(Android™) Streaming Compression --> Streaming Encryption

Demonstrate how to feed a compression stream into an encryption stream. This example does the following:

Data File --> Compress --> Encrypt --> Application Reads

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

    boolean success;

    //  Initialize the compression object.
    CkCompression compress = new CkCompression();
    compress.put_Algorithm("deflate");

    //  Initialize the encryption object.
    CkCrypt2 crypt = new CkCrypt2();
    crypt.put_CryptAlgorithm("chacha20");
    crypt.put_KeyLength(256);
    crypt.put_EncodingMode("hex");
    String ivHex = "000000000000000000000002";
    crypt.SetEncodedIV(ivHex,"hex");
    crypt.put_InitialCount(42);
    String keyHex = "1c9240a5eb55d38af333888604f6b5f0473917c1402b80099dca5cbc207075c0";
    crypt.SetEncodedKey(keyHex,"hex");

    //  Setup the streams.
    //  streamC is for compression
    CkStream streamC = new CkStream();
    //  streamE is for encryption
    CkStream streamE = new CkStream();

    //  The source for the compressor is a file.
    streamC.put_SourceFile("qa_data/hamlet.xml");
    //  The source for the encryptor is the output of the compressor stream.
    success = streamE.SetSourceStream(streamC);

    //  Our application will be reading the output of streamE.
    //  Start the compression and encryption streams in background threads..
    CkTask taskC = compress.CompressStreamAsync(streamC);
    CkTask taskE = crypt.EncryptStreamAsync(streamE);
    success = taskC.Run();
    success = taskE.Run();

    //  Read the compressed and encrypted bytes.
    CkBinData outData = new CkBinData();
    while ((streamE.get_EndOfStream() != true)) {
        if (streamE.get_DataAvailable() == true) {
            success = streamE.ReadBd(outData);
            }

        }

    //  Let's make sure the background task finished.
    //  It should already be the case that the task is finished.
    while (((taskE.get_Finished() != true) or (taskC.get_Finished() != true))) {
        taskE.SleepMs(20);
        }

    //  Get any remaining data that needs to be flushed.
    if (streamE.get_DataAvailable() == true) {
        success = streamE.ReadBd(outData);
        }

    //  Double-check for success..
    if (taskE.get_TaskSuccess() != true) {
        Log.i(TAG, "async encryption failed:");
        Log.i(TAG, taskE.resultErrorText());
        success = false;
        }

    //  Double-check for success..
    if (taskC.get_TaskSuccess() != true) {
        Log.i(TAG, "async compression failed:");
        Log.i(TAG, taskC.resultErrorText());
        success = false;
        }

    //  Save the compressed/encrypted data to a file.
    outData.WriteFile("qa_output/compressedEncrypted.dat");

    Log.i(TAG, "The async compress/encrypt was successful.");

    //  Let's decrypt and decompress to further verify...
    success = crypt.DecryptBd(outData);
    success = compress.DecompressBd(outData);

    //  outData should contain the original data..
    success = outData.WriteFile("qa_output/original_hamlet.xml");

  }

  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."
  }
}