Thanks Michael.

Ok, we can look at a relay out and consider moving some of the EAP motivations 
in section 3 earlier in the document.

And agree, I think we can do a better job of linking the use of 
draft-ietf-tls-external-psk-importer to identify BSKs with the EAP handshake! 
We can fix that up in the next draft too.

Inline for more.

-----Original Message-----
From: Emu <emu-boun...@ietf.org> On Behalf Of Michael Richardson
Sent: Tuesday 13 September 2022 12:13
To: Peter Yee <pe...@akayla.com>; emu@ietf.org
Subject: Re: [Emu] Adoption call for EAP-DPP


I have read draft-friel-tls-eap-dpp-05.
I have no objection to the WG working on such a thing, but I think that there 
is actually quite a lot of work left to do.

I think that the section 3, which explains the EAP connection (and the 
motivation for the work) should probably come before the extension and the 
cryptographic explanation!

I find the document quite weak even in section 3.
I think that the EAP server (Authentication Server) is meant to use the OOB 
public key to authenticate the new device.

I'm rather vague as to how the Authentication Server knows what identity to use 
to look the public key up, and how the privacy of this identity is preserved.

[ofriel] the draft-ietf-tls-external-psk-importer external_identity is HKDF 
derived from the BSK public key as outlined in 
https://datatracker.ietf.org/doc/html/draft-friel-tls-eap-dpp-05#section-2.1. 
This is included in the ImportedIdentity struct which is serialized into 
PskIdentity.identity in the PSK extension, all as per 
draft-ietf-tls-external-psk-importer. Only a server that knows the 
raw/cleartext BSK public key can complete the TLS PSK handshake. 


Does the device get any indication that it has been plugged into the correct 
network?  Is there any authenticatin of the Authentication Server?

[ofriel] The device and server are afforded the same levels of identity 
guarantees and authentication as Wi-Fi DPP. The network gets a guarantee that 
the device connecting knows the BKS private key. The device gets a guarantee 
that the network knows its BSK public key. Similar to Wi-Fi Easy Connect / DPP, 
proof of knowledge of the BSK public key is proof of ownership of the device.



While I acknowledge you are not trying to implement BRSKI (RFC8995) or SZTP 
(RFC8572), it would be good if your Security Considerations addressed some of 
the same issues that those documents deal with.



--
Michael Richardson <mcr+i...@sandelman.ca>, Sandelman Software Works  -= IPv6 
IoT consulting =-



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