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

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, BinData, JsonObject, Crypt2;

...

procedure TForm1.Button1Click(Sender: TObject);
var
secretKey: PWideChar;
jsonStr: PWideChar;
json: HCkJsonObject;
success: Boolean;
bdNotif: HCkBinData;
bdIv: HCkBinData;
crypt: HCkCrypt2;
hexSha1: PWideChar;
bdKey: HCkBinData;

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 := CkJsonObject_Create();
success := CkJsonObject_Load(json,jsonStr);

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

success := CkBinData_AppendEncoded(bdNotif,CkJsonObject__stringOf(json,'notification'),'base64');
success := CkBinData_AppendEncoded(bdIv,CkJsonObject__stringOf(json,'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 := CkCrypt2_Create();
// Because we're using the hex string as the actual AES key, it matters whether the hex is uppercase or lowercase.
// We want lowercase.
CkCrypt2_putEncodingMode(crypt,'hex_lower');
CkCrypt2_putHashAlgorithm(crypt,'sha1');
hexSha1 := CkCrypt2__hashStringENC(crypt,secretKey);
Memo1.Lines.Add(hexSha1);

// Treat the hex string as binary data for the AES key..
bdKey := CkBinData_Create();
CkBinData_AppendString(bdKey,hexSha1,'us-ascii');
CkBinData_RemoveChunk(bdKey,32,8);

CkCrypt2_putKeyLength(crypt,256);
CkCrypt2_putCryptAlgorithm(crypt,'aes');
CkCrypt2_putCipherMode(crypt,'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..
CkCrypt2_SetEncodedIV(crypt,CkBinData__getEncoded(bdIv,'base64'),'base64');
CkCrypt2_SetEncodedKey(crypt,CkBinData__getEncoded(bdKey,'base64'),'base64');

CkCrypt2_DecryptBd(crypt,bdNotif);
Memo1.Lines.Add('Decrypted: ' + CkBinData__getString(bdNotif,'utf-8'));

CkJsonObject_Dispose(json);
CkBinData_Dispose(bdNotif);
CkBinData_Dispose(bdIv);
CkCrypt2_Dispose(crypt);
CkBinData_Dispose(bdKey);

end;