OASIS Mailing List ArchivesView the OASIS mailing list archive below
or browse/search using MarkMail.

 


Help: OASIS Mailing Lists Help | MarkMail Help

xacml message

[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]


Subject: Re: [xacml] Possible Issue: XACML 3.0 WD 9 - 2 questions on Obligation


I don't understand this alternative. Could you clarify?

Regards,
Erik

Hal Lockhart wrote:
> Just thinking out loud, but as an alternative would it make sense to make Obligation (and/or Advice) input a category type? Or do we expect to be using the same attribute for multiple purposes?
>
> Hal
>
>   
>> -----Original Message-----
>> From: Erik Rissanen [mailto:erik@axiomatics.com]
>> Sent: Thursday, March 19, 2009 2:03 AM
>> To: Rich.Levinson
>> Cc: xacml
>> Subject: Re: [xacml] Possible Issue: XACML 3.0 WD 9 - 2 questions on
>> Obligation
>>
>> Hi Rich,
>>
>> I presume you are referring to the following schema fragment:
>>
>>          <xs:element name="AttributeAssignment"
>> type="xacml:AttributeAssignmentType"/>
>>          <xs:complexType name="AttributeAssignmentType" mixed="true">
>>                  <xs:complexContent mixed="true">
>>                          <xs:extension base="xacml:AttributeValueType">
>>                                  <xs:attribute name="AttributeId"
>> type="xs:anyURI" use="required"/>
>>                          </xs:extension>
>>                  </xs:complexContent>
>>          </xs:complexType>
>>
>> This means that an AttributeAssignment has the same content as
>> AttributeValueType, except that the XML attribute AttributeId is
>> required. Like this:
>>
>> <AttributeAssignment AttributeId="urn:....:foo" DataType="urn:...:bar">
>>    some value here
>> </AttributeAssignment>
>>
>> We want to declare the XML attribute, although xs:anyAttribute is
>> already allowed, since without the declaration the AttributeId is not
>> _required_.
>>
>> I haven't thought about the category for attributes in obligations. I
>> have thought them as parameters of the obligation, not parts of the
>> request. But I see the point. What about making the Category an optional
>> XML attribute? That way it won't "pollute" those obligations which just
>> contain obligation parameters, but it will still be possible to return
>> parts of the request.
>>
>> Best regards,
>> Erik
>>
>> Rich.Levinson wrote:
>>     
>>> While reviewing where we have ended up with the handling of Obligation
>>> elements in 3.0, I have 2 questions which I am unable to resolve based
>>> on my reading of the text (question 2 contains a possible issue of
>>> functionality, question 1 might just be clarification either by
>>> response to this email or by issue  for more explanatory info in the
>>> text):
>>>
>>>    1. AttributeId in Obligation in Response: In section 5.41,
>>>       AttributeAssignmentExpression, it says:
>>>           * "It SHALL contain an AttributeId and an expression which
>>>             SHALL by evaluated into the corresponding attribute value."
>>>           * Presumably, this means that these two items will be what
>>>             the PDP puts into the Obligation element that is put into
>>>             the Response. This interpretation is also in agreement, I
>>>             believe, with the description of this element in section
>>>       
>> 5.39:
>>     
>>>                 o "The expressions SHALL be evaluated by the PDP to
>>>                   constant <AttributeValue> elements, which shall be
>>>                   the attribute assignments in the <Obligation>
>>>                   returned to the PEP. "
>>>           * Presumably the two items above (AttributeValue,
>>>             AttributeId) are then put by the PDP into the
>>>             AttributeAssignment element (section 5.36) which is child
>>>             to the Obligation (section 5.34)
>>>           * Here is my basic question on section 5.36, which may be
>>>             simply that I do not understand the mechanics of the
>>>             extension element in the schema: it appears on lines
>>>             2543-2546 that AttributeId might be defined here as an
>>>             attribute of AttributeValue:
>>>                 o "
>>>
>>>                         <xs:extension base="xacml:AttributeValueType">
>>>
>>>                            <xs:attribute name="AttributeId"
>>>                   type="xs:anyURI"
>>>
>>>                                       use="required"/>
>>>
>>>                         </xs:extension>
>>>
>>>                   "
>>>                 o So, that's the 1st part of the question. Is this the
>>>                   same AttributeId identified in section 5.41, and
>>>                   does it show up in the output Obligation as an
>>>                   attribute of the AttributeAssignment element or of
>>>                   the AttributeValue element? (It appears based on the
>>>                   above that it might be the latter, if not please
>>>                   explain.)
>>>                 o If it is the an attribute of AttributeValue, the 2nd
>>>                   part of the question is does this not kind of
>>>                   violate section 5.31 AttributeValue, because this
>>>                   AttributeId would presumably now be part of the
>>>                   xs:anyAttribute.
>>>    2. (2nd question) Should we include the "Category" in the
>>>       Obligation (probably not because that would apply to all
>>>       AttributeAssignments) or preferably in the AttributeAssignment
>>>       (assuming the AttributeId is already there from question 1)?
>>>           * The reason for asking is that it does not seem
>>>             unreasonable that in many cases the AttributeId assigned
>>>             to the Obligation/AttributeAssignment will be the same
>>>             AttributeId used to pull an attribute out of the Request.
>>>             Granted, it doesn't have to be, but let's assume that is
>>>             what some people might want to do.
>>>           * Assuming people want to do this, we now run into the same
>>>             ambiguity that led to the addition of Category to
>>>             MissingAttributeDetail (section 5.56), namely that if the
>>>             PEP needs to know how to correlate the returned attributes
>>>             with the input request, then both AttributeId and Category
>>>             are needed, in general.
>>>
>>>     Thanks,
>>>     Rich
>>>       
>> ---------------------------------------------------------------------
>> To unsubscribe from this mail list, you must leave the OASIS TC that
>> generates this mail.  Follow this link to all your TCs in OASIS at:
>> https://www.oasis-open.org/apps/org/workgroup/portal/my_workgroups.php
>>
>>     
>
>
> ---------------------------------------------------------------------
> To unsubscribe from this mail list, you must leave the OASIS TC that
> generates this mail.  Follow this link to all your TCs in OASIS at:
> https://www.oasis-open.org/apps/org/workgroup/portal/my_workgroups.php 
>
>   



[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]