xt should do nothing and return 1. Note that a parameter that is unknown in the underlying context is simply ignored. Also, what happens when a needed parameter isn&#39;t passed down is defined by the implementation.</p>

<p>EVP_MAC_gettable_params() returns an <a href="../man3/OSSL_PARAM.html">OSSL_PARAM(3)</a> array that describes the retrievable and settable parameters. EVP_MAC_gettable_params() returns parameters that can be used with EVP_MAC_get_params().</p>

<p>EVP_MAC_gettable_ctx_params() and EVP_M