Re: [Curdle] RFC 8308 on Extension Negotiation in the Secure Shell (SSH) Protocol

[denis bider <[e-mail]>]

To be sure, the latest OpenSSH version is 7.6. I know that versions up to
7.5 will disconnect on receiving binary extension-values. Fortunately
OpenSSH makes it easy to identify itself, so we have a workaround for that
(not sending "delay-compression" to OpenSSH 7.5 and older, which does not
support "delay-compression" anyway).

On Thu, Mar 22, 2018 at 6:55 AM, denis bider <[e-mail]>
wrote:

> Those sound like good ideas. I would like more people to try that. :)
>
> If you want to test with Bitvise SSH Server, you can download it free of
> charge from our website. It's easy to set up if you have a Windows
> computer. You can also access it already set up here:
>
> Host: experiment.bitvise.com
> Port: 10739
> User: test
> Pass: test
>
> If you want to test RSA authentication, the server will provide
> instructions in the SSH authentication banner, or you can find them in
> Welcome.txt after you are logged in.
>
> If you want to test Bitvise SSH Client, you can also download it free of
> charge from our website. It can be used free of cost in any environment.
> You just need a Windows installation.
>
> The real juice however would be in testing other implementations. I would
> suggest setting up and trying the latest OpenSSH versions, both server and
> client.
>
>
> On Thu, Mar 22, 2018 at 5:13 AM, Peter Gutmann <[e-mail]>
> wrote:
>
>> denis bider <[e-mail]> writes:
>>
>> >Where I'm less comfortable is the hinges that are not yet widely
>> deployed. As
>> >long as a hinge is not in common use, it is in danger of rusting. These
>> hinges
>> >include:
>> >
>> >- EXT_INFO sent by client (only server sends it for "server-sig-algs").
>> >- Extensions with binary extension-value (for example
>> "delay-compression").
>>
>> I was going to try sending in extensions with undefined values, and binary
>> data embdded in them, to see what happens.  If it's the same as previous,
>> in
>> some instances inadvertent, cases of sending unexpected data values then I
>> expect all sorts of fireworks.
>>
>> >EXT_INFO with the "server-sig-algs" extension is widely deployed. It's
>> well
>> >tested with rsa-sha2-256 and rsa-sha2-512 signatures, and I have no
>> concerns
>> >about it. As far as I know, there are no compatibility issues to be
>> >experienced by an implementation that follows the just-published spec.
>>
>> OK, that's good to know.
>>
>> Peter.
>>
>
>