(PowerShell) ClickBank Decrypt Instant Notification

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

Chilkat .NET Downloads Chilkat .NET Assemblies

Add-Type -Path "C:\chilkat\ChilkatDotNet47-9.5.0-x64\ChilkatDotNet47.dll"

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

# secret key from your ClickBank account
$secretKey = "MY_SECRET_KEY"

$jsonStr = "{`"notification`":`"BASE64_NOTIFICATION`",`"iv`":`"BASE64_IV`"}"

$json = New-Object Chilkat.JsonObject
$success = $json.Load($jsonStr)

# Get the encrypted notification (binary) and IV from the JSON.
$bdNotif = New-Object Chilkat.BinData
$bdIv = New-Object Chilkat.BinData

$success = $bdNotif.AppendEncoded($json.StringOf("notification"),"base64")
$success = $bdIv.AppendEncoded($json.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.

$crypt = New-Object 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.
$crypt.EncodingMode = "hex_lower"
$crypt.HashAlgorithm = "sha1"
$hexSha1 = $crypt.HashStringENC($secretKey)
$($hexSha1)

# Treat the hex string as binary data for the AES key..
$bdKey = New-Object Chilkat.BinData
$bdKey.AppendString($hexSha1,"us-ascii")
$bdKey.RemoveChunk(32,8)

$crypt.KeyLength = 256
$crypt.CryptAlgorithm = "aes"
$crypt.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..
$crypt.SetEncodedIV($bdIv.GetEncoded("base64"),"base64")
$crypt.SetEncodedKey($bdKey.GetEncoded("base64"),"base64")

$crypt.DecryptBd($bdNotif)
$("Decrypted: " + $bdNotif.GetString("utf-8"))