Android™

Encrypt / Decrypt a File and Verify it has not Changed

See more Encryption Examples

Demonstrates how to encrypt and decrypt a file, and verify it has not changed. Android™

// 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);

    boolean success = false;

    // This 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(128);
    crypt.put_PaddingScheme(0);

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

    String keyHex = "00010203040506071011121314151617";
    crypt.SetEncodedKey(keyHex,"hex");

    String dataFile = "qa_data/zips/HBIQ040615300005.ZIP";
    String outFile = "qa_output/HBIQ040615300005.enc";
    String outFile2 = "qa_output/HBIQ040615300005.ZIP";

    success = crypt.CkEncryptFile(dataFile,outFile);
    success = crypt.CkDecryptFile(outFile,outFile2);

    CkFileAccess fac = new CkFileAccess();
    boolean bEqual = fac.FileContentsEqual(dataFile,outFile2);
    if (bEqual != true) {
        Log.i(TAG, "Decrypted file not equal to the original.");
        }
    else {
        Log.i(TAG, "Success.");
        }


  }

  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."
  }
}