RE: [security-services] Comparison rules for SAML elements(ISSUE:[DS-14-11: CompareElements])

[Irving Reid <Irving.Reid@baltimore.com>]

> From: Stephen Farrell [mailto:stephen.farrell@baltimore.ie]
> 
> Don't you need some C14N style stuff about elements and attributes
> too? 
> 
> Examples that might be relevant (not sure, but in acending order
> of liklihood):
> 
> - is absence the same as the presence of a default value?

I don't think we define any default values in our schema.

> - is <foo></foo> the same as <foo/>?

By the definition of XML, yes.

> - <Subject><fred/><bill/></Subject> = 
> <Subject><bill/><fred/></Subject>?
> - if I have an authentication assertion about <fred> and an
>   attribute assertion about <Subject><fred/><bill/></Subject> does
>   that attribute apply to the subject of the authentication assertion?
> 
> Now, maybe some of these things are well-defined in the current spec,
> but if so, it wasn't clear to me I'm afraid.

I'm still not entirely comfortable with the multiple-subject stuff either.
The intent of the language in core-25, if I'm not mistaken, is to say that
you can put more than one subject name in to your assertion, but it would be
a bad idea to have those subject names refer to more than one real-world
entity.

Given that, your second example where the authn assertion names Fred and the
attr assertion names Fred and Bill, the attribute would apply to Fred.

This is more an issue of the semantics of multiple subjects, rather than a
general rule for matching values.

 - irving -


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