(Android™) TCP or TLS over Multiple Hop SSH to Remote Server

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.

Chilkat Android™ Downloads Android™ Java Libraries Android C/C++ Libraries

// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;

import android.app.Activity;
import com.chilkatsoft.*;

import android.widget.TextView;
import android.os.Bundle;

public class SimpleActivity extends Activity {

  private static final String TAG = "Chilkat";

  // Called when the activity is first created.
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

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

    CkSsh ssh1 = new CkSsh();

    // Connect directly to the 1st SSH server.
    boolean success = ssh1.Connect("serverssh1.com",22);
    if (success != true) {
        Log.i(TAG, ssh1.lastErrorText());
        return;
        }

    // Authenticate using login/password:
    success = ssh1.AuthenticatePw("ssh1Login","ssh1Password");
    if (success != true) {
        Log.i(TAG, ssh1.lastErrorText());
        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.
    CkSsh ssh2 = new CkSsh();
    success = ssh2.ConnectThroughSsh(ssh1,"serverssh2.com",22);
    if (success != true) {
        Log.i(TAG, ssh2.lastErrorText());
        return;
        }

    // Authenticate with ssh2...
    success = ssh2.AuthenticatePw("ssh2Login","ssh2Password");
    if (success != true) {
        Log.i(TAG, ssh2.lastErrorText());
        return;
        }

    CkSocket socket = new CkSocket();

    // 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
    success = socket.UseSsh(ssh2);
    if (success != true) {
        Log.i(TAG, socket.lastErrorText());
        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;
    success = socket.Connect("www.chilkatsoft.com",443,useTls,maxWaitMillisec);
    if (success != true) {
        Log.i(TAG, socket.lastErrorText());
        return;
        }

    // 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.put_StringCharset("utf-8");

    // Send an HTTP HEAD request:
    success = socket.SendString("HEAD / HTTP/1.1\r\nHost: www.chilkatsoft.com\r\n\r\n");
    if (success != true) {
        Log.i(TAG, socket.lastErrorText());
        return;
        }

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

    // Get the 1st response line, which should be "HTTP/1.1 200 OK"
    String responseStatusLine = socket.receiveToCRLF();
    if (socket.get_LastMethodSuccess() != true) {
        Log.i(TAG, socket.lastErrorText());
        return;
        }

    Log.i(TAG, "StatusLine: " + responseStatusLine);

    // Now get the 1st line of the response header:
    String responseHeaderLine = socket.receiveToCRLF();
    if (socket.get_LastMethodSuccess() != true) {
        Log.i(TAG, socket.lastErrorText());
        return;
        }

    Log.i(TAG, "HeaderLine: " + responseHeaderLine);

    // Now read the remainder of the response header by reading until a double CRLF is seen:
    String remainderOfHeader = socket.receiveUntilMatch("\r\n\r\n");
    if (socket.get_LastMethodSuccess() != true) {
        Log.i(TAG, socket.lastErrorText());
        return;
        }

    Log.i(TAG, "Remainder: " + remainderOfHeader);

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

  }

  static {
      System.loadLibrary("chilkat");

      // Note: If the incorrect library name is passed to System.loadLibrary,
      // then you will see the following error message at application startup:
      //"The application <your-application-name> has stopped unexpectedly. Please try again."
  }
}