== 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 [[doc_user/openecu_user_guide_simulink_chunk/pcp_ccp_security.html|pcp_CCPSecurity]] block:

{{attachment:ccp_sec_1.png}}

{{{key_validator}}} is the name of the key validator function and is described in detail in the [[doc_user/openecu_user_guide_c_api/openecu_user_guide_c_api.html#ccp_seed_key_security_key_validator|user guide]].

Here is the complete source code for key_validator.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:

{{attachment:ccp_sec_6.png}}

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

{{attachment:ccp_sec_2.png}}

{{attachment:ccp_sec_3.png}}

{{attachment:ccp_sec_4.png}}

{{attachment:ccp_sec_5.png}}

There is more on that in the [[http://www.pi-innovo.com/assets/softwares/public/PiSnoop/LatestHelp/snoop_help_seed_key.htm|PiSnoop Documentation]].

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

For further information, see the [[doc_user/openecu_user_guide_c_api/openecu_user_guide_c_api.html#ccp_seed_key_security_overview|user guide]].  If
you have further questions, feel free to [[OpenECU Support Contact|contact OpenECU support]].