tunnel through ssh1.)
        // The connection with ssh1 is still alive, and may be used for more connections.
        ssh2.disconnect();

        ssh1.disconnect();
    }
}