private XElement EncryptElement(XElement plaintextElement)
{
// EncryptedXml works with XmlDocument, not XLinq. When we perform the conversion
// we'll wrap the incoming element in a dummy <root /> element since encrypted XML
// doesn't handle encrypting the root element all that well.
var xmlDocument = new XmlDocument();
xmlDocument.Load(new XElement("root", plaintextElement).CreateReader());
var elementToEncrypt = (XmlElement)xmlDocument.DocumentElement.FirstChild;
// Perform the encryption and update the document in-place.
var encryptedXml = new EncryptedXml(xmlDocument);
var encryptedData = _encryptor.PerformEncryption(encryptedXml, elementToEncrypt);
EncryptedXml.ReplaceElement(elementToEncrypt, encryptedData, content: false);
// Strip the <root /> element back off and convert the XmlDocument to an XElement.
return(XElement.Load(xmlDocument.DocumentElement.FirstChild.CreateNavigator().ReadSubtree()));
}
