EVP_PKEY_new_mac_key
sigkey = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL,
EVP_PKEY *EVP_PKEY_new_mac_key(int type, ENGINE *e, const unsigned char *key,
mac_key = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL, secret, secret_len);
if ((mac_pkey = EVP_PKEY_new_mac_key(mac_type, NULL, CBS_data(mac_key),