(PureBasic) 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 PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkTask.pb"
IncludeFile "CkBinData.pb"
IncludeFile "CkCompression.pb"
IncludeFile "CkStream.pb"
IncludeFile "CkCrypt2.pb"

Procedure ChilkatExample()

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

    success.i

    ; Initialize the compression object.
    compress.i = CkCompression::ckCreate()
    If compress.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkCompression::setCkAlgorithm(compress, "deflate")

    ; Initialize the encryption object.
    crypt.i = CkCrypt2::ckCreate()
    If crypt.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkCrypt2::setCkCryptAlgorithm(crypt, "chacha20")
    CkCrypt2::setCkKeyLength(crypt, 256)
    CkCrypt2::setCkEncodingMode(crypt, "hex")
    ivHex.s = "000000000000000000000002"
    CkCrypt2::ckSetEncodedIV(crypt,ivHex,"hex")
    CkCrypt2::setCkInitialCount(crypt, 42)
    keyHex.s = "1c9240a5eb55d38af333888604f6b5f0473917c1402b80099dca5cbc207075c0"
    CkCrypt2::ckSetEncodedKey(crypt,keyHex,"hex")

    ; Setup the streams.  
    ; streamC is for compression
    streamC.i = CkStream::ckCreate()
    If streamC.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; streamE is for encryption
    streamE.i = CkStream::ckCreate()
    If streamE.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; The source for the compressor is a file.
    CkStream::setCkSourceFile(streamC, "qa_data/hamlet.xml")
    ; The source for the encryptor is the output of the compressor stream.
    success = CkStream::ckSetSourceStream(streamE,streamC)

    ; The sink for the encryptor is the output file.
    CkStream::setCkSinkFile(streamE, "qa_output/compressed_encrypted.dat")

    ; Start the compression and encryption streams in background threads..
    taskC.i = CkCompression::ckCompressStreamAsync(compress,streamC)
    taskE.i = CkCrypt2::ckEncryptStreamAsync(crypt,streamE)
    success = CkTask::ckRun(taskC)
    success = CkTask::ckRun(taskE)

    ; 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 ((CkTask::ckFinished(taskE) <> 1) OR (CkTask::ckFinished(taskC) <> 1))
        CkTask::ckSleepMs(taskE,20)
    Wend

    ; check for success..
    If CkTask::ckTaskSuccess(taskE) <> 1
        Debug "async encryption failed:"
        Debug CkTask::ckResultErrorText(taskE)
        success = 0
    EndIf

    ; check for success..
    If CkTask::ckTaskSuccess(taskC) <> 1
        Debug "async compression failed:"
        Debug CkTask::ckResultErrorText(taskC)
        success = 0
    EndIf

    CkTask::ckDispose(taskE)

    CkTask::ckDispose(taskC)

    ; Load the file that was produced and decrypt/decompress to verify.
    binData.i = CkBinData::ckCreate()
    If binData.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkBinData::ckLoadFile(binData,"qa_output/compressed_encrypted.dat")
    success = CkCrypt2::ckDecryptBd(crypt,binData)
    success = CkCompression::ckDecompressBd(compress,binData)

    ; binData should contain the original data..
    success = CkBinData::ckWriteFile(binData,"qa_output/original_hamlet.xml")

    Debug "Finished."


    CkCompression::ckDispose(compress)
    CkCrypt2::ckDispose(crypt)
    CkStream::ckDispose(streamC)
    CkStream::ckDispose(streamE)
    CkBinData::ckDispose(binData)


    ProcedureReturn
EndProcedure