On Tue, Dec 8, 2020 at 5:07 PM Konrad, Martin <konrad@frib.msu.edu> wrote:

Hi, I have a few hosts in my ~/.ssh/config file which have ProxyJump lines specifying _multiple_ jump hosts:

Host foo ForwardAgent yes ProxyJump first.example.com, second.example.com

It seems like X2Go doesn't like this kind of configuration. I complains when I try to establish any connection (even when trying to connect to other hosts which don't have a line like this):

"Cannot connect to first.example.com:22 Failed to process system configuration"

Everything works fine in cases that require only a single jump host. As far as I can tell from the ssh_config (5) man page my configuration with multiple jump hosts is valid. Any suggestions how to deal with this?

Well, x2goclient is using libssh. While libssh can parse the ssh_config I am not sure to what extent the format is supported. It looks like proxyjump is only supported starting from libssh 0.9.0 and x2goclient has 0.8.something, IIRC.

See https://bugs.libssh.org/rLIBSSH990794c58045d5afe69d2fa861fe32b7f547b1fd

So for now you might try if works with ProxyCommand instead. If not you can always use an ssh outside of x2goclient to build the tunnel via ProxyJump ("ssh -L12345:localhost:22 foo"). Then you can configure your session to connect to localhost:12345. For Windows this can also be accomplished using the built in ssh but due to some bugs you (again) have to use ProxyCommand:

Create %USERPROFILE%\.ssh\config (without Suffix!):

Host tunnel Hostname foo User <your user on foo> ProxyCommand ssh.exe -q -m hmac-sha2-512-etm@openssh.com %r@first.example.com ssh -W %h:%p %r@second.example.com LocalForward localhost:12345 localhost:22

Notes:

• ProxyJump does not work here, error: "posix_spawn: now such file or directory"
• Windows SSH and OpenSSH do not agree on the MAC, so you have to specify it explicitly
• I have not tested the above ProxyCommand chaining, there might be some teeaking required

Uli