Re: [security-services] Random Overdue Question on SubjectConfirmation

[Brian Campbell <bcampbell@pingidentity.com>]

Thanks for clarifying Scott.

On Wed, Jun 16, 2010 at 1:46 PM, Scott Cantor <cantor.2@osu.edu> wrote:
>> Thanks Scott, I'll admit to being in the 99.9% of the population that
>> doesn't fully understand subject confirmation but aren't NotOnOrAfter and
>> Recipient in SubjectConfirmationData also redundant
>> AudienceRestriction/Audience and NotOnOrAfter Conditions?
>
> Recipient (badly named, it's inherited from SAML 1.1), is a location, not an
> identity. Audience is an identity. Who as opposed to where. They are largely
> redundant from the standpoint of the SSO threat model, but they aren't at
> all the same thing. One is also assertion-wide and one is limited to
> satisfying a particular confirmation.
>
> The NotOnOrAfter attributes are separate because a limit on satisfying one
> confirmation method doesn't have to be a limit on use of the assertion for
> some other purpose, or a limit on an additional confirmation method. A
> typical use case would be to limit bearer confirmation, but leave a holder
> of key confirmation for delegation unbounded (other than by the Condition as
> an upper bound).
>
> Subject confirmation really isn't that complicated. An assertion without one
> is just data. An assertion with one is a security token that is bound to the
> client(s) that can satisfy the confirmation. The method determines what the
> underlying security technology for the token is, because SAML has none
> itself.
>
> In effect, you need "subject confirmation profiles" for any of the possible
> proof mechanisms you want to support, just like WSS needed token profiles.
>
> -- Scott
>
>
>