(Delphi ActiveX) ClickBank Decrypt Instant Notification

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

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
secretKey: WideString;
jsonStr: WideString;
json: TChilkatJsonObject;
success: Integer;
bdNotif: TChilkatBinData;
bdIv: TChilkatBinData;
crypt: TChilkatCrypt2;
hexSha1: WideString;
bdKey: TChilkatBinData;

begin
// 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 := TChilkatJsonObject.Create(Self);
success := json.Load(jsonStr);

// Get the encrypted notification (binary) and IV from the JSON.
bdNotif := TChilkatBinData.Create(Self);
bdIv := TChilkatBinData.Create(Self);

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 := TChilkatCrypt2.Create(Self);
// 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);
Memo1.Lines.Add(hexSha1);

// Treat the hex string as binary data for the AES key..
bdKey := TChilkatBinData.Create(Self);
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.ControlInterface);
Memo1.Lines.Add('Decrypted: ' + bdNotif.GetString('utf-8'));
end;