Hi Tuomas,
Thanks for taking the time to respond.
In the first question I was wondering if there was any debate about the
inclusion of other algorithms. Especially in terms of interoperability
with, for example, TLS. You're right that low-end devices can do ECDHE.
Therefore, it would not make sense to decrease the level of security. In
addition, I have seen that the new version TLS 1.3 includes a derivation
function with HKDF [RFC5869], which is could be compatible with ECDH.
Regarding the problem of the proposed scenario, it is a very interesting
solution. A good option to take into account.
Best regards.
El 30/01/2019 a las 11:35, Aura Tuomas escribió:
Hi Eduardo,
1.
I' not sure what kind of alternative key derivation you are suggesting. Are you
thinking about alternative ECDH curves, or RSA maybe? I believe even the
low-end devices can do ECDHE these days so it is not obvious to me why that
should be sometimes avoided.
2.
This is a valid scenario for real-world deployments. Thank you for bringing it
up.
Managed handovers where the previous authentication / management server is
still online and co-operative, are already supported. After copying the
EAP-NOOB associations for the peer devices to the new server, the old server
can send a new Realm field in the next Reconnect Exchange and then be taken
offline. Alternatively, Radius routing can be set at the access networks to
capture the old realm, and the new server can send the new Realm in Reconnect.
We should check the EAP-NOOB spec though to make sure that there is nothing to
prevent such usage.
Unmanaged handovers where the old server just goes out of business are messier.
We simply need to copy the server-side EAP-NOOB association database because
there is nothing else for re-bootstrapping the security association - except of
course a new user-assisted OOB step.
Regards,
Tuomas
-Original Message-
From: Emu On Behalf Of Eduardo Inglés UM
Sent: Wednesday, 9 January, 2019 20:25
To:emu@ietf.org
Subject: [Emu] Questions about EAP-NOOB draft
Importance: High
Dear Tuomas,
First of all, I would like to say that EAP-NOOB draft is very complete and
understandable. Also, with regard to the rest of the solutions I have found, I
think it is a great solution so far and I like the way to approach the problems.
I am working on implementing EAP-NOOB on resource-constrained devices for our
use case. But I have the following 2 questions:
1. Regarding the key derivation section. There, it is explained the use of
ECDHE for the key exchange. Do you have in mind to accept any alternatives
besides the one explained in the draft? Maybe weaker methods or stronger but
not so constrained.
2. I have a concrete use case. Specifically, I am interested in knowing how the
Reconnect State works.
In the scenario there are some devices that are going to be installed and then
they will be inaccessible to be able to repeat the OOB step.
These devices already have the corresponding security associations with a
specific RealM. For example, a device from the University of Murcia is managed
by a company called Odins.
Now we assume that Odins stops managing those devices and Ericsson becomes the
new manager with his own AAA Infrastructure. To establish the new RealM, I
understand that the device should be restarted and the entire process done. Is
there a mechanism to allow migration without having to repeat the OOB step?
Regards,
Eduardo Inglés.
___
Emu mailing list
Emu@ietf.org
https://www.ietf.org/mailman/listinfo/emu
___
Emu mailing list
Emu@ietf.org
https://www.ietf.org/mailman/listinfo/emu
