(Chilkat for Android™ API)
Encrypting and Decrypting Content

Demonstrates how to encrypt and decrypt the content of an XML node using 128-bit CBC AES encryption.

The input XML, available at http://www.chilkatsoft.com/data/fox.xml, is this:

<root>
    <fox1>The quick brown fox jumps over the lazy dog</fox1>
    <fox2>The quick brown fox jumps over the lazy dog
        <child1>ABC</child1>
        <child2>XYZ</child2>
    </fox2>
</root>

Download: Chilkat for Android™ Java 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 {
  // Called when the activity is first created.
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    TextView tv = new TextView(this);
    String outStr = "";

    CkXml xml = new CkXml();

    boolean success;
    //  The sample input XML is available at http://www.chilkatsoft.com/data/fox.xml
    success = xml.LoadXmlFile("fox.xml");
    if (success != true) {
        outStr += xml.lastErrorText() + "\n";
        tv.setText(outStr);
        setContentView(tv);
        return;
    }

    //  Navigate to the "fox1" node, which is the 1st child:
    xml.FirstChild2();

    //  Encrypt the content:
    xml.EncryptContent("myPassword");

    //  Navigate back to the root:
    xml.GetRoot2();

    //  Examine the new XML document:
    outStr += xml.getXml() + "\n";

    //  This is the XML w/ the encrypted content:
    //  
<root>
    <fox1>1hTtf7XmO+78H+OIr5eWHIuXxP78KPeYrZbsD0HX4negO9ZRqYMBY4s46sPNp+Q+
    </fox1>
    <fox2>The quick brown fox jumps over the lazy dog
        <child1>ABC</child1>
        <child2>XYZ</child2>
    </fox2>
</root>


    //  Now decrypt and show that the original content was restored:
    xml.FirstChild2();
    xml.DecryptContent("myPassword");
    xml.GetRoot2();
    outStr += xml.getXml() + "\n";

    //  Now encrypt the content of the "fox2" node.
    //  First navigate to the "fox2" child.
    xml.FindChild2("fox2");
    xml.EncryptContent("myPassword");
    xml.GetRoot2();
    outStr += xml.getXml() + "\n";

    //  This is the XML w/ the "fox2" encrypted content:
    //  
<root>
    <fox1>The quick brown fox jumps over the lazy dog</fox1>
    <fox2>1hTtf7XmO+78H+OIr5eWHIuXxP78KPeYrZbsD0HX4negO9ZRqYMBY4s46sPNp+Q+

        <child1>ABC</child1>
        <child2>XYZ</child2>
    </fox2>
</root>


    //  Notice that the *content* of the node is encrypted.  The child nodes are NOT encrypted.
    //  This is intentional.  To encrypt the content + the subtrees rooted at a given node,
    //  one would call ZipTree to transform the content and subtrees
    //  to Base64-encoded compressed content, and then call
    //  EncryptContent to encrypt.

    //  Finally, decrypt the "fox2" content:
    xml.FindChild2("fox2");
    xml.DecryptContent("myPassword");
    xml.GetRoot2();
    outStr += xml.getXml() + "\n";
    tv.setText(outStr);
    setContentView(tv);
  }

  static {
      // Important: Make sure the name passed to loadLibrary matches the shared library
      // found in your project's libs/armeabi directory.
      //  for "libchilkat.so", pass "chilkat" to loadLibrary
      //  for "libchilkatemail.so", pass "chilkatemail" to loadLibrary
      //  etc.
      // 
      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."
  }
}