KeyInfoHeaderBlock keyInfoHb = new KeyInfoHeaderBlock(keyInfo);
Key kek = null;
try{
if (keyInfoHb.containsSecurityTokenReference()){
kek = processSecurityTokenReference(keyInfoHb, callbackHandler);
} else if (keyInfoHb.containsKeyValue()) {
SecurityEnvironment secEnv = new DefaultSecurityEnvironmentImpl(callbackHandler);
KeyValue keyValue = keyInfoHb.getKeyValue(0);
keyValue.getElement().normalize();
kek = secEnv.getPrivateKey(null, keyValue.getPublicKey(), false);