int X509_supported_extension(X509_EXTENSION *ex)
{
    /*
     * This table is a list of the NIDs of supported extensions: that is
     * those which are used by the verify process. If an extension is
     * critical and doesn't appear in this list then the verify process will
     * normally reject the certificate. The list must be kept in numerical
     * order because it will be searched using bsearch.
     */

    static const int supported_nids[] = {
        NID_netscape_cert_type, /* 71 */
        NID_key_usage,          /* 83 */
        NID_subject_alt_name,   /* 85 */
        NID_basic_constraints,  /* 87 */
        NID_certificate_policies, /* 89 */
        NID_ext_key_usage,      /* 126 */
        NID_sbgp_ipAddrBlock,   /* 290 */
        NID_sbgp_autonomousSysNum, /* 291 */
        NID_policy_constraints, /* 401 */
        NID_proxyCertInfo,      /* 663 */
        NID_name_constraints,   /* 666 */
        NID_policy_mappings,    /* 747 */
        NID_inhibit_any_policy  /* 748 */
    };

    int ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));

    if (ex_nid == NID_undef)
        return 0;

    if (OBJ_bsearch_nid(&ex_nid, supported_nids,
                        sizeof(supported_nids) / sizeof(int)))
        return 1;
    return 0;
}