Re: Fixing exchange of host keys in the SSH key exchange

"denis bider \(Bitvise\)" <ietf-ssh3@denisbider.com> Thu, 06 April 2017 20:34 UTC

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Message-ID: <05DC33124D144EC0B39A5BF58C8E3A33@Khan>
From: "denis bider \(Bitvise\)" <ietf-ssh3@denisbider.com>
To: "S.P.Zeidler" <spz@serpens.de>
Cc: <ietf-ssh@netbsd.org>, <djm@mindrot.org>, "Simon Tatham" <anakin@pobox.com>
References: <2216143EDEE342A3A5C9BB786F7FEF7A@Khan> <20170403200250.GB21972@serpens.de>
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Subject: Re: Fixing exchange of host keys in the SSH key exchange
Date: Tue, 4 Apr 2017 01:27:25 -0600
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OpenSSH documents this as a private extension:

https://github.com/openssh/openssh-portable/blob/master/PROTOCOL#L286

Our SSH Server and Client do not implement this mechanism at this time, but it’s something I would like us to support.

denis


From: S.P.Zeidler 
Sent: Monday, April 3, 2017 14:02
To: denis bider (Bitvise) 
Cc: ietf-ssh@netbsd.org ; djm@mindrot.org ; Simon Tatham 
Subject: Re: Fixing exchange of host keys in the SSH key exchange

Hi,

if I may stick an oar in sideways: if you go to all the trouble,
could you add a mechanism by which the server could advise that
the host key used by the client was still valid but deprecated,
and to download the new host key once connected?

Speaking as an admin of a bunch of servers whose users -do- ask
when the host key changes, I currently feel a need for a better
mechanism for updates to longer keys than "send mail".

regards,
spz
-- 
spz@serpens.de (S.P.Zeidler)