iTextSharp.text.pdf.security.CertificateUtil.GetOCSPURL C# (CSharp) 메소드

        public static String GetOCSPURL(X509Certificate certificate)
        {
            try {
                Asn1Object obj = GetExtensionValue(certificate, X509Extensions.AuthorityInfoAccess.Id);
                if (obj == null) {
                    return null;
                }

                Asn1Sequence AccessDescriptions = (Asn1Sequence) obj;
                for (int i = 0; i < AccessDescriptions.Count; i++) {
                    Asn1Sequence AccessDescription = (Asn1Sequence) AccessDescriptions[i];
                    if ( AccessDescription.Count != 2 ) {
                        continue;
                    } else {
                        if ((AccessDescription[0] is DerObjectIdentifier) && ((DerObjectIdentifier)AccessDescription[0]).Id.Equals("1.3.6.1.5.5.7.48.1")) {
                            String AccessLocation =  GetStringFromGeneralName((Asn1Object)AccessDescription[1]);
                            if ( AccessLocation == null ) {
                                return "" ;
                            } else {
                                return AccessLocation ;
                            }
                        }
                    }
                }
            } catch {
            }
            return null;
        }

        private OcspResp GetOcspResponse(X509Certificate checkCert, X509Certificate rootCert, String url)
        {
            if (checkCert == null || rootCert == null)
            {
                return(null);
            }
            if (url == null)
            {
                url = CertificateUtil.GetOCSPURL(checkCert);
            }
            if (url == null)
            {
                return(null);
            }
            LOGGER.Info("Getting OCSP from " + url);
            OcspReq request = GenerateOCSPRequest(rootCert, checkCert.SerialNumber);

            byte[] array = request.GetEncoded();

            HttpWebRequest con = (HttpWebRequest)WebRequest.Create(url);

            con.ContentLength = array.Length;
            con.ContentType   = "application/ocsp-request";
            con.Accept        = "application/ocsp-response";
            con.Method        = "POST";
            Stream outp = con.GetRequestStream();

            outp.Write(array, 0, array.Length);
            outp.Close();
            HttpWebResponse response = (HttpWebResponse)con.GetResponse();

            if (response.StatusCode != HttpStatusCode.OK)
            {
                throw new IOException(MessageLocalization.GetComposedMessage("invalid.http.response.1", (int)response.StatusCode));
            }
            Stream   inp          = response.GetResponseStream();
            OcspResp ocspResponse = new OcspResp(inp);

            inp.Close();
            response.Close();
            return(ocspResponse);
        }