Re: [TLS] Computation of static secret in anonymous DH

Eric Rescorla <ekr@rtfm.com> Fri, 26 June 2015 19:51 UTC

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From: Eric Rescorla <ekr@rtfm.com>
Date: Fri, 26 Jun 2015 12:51:01 -0700
Message-ID: <CABcZeBPwkTLB2NyobMRop7Zr_jprTShtpFUY75mZUCDT8GgMnQ@mail.gmail.com>
To: Ilari Liusvaara <ilari.liusvaara@elisanet.fi>
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Subject: Re: [TLS] Computation of static secret in anonymous DH
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On Fri, Jun 26, 2015 at 12:47 PM, Ilari Liusvaara <
ilari.liusvaara@elisanet.fi> wrote:

> On Fri, Jun 26, 2015 at 12:31:01PM -0700, Eric Rescorla wrote:
> > Note: I have updated the WIP (and that's what I sent to Hugo) so it now
> > contains the
> > changes the values Hugo describes.
>
> Small nit:
>
> master_secret= HKDF(xSS, xES, "master secret")
>
> Should that be:
>
> master_secret= HKDF(xSS, xES, "master secret", L)
>
> (the length parameter is seemingly missing)?
>

Yes, thanks for the correction.



>
> Also, is that label NUL-terminated or not (I think it is)? Another
> reason why I think it is not a good idea to use notes to change
> meaning of explcit algorithms...


They are all NUL-terminated.

I'm happy to add a wrapper as you suggest, just haven't gotten to it yet.

-Ekr


>
>
> -Ilari
>