(Node.js) ClickBank Decrypt Instant Notification

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

Install Chilkat for Node.js and Electron using npm at Chilkat npm packages for Node.js Chilkat npm packages for Electron on Windows, Linux, MacOSX, and ARM

var os = require('os');
if (os.platform() == 'win32') {  
    if (os.arch() == 'ia32') {
        var chilkat = require('@chilkat/ck-node21-win-ia32');
    } else {
        var chilkat = require('@chilkat/ck-node21-win64'); 
    }
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node21-arm');
    } else if (os.arch() == 'x86') {
        var chilkat = require('@chilkat/ck-node21-linux32');
    } else {
        var chilkat = require('@chilkat/ck-node21-linux64');
    }
} else if (os.platform() == 'darwin') {
    if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node21-mac-m1');
    } else {
        var chilkat = require('@chilkat/ck-node21-macosx');
    }
}

function chilkatExample() {

    // 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 = "MY_SECRET_KEY";

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

    var json = new chilkat.JsonObject();
    var success = json.Load(jsonStr);

    // Get the encrypted notification (binary) and IV from the JSON.
    var bdNotif = new chilkat.BinData();
    var bdIv = new 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.

    var crypt = new 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";
    var hexSha1 = crypt.HashStringENC(secretKey);
    console.log(hexSha1);

    // Treat the hex string as binary data for the AES key..
    var bdKey = new 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);
    console.log("Decrypted: " + bdNotif.GetString("utf-8"));

}

chilkatExample();