Re: [Ace] draft-ietf-ace-oauth-authz-35 - unauthorized AS address, DoS, and privacy

[Benjamin Kaduk <[e-mail]>]

On Thu, Sep 10, 2020 at 02:46:43PM -0400, Michael Richardson wrote:
> 
> John Mattsson <john.mattsson=[e-mail]> wrote:
>     > - That RS shares the AS address with anybody that asks can be a severe
>     > privacy problem. If RS is a medical device, the AS address can reveal
>     > sensitive information. If RS is a blood pressure sensor it could
>     > e.g. be “AS address =
>     > coaps://as.hopkinsmedicine.org/kimmel_cancer_center/”
> 
>     > The requirement "the client MUST be able to determine whether an AS has
>     > the authority to issue access tokens for a certain RS. This can for
>     > example be done through pre-configured lists, or through an online
>     > lookup mechanism that in turn also must be secured." indicates that C
>     > is required to have another mechanism to determine the AS for a
>     > specific RS and that the unauthorized AS address is completely
>     > redundant.
> 
> This is a hard problem.
>   Q: "Who are you?"
>   A: "Depends upon who is asking! Who are you?"
>   A: "Depends upon who is asking! Who are you?"
>   ...
> 
> The DNS-SD WG produced rfc8882, but as I understand it,
>    https://datatracker.ietf.org/doc/html/draft-ietf-dnssd-privacy-05
> was abandonned because the WG did not see implementation/energy.
> I can't seem to find the thread discussing that state.

Interestingly, the corresponding requirements document was just published
recently as RFC 8882.

"A problem with no solution is a hard problem"...

-Ben