Host names hashing

[Dmitry Belyavskiy]

Dear Uri,

Not sure we are trying to protect from collisions and not from host
name's disclosure.

On Wed, Jan 5, 2022 at 3:09 PM Blumenthal, Uri - 0553 - MITLL <
uri at ll.mit.edu> wrote:

> What are the cryptographic consequences of host name hah collision?
>
> My point is - the only reason to consider replacing the algorithm here
> would be to avoid varying around another hash that is not usable
> cryptographically.
>
> Regards,
> Uri
>
> > On Jan 5, 2022, at 07:05, Dmitry Belyavskiy <dbelyavs at redhat.com> wrote:
> >
> > Dear colleagues,
> >
> > OpenSSH uses SHA1 without any alternate options for hostname hashing
> (looks
> > like this is the last place where an alternate option for SHA1 is not
> > available). SHA1 HMAC is considered safe enough for now, but it may
> change
> > so it's definitely worth migrating to more safe algorithms (SHA2?).
> >
> > I'd like to discuss possible options of such migration.
> >
> > Many thanks!
> > --
> > Dmitry Belyavskiy
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> > openssh-unix-dev at mindrot.org
> > https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev
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>


-- 
Dmitry Belyavskiy