Call for testing: OpenSSH 8.2

Damien Miller djm at
Thu Feb 6 16:25:50 AEDT 2020

On Wed, 5 Feb 2020, Phil Pennock wrote:

> On 2020-02-06 at 14:41 +1100, Damien Miller wrote:
> > No, sorry - the rules evaluation is enough of a mess without adding
> > more corner cases where first-match-doesn't-always-win...
> Fair.  Thanks for the feedback. :)
> > I don't think that is correct. Host legacy won't have ssh-dss enabled
> > because that isn't in the default set of algs to begin with.
> Ugh.  Okay, bad example, sorry.  I should have stuck to what I'm
> actually using.  For $reasons, I'm disabling all RSA by default,
> sticking to ECC for pubkey usage in SSH.  I re-enable it where needed
> for some hosts.  Legacy was my euphemism for "no ECC".
>   Host legacy
>     HostKeyAlgorithms +rsa-sha2-256,rsa-sha2-512
>   Host *
>     HostKeyAlgorithms -ssh-rsa*,ssh-dss*,rsa-sha*
> This will re-enable ssh-rsa for host legacy.

I'll quibble by saying ssh-rsa was never disabled for host legacy to
begin with, but yeah - the result is the same: we only support a single
+/- modification.

> FWIW, while has updated to allow rsa-sha2-* algorithms,
> very public hosts which will currently cause people pain because they
> only allow ssh-rsa include:
>  *
>  *   (also ssh-dss)
>  * AWS codecommit hosts (at least, the one I touch)

That's why we're warning people now :) Hopefully these will fix their
sh^wstuff before we actually turn off ssh-rsa.


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