Re: [nfsv4] Martin Duke's Discuss on draft-ietf-nfsv4-rpc-tls-08: (with DISCUSS and COMMENT)

[Martin Duke <[e-mail]>]

That looks good. Ping me when there's a new version.

On Tue, Jul 14, 2020 at 4:52 AM Chuck Lever <[e-mail]> wrote:

> To address this issue, I've added the following text (in italics) to the
> Security Considerations section.
>
>    One purpose of the mechanism described in the current document is to
>    protect RPC-based applications against threats to the confidentiality
>    of RPC transactions and RPC user identities.  A taxonomy of these
>    threats appears in Section 5 of [RFC6973].  Also, Section 6 of
>    [RFC7525] contains a detailed discussion of technologies used in
>    conjunction with TLS.  Implementers should familiarize themselves
>    with these materials.
>
>    Once a TLS session is established, the RPC payload carried on TLS
>    version 1.3 is forward-secure.  However, implementers need to be
>    aware that replay attacks can occur during session establishment.
>    Remedies for such attacks are discussed in detail in Section 8 of
>    [RFC8446].
>
> *Further, the current document does not provide a profile   that defines
> the use of 0-RTT data (see Appendix E.5 of [RFC8446]).   Therefore,
> RPC-over-TLS implementations MUST NOT use 0-RTT data.*
>
>
> On Jul 8, 2020, at 9:50 AM, Martin Duke <[e-mail]> wrote:
>
> Thank you for that reference.
>
> I agree that simply saying that Early Data MUST NOT be used is sufficient.
> I am skeptical that implementers of this draft will read E.5 of RFC 8446.
>
> On Tue, Jul 7, 2020 at 10:27 PM Benjamin Kaduk <[e-mail]> wrote:
> On Thu, Jun 25, 2020 at 01:56:10PM -0700, Martin Duke via Datatracker
> wrote:
> > Martin Duke has entered the following ballot position for
> > draft-ietf-nfsv4-rpc-tls-08: Discuss
> >
> > When responding, please keep the subject line intact and reply to all
> > email addresses included in the To and CC lines. (Feel free to cut this
> > introductory paragraph, however.)
> >
> >
> > Please refer to
> https://www.ietf.org/iesg/statement/discuss-criteria.html
> > for more information about IESG DISCUSS and COMMENT positions.
> >
> >
> > The document, along with other ballot positions, can be found here:
> > https://datatracker.ietf.org/doc/draft-ietf-nfsv4-rpc-tls/
> >
> >
> >
> > ----------------------------------------------------------------------
> > DISCUSS:
> > ----------------------------------------------------------------------
> >
> > This presumably a trivial fix but I think it's important enough to be a
> DISCUSS:
> >
> > I think the document needs some discussion of the security properties of
> TLS1.3
> > early data over TCP, if only to refer to Section 8 of RFC 8446 (replay)
> and
> > mention that it is not forward-secure, unlike the rest of the payload.
>
> I actually think that the situation is well-defined without such additional
> text -- Appendix E.5 notes that:
>
>    Application protocols MUST NOT use 0-RTT data without a profile that
>    defines its use.  That profile needs to identify which messages or
>    interactions are safe to use with 0-RTT and how to handle the
>    situation when the server rejects 0-RTT and falls back to 1-RTT.
>
> Since this document does not provide such a profile, early data MUST NOT be
> used, and there's no need to say more.
>
>
> --
> Chuck Lever
>
>
>
>