function signXml(certObject, dataToSign) {
try {
var oSigner = CreateObject("CAdESCOM.CPSigner");
} catch (err) {
errormes = "Failed to create CAdESCOM.CPSigner: " + err.number;
alert(errormes);
throw errormes;
}

if (oSigner) {
oSigner.Certificate = certObject;
}
else {
errormes = "Failed to create CAdESCOM.CPSigner";
alert(errormes);
throw errormes;
}

var oSignedXML = CreateObject("CAdESCOM.SignedXML");
oSignedXML.Content = dataToSign;
oSignedXML.SignatureType = CADESCOM_XML_SIGNATURE_TYPE_ENVELOPED;
oSignedXML.SignatureMethod = XmlDsigGost3410Url;
oSignedXML.DigestMethod = XmlDsigGost3411Url;

var sSignedMessage = "";
try {
sSignedMessage = oSignedXML.Sign(oSigner);
}
catch (err) {
errormes = "Не удалось создать подпись из-за ошибки: " + GetErrorMessage(err);
alert(errormes);
throw errormes;
}

return sSignedMessage;
}

public bool VerifyRequestDataSignature()
{
var signedXml = new SignedXml();
var xmlNode = _clientXmlDocument.GetElementsByTagName("Signature").Item(0);
if (xmlNode == null)
{
throw new Exception("Не найден элемент Signature");
}
signedXml.LoadXml((XmlElement)xmlNode);
var result = signedXml.CheckSignature();
return result;
}