Example: Programmatic logins

This example illustrates how application programs can perform a
programmatic login using Java Authentication and Authorization Service (JAAS).

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

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

As shown in the example, the new login context is initialized with the WSLogin login configuration and the WSCallbackHandlerImpl callback handler. Use the WSCallbackHandlerImpl instance on a server-side application where you do not want prompting. A WSCallbackHandlerImpl instance is initialized by the specified user ID, password, and realm information. The present WSLoginModuleImpl class implementation that is specified by the WSLogin login configuration can only retrieve authentication information from the specified callback handler. You can construct a login context with a Subject object, but the Subject is disregarded by the present WSLoginModuleImpl implementation. For product client-container applications, replace WSLogin login configuration 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 callback handler 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 callback handler implementations, depending on the particular application environment. You can develop a new callback handler if neither of these implementations fit your particular application requirement.

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

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

Attention: The first line starting with env.put was split into two lines for illustration purposes only.

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.mycompany.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     }