at will be called for every certificate being validated. The callback is called several times for each certificate, so you must be careful to do the proxy policy interpretation at the right time. You also need to fill in the defaults when the EE certificate is checked.</p>

</li>
<li><p>a data structure that is shared between your application code and the callback.</p>

</li>
<li><p>a wrapper function that sets it all up.</p>

</li>
<li><p>an ex_data index function that creates an index into the generic ex_