There appears to be one more issue with this. I created a callback
handler with a no-arg constructor so I could examine the behavior of
what's going on, and I've discovered that there appears to be an issue
with the classloader used to resolve the callback handler. My callback
handler object is getting NoClassDefFound errors trying to access the
org.apache.geronimo.security.realm.providers.CertificateChainCallback
class. It's not clear to me why this is a problem, since it appears the
client config has a dependency on the geronimo-security module.
Rick
Rick McGuire wrote:
I've run into a serious problem with app client security callback
handlers in Geronimo 2.0. These appear to be completely broken, and
I'm not sure I understand how to fix this. Here's the scenario:
In 1.2, a security callback handler class can be specified in the
plan. In the main() method of the AppClientContainer, this was
handled thusly:
if (callbackHandlerClass != null) {
//look for a constructor taking the args
CallbackHandler callbackHandler;
try {
Constructor cArgs =
callbackHandlerClass.getConstructor(new Class[] {String[].class});
callbackHandler = (CallbackHandler)
cArgs.newInstance(new Object[] {args});
} catch (NoSuchMethodException e) {
callbackHandler = (CallbackHandler)
callbackHandlerClass.newInstance();
}
loginContext = new LoginContext(realmName,
callbackHandler);
try {
loginContext.login();
} catch (LoginException e) {
loginContext = null;
throw e;
}
clientSubject = loginContext.getSubject();
}
The appclient container looked for a constructor on the target
callback handler that took an array of Strings as an argument, and
constructed that callback handler using the string arguments passed to
the AppClientContainer main() method. The callback handler would scan
the application args looking for options that applied to its
authentication technique, and it was passed to the loginContext in an
initialized state, ready to provide addtional information to the login
process.
In 2.0, this has changed drastically, breaking any call back handlers
written for 1.2, and I don't even see an obvious method of fixing
this. Here's the new code for managing the callback handler:
if (callbackHandlerClass != null) {
callbackHandler = (CallbackHandler)
holder.newInstance(callbackHandlerClass, classLoader, componentContext);
loginContext = new LoginContext(realmName,
callbackHandler);
try {
loginContext.login();
} catch (LoginException e) {
loginContext = null;
throw e;
}
clientSubject = loginContext.getSubject();
}
Same relative point in the AppClientContainer startup, but with two
key differences:
1. The holder.newInstance() call appears to be looking for a
no-argument constructor on the callbackHandlerClass (which likely
fails with the 1.2 classes because they are expecting to have
their void CallbackHandler(String []) constructor called).
2. The new callback handler instance is no longer being given access
to the appclient args to initialize. There appears to be some
injection processing going on in the holder.newInstance() call,
but it's not clear how to specify what information get injected,
or even if the information from the appclient args is available.
So, how is this supposed to work, and if this is currently working
correctly in 2.0, what is the process for converting a handler written
for 1.2 into an equivalent for 2.0?
Rick
