DocumentBuilder db = dbf.newDocumentBuilder();
Document doc = db.parse(new FileInputStream(filename));
NodeList sigs = doc.getElementsByTagNameNS(Constants.SignatureSpecNS, Constants._TAG_SIGNATURE);
XMLSignature sig = new XMLSignature((Element)sigs.item(0), new File(filename).toURL().toString());
boolean check = sig.checkSignatureValue(sig.createSecretKey("secret".getBytes()));
System.out.println(
"-------------------------------------------------------------");
System.out.println("Verification of " + filename + ": " + check);
System.out.println(