Visual FoxPro

ClickBank Decrypt Instant Notification

See more ClickBank Examples

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

LOCAL lnSuccess
LOCAL lcSecretKey
LOCAL lcJsonStr
LOCAL loJson
LOCAL loBdNotif
LOCAL loBdIv
LOCAL loCrypt
LOCAL lcHexSha1
LOCAL loBdKey

lnSuccess = 0

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

* secret key from your ClickBank account
lcSecretKey = "MY_SECRET_KEY"

lcJsonStr = '{"notification":"BASE64_NOTIFICATION","iv":"BASE64_IV"}'

loJson = CreateObject('Chilkat.JsonObject')
lnSuccess = loJson.Load(lcJsonStr)

* Get the encrypted notification (binary) and IV from the JSON.
loBdNotif = CreateObject('Chilkat.BinData')
loBdIv = CreateObject('Chilkat.BinData')

lnSuccess = loBdNotif.AppendEncoded(loJson.StringOf("notification"),"base64")
lnSuccess = loBdIv.AppendEncoded(loJson.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.

loCrypt = CreateObject('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.
loCrypt.EncodingMode = "hex_lower"
loCrypt.HashAlgorithm = "sha1"
lcHexSha1 = loCrypt.HashStringENC(lcSecretKey)
? lcHexSha1

* Treat the hex string as binary data for the AES key..
loBdKey = CreateObject('Chilkat.BinData')
loBdKey.AppendString(lcHexSha1,"us-ascii")
loBdKey.RemoveChunk(32,8)

loCrypt.KeyLength = 256
loCrypt.CryptAlgorithm = "aes"
loCrypt.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..
loCrypt.SetEncodedIV(loBdIv.GetEncoded("base64"),"base64")
loCrypt.SetEncodedKey(loBdKey.GetEncoded("base64"),"base64")

loCrypt.DecryptBd(loBdNotif)
? "Decrypted: " + loBdNotif.GetString("utf-8")

RELEASE loJson
RELEASE loBdNotif
RELEASE loBdIv
RELEASE loCrypt
RELEASE loBdKey