Re: [kitten] New URI Discovery Draft

[Nathaniel McCallum <[e-mail]>]

On Sat, 2016-09-24 at 18:29 +0200, Petr Spacek wrote:
> On 24.9.2016 00:25, Nathaniel McCallum wrote:
> > https://datatracker.ietf.org/doc/draft-mccallum-kitten-krb-service-
> > disc
> > overy/
> > 
> > I've submitted a new version of the draft. This version matches the
> > code that is now merged into MIT Kerberos.
> > 
> > We need to move forward. If that is as an individual submission,
> > then
> > so be it. But we really can't wait any longer. So unless I hear
> > some
> > noise to the contrary ASAP, I plan to go this route.
> 
> 
> Hello,
> 
> in general it makes sense. The new URI format opened an encoding-
> Pandora-box
> so it needs more work to make it fully specified. Here are nits I
> found in the
> 03 version of the draft:
> 
> 1]
> > 4.  Required URI Format
> >    krb5srv:[flags]:transport:residual
> 
> Nitpick: I do not really like naming "transport:residual". Something
> like
> "transport-type:transport-options" would be more descriptive.

transport-info? transport-data? transport-spec?

> 2] Is this a good idea?
> >    Flags are not considered critical, therefore flags that are not
> > used
> >    or unknown to the implementation SHOULD be ignored.
> 
> Just wondering out loud, not insisting on it:
> If we say there is no criticality, it will be impossible to add later
> on.
> 
> What about using capitalization to indicate criticality of a flag?
> Records
> with critical but unsupported flags should be skipped as if there
> were not
> present in DNS. Records with non-critical unsupported flags should be
> used as
> usual.
> 
> Or maybe we can limit valid flags to lowercase ASCII letters for now
> so there
> is a room for extension in future?

I had proposed using case for criticality in another conversation and
I'm increasingly coming to prefer this method if criticality is defined
as "don't use this server if you don't understand the flag."

Note that with either case-insensitivity or critical-uppercase we have
the same number of letters. So I don't think there is any cost except
the (minor) cost of updating the exiting MIT code.