PIP - comments/questions

Hi,

    
I've a few comments/questions regarding to XACML. If this is the
      wrong mailing list, let me know.

    

    
      
The most XACML-Implementations, that I saw, integrated the
        PIP's into the PDP. I think that is no good solution, but the
        devs had not choice:

        On the one hand the meaning of the context handler isn't really
        described as importent as I guess it is. On the other hand there
        is no XML/JSON-specification how to request a PIP. So when PDP
        and PEP/context handler are on two machines, then the PIP has to
        be on the the PDP machine and cannot be on a third machine (e.g.
        as microservice).

        Why is there no detailed PIP definition?

      
It's not really clear defined what's the recommended way to
        retreive missing attributes in XACML. PIP's or Response Status
        Detail?

      
I think it would be usefull, if an AttributeDesignator has an
        optional "_expression_" and "expressionType" attribute, so PIP's
        could use them for SQL-queries or Spring _expression_ Language
        etc.

      
Why are VariableDefinitions only for policies and not
        policySets?

    
    thank you and best regards

    Benedict