Hi All,

A new version handling the RTGDIR comments is posted.
https://datatracker.ietf.org/doc/draft-ietf-pce-pceps/

See diff at - https://www.ietf.org/rfcdiff?url2=draft-ietf-pce-pceps-13

Thanks Dan for the comments.

Regards,
Dhruv


On Thu, May 11, 2017 at 10:07 PM, Dhruv Dhody <[email protected]>
wrote:

> Hi Dan,
>
> Thanks for your review. Please see inline...
>
> > -----Original Message-----
> > From: Pce [mailto:[email protected]] On Behalf Of Dan Frost
> > Sent: 11 May 2017 19:01
> > To: [email protected]
> > Cc: [email protected]; [email protected]; [email protected]
> > Subject: [Pce] RtgDir review: draft-ietf-pce-pceps-12
> >
> >
> > Hello,
> >
> > I have been selected as the Routing Directorate reviewer for this draft.
> > The Routing Directorate seeks to review all routing or routing-related
> drafts as
> > they pass through IETF last call and IESG review, and sometimes on
> special
> > request. The purpose of the review is to provide assistance to the
> Routing ADs.
> > For more information about the Routing Directorate, please see
> > http://trac.tools.ietf.org/area/rtg/trac/wiki/RtgDir
> >
> > Although these comments are primarily for the use of the Routing ADs, it
> would
> > be helpful if you could consider them along with any other IETF Last Call
> > comments that you receive, and strive to resolve them through discussion
> or by
> > updating the draft.
> >
> > Document: draft-ietf-pce-pceps-12
> > Reviewer: Dan Frost
> > Review Date: 2017-05-11
> > IETF LC End Date:
> > Intended Status: Standards Track
> >
> > Summary:
> >
> > I have significant concerns about this document and recommend that the
> > Routing ADs discuss these issues further with the authors.
> >
> > Comments:
> >
> > This document proposes to add a STARTTLS mechanism to the PCE protocol.
> > If this basic approach is accepted, then the document is in good shape.
> > It's clear, complete, and straightforward. The question is whether
> mandating
> > STARTTLS is actually a good idea.
> >
> [Dhruv] Yes, this has been discussed in the WG.
> The individual draft in fact asked for another port no, and during the WG
> adoption process, it was discussed in the WG as well as with security
> experts, and concluded that we should use STARTTLS.
> As far as I am aware, use of different port for secured version of a
> protocol has not been followed by IETF for some time now.
>
> > Major Issues:
> >
> > My main concern with this document is that it takes as given that
> STARTTLS is
> > the right way to secure PCEP with TLS. Perhaps this argument was already
> had at
> > some point and this draft is the result, but if so then at a bare
> minimum it needs
> > rationale explaining why STARTTLS was chosen over alternatives, and text
> that
> > addresses weaknesses and mitigations associated with STARTTLS
> processing, in
> > particular the possibility and relative ease of downgrade attacks.
> >
> [Dhruv] I see the benefit of adding text, something in line of -
>
> "As per the recommendation from [RFC7525], PCEP peers that support PCEPS,
> SHOULD prefer strict TLS configuration i.e. do not allow non-TLS PCEP
> sessions to be established."
>
> I will discuss further with my co-authors/chairs/AD, if we also need to
> spell out the full rationale here.
>
> > The obvious alternative would be to not use STARTTLS and simply allocate
> > another TCP port for PCEP-over-TLS. This avoids complicating the PCE
> protocol
> > and introducing the potential for downgrade attacks based on STARTTLS.
> PCE is
> > used to convey critical path-determination information in carrier
> networks,
> > among other things. That it's not fully authenticated and encrypted in
> all cases
> > already is an unfortunate legacy of a bygone era. Ideally operators
> should move
> > as quickly as possible to secure PCEP and aim to entirely remove the
> unsecure
> > form.
> > STARTTLS serves a weaker goal of "opportunistic" security, which, while
> it has its
> > uses, makes little sense for PCE compared to simply deprecating the
> unsecured
> > version.
> >
> > Minor Issues:
> >
> > * Section 3.3: "A RECOMMENDED value for StartTLSWait timer is 60
> seconds."
> > This seems like a very long time to wait for an initial reply on an
> already-
> > established TCP connection.
> >
> [Dhruv] We saw a benefit in keeping this same as the OpenWait time in the
> PCEP session establishment.
>
> > * Section 3.2, fifth paragraph (beginning with "A PCEP speaker
> > receiving..."):
> >
> > This paragraph states: "A PCEP speaker receiving any other message apart
> from
> > StartTLS, open, or PCErr MUST treat it as an unexpected message..."
> >
> > As written this is confusing and seems to imply that no other PCEP
> messages can
> > ever be sent. It looks like this is meant to be scoped to the context of
> the first
> > message sent/received on session initiation?
> >
> [Dhruv] Yes. I will add clarification that this is for the first message.
>
> > * Section 8.6
> >
> > The subsection titles of Section 8 have been taken from Section 8 of RFC
> 5440,
> > but Section 8.6 here is called "Impact on Network Operations"
> > while in RFC 5440 it's called "Impact on Network Operation". Funnily
> enough,
> > that final "s" makes a difference. Without it, the section refers to an
> impact on
> > the functioning of the network itself. With it, it would usually be
> taken to refer
> > to impact on human operations and management procedures.
> >
> > It looks correct to say that the mechanism of this draft should not
> significantly
> > impact the functioning of the network. On the other hand, it certainly
> does
> > impact operations and management procedures, as staff have to develop
> > policies around security requirements for PCEP within the organization,
> methods
> > for verifying whether device security parameters are configured
> correctly,
> > checking for unexpected downgrades to insecure sessions, etc. It would
> be an
> > improvement for the document to address the impact of PCEPS on
> operational
> > processes.
> >
> [Dhruv] Agreed. I will work on text in this section, along these lines.
>
> > Nits:
> [Dhruv] Ack for all.
>
> Thanks for your review.
>
> Regards,
> Dhruv
>
> >
> > Sec 3.1, first paragraph:
> > OLD
> >     The steps involved in the PCEPS establishment consists of following
> >     successive steps:
> > NEW
> >     The steps involved in establishing a PCEPS session are as follows:
> > END
> >
> > Sec 3.4, Step 3:
> > s/Any attempt of initiate a TLS/Any attempt to initiate a TLS/
> >
> >
> > Cheers,
> > -d
> >
> > _______________________________________________
> > Pce mailing list
> > [email protected]
> > https://www.ietf.org/mailman/listinfo/pce
>
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