CPSigner cps = new CPSigner();
            cps.Options = CAPICOM_CERTIFICATE_INCLUDE_OPTION.CAPICOM_CERTIFICATE_INCLUDE_WHOLE_CHAIN;
            cps.Certificate = GetSignerCertificate(certificate.Thumbprint);
            cps.TSAAddress = @"http://www.cryptopro.ru/tsp/tsp.srf";

            CadesSignedData csd = new CadesSignedData();
            csd.Content = ss.ToArray();
            byte[] pk = csd.Sign(cps, true);

            csd = new CadesSignedData();
            csd.Content = ss.ToArray();
            csd.Verify(pk, true);

        // Подписываем PDF документ
        public byte[] SignPdf(byte[] sourcePdf, X509Certificate2 certificate)
        {
            MemoryStream signedPdfStream = new MemoryStream();

            PdfReader reader = new PdfReader(sourcePdf);
            PdfStamper stamper = PdfStamper.CreateSignature(reader, signedPdfStream, '\0');

            // загружаем сертификат в объект iTextSharp
            X509CertificateParser parser = new X509CertificateParser();
            Org.BouncyCastle.X509.X509Certificate[] chain = new Org.BouncyCastle.X509.X509Certificate[] { 
                parser.ReadCertificate(certificate.RawData)
            };

            // задаем параметры подписи
            PdfName filterName = new PdfName("CryptoPro PDF");
            PdfSignatureAppearance sap = stamper.SignatureAppearance;
            sap.SetCrypto(null, chain, null, filterName);
            sap.SignDate = DateTime.Now;
            sap.Reason = "I like to sign";
            sap.Location = PdfPKCS7.GetSubjectFields(chain[0]).GetField("L") + ", " + PdfPKCS7.GetSubjectFields(chain[0]).GetField("C");
            sap.Contact = PdfPKCS7.GetSubjectFields(chain[0]).GetField("CN") + " <" + PdfPKCS7.GetSubjectFields(chain[0]).GetField("E") + ">";
            sap.Acro6Layers = true;
            sap.Render = PdfSignatureAppearance.SignatureRender.NameAndDescription;

            // создаем подпись
            PdfSignature pdfSignature = new PdfSignature(filterName, PdfName.ADBE_PKCS7_DETACHED);
            pdfSignature.Date = new PdfDate(sap.SignDate);
            pdfSignature.Name = PdfPKCS7.GetSubjectFields(chain[0]).GetField("CN");
            pdfSignature.Reason = sap.Reason;
            pdfSignature.Location = sap.Location;
            pdfSignature.Contact = sap.Contact;
            sap.CryptoDictionary = pdfSignature;

            // задаем размер буфера подписи
            int intCSize = 40000;
            Dictionary<PdfName, int> hashtable = new Dictionary<PdfName, int>();
            hashtable[PdfName.CONTENTS] = intCSize * 2 + 2;
            sap.PreClose(hashtable);

            // получаем и копируем контент
            Stream rangeStream = sap.GetRangeStream();
            MemoryStream contentStream = new MemoryStream();
            rangeStream.CopyTo(contentStream);
            byte[] content = contentStream.ToArray();

            // вычисляем подпись
            //byte[] signature = SignWithSimpleEDS(content, certificate);  // - вызывается создание обычной подпись
            byte[] signature = SignWithAdvancedEDS(content, certificate);  // - вызывается создание УЭЦП

            // помещаем подпись в документ
            byte[] signBuff = new byte[intCSize];
            Array.Copy(signature, 0, signBuff, 0, signature.Length);
            PdfDictionary dictionary = new PdfDictionary();
            dictionary.Put(PdfName.CONTENTS, new PdfString(signBuff).SetHexWriting(true));
            sap.Close(dictionary);

            byte[] signedPdf = signedPdfStream.ToArray();
            return signedPdf;
        }

        // Вычисляем обычную ЭЦП
        public static byte[] SignWithSimpleEDS(byte[] content, X509Certificate2 certificate)
        {
            byte[] signature = null;

            try
            {
                ContentInfo contentInfo = new ContentInfo(content);
                SignedCms signedCms = new SignedCms(contentInfo, true);
                CmsSigner cmsSigner = new CmsSigner(certificate);
                cmsSigner.IncludeOption = X509IncludeOption.WholeChain;
                signedCms.ComputeSignature(cmsSigner, true);
                signature = signedCms.Encode();
            }
            catch (Exception ex)
            {
                throw ex;
            }

            return signature;
        }

        // Вычисляем УЭЦП
        public static byte[] SignWithAdvancedEDS(byte[] content, X509Certificate2 certificate)
        {
            byte[] signature = null;

            try
            {
                string tspServerAddress = @"http://www.cryptopro.ru/tsp/tsp.srf";

                CPSigner cps = new CPSigner();
                cps.Options = CAPICOM_CERTIFICATE_INCLUDE_OPTION.CAPICOM_CERTIFICATE_INCLUDE_WHOLE_CHAIN;
                cps.Certificate = GetCAPICOMCertificate(certificate.Thumbprint);
                cps.TSAAddress = tspServerAddress;
                CadesSignedData csd = new CadesSignedData();
                csd.Content = content;
                signature = csd.Sign(cps, true);

                // тестовая проверка подписи
                CadesSignedData csd2 = new CadesSignedData();
                csd2.Content = content;
                csd2.Verify(signature, true);
            }
            catch (Exception ex)
            {
                throw ex;
            }

            return signature;
        }

        // Ищем сертификат
        public static ICertificate GetCAPICOMCertificate(string certificateThumbprint)
        {
            ICertificate cert = null;

            certificateThumbprint = certificateThumbprint.Replace(" ", "").ToUpper();

            string storeName = "My";
            CAPICOM_STORE_LOCATION storeLocation = CAPICOM_STORE_LOCATION.CAPICOM_CURRENT_USER_STORE;

            try
            {
                Store sto = new Store();
                sto.Open(storeLocation, storeName, CAPICOM_STORE_OPEN_MODE.CAPICOM_STORE_OPEN_READ_ONLY);
                foreach (ICertificate c in sto.Certificates)
                {
                    if ((c.Thumbprint == certificateThumbprint) && (c.HasPrivateKey()) && (c.IsValid().Result))
                    {
                        cert = c;
                        break;
                    }
                }
                sto.Close();
            }
            catch (Exception ex)
            {
                throw ex;
            }

            return cert;
        }