late exdata, three callbacks must be provided. The semantics of those callbacks are described below.</p>

<p>When copying or releasing objects with exdata, the callback functions are called in increasing order of their <b>index</b> value.</p>

<p>If a dynamic library can be unloaded, it should call CRYPTO_free_ex_index() when this is done. This will replace the callbacks with no-ops so that applications don&#39;t crash. Any existing exdata will be leaked.</p>

<p>To set or get the exdata on an object, the a