(Swift 3,4,5...) 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 Downloads for the Swift Programming Language MAC OS X (Cocoa) Objective-C/Swift Libs iOS Objective-C/Swift Libs

func chilkatTest() {
    // This requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    var success: Bool

    // Initialize the compression object.
    let compress = CkoCompression()!
    compress.algorithm = "deflate"

    // Initialize the encryption object.
    let crypt = CkoCrypt2()!
    crypt.cryptAlgorithm = "chacha20"
    crypt.keyLength = 256
    crypt.encodingMode = "hex"
    var ivHex: String? = "000000000000000000000002"
    crypt.setEncodedIV(ivHex, encoding: "hex")
    crypt.initialCount = 42
    var keyHex: String? = "1c9240a5eb55d38af333888604f6b5f0473917c1402b80099dca5cbc207075c0"
    crypt.setEncodedKey(keyHex, encoding: "hex")

    // Setup the streams.  
    // streamC is for compression
    let streamC = CkoStream()!
    // streamE is for encryption
    let streamE = CkoStream()!

    // 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..
    var taskC: CkoTask? = compress.compressStreamAsync(streamC)
    var taskE: CkoTask? = crypt.encryptStreamAsync(streamE)
    success = taskC!.run()
    success = taskE!.run()

    // Read the compressed and encrypted bytes.
    let outData = CkoBinData()!
    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 {
        print("async encryption failed:")
        print("\(taskE!.resultErrorText!)")
        success = false
    }

    // Double-check for success..
    if taskC!.taskSuccess != true {
        print("async compression failed:")
        print("\(taskC!.resultErrorText!)")
        success = false
    }

    taskE = nil
    taskC = nil

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

    print("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")

}