if (stream != null) {
XmlDocument doc = new XmlDocument ();
doc.PreserveWhitespace = true; // REALLY IMPORTANT
-#if NET_1_1
doc.XmlResolver = GetResolver ();
-#endif
doc.Load (new XmlSignatureStreamReader (new StreamReader (stream)));
// doc.Load ((Stream) obj);
s = canonicalizer.Canonicalize (doc);