// initial client security context
clientContext = new WindowsSecurityContextImpl();
clientContext.setPrincipalName(WindowsAccountImpl.getCurrentUsername());
clientContext.setCredentialsHandle(clientCredentials.getHandle());
clientContext.setSecurityPackage(securityPackage);
clientContext.initialize(null, null, WindowsAccountImpl.getCurrentUsername());
final SimpleHttpRequest request = new SimpleHttpRequest();
request.setMethod("POST");
request.setContentLength(0);
final String clientToken = BaseEncoding.base64().encode(clientContext.getToken());
request.addHeader("Authorization", securityPackage + " " + clientToken);