Document doc = DOMUtils.createDocument();
builder.prepare(doc, stsProperties.getSignatureCrypto());
Element encryptedKeyElement = builder.getEncryptedKeyElement();
byte[] secret = builder.getEphemeralKey();
EntropyType entropyType = new EntropyType();
entropyType.getAny().add(encryptedKeyElement);
JAXBElement<EntropyType> entropyJaxbType =
new JAXBElement<EntropyType>(QNameConstants.ENTROPY, EntropyType.class, entropyType);
request.getAny().add(entropyJaxbType);
RequestSecurityTokenResponseCollectionType response =