Re: [kitten] [nfsv4] draft-ietf-nfsv4-rpcsec-gssv3: request for review

[Benjamin Kaduk <[e-mail]>]

On Mon, 4 Aug 2014, Nico Williams wrote:

> On Mon, Aug 04, 2014 at 12:00:16PM -0400, J. Bruce Fields wrote:
> > On Fri, Aug 01, 2014 at 05:15:36PM -0500, Nico Williams wrote:
> > > It was always my intention that traditional (read: multi-user
> > > shared-cache) NFS client implementations would just always use
> > > "multi-principal" contexts when doing any RPCs on a user's behalf.
> > >
> > > That is, addressing the "user can impersonate the server to the client"
> > > problem was always my first and foremost goal with this protocol, though
> > > I didn't always say so explicitly (since at the time the attack was not
> > > well-known, I didn't want to publicize it).
> >
> > Oh, that's really helpful to know.
>
> Yeah :(  I mentioned it several times at meetings.  The cat has been
> out of the bag for a long time as to the vulnerability for shared-cache
> clients, so we might as well state this motivation clearly.

I don't remember seeing new text clarifying the potential attack going by,
so I'll note that what we did for rxgk is in section 7 of
https://tools.ietf.org/html/draft-wilkinson-afs3-rxgk-afs-06

-Ben