adding alternative WebApplicationService implementation

[Peter Kharchenko]

Scott, everyone,
 I am working on CASifying a closed-source app that takes 
username/password on the frontend, and allows to provide a pluggable 
module on the back end to validate the credentials. The backend can only 
answer "valid/invalid", so I have to provide the real username together 
with the ticket (and the ticket has to be passed under a different param 
name as well).
 I am sure this has been encountered numerous times, but I couldn't find 
an answer searching the archives, so figured I'd ask.

 As far as I can tell, I would need to provide an alternative to 
SimpleWebApplicationServiceImpl that would append both the ticket and 
username (under some configurable params). I would use a different 
keyword instead of "service" or "TARGET" to distinguish it from standard 
and SAML service implementations. And then I would simply add the new 
ServiceImpl to "argumentExtractors" list in cas-servlet.xml. The 
validation config can stay the same. Does this sound right?

thanks in advance,
-peter.