verify function is defined as an X509_STORE_CTX_verify type which has the following signature:</p>

<pre><code>int (*verify)(X509_STORE_CTX *);</code></pre>

<p>This function should receive the current X509_STORE_CTX as a parameter and return 1 on success or 0 on failure.</p>

<p>X509 certificates may contain information about what purposes keys contained within them can be used for. For example &quot;TLS WWW Server Authentication&quot; or &quot;Email Protection&quot;. This &quot;key usage&quot; information