Re: [IPsec] Fw: Preshared key authentication in IKEv2

Tero Kivinen <kivinen@iki.fi> Mon, 02 November 2009 14:43 UTC

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Date: Mon, 2 Nov 2009 16:43:43 +0200
From: Tero Kivinen <kivinen@iki.fi>
To: "Valery Smyslov" <svanru@gmail.com>
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Cc: ipsec@ietf.org, Paul Hoffman <paul.hoffman@vpnc.org>
Subject: Re: [IPsec] Fw: Preshared key authentication in IKEv2
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Valery Smyslov writes:
> Hi Paul and Tero,
> 
> thank you for your answers.
> 
> > > The PRF (or set of PRFs) is known by the receiving party. If the two
> > > parties always only use one PRF, it is known. The padding is not a
> > > universal solution for the reasons you give, but it works in the
> > > common case of peers who know each other's crypto choices.
> >
> > As Paul said recipient knows which algorithms it support, and it can
> 
> Sometimes it doesn't. I refer to implementations with pluggable
> crypto, when crypto providers are separated from IKE implementation
> and can be added/removed later.

Then you need to store the original shared key not the hashed version
of it.
-- 
kivinen@iki.fi