(MFC) Stream a file to compression to encryption to an output file.

Runs a chain of streams to read a source file, compress, encrypt, and write an output file.

Chilkat C/C++ Library Downloads MS Visual C/C++ Libs

See Also: Using MFC CString in Chilkat

#include <CkCompression.h>
#include <CkCrypt2.h>
#include <CkStream.h>
#include <CkTask.h>
#include <CkBinData.h>

void ChilkatSample(void)
    {
    CkString strOut;

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

    bool success;

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

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

    //  Setup the streams.
    //  streamC is for compression
    CkStream streamC;
    //  streamE is for encryption
    CkStream streamE;

    //  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);

    //  The sink for the encryptor is the output file.
    streamE.put_SinkFile("qa_output/compressed_encrypted.dat");

    //  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();

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

    //  check for success..
    if (taskE->get_TaskSuccess() != true) {
        strOut.append("async encryption failed:");
        strOut.append("\r\n");
        strOut.append(taskE->resultErrorText());
        strOut.append("\r\n");
        success = false;
    }

    //  check for success..
    if (taskC->get_TaskSuccess() != true) {
        strOut.append("async compression failed:");
        strOut.append("\r\n");
        strOut.append(taskC->resultErrorText());
        strOut.append("\r\n");
        success = false;
    }

    delete taskE;
    delete taskC;

    //  Load the file that was produced and decrypt/decompress to verify.
    CkBinData binData;
    success = binData.LoadFile("qa_output/compressed_encrypted.dat");
    success = crypt.DecryptBd(binData);
    success = compress.DecompressBd(binData);

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

    strOut.append("Finished.");
    strOut.append("\r\n");


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }