Example: JAAS programmatic login

The following example illustrates how application programs can perform a programmatic login using JAAS:.

LoginContext lc = null;
            
 try {
       lc = new LoginContext("WSLogin",         
                  new WSCallbackHandlerImpl("userName", "realm", "password"));
 } catch (LoginException le) {
        System.out.println("Cannot create LoginContext. " + le.getMessage());
        // insert error processing code 
 } catch SecurityException(se) {
        System.out.printlin("Cannot create LoginContext." + se.getMessage();
        // Insert error processing 
  }

  try {
         lc.login(); 
  } catch(LoginExcpetion le) {
         System.out.printlin("Fails to create Subject. " + le.getMessage());
          // Insert error processing code

As shown in the example, the new LoginContext is initialized with the WSLogin login configuration and the WSCallbackHandlerImpl CallbackHandler. Use the WSCallbackHandlerImpl instance on a server-side application where prompting is not desirable. A WSCallbackHandlerImpl instance is initialized by the specified user ID, password, and realm information. The present WSLoginModuleImpl class implementation that is specified by WSLogin can only retrieve authentication information from the specified CallbackHandler. You can construct a LoginContext with a Subject object, but the Subject is disregarded by the present WSLoginModuleImpl implementation. For product client container applications, replace WSLogin by ClientContainer login configuration, which specifies the WSClientLoginModuleImpl implementation that is tailored for client container requirements.

For a pure Java application client, the product provides two other CallbackHandler implementations: WSStdinCallbackHandlerImpl and WSGUICallbackHandlerImpl, which prompt for user ID, password, and realm information on the command line and pop-up panel, respectively. You can choose either of these product CallbackHandler implementations depending on the particular application environment. You can develop a new CallbackHandler if neither of these implementations fit your particular application requirement.

You also can develop your own LoginModule if the default WSLoginModuleImpl implementation fails to meet all your requirements. WAS provides utility functions that the custom LoginModule can use, which are described in the next section.

In cases where there is no java.naming.provider.url set as a system property or in the jndi.properties file, a default InitialContext does not function if the product server is not at the localhost:2809 location. In this situation, perform a new InitialContext programmatically ahead of the JAAS login. JAAS needs to know where the SecurityServer resides to verify that the user ID or password entered is correct, prior to doing a commit(). By performing a new InitialContext in the way specified below, the security code has the information needed to find the SecurityServer location and the target realm.

Note that The first line starting with env.put was split into two lines because it extends beyond the width of the printed page.

...
   import java.util.Hashtable;
   import javax.naming.Context;
   import javax.naming.InitialContext;
   ...
   
// Perform an InitialContext and default lookup prior to logging in so that target realm
// and bootstrap host/port can be determined for SecurityServer lookup.
   
   Hashtable env = new Hashtable();
   env.put(Context.INITIAL_CONTEXT_FACTORY, 
           "com.ibm.websphere.naming.WsnInitialContextFactory");
   env.put(Context.PROVIDER_URL, "corbaloc:iiop:myhost.companyname.com:2809");
   Context initialContext = new InitialContext(env);
   Object obj = initialContext.lookup("");
   
    LoginContext lc = null;
    try {
       lc = new LoginContext("WSLogin",         
                  new WSCallbackHandlerImpl("userName", "realm", "password"));
    } catch (LoginException le) {
        System.out.println("Cannot create LoginContext. " + le.getMessage());
        // insert error processing code 
    } catch SecurityException(se) {
        System.out.printlin("Cannot create LoginContext." + se.getMessage();
        // Insert error processing 
    }

    try {
         lc.login(); 
    } catch(LoginException le) {
         System.out.printlin("Fails to create Subject. " + le.getMessage());
          // Insert error processing code
    }

 

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