On Wed, Nov 22, 2006 at 09:35:46AM -0800, Lakshminath Dondeti wrote:
> At 03:46 AM 11/22/2006, Yoshihiro Ohba wrote:
> >Hi Uri,
> >
> >On Wed, Nov 22, 2006 at 09:41:03AM -0500, Blumenthal, Uri wrote:
> >> >The problem we are facing with EMSK is that the key and its usage were
> >> >not defined *at one time".
> >>
> >> True, definition of EMSK has been done in advance, PRIOR to its usage -
> >> so that by the time EMSK usage is defined, all the compliant methods
> >> already have implemented EMSK generation and have it available. This is
> >> not a problem.
> >>
> >> Especially since it is likely that most real-life implementations are
> >> modular enough to allow component upgrades.
> >
> >For any method, how a compliant implementation and a non-compliant
> >implementation can be distinguished?  If they are indistinguishable,
> >then there will be an interoperability problem.
> 
> This is not rocket science!  I have some second-hand experience with 
> IPsec interoperability; if implementation X does not interoperate 
> with implementation Y, people then figure out which one is 
> non-compliant and have that implementation fixed.

A HOKEY compliant implementation should be able to revert to the
legacy mode of operation (i.e., use of MSK in the current way) so that
it still interoperates with a HOKEY non-compliant implementation
without ending up with a communication failure or changing the HOKEY
non-compliant implementation.  Note that a HOKEY non-compliant
implementation is still RFC3748 compliant as long as it generates MSK
and EMSK even if it does not use EMSK.

> 
> 
> >For a future method that will be defined after we define an EMSK
> >usage, I agree that we can definetly mandate use of EMSK.
> 
> This is moot.  EMSK derivation is already defined as mandatory.  Are 
> you proposing something stronger than a MUST?

"EMSK derivation is a MUST" does not mean that "use of EMSK is MUST".

Yoshihiro Ohba


> 
> Lakshminath
> 
> >But
> >ignoring the existing implementations does not make sense, considering
> >the fact that some of them are already part of Wi-Fi certificate.
> >
> >Yoshihiro Ohba
> >
> >
> >>
> >> The problem is shortsightedness of some implementors, whose logic is "if
> >> I don't need this feature NOW, no way I'll spend resources implementing
> >> it".
> >>
> >> >For this reason, I don't agree with
> >> >mandating the use of EMSK for all implementations.
> >>
> >> We cannot mandate what has not been defined yet. This is why we have
> >> mandated only EMSK generation, not EMSK usage.
> >>
> >> Note the grammatic form of the verb: it IS a done deal, RFC 3578 IS a
> >> standard.
> >>
> >> > Only making use of
> >> >EMSK optional makes sense to me, regardless of how it is going to be
> >> >used.
> >>
> >> There is no use of EMSK currently defined, neither optional nor
> >> mandatory. So no need to make it anything.
> >>
> >> It is mandatory to generate EMSK and make it available for applications.
> >>
> >> How many times does is this dead horse going to be beaten?
> >>
> >>
> >> Yoshihiro Ohba
> >>
> >> On Tue, Nov 21, 2006 at 08:50:46AM -0800, Madjid Nakhjiri wrote:
> >> > Hi Yoshi,
> >> >
> >> > I don't quite agree with this. Defining the full functionality of a
> >> new EAP
> >> > method (including how it spits out MSK and EMSK) should be the job the
> >> EAP
> >> > method designer. 3748, EAP keying framework and hokey specs then
> >> define how
> >> > MSK or EMSK is used. This is modular design. People who use EMSK then
> >> do not
> >> > have to worry about the crypto behind EMSK generation.
> >> > Using your analogy is "go buy the key and lock" but then wait to see
> >> which
> >> > door you want to install it on:)
> >>
> >> > I as a home owner do not need to know how to make locks.
> >> >
> >> > R,
> >> >
> >> > Madjid
> >> >
> >> > -----Original Message-----
> >> > From: Yoshihiro Ohba [mailto:[EMAIL PROTECTED]
> >> > Sent: Friday, November 17, 2006 11:36 AM
> >> > To: Blumenthal, Uri
> >> > Cc: [EMAIL PROTECTED]; [email protected]
> >> > Subject: Re: [Hokeyp] [Emu] Re: MSK but no EMSK
> >> >
> >> > Hi Uri,
> >> >
> >> > I have a different view.  Mandating generation of EMSK without having
> >> > defined its usage *when it was introduced* seems not much different
> >> > from not having defining it at all.  It looks like selling a key
> >> > without a lock, make the lock later and say "You MUST use this key and
> >> > lock for your car."  Make sense??
> >> >
> >> > Yoshihiro Ohba
> >> >
> >> >
> >> >
> >> > On Fri, Nov 17, 2006 at 09:22:04AM -0500, Blumenthal, Uri wrote:
> >> > > >The discussion focuses on the problem EMSK is optional or
> >> mandatory.
> >> > >
> >> > > I don't think this is a problem - GENERATION of EMSK is compulsoty
> >> as
> >> > > spelled out in RFC 3578.
> >> > >
> >> > > The problem is non-compliance. Some, er, people seem to think "the
> >> > > standard says do A, but since I don't use A at the moment - I won't
> >> > > bother."
> >> > >
> >> > > >RFC3578 defined EMSK is mandatory,
> >> > >
> >> > > And that should be the end of discussion.
> >> > >
> >> > > >                     but it is not used at all.
> >> > >
> >> > > First - do you know all the applications that use key-generating EAP
> >> > > methods? But really - who cares?
> >> > >
> >> > > >If EMSK must be used, it is mandatory. if no, I think,
> >> > > >it may be better that it is optional.
> >> > >
> >> > > VERY strongly disagree. Mandatory is what is explicitly specified as
> >> > > mandatory, period. Otherwise many would implement just those pieces
> >> and
> >> > > features of the standard that his particular product needs today.
> >> > >
> >> > > (I'm proud of my restraint - not even once using a term "B*S*" :-)
> >> > > _______________________________________________
> >> > > Hokeyp mailing list
> >> > > [EMAIL PROTECTED]
> >> > > http://www.opendiameter.org/mailman/listinfo/hokeyp
> >> > >
> >> >
> >> > _______________________________________________
> >> > Emu mailing list
> >> > [email protected]
> >> > https://www1.ietf.org/mailman/listinfo/emu
> >> >
> >> >
> >>
> >>
> >
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> 

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