X509_check_trust
if (X509_check_trust(x, NID_OCSP_sign, 0) != X509_TRUST_TRUSTED) {
trust = X509_check_trust(mx, ctx->param->trust, 0);
tr_ok = X509_check_trust(x, ctx->param->trust, X509_TRUST_NO_SS_COMPAT);
trust = X509_check_trust(x, ctx->param->trust, 0);
int X509_check_trust(X509 *x, int id, int flags);