xacml message
[Date Prev]
| [Thread Prev]
| [Thread Next]
| [Date Next]
--
[Date Index]
| [Thread Index]
| [Elist Home]
Subject: RE: [xacml] Comparing XACML with WS Policy framework
- From: Tim Moses <tim.moses@entrust.com>
- To: Tim Moses <tim.moses@entrust.com>, 'XACML' <xacml@lists.oasis-open.org>
- Date: Thu, 30 Jan 2003 08:55:15 -0500
Title: Comparing ACME with WS Policy framework
Colleagues - A couple more
observations:
1.
Early in the XACML project we clarified that "combining" meant combining the
"results" of policies or rules, rather than combining policies themselves.
It seems now that there is a need to combine policies and rules also.
I expect that it is only practical to combine isomorphic policies or
rules. This is why the WSS-QoP specification defined a rigid structure of
services containing mechanisms, with an implied logic ("and" for services and
"or" for mechanisms).
2.
WSPF supports capabilities. In this context "capabilities" means functions
that a service "can", and "is willing", to perform, but that it is not
"required" to perform. The authors introduce an ad hoc logic system to
express this. XACML is also capable of expressing capabilities within its
formal logic system. This is best illustrated by an
example:
<policyId = Policy1>
<or>
<Capability1>
<true>
</or>
This
indicates that the target of the policy has the capability: Capability1.
It is of little interest to a PDP, which would always evaluate this expression
to "true". However, an algorithm that combines this policy with the
policy:
<policyId = Policy2>
<or>
<Capability1>
</or>
would
create the definitive policy:
<policyId =
Policy3>
<or>
<Capability1>
</or>
which
would be acceptable to the authors of both Policy1 and
Policy2.
All
the best.
Tim.
Colleagues - Here are some preliminary thoughts on the
relationship between the OASIS standard XACML and the proprietary WS Policy
framework. I am interested in other people's views. All the
best. Tim.
-----------------------------------------------------------------
Tim Moses
613.270.3183
[Date Prev]
| [Thread Prev]
| [Thread Next]
| [Date Next]
--
[Date Index]
| [Thread Index]
| [Elist Home]
Powered by eList eXpress LLC