Re: [babel] Secdir early review of draft-ietf-babel-dtls-03

[David Schinazi <[e-mail]>]

Thanks for the review Sean!

I've updated the doc with your comments:
https://github.com/jech/babel-drafts/commit/e202f664712772a4db2bd88c5665ba3193cd4c99

Detailed responses inline.

David


On Wed, Jan 30, 2019 at 11:03 AM Sean Turner <[e-mail]> wrote:

> Reviewer: Sean Turner
> Review result: Has Nits
>
> Hi,
>
> David wanted to make it really easy on me and get as much early input as he
> could get by sending a msg to the TLS list asking for comments [0].
> Version
> -02 addressed those comments.
>
> I'm no babel expert, but I did take the time to read/skim the base protocol
> document to get more familiar with it as well as re-read the babel-tls
> draft.
> The tl;dr here is that babel is multicast but DTLS is not so changes to
> babel
> are needed.
>

To clarify, the changes to make Babel work over unicast have all gone into
the base spec: draft-ietf-babel-rfc6126bis
<https://tools.ietf.org/html/draft-ietf-babel-rfc6126bis>


> Here are my comments in no particular order.  No show stoppers here.
>
> 0) Since DTLS is in the RFC Editor's Abbreviations List - I think you can
> get
> away with: Babel Routing Protocol over DTLS But, that's up to you.
>

I personally prefer spelling it out, but I don't feel too strongly about it.


> 1) (IEGS food fight alert) I see that the updates header updates 6126bis.
> Not
> sure how this will fly in the face of the draft IESG Statement [1].
>

Thanks for pointing this out. We'll follow any guidance the IESG gives us
during their review.


> 2) (This might just be document organization) The applicability section
> kind of
> jumped out at me because there's also an applicability draft.  Further, it
> and
> 6126bis says the HMAC mechanism is preferred.  I'd just drop the entire
> section
> ;)
>

The authors felt we should insist that HMAC is better suited for many
deployments
as it better fits with the traditional Babel multicast model. The
applicability draft
focuses on Babel itself.


> 3) s2.1 - maybe add a pointer to the IANA considerations section.
>

Done

4) s2.1 - Because you're doing client authentication do you need say
> anything
> about the type of cert, whether certificate_authorities,
> signature_algorithms_cert, signature_algorithms should be sent (for 1.3
> connections)?
>

We've had this conversation on the Babel mailing list, and we landed on
having the
babel-dtls draft not define any of these, punting that to the usage
profiles drafts.
For example, the Babel Homenet profile draft will define all of these.


> 5) s4 - add that IANA is requested to point to this specification for the
> reference.
>

Done

6) AppA - I think you might need to tweak the last sentence in light 1.3?
>

Unfortunately DTLS 1.3 hasn't been published yet, and I'd rather not make
assumptions on what the RFC will say (even though we're pretty sure the
handshake won't change between the current draft and RFC). If it gets
published as RFC before this document does, I'll make these changes.


Cheers,
> spt
>
> [0] https://mailarchive.ietf.org/arch/msg/tls/tIaK0rgm5zCVuYmLm5qsCIvKXKw
> [1] https://mailarchive.ietf.org/arch/msg/ietf/-1u_1-peHKAmUDuLyGAJYu0fPCE
>
>