Antw: Re: EAP-PWD with wrong password

[Stefan Winter]

Hi,

> "When their talk ends nowhere all that can be said is that the two
> parties disagree about what the password is.
> "
> I understand that it is like that by design:
> 
> EAP-PWD RFC says in 2.8.5.3 EAP-pwd-Confirm-Exchange: "If the value of
> Confim_S i incorrect, the peer MUST terminate the exchange"
> ... I think this could be the point where it happens (I'm not too deep into
> EAP-PWD).
> I understand, that the freeradius-module is written like in the RFC defined.

Yes, I believe it was even written by the RFC author himself :-)

> RADIUS RFC says: If any value of the received Attributes is not acceptable,
> then the RADIUS Server MUST transmit a packet with the Code field set to 3
> (Access-Reject).
> I think, that does not match here, because it is not the server who does not
> accept the packet

Exactly: the server *does* send something back. Its last message is the
Confirm.


> ,but:
> 
> "Upon receipt of an Access-Request from a valid client, an appropriate reply
> MUST be transmitted."
> So, the question is for me: Is this a "valid" client or not? MUST there be a
> reply?

There is nothing to reply to because there is no Access-Request. The
client receives a Confirm, and walks away.

The server just sits there waiting for an incoming Access-Request which
never comes.

> Wouldn't it be an idea, the EAP-PWD peer sends back an explizit "I disagree
> with you, let us stop talking" (some kind of NAK)? Just asking :-)

Yes. In that case, it would be up to the client to send such a message
to the server, because it evaluated the Confirm and it didn't compare
well to its own expectation.

Unfortunately, nothing like that is foreseen in the RFC. And if such a
message doesn't even exist, then it is asked a bit much from a client to
send it :-)

Greetings,

Stefan Winter

-- 
Stefan WINTER
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