[radext] Re: Lack of Channel Bindings in RADIUS/(D)TLS

[Fabian Mauchle <[e-mail]>]

On 27.07.2024 00:00, Bernard Aboba wrote:> RFC 7585 "Dynamic Peer 
Discovery" (published in 2017) establishes
> authorization requirements that are quite different from those that 
> apply to RADIUS/UDP.   From Section 2.1.1.3 <http://2.1.1.3>:
> 
> "This document defines one mandatory-to-implement mechanism that allows 
> verification of whether the contacted host is authoritative for an NAI 
> realm or not."
> 
> Does "RADIUS over (D)TLS" authorization imply the RFC 7585 definition, 
> something closer to the RADIUS/UDP model or both??

Basically both.
RADIUS (D)TLS allows many ways to authenticate and authorize peers, of 
which certificates/PKIX and TLS-PSK are mandatory for servers.

If using TLS-PSK it more resembles RADIUS/UDP with a shared secret.

If certificates in a PKIX are used, it includes the RFC 7585 mandatory 
mechanism.
My proposal [1] tries to generalize this outside dynamic discovery and 
mandates identification of servers (i.e. the simple OID policy check is 
not enough)


[1] https://github.com/radext-wg/draft-ietf-radext-radiusdtls-bis/pull/4

-- 
Fabian