.. ............................................................................
.. Project:       OpenECU
.. Version:       $Id:  $
.. File:          $URL:  $
.. Description:   <TODO: add file description>
..
.. Copyright (C) 2023 Pi Innovo
.. ............................................................................


.. _ccp_security:

CCP Security
====================

How do I use CCP Security?
------------------------------------

The following is a simple example of how to set up a model with CAN
Calibration Protocol (CCP) security. This example uses PiSnoop as the
calibration tool.

First, include in your model a pcp_CCPSecurity block:

.. image:: ccp_security_img1.jpg
   :alt: CCP Security Block

``key_validator`` is the name of the key validator function and is described
in detail in the user guide ccp_seed_key_security_key_validator.

Here is the complete source code for key_validator.c:

.. code-block:: c

   #include "openecu.h"

   BOOL key_validator(const U8 privilege_level, const U8 *const seed, const U8 *const key, const U8 key_size)
   {
       /* Ignore key_size, get 6 bytes in CCP v2.1 but only 4 typically relevant */

       return (seed[0] == key[3] &&
               seed[1] == key[2] &&
               seed[2] == key[1] &&
               seed[3] == key[0] );
   }

In the model, this file will need to be added as custom code; e.g., in R2008b:

.. image:: ccp_security_img6.jpg
   :alt: Custom Code in R2008b

In PiSnoop, the workspace will need to be set up so that the CCP protocol has
the seed/key enabled, e.g., using the 'own code' security option like this:

.. image:: ccp_security_img2.jpg
   :alt: PiSnoop Workspace Setup

.. image:: ccp_security_img3.jpg
   :alt: PiSnoop Workspace Setup

.. image:: ccp_security_img4.jpg
   :alt: PiSnoop Workspace Setup

.. image:: ccp_security_img5.jpg
   :alt: PiSnoop Workspace Setup

Doing all this, one can modify calibrations and reflash, but only with
security turned on.

For further information, see the user guide ccp_seed_key_security_overview. If
you have further questions, feel free to contact OpenECU support.