(AutoIt) ClickBank Decrypt Instant Notification

Demonstrates how to decrypt a ClickBank instant notification. See Instant Notification Service for more information and alternative code snippets.

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

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

; secret key from your ClickBank account
Local $secretKey = "MY_SECRET_KEY"

Local $sJsonStr = "{""notification"":""BASE64_NOTIFICATION"",""iv"":""BASE64_IV""}"

$oJson = ObjCreate("Chilkat.JsonObject")
Local $bSuccess = $oJson.Load($sJsonStr)

; Get the encrypted notification (binary) and IV from the JSON.
$oBdNotif = ObjCreate("Chilkat.BinData")
$oBdIv = ObjCreate("Chilkat.BinData")

$bSuccess = $oBdNotif.AppendEncoded($oJson.StringOf("notification"),"base64")
$bSuccess = $oBdIv.AppendEncoded($oJson.StringOf("iv"),"base64")

; Get an SHA1 digest (as a hex string) of the secret key.
; A SHA1 digest is 20 bytes.  Therefore the hex string is 40 chars.
; Treat each us-ascii char as a binary byte of the secret key.
; 256-bit AES needs a 256-bit key, which is 32-bytes.  Therefore
; use the 1st 32 us-ascii chars of the hex SHA1 as the AES secret key.

$oCrypt = ObjCreate("Chilkat.Crypt2")
; Because we're using the hex string as the actual AES key, it matters whether the hex is uppercase or lowercase.
; We want lowercase.
$oCrypt.EncodingMode = "hex_lower"
$oCrypt.HashAlgorithm = "sha1"
Local $sHexSha1 = $oCrypt.HashStringENC($secretKey)
ConsoleWrite($sHexSha1 & @CRLF)

; Treat the hex string as binary data for the AES key..
$oBdKey = ObjCreate("Chilkat.BinData")
$oBdKey.AppendString($sHexSha1,"us-ascii")
$oBdKey.RemoveChunk(32,8)

$oCrypt.KeyLength = 256
$oCrypt.CryptAlgorithm = "aes"
$oCrypt.CipherMode = "cbc"

; We can use any encoding because were just getting the binary bytes in an encoding, and then setting from the same encoding.
; We'll just use base64..
$oCrypt.SetEncodedIV $oBdIv.GetEncoded("base64"),"base64"
$oCrypt.SetEncodedKey $oBdKey.GetEncoded("base64"),"base64"

$oCrypt.DecryptBd($oBdNotif)
ConsoleWrite("Decrypted: " & $oBdNotif.GetString("utf-8") & @CRLF)