(Tcl) Streaming Decrypt HTTP Response

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

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load ./chilkat.dll

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

set rest [new_CkRest]

set bTls 1
set port 443
set bAutoReconnect 1
set success [CkRest_Connect $rest "chilkatdownload.com" $port $bTls $bAutoReconnect]

# Send the request to download a file.
set success [CkRest_SendReqNoBody $rest "GET" "/9.5.0.83/chilkat-9.5.0-python-3.8-x64.zip"]
if {$success != 1} then {
    puts [CkRest_lastErrorText $rest]
    delete_CkRest $rest
    exit
}

# Read the response header.
set responseStatusCode [CkRest_ReadResponseHeader $rest]
if {$responseStatusCode < 0} then {
    puts [CkRest_lastErrorText $rest]
    delete_CkRest $rest
    exit
}

puts "Response status code = $responseStatusCode"

# 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 {$responseStatusCode != 200} then {
    set errResponse [CkRest_readRespBodyString $rest]
    if {[CkRest_get_LastMethodSuccess $rest] != 1} then {
        puts [CkRest_lastErrorText $rest]
    }     else {
        puts "$errResponse"
    }

    delete_CkRest $rest
    exit
}

# 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..
set crypt [new_CkCrypt2]

CkCrypt2_put_CryptAlgorithm $crypt "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".
CkCrypt2_put_CipherMode $crypt "cbc"
CkCrypt2_put_KeyLength $crypt 128
CkCrypt2_SetEncodedKey $crypt "000102030405060708090A0B0C0D0E0F" "hex"
CkCrypt2_SetEncodedIV $crypt "000102030405060708090A0B0C0D0E0F" "hex"

set receiveStream [new_CkStream]

# The decryptStream's source will be the receiveStream.
set decryptStream [new_CkStream]

# The decrypt stream's sink will be a file.
CkStream_put_SinkFile $decryptStream "qa_output/chilkat-9.5.0-python-3.8-x64.zip"
CkStream_SetSourceStream $decryptStream $receiveStream

# Create and run a background async task to decrypt incoming data and write to a file.
# decryptStreamTask is a CkTask
set decryptStreamTask [CkCrypt2_DecryptStreamAsync $crypt $decryptStream]
set success [CkTask_Run $decryptStreamTask]

set success [CkRest_ReadRespBodyStream $rest $receiveStream 1]
if {$success != 1} then {
    puts [CkRest_lastErrorText $rest]
    delete_CkRest $rest
    delete_CkCrypt2 $crypt
    delete_CkStream $receiveStream
    delete_CkStream $decryptStream
    exit
}

puts "Successfully received the .zip file."

delete_CkRest $rest
delete_CkCrypt2 $crypt
delete_CkStream $receiveStream
delete_CkStream $decryptStream