Re: [Emu] review of draft-ietf-emu-eaptunnel-req-04

  Hi Katrin,

  Yes, EAP-pwd uses the password for mutual authentication. If the
server doesn't know the password the exchange will fail. The key
differentiator (from, say, EAP-GPSK) is that it uses a zero knowledge
proof and is resistant to off-line dictionary attack.

  Dan.

On Wed, March 3, 2010 2:33 pm, Hoeper Katrin-QWKN37 wrote:
> Sorry Dan,
>
> Is EAP-pwd using the password for mutual authentication?
>
>> -----Original Message-----
>> From: emu-bounces@ietf.org [mailto:emu-bounces@ietf.org] On Behalf Of
>> Hoeper Katrin-QWKN37
>> Sent: Wednesday, March 03, 2010 4:28 PM
>> To: Dan Harkins
>> Cc: emu@ietf.org
>> Subject: Re: [Emu] review of draft-ietf-emu-eaptunnel-req-04
>>
>> How does that authenticate the server if a user enters a password?
>>
>> If the server says, yes that was the right password?
>>
>>
>>
>> > -----Original Message-----
>> > From: Dan Harkins [mailto:dharkins@lounge.org]
>> > Sent: Wednesday, March 03, 2010 4:14 PM
>> > To: Hoeper Katrin-QWKN37
>> > Cc: Dan Harkins; Joseph Salowey; emu@ietf.org
>> > Subject: RE: [Emu] review of draft-ietf-emu-eaptunnel-req-04
>> >
>> >
>> >   Since they both use the same low-entropy password to perform their
>> > mutual authentication it is not, strictly speaking, just the peer's
>> > credential.
>> >
>> >   Dan.
>> >
>> > On Wed, March 3, 2010 1:45 pm, Hoeper Katrin-QWKN37 wrote:
>> > >
>> > > See inline.
>> > >> -----Original Message-----
>> > >> From: Dan Harkins [mailto:dharkins@lounge.org]
>> > >> Sent: Wednesday, March 03, 2010 3:39 PM
>> > >> To: Hoeper Katrin-QWKN37
>> > >> Cc: Dan Harkins; Joseph Salowey; emu@ietf.org
>> > >> Subject: RE: [Emu] review of draft-ietf-emu-eaptunnel-req-04
>> > >>
>> > >>
>> > >>   Hi Katrin,
>> > >>
>> > >> On Wed, March 3, 2010 12:31 pm, Hoeper Katrin-QWKN37 wrote:
>> > >> > Dan,
>> > >> >
>> > >> > OK, I understand that the tunnel provides all these other
> feats.
>> > >> >
>> > >> > But why can't the server authenticate during the tunnel
> protocol?
>> I
>> > >> > still don't understand the use case for mutually anonymous
>> tunnels.
>> > >>
>> > >>   Because it doesn't have the right credential.
>> > >>
>> > >> > If the server has a certificate why can't it send it to the
> peer
>> > > before
>> > >> > or during the tunnel establishment?
>> > >>
>> > >>   If the server has a certificate then sending it to the peer
>> > >> would not really solve any problem. The peer would still need to
>> > >> have a reason to trust it and we're back to the problem of
> putting
>> > >> a trusted certificate in some certificate store. A global PKI to
>> > >> solve all of our certificate issues still has not materialized.
>> > >>
>> > >> > If the peer and server share a secret, than this could be used
> to
>> > >> > establish the tunnel.
>> > >>
>> > >>   If the peer and server share a secret they could use one of the
>> PSK
>> > >> ciphersuites for TLS but those are susceptible to a dictionary
>> attack
>> > >> and are therefore inappropriate.
>> > >>
>> > >>   The tunnel is being established with EAP-TLS so we are limited
> to
>> > >> TLS ciphersuites and the authentication they provide. If a TLS
>> > > ciphersuite
>> > >> was appropriate always and everywhere then we would not need any
>> other
>> > >> EAP methods, we'd just do EAP-TLS. But that is not the case. Also
>> it
>> > > is
>> > >> a requirement to tunnel additional EAP methods inside the tunnel
> so
>> > >> obviously there are EAP methods that provide something that a TLS
>> > >> ciphersuite does not.
>> > >>
>> > >> > What I am saying is what kind of server authentication
>> credentials
>> > > could
>> > >> > be used inside an anonymous tunnel that could not be used to
>> > >> > authenticate the server in the tunnel protocol? (given that
>> privacy
>> > > is
>> > >> > not the issue)
>> > >>
>> > >>   A low-entropy password that can easily be remembered and
> entered
>> by
>> > > a
>> > >> human with low probability of error.
>> > > [KH] I asked what kind of SERVER credentials not peer credentials.
>> > >>
>> > >>   Dan.
>> > >>
>> > >
>> > >
>> >
>>
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