Re: [manet] Ben Campbell's No Objection on draft-ietf-manet-dlep-26: (with COMMENT)

["Ben Campbell" <[e-mail]>]

On 15 Dec 2016, at 2:45, Henning Rogge wrote:

> On Wed, Dec 14, 2016 at 5:31 PM, Ben Campbell <[e-mail]> wrote:
>>> We (the co-authors) have received feedback from some radio vendors 
>>> stating
>>> that a "MUST use TLS" in all cases would be a show-stopper. We see
>>> deployments where a small number of devices co-exist on the LAN 
>>> segment -
>>> for example, a router, a line-of-sight radio, a satellite terminal, 
>>> and a
>>> small number of other devices. We're open to the construction you 
>>> suggest,
>>> and will discuss it.
>>
>> Understood. That suggests there are reasons to not _use_ TLS other 
>> than the
>> listed one, so "MUST unless" may not be what you want.  Any thoughts 
>> on why
>> TLS should not be mandatory to _implement_?
>
> I might exaggerate it a little bit but I think using TLS for DLEP is
> at best a waste of time to implement. I have yet to hear about an
> attacker model for a single hop DLEP connection (which is necessary
> because otherwise the bridged datapath is broken!) which is not easily
> dealt with MAC-layer security.
>
> At worst TLS will kill one of the most important aspects of DLEP, easy
> integration and autodiscovery of radios by different vendors to any
> kind of router.
>
> TLS also opens  can of worms (additional questions). How is the DLEP
> certificates be handled? Are there mandatory types of certificate
> algorithms (if not, you break interoperability)? How do you secure the
> UDP part of DLEP for discovery (DTLS?) ? How do you make sure that the
> DTLS connection is to the same endpoint as the TLS connection?
>
> There is a LOT of work in this direction without any gain.

IIRC, you are arguing against even the existing "SHOULD implement" 
requirement?

When you talk about a single-hop connection, are you assuming a direct 
connection from the router to the modem, or that the router and modem 
are on the same LAN segment?

Thanks!

Ben.