Subject: [eap] clarification in rfc2284-bis-02.txt

From: [email-masked] (Mohan Parthasarathy)
Date: Fri, 2 May 2003 17:57:42 -0700

Hello,

In section 3.1, Lower layer requirements,

       As a result of these considerations, EAP SHOULD be used only when
       lower layers provide physical security for data (e.g. wired PPP
       or IEEE 802 links), or for insecure links, where per-packet
       authentication, integrity and replay protection is provided.
       Where keying material for the lower layer ciphersuite is itself
       provided by EAP, typically the lower layer ciphersuite cannot be
       enabled until late in the EAP conversation, after key derivation
       has completed.  Thus it may only be possible to use the lower
       layer ciphersuite to protect a portion of the EAP conversation,
       such as the EAP Success or Failure packet.

I have couple of questions.=20

1) How do you delay the EAP success packet so that it can be
   protected ? For example, if you are using ECP, you should have
reached
   the IPCP negotiation phase. But IPCP has not begun until EAP success
   packet is transmitted. right ? what am I missing ?

2) Under what conditions the EAP failure packet can be protected ?
Doesn't failure
   imply that key has not been derived ?

thanks
mohan

  =20

---

From: [email-masked] ([email-masked])
Date: Mon, 5 May 2003 13:39:32 +0300

On May 3, Mohan Parthasarathy wrote:

>    reached the IPCP negotiation phase. But IPCP has not begun until=20
>    EAP success packet is transmitted. right ? what am I missing ?
>=20
>    Doesn't failure imply that key has not been derived ?

I think the draft is misleading here: as far as I know (please correct
me if I'm wrong :), existing lower layers that use EAP transmit the
EAP success packet unprotected, and enable the ciphersuite only after
that.

If this is indeed the case, I suggest we the text to:

  "... When keying material for the lower layer ciphersuite is itself
   provided by EAP, typically the lower layer ciphersuite is enabled=20
  only after the EAP conversion has concluded. Thus, the EAP =
conversation=20
  itself is usually not protected."

Best regards,
Pasi

---

From: [email-masked] (Mohan Parthasarathy)
Date: Tue, 6 May 2003 10:09:49 -0700

Pasi,

> >      As a result of these considerations, EAP SHOULD be=20
> used only when
> >      provided by EAP, typically the lower layer ciphersuite=20
> cannot be
> >      enabled until late in the EAP conversation, after key=20
> derivation
>   only after the EAP conversion has concluded. Thus, the EAP=20
> conversation=20
This sounds reasonable to me. Is that acceptable to everyone ?

-thanks
mohan