(Android™) AES Encrypt String (utf-8 byte representation) and return Base64

Demonstrates how to AES encrypt the utf-8 byte representation of a string and return in base64 format.

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.

    CkCrypt2 crypt = new CkCrypt2();

    crypt.put_CryptAlgorithm("aes");
    crypt.put_CipherMode("cbc");
    crypt.put_KeyLength(256);
    crypt.put_Charset("utf-8");
    crypt.put_EncodingMode("base64");

    String ivHex = "000102030405060708090A0B0C0D0E0F";
    crypt.SetEncodedIV(ivHex,"hex");
    String keyHex = "000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F";
    crypt.SetEncodedKey(keyHex,"hex");

    String encryptedStr = crypt.encryptStringENC("This is the original string");
    Log.i(TAG, encryptedStr);

    // Let's say we want to URL encode the base64 string..
    crypt.put_CryptAlgorithm("none");
    crypt.put_EncodingMode("url");
    String urlEncoded = crypt.encryptStringENC(encryptedStr);
    Log.i(TAG, urlEncoded);

    // Sample output:

    //  q3fmgEqjqa9o//ZS6aPuh4Wtbrrxx/WOIQSKeVnesZg=
    //  q3fmgEqjqa9o%2F%2FZS6aPuh4Wtbrrxx%2FWOIQSKeVnesZg%3D

    // -------------------------------------------------------------------
    // Now let's do the reverse...
    // 

    // We start with a string that is the binary encrypted data, base64 encoded, and then URL encoded.
    String encBase64Url = "q3fmgEqjqa9o%2F%2FZS6aPuh4Wtbrrxx%2FWOIQSKeVnesZg%3D";

    // We'll use the same crypt object.  If using a new instance of the crypt object,
    // make sure *all* settings are identical:  the algorithm, cipher mode, key length, charset, encoding mode, IV, and secret key.

    // Decode from URL...
    crypt.put_CryptAlgorithm("none");
    crypt.put_EncodingMode("url");
    String encBase64 = crypt.decryptStringENC(urlEncoded);
    Log.i(TAG, encBase64);

    // Now decrypt...
    crypt.put_CryptAlgorithm("aes");
    crypt.put_EncodingMode("base64");
    String originalStr = crypt.decryptStringENC(encBase64);
    Log.i(TAG, originalStr);

  }

  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."
  }
}