Re: [secdir] Sector review of draft-ietf-manet-rfc6779bis-05

"Dearlove, Christopher (UK)" <chris.dearlove@baesystems.com> Tue, 24 May 2016 08:58 UTC

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From: "Dearlove, Christopher (UK)" <chris.dearlove@baesystems.com>
To: Vincent Roca <vincent.roca@inria.fr>, IESG <iesg@ietf.org>, "secdir@ietf.org" <secdir@ietf.org>, "draft-ietf-manet-rfc6779bis.all@ietf.org" <draft-ietf-manet-rfc6779bis.all@ietf.org>
Thread-Topic: Sector review of draft-ietf-manet-rfc6779bis-05
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Date: Tue, 24 May 2016 08:58:44 +0000
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Subject: Re: [secdir] Sector review of draft-ietf-manet-rfc6779bis-05
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The MIB information can largely, though not quite entirely, be reconstructed from the routing signalling. And there’s no proposal on the table that encrypts that. (Future work, perhaps.)

Consequently mandating encryption of MIB data really doesn’t help much. In fact I think that although the MIB information may add a little, it isn’t regular, and only some of it might be requested, unlike the routing signalling that is continual and everywhere. So I’d classify it as secondary in value to an attacker.

That said, encrypting it is easier, because encrypting routing signalling either requires a shared secret key everywhere, which is weak, or runs into the chicken and egg problem of which comes first, establishing the routing - in particular the neighbour discovery - or establishing the encryption for that signalling. There are solutions, but as I said, none yet proposed. Whereas for MIB information routing is already in place, and hence can be used.

What does that mean? Speaking just for myself, I think that means that the current draft might have the balance in the right place. But I’ll leave that for others to discuss/decide.

(In fact even authenticating the routing signalling isn’t mandated; although implementing an approach  - a weak one, but there are better -  to it is. However anyone using this in a sensitive scenario would be ill-advised not to use an authentication mechanism, hence this just being an aside.)

--
Christopher Dearlove
Senior Principal Engineer
BAE Systems Applied Intelligence Laboratories
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T:  +44 (0)1245 242194  |  E: chris.dearlove@baesystems.com<mailto:chris.dearlove@baesystems.com>

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From: Vincent Roca [mailto:vincent.roca@inria.fr]
Sent: 24 May 2016 07:37
To: IESG; secdir@ietf.org; draft-ietf-manet-rfc6779bis.all@ietf.org
Cc: Vincent Roca
Subject: Sector review of draft-ietf-manet-rfc6779bis-05

Hello,

I have reviewed this document as part of the security directorate’s ongoing
effort to review all IETF documents being processed by the IESG. These
comments were written primarily for the benefit of the security area
directors.  Document editors and WG chairs should treat these comments just
like any other last call comments.


Summary: ready

The security considerations section is a carbon copy of that of RFC 6779 published in 2012. The only modification is the addition of a reference to "Mobile Ad Hoc Network (MANET)".

As explained by the authors, information contained in this MIB is highly sensitive, both from the security and privacy point of views. This is all the most true when considering some of the target use-cases (emergency services or military tactical applications).

If I find this section globally well written. I'm just a bit surprised by the following sentence:
            "It is thus important to control even GET and/or NOTIFY access to these objects
             and possibly to even encrypt the values of these objects when sending them
            over the network via SNMP."
I would rather say that it is essential to encrypt and verify the integrity of all the SNMP traffic. Here I find the style not sufficiently directive... But this is a detail.


Cheers,

  Vincent
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