в java 6 компилилось вот такое:
Document doc_verify = stringToDoc(xml);
Element nscontext = XMLUtils.createDSctx(doc_verify, "ds", "http://www.w3.org/2000/09/xmldsig#");
NodeList list = XPathAPI.selectNodeList(doc_verify, "//ds:Signature", nscontext);
Element sigElement = (Element) list.item(list.getLength() - 1);
XMLSignature signature = new XMLSignature(sigElement, "");
org.apache.xml.security.keys.KeyInfo ki = signature.getKeyInfo();
X509Certificate certKey = ki.getX509Certificate();
signature.checkSignatureValue(certKey);
но kalkan под java 7. А в java 7 этот код выдает:
Unresolved compilation problems:
XMLUtils cannot be resolved
XPathAPI cannot be resolved