Xpra: Ticket #2577: I don't get a password prompt for xpra attach from Win10 client access to a non-standard ssh port 5222

This works starting up xpra on the remote:

ssh -p 5222 user@fqdn xpra start :100 --start=mate-terminal

This starts xpra on Win10 but doesn't ask for my ssh user password:

"\Program Files\Xpra\Xpra.exe" attach --ssh="ssh -p 5222" ssh://user@fqdn:5222/100

The connection works if I leave out --ssh="ssh -p 5222" (I get a password prompt in Win10. Originally I needed to use --ssh="ssh -i" for ssh key setup.

The systray icon in Win10 only has "Information" and "Close Menu" selectable. Other entries are greyed out.

Client OS: Windows 10 Client version: 4.0-r25058 Server OS: CentOS 7.7 (inside a Docker systemd container i.e. "anything that would make the setup unusual") Server version: 3.0.6-0.20200125r25073xpra1.el7_7



Wed, 05 Feb 2020 13:52:13 GMT - akikoo:

"This starts xpra on Win10" meaning it starts the systray icon but doesn't open the remote mate-terminal.


Wed, 05 Feb 2020 17:39:32 GMT - Antoine Martin: owner, description changed

The connection works if I leave out --ssh="ssh -p 5222" (I get a password prompt in Win10.

Then why are you setting --ssh="ssh -p 5222"? Don't. The connection string ​ssh://user@fqdn:5222/100 already has the port number.

When you don't set --ssh=, you end up using the paramiko backend, which will prompt for passwords, etc. When you set --ssh=ssh, you end up using the openssh backend. Which you can debug by setting:

set XPRA_SSH_DEBUG=1

Before running xpra. It will then log the full command it will try to use. But I doubt that the openssh backend will work on MS Windows. Normally, the other backend on MS Windows is "plink.exe".


Wed, 05 Feb 2020 19:29:37 GMT - akikoo:

Then why are you setting --ssh="ssh -p 5222"?

I thought it would be needed to use ssh keys for authentication.

Edit: I was able to use plink earlier with ssh keys, but I noticed ssh is installed by default on Win10 so I thought it could be used in place of plink.


Thu, 06 Feb 2020 02:54:22 GMT - Antoine Martin: status changed; resolution set

I thought it would be needed to use ssh keys for authentication.

No, paramiko handles keys just fine. Even new format keys as of paramiko 2.7: #2307. You can see which paths it will use for loading the keys by running the Path_info.exe utility, or running with -d ssh.

Edit: I was able to use plink earlier with ssh keys, but I noticed ssh is installed by default on Win10 so I thought it could be used in place of plink.

It can be used as long as there is no user interaction required: we attach to the ssh subprocess stdin and stdout pipes to communicate with the server and on MS Windows the OS seems unable to talk to the controlling tty directly for user input.

I am closing as invalid since using openssh "ssh" on MS Windows is impossible, at least for now.


Sat, 23 Jan 2021 05:55:04 GMT - migration script:

this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/2577