(Node.js) 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

Install Chilkat for Node.js and Electron using npm at Chilkat npm packages for Node.js Chilkat npm packages for Electron on Windows, Linux, MacOSX, and ARM

var os = require('os');
if (os.platform() == 'win32') {  
    if (os.arch() == 'ia32') {
        var chilkat = require('@chilkat/ck-node21-win-ia32');
    } else {
        var chilkat = require('@chilkat/ck-node21-win64'); 
    }
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node21-arm');
    } else if (os.arch() == 'x86') {
        var chilkat = require('@chilkat/ck-node21-linux32');
    } else {
        var chilkat = require('@chilkat/ck-node21-linux64');
    }
} else if (os.platform() == 'darwin') {
    if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node21-mac-m1');
    } else {
        var chilkat = require('@chilkat/ck-node21-macosx');
    }
}

function chilkatExample() {

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

    var success;

    // Initialize the compression object.
    var compress = new chilkat.Compression();
    compress.Algorithm = "deflate";

    // Initialize the encryption object.
    var crypt = new chilkat.Crypt2();
    crypt.CryptAlgorithm = "chacha20";
    crypt.KeyLength = 256;
    crypt.EncodingMode = "hex";
    var ivHex = "000000000000000000000002";
    crypt.SetEncodedIV(ivHex,"hex");
    crypt.InitialCount = 42;
    var keyHex = "1c9240a5eb55d38af333888604f6b5f0473917c1402b80099dca5cbc207075c0";
    crypt.SetEncodedKey(keyHex,"hex");

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

    // The source for the compressor is a file.
    streamC.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..
    // taskC: Task
    var taskC = compress.CompressStreamAsync(streamC);
    // taskE: Task
    var taskE = crypt.EncryptStreamAsync(streamE);
    success = taskC.Run();
    success = taskE.Run();

    // Read the compressed and encrypted bytes.
    var outData = new chilkat.BinData();
    while ((streamE.EndOfStream !== true)) {
        if (streamE.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.Finished !== true) || (taskC.Finished !== true))) {
        taskE.SleepMs(20);
    }

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

    // Double-check for success..
    if (taskE.TaskSuccess !== true) {
        console.log("async encryption failed:");
        console.log(taskE.ResultErrorText);
        success = false;
    }

    // Double-check for success..
    if (taskC.TaskSuccess !== true) {
        console.log("async compression failed:");
        console.log(taskC.ResultErrorText);
        success = false;
    }

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

    console.log("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");

}

chilkatExample();