Subject: Re: [X2Go-Dev] Bug#472: Bug#472: Bug#472: Debian now has diffie-hellman-group1-sha1 disabled

From: Michael DePaulo <[email-masked]>
Date: Mon, 13 Oct 2014 19:22:11 -0400

On Mon, Oct 13, 2014 at 3:33 PM, Michael DePaulo <[email-masked]> wrote:
> [...]
>
> Looking through the libssh git logs, it appears that libssh 0.6 was
> the first version to add support for a non-sha1 key exchange method,
> ecdh_sha2_nistp256 [1].
>
> 0.6 also added support for [email-masked] [1].
>
> In a few hours or so, I will test if using a libssh 0.6.x linked
> version of x2goclient fixes this bug.
>
> Jessie does include libssh 0.6.3 (Thanks to our DD, Mike#1)[2].
>
> -Mike#2
>
> [1] http://git.libssh.org/projects/libssh.git/log/?id=libssh-0.6.0&qt=grep&q=sha2
> [2] https://packages.debian.org/jessie/libssh-4

The bad news:
I can confirm that X2Go Client for Windows 4.0.2.1+hotfix+build6 (and
all prior versions/builds) ARE AFFECTED by this bug and ARE UNABLE to
connect to a Debian Jessie server with openssh-server 6.7p1-2 (from
sid) installed. Said version of X2go Client for Windows bundles and
uses libssh 0.5.5.

The good news:
I can confirm that X2Go Client for Windows 4.0.3.0 nightly builds
(mingw 4.8 tested) ARE NOT AFFECTED by this bug and ARE ABLE to
connect to a Debian Jessie server with openssh-server 6.7p1-2 (from
sid) installed. Said version of X2Go Client bundles and uses libssh
0.6.3.

See bug #590 for the details on X2Go Client for Windows having libssh
upgraded to 0.6.x during 4.0.3.0's development cycle.

-Mike#2