/// <summary>
        /// Получить цифровую подпись
        /// </summary>
        /// <param name="xmlDocument">Xml-документ</param>
        /// <param name="certificate">Сертификат подписи</param>
        /// <param name="references">Ссылки на подписываемые узлы xml</param>
        /// <returns>Цифровая подпись в Xml-формате</returns>
        public static XmlElement ComputeSmev3Signature(XmlDocument xmlDocument, X509Certificate2 certificate, params string[] references)
        {
            // Пробельные символы участвуют в вычислении подписи и должны быть сохранены для совместимости с другими реализациями.
            xmlDocument.PreserveWhitespace = true;

            var signedXml = new SignedXml(xmlDocument)
            {
                SigningKey = certificate.PrivateKey
            };
            //var signedXml = new SmevSignedXml(xmlDocument) { SigningKey = certificate.PrivateKey };
            foreach (var referenceUri in references)
            {
                var reference = new Reference();
                reference.Uri = "#" + referenceUri;
                // Задаём алгоритм хэширования подписываемого узла - ГОСТ Р 34.11-94. Необходимо
                // использовать устаревший идентификатор данного алгоритма, т.к. именно такой
                // идентификатор используется в СМЭВ.
#pragma warning disable 612
                reference.DigestMethod = CPSignedXml.XmlDsigGost3411UrlObsolete;
#pragma warning restore 612

                // Добавляем transform на подписываемые данные
                // для удаления вложенной подписи.
                //var env = new XmlDsigEnvelopedSignatureTransform();
                //reference.AddTransform(env);

                // Добавляем transform для канонизации.
                var c14 = new XmlDsigExcC14NTransform();
                reference.AddTransform(c14);

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

                signedXml.AddReference(reference);
            }
            var keyInfo = new KeyInfo();
            keyInfo.AddClause(new KeyInfoX509Data(certificate));
            signedXml.KeyInfo = keyInfo;

            ////"http://www.w3.org/2001/10/xml-exc-c14n#"
            signedXml.SignedInfo.CanonicalizationMethod = SignedXml.XmlDsigExcC14NTransformUrl;

            //"http://www.w3.org/2001/04/xmldsig-more#gostr34102001-gostr3411"
            // Можно явно проставить алгоритм подписи: ГОСТ Р 34.10.
            // Если сертификат ключа подписи ГОСТ Р 34.10
            // и алгоритм ключа подписи не задан, то будет использован
#pragma warning disable 612
            signedXml.SignedInfo.SignatureMethod = CPSignedXml.XmlDsigGost3410UrlObsolete;
#pragma warning restore 612

            //Вычисляем сигнатуру
            signedXml.ComputeSignature();

            //Формируем Xml сигнатуры
            var xmlDigitalSignature = signedXml.GetXml();

            return xmlDigitalSignature;
        }

<?xml version="1.0" encoding="utf-8"?><soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"><S:Body xmlns:S="http://schemas.xmlsoap.org/soap/envelope/"><AckRequest xmlns="urn://x-artefacts-smev-gov-ru/services/message-exchange/types/1.1"><AckTargetMessage xmlns="urn://x-artefacts-smev-gov-ru/services/message-exchange/types/basic/1.1" Id="SIGNED_BY_CALLER" accepted="true">31455816-928a-11e5-a2d4-6a386eb936c1</AckTargetMessage><CallerInformationSystemSignature><Signature xmlns="http://www.w3.org/2000/09/xmldsig#"><SignedInfo><CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#" /><SignatureMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#gostr34102001-gostr3411" /><Reference URI="#SIGNED_BY_CALLER"><Transforms><Transform Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#" /><Transform Algorithm="urn://smev-gov-ru/xmldsig/transform" /></Transforms><DigestMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#gostr3411" /><DigestValue>z3iAFPZdGIp/P2FGbZXtvz0GKu2t1hWlzxQcDgyvZ80=</DigestValue></Reference></SignedInfo><SignatureValue>FscWYCvo2swv+Sd7ipnH0zkRAV5B7zqpVVaf1KDebuPVaYCHAcpv2qdXKllEsjvKVHIawI8z2UZt80n7g8qnaQ==</SignatureValue><KeyInfo><X509Data><X509Certificate>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</X509Certificate></X509Data></KeyInfo></Signature></CallerInformationSystemSignature></AckRequest></S:Body></soapenv:Envelope>

<?xml version="1.0" encoding="utf-8"?>
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
	<S:Body xmlns:S="http://schemas.xmlsoap.org/soap/envelope/">
		<AckRequest xmlns="urn://x-artefacts-smev-gov-ru/services/message-exchange/types/1.1">
			<AckTargetMessage xmlns="urn://x-artefacts-smev-gov-ru/services/message-exchange/types/basic/1.1" Id="SIGNED_BY_CALLER" accepted="true">31455816-928a-11e5-a2d4-6a386eb936c1</AckTargetMessage>
			<CallerInformationSystemSignature>
				<Signature xmlns="http://www.w3.org/2000/09/xmldsig#">
					<SignedInfo>
						<CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#" />
						<SignatureMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#gostr34102001-gostr3411" />
						<Reference URI="#SIGNED_BY_CALLER">
							<Transforms>
								<Transform Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#" />
								<Transform Algorithm="urn://smev-gov-ru/xmldsig/transform" />
							</Transforms>
							<DigestMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#gostr3411" />
							<DigestValue>z3iAFPZdGIp/P2FGbZXtvz0GKu2t1hWlzxQcDgyvZ80=</DigestValue>
						</Reference>
					</SignedInfo>
					<SignatureValue>FscWYCvo2swv+Sd7ipnH0zkRAV5B7zqpVVaf1KDebuPVaYCHAcpv2qdXKllEsjvKVHIawI8z2UZt80n7g8qnaQ==</SignatureValue>
					<KeyInfo>
						<X509Data>
							<X509Certificate>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</X509Certificate>
						</X509Data>
					</KeyInfo>
				</Signature>
			</CallerInformationSystemSignature>
		</AckRequest>
	</S:Body>
</soapenv:Envelope>