Strange crypto choices

Yegor Ievlev koops1997 at gmail.com
Mon May 28 07:19:55 AEST 2018


Can we prefer RSA to ECDSA? For example:
HostKeyAlgorithms
ssh-rsa,ssh-ed25519,ecdsa-sha2-nistp521,ecdsa-sha2-nistp384,ecdsa-sha2-nistp256

On Sun, May 27, 2018 at 10:50 AM, Damien Miller <djm at mindrot.org> wrote:
> there are more implications to changing key algorithms than KEX
> algorithms. If a change is made to the specification, then it might
> invalidate all the keys that are out there, this isn't the case with
> any other negotiated algorithm,
>
>
> On Sun, 27 May 2018, Yegor Ievlev wrote:
>
>> I don't think we should wait for a RFC in order to use stronger
>> crypto. We already prefer Curve25519 for key exchange without waiting
>> for it. So why wait for a RFC in this case?
>>
>> On Sun, May 27, 2018 at 5:09 AM, Damien Miller <djm at mindrot.org> wrote:
>> > On Sat, 26 May 2018, Christian Weisgerber wrote:
>> >
>> >> On 2018-05-25, Yegor Ievlev <koops1997 at gmail.com> wrote:
>> >>
>> >> > The defaults for HostKeyAlgorithms option are: [...]
>> >> > Why does OpenSSH prefer older and less secure
>> >> > (https://safecurves.cr.yp.to/) ECDSA with NIST curves over Ed25519?
>> >>
>> >> I asked Markus and Damien about this in the past but honestly don't
>> >> remember the answer.  Some of the potential reasons (lack of
>> >> standardization, no DNS fingerprint, ...) seem to no longer apply.
>> >> I've been wanting to hassle Markus and Damien about this again,
>> >> once I run into them in person, but that opportunity hasn't presented
>> >> itself yet.
>> >
>> > Yeah, there's no RFC for ed25519 keys yet. There's an I-D in progress at
>> > https://tools.ietf.org/id/draft-ietf-curdle-ssh-ed25519-01.html
>> >
>> > Christian is right about our reasoning for the other choices.
>> >
>> > -d
>> > _______________________________________________
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>> > openssh-unix-dev at mindrot.org
>> > https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev
>>


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