Re: [TLS] bootstrapping of constrained devices

["Dan Harkins" <[e-mail]>]

  Hi Robert,

On Fri, March 21, 2014 8:19 am, Robert Cragie wrote:
> Hi Rene,
>
> There is certainly a place for device certificates but they are
> generally quite expensive in terms of the infrastructure needed to
> support them as Michael points out.

  And they only allow for an authenticated statement that the thing
is a particular thing from a particular manufacturer. Not that it is
_your_ thing.

> There are no specific links I can point to but the use case is using
> relatively short codes which are put into e.g. a home router through a
> web interface to provide steering, a basis for authenticating another
> device onto the network and a secure channel for delivery of
> configuration/bootstrapping information. WPS PIN is an example of this
> (notwithstanding its implementational flaws). Using TLS/DTLS as a basis
> provides the possibility of reuse at the application layer, which is a
> bonus for the relatively constrained devices generally considered to be
> in use in the IoT.

  Yes, WPS PIN is horribly broken and should be avoided. A TLS PAKE like
TLS-SRP or TLS-pwd would work for this use case.

  Also, usable certificate can be obtained by something like EST using
a TLS PAKE or a manufacturing certificate plus a whitelist of some sort.

  Dan.

> Robert
>
> On 21/03/2014 12:26 PM, Michael Sweet wrote:
>> Rene,
>>
>> Installing device certificates during manufacturing is not a simple
>> process - the factory would need to act as a CA or would need to have
>> a supply of certificates that matches whatever identifiers are used by
>> the devices.  Not to mention how you'd manage revocation if the root
>> was compromised...
>>
>>
>> On Mar 20, 2014, at 9:52 PM, Rene Struik <[e-mail]
>> <mailto:[e-mail]>> wrote:
>>
>>> Hi Robert:
>>>
>>> Wouldn't it be much easier to embed device certificates with
>>> constrained devices at manufacturing? This may do away with need to
>>> store info that is not public on servers.
>>>
>>> If you could provide some links to discussions in "IoT community
>>> groups" interested in this, that would help.
>>>
>>> Best regards, Rene
>>>
>>> ==
>>> There is a lot of interest in the IoT community in using some form of
>>> PAKE in conjunction with DTLS (or TLS with EAP) for authenticating
>>> commissioning/bootstrapping of IoT devices onto IoT networks
>>>
>>> On 3/20/2014 1:21 PM, Robert Cragie wrote:
>>>>
>>>> It should be remembered that TLS is used in places other than web
>>>> browsers - the existence of the DICE WG is testament to this. There
>>>> is a lot of interest in the IoT community in using some form of PAKE
>>>> in conjunction with DTLS (or TLS with EAP) for authenticating
>>>> commissioning/bootstrapping of IoT devices onto IoT networks. I
>>>> realise this is different to the original proposition in this thread
>>>> but wanted to draw this to the attention of the WG nevertheless.
>>>>
>>>> Robert
>>>>
>>>> On 20 Mar 2014 12:28, "Daniel Kahn Gillmor" <[e-mail]
>>>> <mailto:[e-mail]>> wrote:
>>>>
>>>>     On 03/20/2014 12:18 PM, Paul Hoffman wrote:
>>>>     > As an important note, you did not define "we" above. A few
>>>>     possible expansions would be:
>>>>     >
>>>>     > - The TLS WG, where this thread currently lives, does not get
>>>>     to define Web UI without a charter change.
>>>>     >
>>>>     > - The HTTPbis WG has not asked the TLS WG to take over this
>>>>     work, nor has it embraced anything like it.
>>>>     >
>>>>     > - The IETF doesn't do this kind of work as a whole body.
>>>>     >
>>>>     > - The IAB (of which none of us are part of the "we") might
>>>>     take the topic on and suggest ways which the IETF might do the
>>>> work.
>>>>
>>>>     yep, thanks for the clarification.  I actually meant "we" in the
>>>>     broad
>>>>     sense of "the community of people who care about making
>>>>     communications
>>>>     on the web more secure", which includes groups you didn't even
>>>>     mention
>>>>     above, like web site designers, systems administrators, etc.
>>>>
>>>>     It's still on-topic here (despite the broad scope implied above)
>>>>     because
>>>>     the TLS WG does have a role to play, by considering the merits of
>>>>     proposals like http://tools.ietf.org/html/draft-thomson-tls-care,
>>>> as
>>>>     well as considering alternatives that deal with this particular
>>>>     use case.
>>>>
>>>>     >> option (A) is seriously hard, maybe impossible given the
>>>>     state of the
>>>>     >> web.  option (B) is terrible.
>>>>     >
>>>>     > Exactly right, for any value of "we".
>>>>
>>>>     :(
>>>>
>>>>             --dkg
>>>>
>>>>
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>>>>
>>>>
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>>>
>>>
>>> --
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>>
>> _________________________________________________________
>> Michael Sweet, Senior Printing System Engineer, PWG Chair
>>
>
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