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Re: Comments on aci-model-04



> 
> However semantically they may be different.  The underlying
> implementation of the access decision function (which looks at ACL
> entries and compares them against the subject's credentials to render
> a yes/no decision about a particular access request) may treat "group"
> entries differently from "role" entries.  For example, it might
> implement "union semantics" for groups but "intersection semantics"
> for roles.  Thus if an ACL contained 4 entries:
> 

Bob
This is another example of the lack of precise definition that worries 
me. There is too much vagary (vagueness?) in the acl model as it 
stands. I have already commented previously that nowhere is it 
stated which permissions are needed (i.e. which grants are needed) 
for which operations, in order for them to be successfully 
performed. Now we also seem to have a variable ACDF in which 
different implementations use the same ACI and derive different 
results. So without a fixed and clearly defined ACDF, and fixed 
permissions per operation, it seems pointless to talk about 
precedences of various ACIs (which we have been doing) , since 
by extension, each ACDF can determine its own precedence rules.

Comments?
David

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David Chadwick
IS Institute, University of Salford, Salford M5 4WT
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