This document describes how to add an object into the Subject from a login module and describes other infrastructure considerations to make sure that the Java object gets propagated. Prior to completing this task, verify that security propagation is enabled in the administrative console.
Whenever you plug a custom login module into the login infrastructure of WebSphere Application Server, make sure that the code is trusted. When you add the login module into the profile_root/classes directory, the login module has Java 2 Security AllPermissions permissions. For more information, see Creating a classes subdirectory in your profile for custom classes. However, because the login module might be run after the application code on the call stack, you might add doPrivileged code so that you do not need to add additional properties to your applications. The following code sample shows how to add doPrivileged code. For information on what to do during initialization, login and commit, see Custom login module development for a system login configuration.
public customLoginModule()
{
public void initialize(Subject subject, CallbackHandler callbackHandler,
Map sharedState, Map options)
{
}
public boolean login() throws LoginException
{
// Construct callback for the WSTokenHolderCallback so that you
// can determine if
// your custom object has propagated
Callback callbacks[] = new Callback[1];
callbacks[0] = new WSTokenHolderCallback("Authz Token List: ");
try
{
_callbackHandler.handle(callbacks);
}
catch (Exception e)
{
throw new LoginException (e.getLocalizedMessage());
}
// Checks to see if any information is propagated into this login
List authzTokenList = ((WSTokenHolderCallback) callbacks[1]).
getTokenHolderList();
if (authzTokenList != null)
{
for (int i = 0; i< authzTokenList.size(); i++)
{
TokenHolder tokenHolder = (TokenHolder)authzTokenList.get(i);
// Look for your custom object. Make sure you use
// "startsWith"because there is some data appended
// to the end of the name indicating in which Subject
// Set it belongs. Example from getName():
// "com.acme.CustomObject (1)". The class name is
// generated at the sending side by calling the
// object.getClass().getName() method. If this object
// is deserialized by WebSphere Application Server,
// then return it and you do not need to add it here.
// Otherwise, you can add it below.
//
Note: If your class appears in this list and does
// not use custom serialization (for example, an
// implementation of the Token interface described in
// the Propagation Token Framework), then WebSphere
// Application Server automatically deserializes the
// Java object for you. You might just return here if
// it is found in the list.
if (tokenHolder.getName().startsWith("com.acme.CustomObject"))
return true;
}
}
// If you get to this point, then your custom object has not propagated
myCustomObject = new com.acme.CustomObject();
myCustomObject.put("mykey", "mydata");
}
public boolean commit() throws LoginException
{
try
{
// Assigns a reference to a final variable so it can be used in
// the doPrivileged block
final com.acme.CustomObject myCustomObjectFinal = myCustomObject;
// Prevents your applications from needing a JAAS getPrivateCredential
// permission.
java.security.AccessController.doPrivileged(new java.security.
PrivilegedExceptionAction()
{
public Object run() throws java.lang.Exception
{
// Try not to add a null object to the Subject or an object
// that already exists.
if (myCustomObjectFinal != null && !subject.getPrivateCredentials().
contains(myCustomObjectFinal))
{
// This call requires a special Java 2 Security permission,
// see the JAAS API
// documentation.
subject.getPrivateCredentials().add(myCustomObjectFinal);
}
return null;
}
});
}
catch (java.security.PrivilegedActionException e)
{
// Wraps the exception in a WSLoginFailedException
java.lang.Throwable myException = e.getException();
throw new WSLoginFailedException (myException.getMessage(), myException);
}
}
// Defines your login module variables
com.acme.CustomObject myCustomObject = null;
}
If you are careful adding custom objects and follow all the steps to make sure that WebSphere Application Server can serialize and deserialize the object at each hop, then it is sufficient to use custom Java objects only.
When you add a custom object into the Subject and expect WebSphere Application Server to propagate the object, make sure that the class definition for that custom object exists in the profile_root/classes directory on all of the nodes where serialization or deserialization might occur. Also, verify that the Java class versions are the same.
Although you can add custom objects to the propagation exclude list, be aware of a side effect. WebSphere Application Server stores the opaque token, or the serialized Subject contents, in a local cache for the life of the single sign-on (SSO) token. The life of the SSO token, which has a default of two hours, is configured in the SSO properties on the administrative console. The information that is added to the opaque token includes only the objects not in the exclude list.
If your authentication cache does not match your SSO token timeout, configure the authentication cache properties. See Configuring the authentication cache. It is recommended that you make your authentication cache timeout value equal to the SSO token timeout.