(PowerShell) 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 .NET Downloads Chilkat .NET Assemblies Chilkat for Mono

Add-Type -Path "C:\chilkat\ChilkatDotNet47-9.5.0-x64\ChilkatDotNet47.dll"

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

# Initialize the compression object.
$compress = New-Object Chilkat.Compression
$compress.Algorithm = "deflate"

# Initialize the encryption object.
$crypt = New-Object Chilkat.Crypt2
$crypt.CryptAlgorithm = "chacha20"
$crypt.KeyLength = 256
$crypt.EncodingMode = "hex"
$ivHex = "000000000000000000000002"
$crypt.SetEncodedIV($ivHex,"hex")
$crypt.InitialCount = 42
$keyHex = "1c9240a5eb55d38af333888604f6b5f0473917c1402b80099dca5cbc207075c0"
$crypt.SetEncodedKey($keyHex,"hex")

# Setup the streams.  
# streamC is for compression
$streamC = New-Object Chilkat.Stream
# streamE is for encryption
$streamE = New-Object 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 = $compress.CompressStreamAsync($streamC)
$taskE = $crypt.EncryptStreamAsync($streamE)
$success = $taskC.Run()
$success = $taskE.Run()

# Read the compressed and encrypted bytes.
$outData = New-Object Chilkat.BinData
while (($streamE.EndOfStream -ne $true)) {
    if ($streamE.DataAvailable -eq $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 -ne $true) -or ($taskC.Finished -ne $true))) {
    $taskE.SleepMs(20)
}

# Get any remaining data that needs to be flushed.
if ($streamE.DataAvailable -eq $true) {
    $success = $streamE.ReadBd($outData)
}

# Double-check for success..
if ($taskE.TaskSuccess -ne $true) {
    $("async encryption failed:")
    $($taskE.ResultErrorText)
    $success = $false
}

# Double-check for success..
if ($taskC.TaskSuccess -ne $true) {
    $("async compression failed:")
    $($taskC.ResultErrorText)
    $success = $false
}

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

$("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")