public string GetSignatureForVersion(VERSION version)
{
	var composition = version.Cast<ORIGINAL_VERSION>().data as COMPOSITION;

	// При создании Ehr в data приходит EHR_STATUS, а не COMPOSITION
	if (composition == null)
		return string.Empty;

	X509Certificate2 certificate = GetCertificate(composition.archetype_details.template_id.value);

	if (certificate == null)
		return string.Empty;

	var doc = new XmlDocument
				{
					PreserveWhitespace = false
				};
	doc.LoadXml(version.Serialize<VERSION>());

	var reference = new Reference { DigestMethod = CPSignedXml.XmlDsigGost3411Url, Uri = string.Empty };
	// Добавляем transform на подписываемые данные для удаления вложенной подписи.
	reference.AddTransform(new XmlDsigEnvelopedSignatureTransform());
	// Добавляем transform для канонизации.
	reference.AddTransform(new XmlDsigC14NTransform());

	var keyInfo = new KeyInfo();
	keyInfo.AddClause(new KeyInfoX509Data(certificate));

	var signedXml = new SignedXml(doc)
						{
							SigningKey = certificate.PrivateKey
						};
	signedXml.AddReference(reference);
	signedXml.KeyInfo = keyInfo;

	signedXml.ComputeSignature();

	XmlElement xmlElement = signedXml.GetXml();

	return Convert.ToBase64String(Encoding.UTF8.GetBytes(xmlElement.InnerXml));
}