(Swift 2) ClickBank Decrypt Instant Notification

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

Chilkat Downloads for the Swift Programming Language MAC OS X (Cocoa) Objective-C/Swift Libs iOS Objective-C/Swift Libs

func chilkatTest() {
    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    // secret key from your ClickBank account
    var secretKey: String? = "MY_SECRET_KEY"

    var jsonStr: String? = "{\"notification\":\"BASE64_NOTIFICATION\",\"iv\":\"BASE64_IV\"}"

    let json = CkoJsonObject()
    var success: Bool = json.Load(jsonStr)

    // Get the encrypted notification (binary) and IV from the JSON.
    let bdNotif = CkoBinData()
    let bdIv = CkoBinData()

    success = bdNotif.AppendEncoded(json.StringOf("notification"), encoding: "base64")
    success = bdIv.AppendEncoded(json.StringOf("iv"), encoding: "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.

    let crypt = CkoCrypt2()
    // 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"
    var hexSha1: String? = crypt.HashStringENC(secretKey)
    print("\(hexSha1!)")

    // Treat the hex string as binary data for the AES key..
    let bdKey = CkoBinData()
    bdKey.AppendString(hexSha1, charset: "us-ascii")
    bdKey.RemoveChunk(32, numBytes: 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"), encoding: "base64")
    crypt.SetEncodedKey(bdKey.GetEncoded("base64"), encoding: "base64")

    crypt.DecryptBd(bdNotif)
    print("Decrypted: \(bdNotif.GetString("utf-8"))")

}