Re: [TLS] implementation of cookies in DTLS

Nikos Mavrogiannopoulos <nmav@gnutls.org> Sun, 13 March 2011 17:54 UTC

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Date: Sun, 13 Mar 2011 18:55:45 +0100
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Subject: Re: [TLS] implementation of cookies in DTLS
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On 03/13/2011 06:44 PM, Nikos Mavrogiannopoulos wrote:
> Hello, I've been reading the section "Denial of Service
> Countermeasures" of DTLS and as I understand it the proposed
> subsystem (client-hello and client-hello-verify-request) is expected
> to operate before allocating state for the session to discard
> requests from clients with forged addresses.

Moreover I think that the requirement that the version field
in Client Hello Verify request message, matches the version field
in the Server Hello is pretty awkward.  The Client Hello Verify request
is being sent by the server without allocating any state. Its
quite difficult to mandate that he makes the same decision as if
state was allocated. Requiring the version of DTLS 1.0 would
be more sensible there...

regards,
Nikos