Re: [radext] Shepherd review of draft-ietf-radext-tls-psk-03

Alan DeKok <> Wed, 22 November 2023 21:50 UTC

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Date: Wed, 22 Nov 2023 16:50:38 -0500
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Subject: Re: [radext] Shepherd review of draft-ietf-radext-tls-psk-03
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On Nov 14, 2023, at 5:40 AM, Fabian Mauchle <> wrote:
> From the extensive discussions at the IETF118 we concluded that a server should reject a connection if it doesn't recognize the PSK identity as a configured client or as a resumption ticket; for the PSK identity is part of the server authentication.

  I'll make some changes to the doc and push them out.

> However, looking at the TLS spec (RFC8446), it does not mandate any mechanism how to create the session tickets and thus there is no guarantee that an implementation will be able to distinguish between externally established PSK and session resumption.
> I'm therefore reluctant to put an unconditional MUST on this.
> My proposal therefore would be:

  I've written substantially more text explaining the issues.  :(

> 5.  Guidance for RADIUS Clients
> (add to the end of the section, before 5.1)
> + If a client initiated a connection using a pre-shared key with TLS1.3
> + by inlcuding the pre-shared key extension, it MUST reject the
> + conneciton if the server did not select the pre-shared key to continue
> + the handshake.

  I've added that, thanks.

> 6.2.1.  Requirements for TLS-PSK

  I've reworked that substantially.  It should be a lot clearer.  And, allow the behaviour of OpenSSL.

  Alan DeKok.