iTextSharp.text.pdf.AcroFields.VerifySignature C# (CSharp) Метод

        public PdfPKCS7 VerifySignature(String name) {
            PdfDictionary v = GetSignatureDictionary(name);
            if (v == null)
                return null;
            PdfName sub = v.GetAsName(PdfName.SUBFILTER);
            PdfString contents = v.GetAsString(PdfName.CONTENTS);
            PdfPKCS7 pk = null;
            if (sub.Equals(PdfName.ADBE_X509_RSA_SHA1)) {
                PdfString cert = v.GetAsString(PdfName.CERT);
                pk = new PdfPKCS7(contents.GetOriginalBytes(), cert.GetBytes());
            }
            else
                pk = new PdfPKCS7(contents.GetOriginalBytes());
            UpdateByteRange(pk, v);
            PdfString str = v.GetAsString(PdfName.M);
            if (str != null)
                pk.SignDate = PdfDate.Decode(str.ToString());
            PdfObject obj = PdfReader.GetPdfObject(v.Get(PdfName.NAME));
            if (obj != null) {
              if (obj.IsString())
                pk.SignName = ((PdfString)obj).ToUnicodeString();
              else if(obj.IsName())
                pk.SignName = PdfName.DecodeName(obj.ToString());
            }
            str = v.GetAsString(PdfName.REASON);
            if (str != null)
                pk.Reason = str.ToUnicodeString();
            str = v.GetAsString(PdfName.LOCATION);
            if (str != null)
                pk.Location = str.ToUnicodeString();
            return pk;
        }
        

        private Nenshkrim MerrNenshkrimInfo(AcroFields af, string name)
        {
            PdfPKCS7 pkcs7 = af.VerifySignature(name);

            var certificate = new X509Certificate2();

            var cert = (Org.BouncyCastle.X509.X509Certificate)pkcs7.Certificates[0];

            certificate.Import(cert.GetEncoded());
            Nenshkrim nenshkruesi = new Nenshkrim();

            nenshkruesi.Nenshkruesi = CertificateInfo.GetSubjectFields(cert).GetField("CN");

            string issuer = certificate.Issuer;
            nenshkruesi.IssuerCN = GetIssuer(issuer, "CN=");
            nenshkruesi.IssuerOU = GetIssuer(issuer, "OU=");
            nenshkruesi.IssuerO = GetIssuer(issuer, "O=");
            nenshkruesi.IssuerC = GetIssuer(issuer, "C=");

            if (nenshkruesi.IssuerC == "KS")
            {
                //largimi i [EMAIL] prej cn
                nenshkruesi.Nenshkruesi = nenshkruesi.Nenshkruesi.Substring(8);
            }

            nenshkruesi.Emri = CertificateInfo.GetSubjectFields(cert).GetField("GIVENNAME");
            nenshkruesi.Mbiemri = CertificateInfo.GetSubjectFields(cert).GetField("SURNAME");
            //algoritmi hash
            nenshkruesi.AlgoritmiHash = pkcs7.GetHashAlgorithm();
            //algoritmi hash
            nenshkruesi.AlgoritmiEnkriptimit = pkcs7.GetEncryptionAlgorithm();
            //data e nenshrimit
            nenshkruesi.DataNenshkrimit = pkcs7.SignDate;
            //certifikata valide prej, deri
            nenshkruesi.CertifikataValidePrej = certificate.GetEffectiveDateString();
            nenshkruesi.CertifikataValideDeri = certificate.GetExpirationDateString();
            nenshkruesi.SerialNumber = certificate.SerialNumber;

            //verifikimi
            if (pkcs7.Verify())
            {
                nenshkruesi.Valid = true;
            }
            else
            {
                nenshkruesi.Valid = false;
            }

            return nenshkruesi;
        }