(Android™) Verify FTP SSL Server Certificate

This example demonstrates how to verify the FTP server's certificate and authenticity. The intent is to verify the authenticity of the server before passing a login/password to it.

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.

    CkFtp2 ftp = new CkFtp2();

    ftp.put_Hostname("ftp.myftpserver.com");
    ftp.put_Username("myUsername");
    ftp.put_Password("myPassword");

    // Establish an AUTH SSL secure channel after connection
    // on the standard FTP port 21.
    ftp.put_AuthSsl(true);

    // The Ssl property is for establishing an implicit SSL connection
    // on port 990.  Do not set it.
    ftp.put_Ssl(false);

    // Indicate that the FTP server must have a verifiable SSL certificate.
    // Do not accept self-signed certs or certificates that are
    // expired, revoked, or cannot be verified to a root authority:
    ftp.put_RequireSslCertVerify(true);

    // You may also set a requirement.  In this example,
    // the certificate's Common Name (CN) must match the
    // required string exactly:
    ftp.SetSslCertRequirement("subjectcn","Chilkat Software, Inc.");

    // Connect and login to the FTP server.
    boolean success = ftp.Connect();
    if (success != true) {
        Log.i(TAG, ftp.lastErrorText());
        return;
        }
    else {
        // LastErrorText contains information even when
        // successful. This allows you to visually verify
        // that the secure connection actually occurred.
        Log.i(TAG, ftp.lastErrorText());
        }

    // After logging on, you may examine the FTP server's cert:
    CkCert cert;
    cert = ftp.GetSslServerCert();
    if (ftp.get_LastMethodSuccess() != true) {
        Log.i(TAG, "No server certificate!");
        }
    else {
        // Display the distinguished name of the SSL cert.
        Log.i(TAG, cert.subjectDN());
        }

    Log.i(TAG, "Secure FTP Channel Established!");

    // Do whatever you're doing to do ...
    // upload files, download files, etc...

    success = ftp.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."
  }
}