on error.</p>

<p>EVP_MAC_init(), EVP_MAC_update(), EVP_MAC_final(), and EVP_MAC_finalXOF() return 1 on success, 0 on error.</p>

<p>EVP_MAC_CTX_get_mac_size() returns the expected output size, or 0 if it isn&#39;t set. If it isn&#39;t set, a call to EVP_MAC_init() will set it.</p>

<p>EVP_MAC_CTX_get_block_size() returns the block size, or 0 if it isn&#39;t set. If it isn&#39;t set, a call to EVP_MAC_init() will set it.</p>

<p>EVP_MAC_do_all_provided() returns nothing at all.</p>

<h1 id="EXAMPLES">EXAMPL