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Re: [saag] SHA-1 to SHA-n transition

Peter Gutmann <pgut001@cs.auckland.ac.nz> Tue, 03 March 2009 15:39 UTC

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From: Peter Gutmann <pgut001@cs.auckland.ac.nz>
To: Nicolas.Williams@sun.com, pgut001@cs.auckland.ac.nz
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Date: Wed, 04 Mar 2009 04:40:15 +1300
Cc: mouse@Rodents-Montreal.ORG, saag@ietf.org
Subject: Re: [saag] SHA-1 to SHA-n transition
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Nicolas Williams <Nicolas.Williams@sun.com> writes:

>TLS-PSK is not sufficient by itself, and for two reasons:
>
>a) As the RFC says: "[h]owever, this document is not intended for web
>   password authentication, but rather for other uses of TLS."

That was added as a sop to the "<whine>we already have PKI in all its infinite
perfection and splendor, why provide an alternative?</whine>" crowd.

>Thus there is nothing about how to derive PSKs from passwords.

Yeah, my fault, I've had an RFC draft prepared but not quite posted yet for
ages.

>b) For any solution to scale that adds mutual authentication we'll need
>either the user to use the same password for all identities or federation.

Huh?  Where did this requirement come from?  You need neither of those two.

Peter.

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