Obtaining the JAAS subject in a portal application?

Question

G'day,
Is there a safe method for obtaining the JAAS subject in a portal application?
There are problems in Java with getting the JAAS subject, as the standard Subject.getSubject() call can return null if called within a privileged action:
Subject s = Subject.getSubject(AccessController.getContext());
Subject.doAs(s, new PrivilegedAction() {
  public Object run() {
    Subject s1 = Subject.getSubject(AccessController.getContext());
    AccessController.doPrivileged(new PrivilegedAction() {
      public Object run() {
        Subject s2 = Subject.getSubject(AccessController.getContext());
        return null;
    return null;
Here, s2 may be null, which is why other app servers have custom approaches (such as JBoss and its SecurityAssociation.getSubject() call).
In fact, when I try the above code in a portal application (protected by the login module used to access the portal), I get NULL value for each subject s, s1, and s2.
I have found a Netweaver API that may be useful for obtaining the subject:
Object object = com.sap.security.core.InternalUMFactory.getEngineResourceHelper();
if (object != null && object instanceof com.sap.security.core.IEngineResourceHelper) {
  com.sap.security.core.IEngineResourceHelper helper =
      (com.sap.security.core.IEngineResourceHelper) object;
  Subject subject = helper.getCurrentSubject();
A portal application containing this code will display the following:
Subject: Principal: tu-1_basic Principal: com.sap.security.api.logon.AuthSchemePrincipal@19b07b7 Private Credential: GSSCredential: name: [email protected] usage: INITIATE_AND_ACCEPT for mechs: 1.2.840.113554.1.2.2 usage:INITIATE_ONLY 1.2.840.113554.1.2.2.3 usage:INITIATE_AND_ACCEPT underlying Kerberos creds: TGT remaining lifetime = 594 Private Credential: com.sap.security.core.server.jaas.SAPLogonTicketCredential@6a527bdd
However, the class name InternalUMFactory suggests that this API may be undocumented or unstable.
Is there a documented API in Netweaver AS Java for obtaining the JAAS subject?
--Geoff

Answer 1

Hi,
We can use the following API to get the current role:
IWDNavigationHelperService wdNavHelperService =
    (IWDNavigationHelperService) WDPortalUtils.getService(IWDNavigationHelperService.KEY);
String navNode = wdNavHelperService.getCurrentNavNode();
Regards,
Ganpati