(VBScript) 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 ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

Dim fso, outFile
Set fso = CreateObject("Scripting.FileSystemObject")
Set outFile = fso.CreateTextFile("output.txt", True)

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

'  Initialize the compression object.
set compress = CreateObject("Chilkat_9_5_0.Compression")
compress.Algorithm = "deflate"

'  Initialize the encryption object.
set crypt = CreateObject("Chilkat_9_5_0.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
set streamC = CreateObject("Chilkat_9_5_0.Stream")
'  streamE is for encryption
set streamE = CreateObject("Chilkat_9_5_0.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 is a Chilkat_9_5_0.Task
Set taskC = compress.CompressStreamAsync(streamC)
' taskE is a Chilkat_9_5_0.Task
Set taskE = crypt.EncryptStreamAsync(streamE)
success = taskC.Run()
success = taskE.Run()

'  Read the compressed and encrypted bytes.
set outData = CreateObject("Chilkat_9_5_0.BinData")
Do While (streamE.EndOfStream <> 1)
    If (streamE.DataAvailable = 1) Then
        success = streamE.ReadBd(outData)
    End If

Loop

'  Let's make sure the background task finished.
'  It should already be the case that the task is finished.
Do While ((taskE.Finished <> 1) Or (taskC.Finished <> 1))
    taskE.SleepMs 20
Loop

'  Get any remaining data that needs to be flushed.
If (streamE.DataAvailable = 1) Then
    success = streamE.ReadBd(outData)
End If

'  Double-check for success..
If (taskE.TaskSuccess <> 1) Then
    outFile.WriteLine("async encryption failed:")
    outFile.WriteLine(taskE.ResultErrorText)
    success = 0
End If

'  Double-check for success..
If (taskC.TaskSuccess <> 1) Then
    outFile.WriteLine("async compression failed:")
    outFile.WriteLine(taskC.ResultErrorText)
    success = 0
End If

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

outFile.WriteLine("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")

outFile.Close