 input.</p>

<p>EVP_MAC_final() does the final computation and stores the result in the memory pointed at by <i>out</i> of size <i>outsize</i>, and sets the number of bytes written in <i>*outl</i> at. If <i>out</i> is NULL or <i>outsize</i> is too small, then no computation is made. To figure out what the output length will be and allocate space for it dynamically, simply call with <i>out</i> being NULL and <i>outl</i> pointing at a valid location, then allocate space and make a second call with <i>out</i> 