Why and when to perform this task
This task explains how you might create your own AuthenticationToken
implementation, which is set in the login Subject and propagated downstream.
This implementation enables you to specify an authentication token that can
be used by a custom login module or application. Consider writing your own
implementation if you want to accomplish one of the following tasks:
- Isolate your attributes within your own implementation.
- Serialize the information using custom serialization. You must deserialize
the bytes at the target and add that information back on the thread. This
task also might include encryption and decryption.
- Affect the overall uniqueness of the Subject using the getUniqueID() application
programming interface (API).
Important: Custom AuthenticationToken implementations are
not used by the security run time in WebSphere Application Server to enforce
authentication. WebSphere Application Security run time uses this token in
the following situations only:
- Call the getBytes() method for serialization
- Call the getForwardable() method to determine whether to serialize the
AuthenticationToken.
- Call the getUniqueId() method for uniqueness
- Call the getName() and the getVersion() methods for adding serialized
bytes to the TokenHolder that is sent downstream
All of the other uses are custom implementations.
To implement
a custom authentication token, you must complete the following steps:
- Write a custom implementation of the AuthenticationToken interface.
There are many different methods for implementing the AuthenticationToken
interface. However, make sure that the methods required by the AuthenticationToken
interface and the token interface are fully implemented. After you implement
this interface, you can place it in the install_dir/classes directory.
Alternatively, you can place the class in any private directory. However,
make sure that the WebSphere Application Server class loader can locate the
class and that it is granted the appropriate permissions. You can add the
Java archive (JAR) file or directory that contains this class into the server.policy file
so that it has the necessary permissions that are needed by the server code.
Tip: All of the token types defined by the propagation framework have
similar interfaces. Basically, the token types are marker interfaces that
implement the com.ibm.wsspi.security.token.Token interface. This interface
defines most of the methods. If you plan to implement more than one token
type, consider creating an abstract class that implements the com.ibm.wsspi.security.token.Token
interface. All of your token implementations, including the AuthenticationToken,
might extend the abstract class and then most of the work is completed.
To
see an implementation of AuthenticationToken, see Example: com.ibm.wsspi.security.token.AuthenticationToken implementation
- Add and receive the custom AuthenticationToken during WebSphere
Application Server logins This task is typically accomplished by
adding a custom login module to the various application and system login configurations.
However, in order to deserialize the information, you must plug in a custom
login module. After the object is instantiated in the login module, you can
add the object to the Subject during the commit() method.
If
you only want to add information to the Subject to get propagated, see Propagating a custom Java serializable object.
If you want to ensure that the information is propagated, if you want to do
your own custom serialization, or if you want to specify the uniqueness for
Subject caching purposes, then consider writing your own AuthenticationToken
implementation.
The code sample in Example: custom AuthenticationToken login module shows how to
determine if the login is an initial login or a propagation login. The difference
between these login types is whether the WSTokenHolderCallback contains propagation
data. If the callback does not contain propagation data, initialize a new
custom AuthenticationToken implementation and set it into the Subject. If
the callback contains propagation data, look for your specific custom AuthenticationToken
TokenHolder instance, convert the byte[] back into your custom AuthenticationToken
object, and set it back into the Subject. The code sample shows both instances.
You
can make your AuthenticationToken read-only in the commit phase of the login
module. If you do not make the token read-only, then attributes can be added
within your applications.
- Add your custom login module to WebSphere Application
Server system login configurations that already contain the com.ibm.ws.security.server.lm.wsMapDefaultInboundLoginModule
for receiving serialized versions of your custom authorization token
Because this login module relies on information in the sharedState
added by the com.ibm.ws.security.server.lm.wsMapDefaultInboundLoginModule,
add this login module after com.ibm.ws.security.server.lm.wsMapDefaultInboundLoginModule.
For information on how to add your custom login module to the existing login
configurations, see Custom login module development for a system login configuration