ppropriate type-specific routine must be used. This is because the containing structure is opaque and the <b>CRYPTO_EX_DATA</b> field is not accessible. In both API&#39;s, the <b>idx</b> parameter should be an already-created index value.</p>

<p>When setting exdata, the pointer specified with a particular index is saved, and returned on a subsequent &quot;get&quot; call. If the application is going to release the data, it must make sure to set a <b>NULL</b> value at the index, to avoid likely double-free c