public static int GetCertificateState(string xml)
{
WebClient wc = new WebClient();
byte[] bytes = wc.DownloadData(caCertUrl);
BIO bio = new BIO(bytes);
X509Certificate certca = X509Certificate.FromDER(bio);
XMLClass xmlEx = new XMLClass();
byte[] bytesCert = UTF8Encoding.UTF8.GetBytes(xml);
string sCert = xmlEx.getX509FromXMLbytes(bytesCert);
BIO bCert = new BIO(Convert.FromBase64String(sCert));
X509Certificate cert = X509Certificate.FromDER(bCert);
int result = cert.CheckOCSP(certca, ocspUrl);
return(result);
}