ossl_dh_check_pub_key_partial
if (!ossl_dh_check_pub_key_partial(dh, pubkey, &ret)) {
int ossl_dh_check_pub_key_partial(const DH *dh, const BIGNUM *pub_key, int *ret);
return ossl_dh_check_pub_key_partial(dh, pub_key, &res);