(DataFlex) Streaming Decrypt HTTP Response

If the an encrypted file was previously uploaded, this example demonstrates how to download and decrypt in a streaming way.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

Use ChilkatAx-9.5.0-win32.pkg

Procedure Test
    Handle hoRest
    Boolean iBTls
    Integer iPort
    Boolean iBAutoReconnect
    Boolean iSuccess
    Integer iResponseStatusCode
    String sErrResponse
    Handle hoCrypt
    Variant vReceiveStream
    Handle hoReceiveStream
    Variant vDecryptStream
    Handle hoDecryptStream
    Variant vDecryptStreamTask
    Handle hoDecryptStreamTask
    String sTemp1
    Boolean bTemp1

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

    Get Create (RefClass(cComChilkatRest)) To hoRest
    If (Not(IsComObjectCreated(hoRest))) Begin
        Send CreateComObject of hoRest
    End

    Move True To iBTls
    Move 443 To iPort
    Move True To iBAutoReconnect
    Get ComConnect Of hoRest "chilkatdownload.com" iPort iBTls iBAutoReconnect To iSuccess

    // Send the request to download a file.
    Get ComSendReqNoBody Of hoRest "GET" "/9.5.0.83/chilkat-9.5.0-python-3.8-x64.zip" To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoRest To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Read the response header.
    Get ComReadResponseHeader Of hoRest To iResponseStatusCode
    If (iResponseStatusCode < 0) Begin
        Get ComLastErrorText Of hoRest To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Showln "Response status code = " iResponseStatusCode

    // We expect a 200 response status if the JPG data is coming.
    // Otherwise, we'll get a string response body with an error message(or no response body).
    If (iResponseStatusCode <> 200) Begin
        Get ComReadRespBodyString Of hoRest To sErrResponse
        Get ComLastMethodSuccess Of hoRest To bTemp1
        If (bTemp1 <> True) Begin
            Get ComLastErrorText Of hoRest To sTemp1
            Showln sTemp1
        End
        Else Begin
            Showln sErrResponse
        End

        Procedure_Return
    End

    // Create an object for decrypting.
    // This example will use "none" for the encryption algorithm, which means it's just a pass-through.
    // Typically you would set the decrypt properties, such as secret key, IV, key length, padding scheme, cipher mode..
    Get Create (RefClass(cComChilkatCrypt2)) To hoCrypt
    If (Not(IsComObjectCreated(hoCrypt))) Begin
        Send CreateComObject of hoCrypt
    End
    Set ComCryptAlgorithm Of hoCrypt To "none"

    // The following settings are ignored in this test because our CryptAlgorithm is "none".
    // However, if you were truly decrypting, you might set CryptAlgorithm = "aes".
    Set ComCipherMode Of hoCrypt To "cbc"
    Set ComKeyLength Of hoCrypt To 128
    Send ComSetEncodedKey To hoCrypt "000102030405060708090A0B0C0D0E0F" "hex"
    Send ComSetEncodedIV To hoCrypt "000102030405060708090A0B0C0D0E0F" "hex"

    Get Create (RefClass(cComChilkatStream)) To hoReceiveStream
    If (Not(IsComObjectCreated(hoReceiveStream))) Begin
        Send CreateComObject of hoReceiveStream
    End
    // The decryptStream's source will be the receiveStream.
    Get Create (RefClass(cComChilkatStream)) To hoDecryptStream
    If (Not(IsComObjectCreated(hoDecryptStream))) Begin
        Send CreateComObject of hoDecryptStream
    End

    // The decrypt stream's sink will be a file.
    Set ComSinkFile Of hoDecryptStream To "qa_output/chilkat-9.5.0-python-3.8-x64.zip"
    Get pvComObject of hoReceiveStream to vReceiveStream
    Get ComSetSourceStream Of hoDecryptStream vReceiveStream To iSuccess

    // Create and run a background async task to decrypt incoming data and write to a file.
    Get pvComObject of hoDecryptStream to vDecryptStream
    Get ComDecryptStreamAsync Of hoCrypt vDecryptStream To vDecryptStreamTask
    If (IsComObject(vDecryptStreamTask)) Begin
        Get Create (RefClass(cComChilkatTask)) To hoDecryptStreamTask
        Set pvComObject Of hoDecryptStreamTask To vDecryptStreamTask
    End
    Get ComRun Of hoDecryptStreamTask To iSuccess

    Get pvComObject of hoReceiveStream to vReceiveStream
    Get ComReadRespBodyStream Of hoRest vReceiveStream True To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoRest To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Showln "Successfully received the .zip file."


End_Procedure