(Visual FoxPro) 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

LOCAL loRest
LOCAL lnBTls
LOCAL lnPort
LOCAL lnBAutoReconnect
LOCAL lnSuccess
LOCAL lnResponseStatusCode
LOCAL lcErrResponse
LOCAL loCrypt
LOCAL loReceiveStream
LOCAL loDecryptStream
LOCAL loDecryptStreamTask

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

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Rest')
loRest = CreateObject('Chilkat.Rest')

lnBTls = 1
lnPort = 443
lnBAutoReconnect = 1
lnSuccess = loRest.Connect("chilkatdownload.com",lnPort,lnBTls,lnBAutoReconnect)

* Send the request to download a file.
lnSuccess = loRest.SendReqNoBody("GET","/9.5.0.83/chilkat-9.5.0-python-3.8-x64.zip")
IF (lnSuccess <> 1) THEN
    ? loRest.LastErrorText
    RELEASE loRest
    CANCEL
ENDIF

* Read the response header.
lnResponseStatusCode = loRest.ReadResponseHeader()
IF (lnResponseStatusCode < 0) THEN
    ? loRest.LastErrorText
    RELEASE loRest
    CANCEL
ENDIF

? "Response status code = " + STR(lnResponseStatusCode)

* 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 (lnResponseStatusCode <> 200) THEN
    lcErrResponse = loRest.ReadRespBodyString()
    IF (loRest.LastMethodSuccess <> 1) THEN
        ? loRest.LastErrorText
    ELSE
        ? lcErrResponse
    ENDIF

    RELEASE loRest
    CANCEL
ENDIF

* 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..
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Crypt2')
loCrypt = CreateObject('Chilkat.Crypt2')
loCrypt.CryptAlgorithm = "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".
loCrypt.CipherMode = "cbc"
loCrypt.KeyLength = 128
loCrypt.SetEncodedKey("000102030405060708090A0B0C0D0E0F","hex")
loCrypt.SetEncodedIV("000102030405060708090A0B0C0D0E0F","hex")

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Stream')
loReceiveStream = CreateObject('Chilkat.Stream')
* The decryptStream's source will be the receiveStream.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Stream')
loDecryptStream = CreateObject('Chilkat.Stream')

* The decrypt stream's sink will be a file.
loDecryptStream.SinkFile = "qa_output/chilkat-9.5.0-python-3.8-x64.zip"
loDecryptStream.SetSourceStream(loReceiveStream)

* Create and run a background async task to decrypt incoming data and write to a file.
loDecryptStreamTask = loCrypt.DecryptStreamAsync(loDecryptStream)
lnSuccess = loDecryptStreamTask.Run()

lnSuccess = loRest.ReadRespBodyStream(loReceiveStream,1)
IF (lnSuccess <> 1) THEN
    ? loRest.LastErrorText
    RELEASE loRest
    RELEASE loCrypt
    RELEASE loReceiveStream
    RELEASE loDecryptStream
    CANCEL
ENDIF

? "Successfully received the .zip file."

RELEASE loRest
RELEASE loCrypt
RELEASE loReceiveStream
RELEASE loDecryptStream