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From: Dan Shelton <dan.f.shelton@gmail.com>
Date: Fri, 7 Jun 2024 01:53:23 +0200
Message-ID: <CAAvCNcAe4ho539uhJ32qQJj5dBxBBAbKgPXXC15R4b=axtEvGA@mail.gmail.com>
Subject: Re: Implement NFSv4 TLS support with /usr/bin/openssl s_client?
To: Linux NFS Mailing List <linux-nfs@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"

On Fri, 26 Jan 2024 at 02:05, Dan Shelton <dan.f.shelton@gmail.com> wrote:
>
> On Thu, 25 Jan 2024 at 22:11, Benjamin Coddington <bcodding@redhat.com> wrote:
> >
> > On 25 Jan 2024, at 15:37, Jeff Layton wrote:
> >
> > > On Thu, 2024-01-25 at 03:21 +0100, Dan Shelton wrote:
> > >> Hello!
> > >>
> > >> Is it possible for a NFSv4 client to implement TLS support via
> > >> /usr/bin/openssl s_client?
> > >>
> > >> /usr/bin/openssl s_client would do the connection, and a normal
> > >> libtirpc client would connect to the other side of s_client.
> > >>
> > >> Does that work?
> > >>
> > >> Dan
> > >
> > > Doubtful. RPC over TLS requires some cleartext setup before TLS is
> > > negotiated. At one time Ben Coddington had a proxy based on nginx that
> > > could handle the TLS negotiation, but I think that might have been based
> > > on an earlier draft of the spec. It would probably need some work to be
> > > brought up to the state of the RFC.
> >
> > Yeah, its' a little bit rotted.  Wasn't super fresh to begin with, but it
> > did help bootstrap some implementation.
> >
> > You could also modify openssl to be aware of the clear text, something like:
> > https://github.com/bcodding/openssl/commit/9bf2c4d66eacccd3530fb2f3a0a6c87d5878348c
> >
> > .. but I think you're definitely in "what are you really trying to do?" territory.
>
> For example legacy NFSv4 client add-on? You cannot expect that
> everyone can or will update to the latest and greatest version, so
> either you have clients without TLS, which is a security risk, or have
> a way to retrofit them.

Is there a public NFSv4.1 server with TLS enabled, which I can use to
test whether openssl with
https://github.com/bcodding/openssl/commit/9bf2c4d66eacccd3530fb2f3a0a6c87d5878348c
can be used to plug in older clients?

Dan
-- 
Dan Shelton - Cluster Specialist Win/Lin/Bsd