Re: [Curdle] draft-ietf-curdle-ssh-kex-sha2 and diffie-hellman-group1-sha1 (1024-bit DH)

Peter Gutmann <pgut001@cs.auckland.ac.nz> Tue, 18 July 2017 03:58 UTC

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From: Peter Gutmann <pgut001@cs.auckland.ac.nz>
To: denis bider <denisbider.ietf@gmail.com>, Tero Kivinen <kivinen@iki.fi>
CC: curdle <curdle@ietf.org>, "Mark D. Baushke" <mdb@juniper.net>
Thread-Topic: [Curdle] draft-ietf-curdle-ssh-kex-sha2 and diffie-hellman-group1-sha1 (1024-bit DH)
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Date: Tue, 18 Jul 2017 03:58:19 +0000
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Subject: Re: [Curdle] draft-ietf-curdle-ssh-kex-sha2 and diffie-hellman-group1-sha1 (1024-bit DH)
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denis bider <denisbider.ietf@gmail.com> writes:

>I can provide anecdotal feedback that we still receive questions from users
>about "how do I make this connection work?" where the problem is that the
>other party supports only diffie-hellman-group1-sha1, and nothing else, so the
>algorithm needs to be enabled.
>
>Users SHOULD upgrade, of course, but in practice, many systems appear to be
>upgraded at 10-year intervals. I expect we will continue to see occasional
>demand for diffie-hellman-group1-sha1 for at least some 5 years. 

+1 on all of that, matches my experience exactly, and not just diffie-hellman-
group-exchange-sha1 but diffie-hellman-group14-sha1 as well.  There's even a
large router manufacturer whose name rhymes with Frisco whose *security
appliances* only support diffie-hellman-group1-sha1 on some of their devices
(yeah, that's so bad that I'm not going to grant them anonymity :-).

Oh, and another router vendor who until a few years ago was using an ssh.com
implementation from 1999.

And who knows what else is out there, I've got so many bug-workarounds enabled
by now that I don't see half the problems any more.

Peter.