Re: [xacml] Problems with XACML and time

[Satoshi Hada <SATOSHIH@jp.ibm.com>]

Hi Steve,

I'm not yet sure I correctly understand
your problem.

You want to check whether the current
time is between 9:00 and 17:00 in an arbitrary time zone, 
which is not specified in the policy.
Assume that the PDP is in the time zone
+14:00, and that the current time is 14:00 in the PDP's time zone.
Then you want to check whether 09:00(+14:00)
<= 14:00(+14:00) <= 17:00(+14:00).
Of course, the result should be true.

However, according to the XML-Schema
specification, you have to normalize 
the three time values. They are normalized
to 19:00 <= 00:00 <= 03:00.
It seems to me that you say that the
result is false because 19:00 <= 00:00 is false.

Does this summarize your problem?

Satoshi Hada
IBM Tokyo Research Laboratory 
mailto:satoshih@jp.ibm.com

Steve Hanna <steve.hanna@sun.com> 2003/07/18 23:23

To:        Satoshi Hada/Japan/IBM@IBMJP         cc:        xacml@lists.oasis-open.org         Subject:        Re: [xacml] Problems with XACML and time

Satoshi Hada wrote:
> Thank you for the clarification. I don't think I fully
> understand the problem, and I will read your mail more
> carefully next week.

OK, thanks for your careful consideration.

> >> The simplest
> >> way to make this change would be to change the definition
of the
> >> XACML time comparison functions to refer to XML Query instead
of
> >> XML Schema, as the time-equal function already does.
>
> I like this change.
>
> >> This solution does not solve the problem mentioned in this
> >> paragraph from my original email:
>
> A quick question:
>
> Do you mean even though we make the above change
> we still have the problem (the change does not solve all the
> problems)?

Yes, changing the time comparison functions to refer
to XML Query
instead of XML Schema does not solve all the problems in my email.
It solves one of them (the need to specify time zones for all
times). But it doesn't solve the second problem (the problems
that arise when midnight GMT falls during normal business
hours, as it does in many parts of the world). Solving that
problem will require an additional change, such as adding the
time-in-range function.

Thanks again for your help,

Steve Hanna