Verifying XML digital signature and getting X509 certificate details from KeyInfo

I need to verify an XML digital signature and as part of the process I need to extract the signer certificate from the signed file "Signature" element.   Using the following methods:
NodeList nl = doc.getElementsByTagNameNS(XMLSignature.xmlNS,"Signature");
DOMValidateContext valContext = new DOMValidateContext(new KeyStoreKeySelector(), nl.item(0));

I need to use the KeyInfo contained in the XMLSignature element to create an  X509Certificate to get the cerficiate details; serial number, validity, subject, issuer, etc.  But have not been able to find how to do this.Start Free Trial