private static void SignXmlFile(string FileName,
            string SignedFileName, AsymmetricAlgorithm Key,
            X509Certificate Certificate)
        {
            XmlDocument doc = new XmlDocument();
            doc.PreserveWhitespace = true;
            doc.Load(new XmlTextReader(FileName));
        
            SignedXml signedXml = new SignedXml(doc);
            signedXml.SigningKey = Key;

            Reference reference = new Reference();
            reference.Uri = "#SIGNED_BY_CALLER";

#pragma warning disable 612
            reference.DigestMethod = CPSignedXml.XmlDsigGost3411UrlObsolete;
#pragma warning restore 612

            XmlDsigSmevTransform smev =
                new XmlDsigSmevTransform();
            reference.AddTransform(smev);

            XmlDsigExcC14NTransform c14 = new XmlDsigExcC14NTransform();
            reference.AddTransform(c14);
            
            signedXml.SignedInfo.CanonicalizationMethod = SignedXml.XmlDsigExcC14NTransformUrl;
#pragma warning disable 612
            signedXml.SignedInfo.SignatureMethod = CPSignedXml.XmlDsigGost3410UrlObsolete;
#pragma warning disable 612

            signedXml.AddReference(reference);
            KeyInfo keyInfo = new KeyInfo();
            keyInfo.AddClause(new KeyInfoX509Data(Certificate));
            signedXml.KeyInfo = keyInfo;
            signedXml.ComputeSignature();

            XmlElement xmlDigitalSignature = signedXml.GetXml();
            doc.GetElementsByTagName("AckRequest", NSNamespaceUrl)[0].AppendChild(doc.CreateNode(XmlNodeType.Element, "ns", "CallerInformationSystemSignature", NSNamespaceUrl));
            doc.GetElementsByTagName("CallerInformationSystemSignature", NSNamespaceUrl)[0].AppendChild(
                doc.ImportNode(xmlDigitalSignature, true));

            // При наличии стартовой XML декларации ее удаляем
            // (во избежание повторного сохранения)
            if (doc.FirstChild is XmlDeclaration)
            {
                doc.RemoveChild(doc.FirstChild);
            }
 doc_signed.xml (5kb) загружен 45 раз(а).
            using (XmlTextWriter xmltw = new XmlTextWriter(SignedFileName,
                new UTF8Encoding(false)))
            {
                xmltw.WriteStartDocument();
                doc.WriteTo(xmltw);
            }
        }