fac = XMLSignatureFactory.getInstance("DOM", "ApacheXMLDSig");
} catch (NoSuchProviderException ex) {
fac = XMLSignatureFactory.getInstance("DOM");
}
KeySelector selector = getConfiguration().getKeySelector();
if (selector == null) {
throw new IllegalStateException("Wrong configuration. Key selector is missing.");
}
DOMValidateContext valContext = new DOMValidateContext(selector, signatureNode);