_PARAM.html">OSSL_PARAM(3)</a> arrays that describe the settable parameters that can be used with EVP_MAC_CTX_set_params(). EVP_MAC_settable_ctx_params() returns the parameters that can be retrieved from the algorithm, whereas EVP_MAC_CTX_settable_params() returns the parameters that can be retrieved in the context&#39;s current state.</p>

<h2 id="Information-functions">Information functions</h2>

<p>EVP_MAC_CTX_get_mac_size() returns the MAC output size for the given context.</p>

<p>EVP_MAC_CTX_get_block