Re: [HOKEY] AD review of draft-ietf-hokey-arch-design

[Glen Zorn <[e-mail]>]

On 10/30/2011 9:47 PM, Stephen Farrell wrote:
> 
> Hiya,
> 
> Coupla things below. But the immediate question is: can
> you shoot out a revised ID before the cutoff? 

Yes, though it may not have everything we've discussed in it (I have to
get on a plane in about 5 hours).

> If so, then
> I'll wait for that then start IETF LC. If not, then I'll
> go ahead anyway since I think we're in good enough shape,
> but better of course if we can get that revised ID first
> so's we don't all have to remember stuff to change/check
> later.
> 

...

>>>>> c) if someone chooses the wrong CAP then they might have been fooled
>>>>> into sending all the user's traffic via a bad actor.
>>>>
>>>> Again, that is not specific to hokey, re-authentication or mobility:
>>>> any
>>>> WiFi AP to which one connects could be a bad actor.
>>>
>>> Doesn't hokey make the client believe its implicitly
>>> authenticated the CAP? Is that really the same as any old
>>> AP?
>>
>> I don't think that that is true, at least in the cases of ERP and AAK;
>> there, (like w/regular EAP), the client never authenticates the AP
>> (unless, of course, the AP is running a stand-alone authenticator).
> 
> Maybe let me try again. Hokey provides a way to move keys
> about so that a CAP can become a SAP. When used successfully
> those keys implicitly authenticate the CAP/SAP as being ones
> that have some kosher reason for being an AP that's "safe"
> for the client.
> 
> Choosing the CAP is (as you've said) not part of hokey.
> Therefore a bad actor might be able to cause AAK to be run
> with a "bad" CAP, perhaps so that that AP can record user
> traffic or to mess with billing.
> 
> The new vulnerability is the ability to influence how AAK
> is being used, previously I guess the client would have
> just picked, which may be more vulnerable in lots of ways,
> but this is (I think) a specific new vulnerability due to
> hokey, that might be exploitable in a systematic way at
> least in theory.
> 
> Does that make sense? (I'm not 100% sure it does, mind you;-)

The part I'm not getting is how AAK "implicitly authenticates the
CAP/SAP" any more than the possession of a valid MSK authenticates a
regular AP w/regular EAP.

...