Subject: Proxy-Server - SSH - strong Cipher crash x2Go-Client

From: <[email-masked]>
Date: Thu, 14 Jan 2021 07:47:33 +0000

Package: x2goClient
Version: 4.1.2.2-2020.02.13

Host-System: Windows 10, und Windows Server 2012 R2 (German Language)
Installations-Typ: Recommended (Default)

*** Problem Description ***
When using x2GoClient via jumpserver (as SSH-Proxy-Server), then is X2GoClient automatic closed (without any Information). Problem are the SSH-Strong-Ciphers, which are configured in SSHd on Jumpserver. Strong Ciphers => x2GoClient crashed. If default Ciphers => x2GoClient and connection works.

*** X2GoClient - Configuration ***
Sitzungsname: test
Pfad: /
Host: ziel-server
Login: test_ye
SSH-Port: 22

Proxy-Server für SSH-Verbindung verwenden
SSH
Host: jumpserver
Port: 22
Gleiche Anmeldung wie für X2Go-Server
Gleiches Kennwort wie für X2Go-Server

XFCE

*** Jumpserver Configuration) ***
Jumpserver SSHd Config: /etc/ssh/sshd_config  (CentOS 7)
Ciphers aes128-ctr,aes192-ctr,aes256-ctr

The ciphers are used for strong Encryption. Then access from x2GoClient via jumpserver cannot handle this.
------

When the Cipher-Restriction is not configured:
Jumpserver SSHd Confg: (CentOS 7)
#Ciphers aes128-ctr,aes192-ctr,aes256-ctr

then the connection from x2GoClient via jumpserver to Destination X2Go-Server does work.

I hope I provided all needed information for you. Let me know if this can be patched, or does our Company need to search for other solution.
Thank you.

Best regards,
Marián Schwarcz