eric pointer to data <i>arg</i>. As far as the function receiving the pointer to the function pointer and <i>arg</i> is concerned, the data that <i>arg</i> points at is opaque, and the pointer should simply be passed back to the callback function when it&#39;s called.</p>

<dl>

<dt id="OSSL_CALLBACK"><b>OSSL_CALLBACK</b></dt>
<dd>

<p>This is a generic callback function. When calling this callback function, the caller is expected to build an <a href="../man3/OSSL_PARAM.html">OSSL_PARAM(3)</a> array of data