ze can be obtained from <i>*out_len</i> by calling the function with <i>buf</i> set to NULL.</p>

<h1 id="NOTES">NOTES</h1>

<p>These functions only work for <b>EVP_PKEY</b>s that contain a provider side key.</p>

<h1 id="RETURN-VALUES">RETURN VALUES</h1>

<p>EVP_PKEY_gettable_params() returns NULL on error or if it is not supported.</p>

<p>All other methods return 1 if a value associated with the key&#39;s <i>key_name</i> was successfully returned, or 0 if there was an error. An error may be returned by m