(Android™) AES XTS Mode

Demonstrates the AES-XTS mode of operation.

Note: This example requires Chilkat v9.5.0.91 or greater.

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

    boolean success;

    // Here we have a sample from CAVS validatition data:

    // COUNT = 301
    // DataUnitLen = 200
    // Key = 
    // 394c97881abd989d29c703e48a72b397
    // a7acf51b59649eeea9b33274d8541df4
    // i = 4b15c684a152d485fe9937d39b168c29
    // PT = 2f3b9dcfbae729583b1d1ffdd16bb6fe2757329435662a78f0
    // CT = f3473802e38a3ffef4d4fb8e6aa266ebde553a64528a06463e

    // Note: The above sample requires an AES-XTS implementation that fully supports ciphertext-stealing
    // because the data to be encrypted is not an even multiple of the AES block size (i.e. not a multiple of 16 bytes).
    // Chilkat fully supports AES-XTS with ciphertext stealing.
    // (i.e. Chilkat implements XEX-based tweaked-codebook mode with ciphertext stealing (XTS))

    String key = "394c97881abd989d29c703e48a72b397";
    String tweakKey = "a7acf51b59649eeea9b33274d8541df4";
    String dataUnit = "4b15c684a152d485fe9937d39b168c29";

    CkBinData bd = new CkBinData();
    bd.AppendEncoded("2f3b9dcfbae729583b1d1ffdd16bb6fe2757329435662a78f0","hex");

    CkCrypt2 crypt = new CkCrypt2();

    crypt.put_CryptAlgorithm("aes");
    crypt.put_CipherMode("xts");
    crypt.put_KeyLength(128);

    crypt.SetEncodedKey(key,"hex");
    crypt.XtsSetEncodedTweakKey(tweakKey,"hex");
    crypt.XtsSetEncodedTweakValue(dataUnit,"hex");

    // In-place encrypt the contents of bd.
    success = crypt.EncryptBd(bd);

    Log.i(TAG, "CT = " + bd.getEncoded("hexlower"));

    // Decrypt to revert back to the unencrypted content:
    success = crypt.DecryptBd(bd);

    Log.i(TAG, "PT = " + bd.getEncoded("hexlower"));

    // Output:
    // CT = f3473802e38a3ffef4d4fb8e6aa266ebde553a64528a06463e
    // PT = 2f3b9dcfbae729583b1d1ffdd16bb6fe2757329435662a78f0

  }

  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."
  }
}