Hi Daniel,

I'm just a reader, but X2GO uses libssh, that support the Kex you are using, so first of all, you have to install an updated version of libssh and eventually check if it has been compiled with the support of these algorithms.

Normally, I think, on the X2GO side there is nothing more to do.

Have a look here:

https://www.libssh.org/features/

On Mon, 18 Feb 2019 11:07:37 +0200 Danie de Jager <danie.dejager@striata.com> wrote:

Package: client

The client does not support chacha20 as I get this error when I try to connect to the X2Go server. I did harden my SSH configuration as guided by Mozzila https://infosec.mozilla.org/guidelines/openssh

When I use defaults it works fine. It seems that the library used by X2Go is missing some newer methods.

Config: server ssh config: KexAlgorithms curve25519-sha256@libssh.org ,ecdh-sha2-nistp521,ecdh-sha2-nistp384,ecdh-sha2-nistp256,diffie-hellman-group-exchange-sha256 Ciphers chacha20-poly1305@openssh.com,aes256-gcm@openssh.com, aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr MACs hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com, umac-128-etm@openssh.com,hmac-sha2-512,hmac-sha2-256,umac-128@openssh.com

Client sshd config: Client using default sshd config

or

HashKnownHosts yes HostKeyAlgorithms ssh-ed25519-cert-v01@openssh.com, ssh-rsa-cert-v01@openssh.com,ssh-ed25519,ssh-rsa, ecdsa-sha2-nistp521-cert-v01@openssh.com, ecdsa-sha2-nistp384-cert-v01@openssh.com, ecdsa-sha2-nistp256-cert-v01@openssh.com ,ecdsa-sha2-nistp521,ecdsa-sha2-nistp384,ecdsa-sha2-nistp256 KexAlgorithms curve25519-sha256@libssh.org ,ecdh-sha2-nistp521,ecdh-sha2-nistp384,ecdh-sha2-nistp256,diffie-hellman-group-exchange-sha256 MACs hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com, umac-128-etm@openssh.com,hmac-sha2-512,hmac-sha2-256,umac-128@openssh.com Ciphers chacha20-poly1305@openssh.com,aes256-gcm@openssh.com, aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr

Error: "kex error : no match for method mac algo client->server: server [ hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com, umac-128-etm@openssh.com,hmac-sha2-512,hmac-sha2-256,umac-128@openssh.com], client [hmac-sha1]"

or sometimes

"crypt_set_algorithms2: no crypto algorithm function found for chacha20-poly1305@openssh.com"

Let me know if I can provide more information.

Regards, *Danie de Jager*

Processing control commands:

reassign -1 x2goclient Bug #1373 [client] kex error : no match for method mac algo Warning: Unknown package 'client' Bug reassigned from package 'client' to 'x2goclient'. Ignoring request to alter found versions of bug #1373 to the same values previously set Ignoring request to alter fixed versions of bug #1373 to the same values previously set forcemerge #1374 -1 Bug #1374 [client] [X2Go-Dev] Bug#1373: kex error : no match for method mac algo Warning: Unknown package 'client' Unable to merge bugs because: package of #1373 is 'x2goclient' not 'client' Failed to forcibly merge 1374: Did not alter merged bugs. Debbugs::Control::set_merged("transcript", GLOB(0x306fdc8), "requester", "Mike Gabriel <mike.gabriel\@das-netzwerkteam.de>", "request_addr", "1373-submit\@bugs.x2go.org", "request_msgid", "<20190218203655.Horde.ZxHTyiUkDbzxblMamIGj2JK\@mail.das-netzwe"..., "request_subject", ...) called at /usr/share/perl5/Debbugs/Control/Service.pm line 552 eval {...} called at /usr/share/perl5/Debbugs/Control/Service.pm line 551 Debbugs::Control::Service::control_line("line", "forcemerge #1374 -1", "clonebugs", HASH(0x2ffc1f0), "limit", HASH(0x2fbae18), "common_control_options", ARRAY(0x2fbaea8), "errors", ...) called at /usr/lib/debbugs/process line 1039

-- 1373: http://bugs.x2go.org/cgi-bin/bugreport.cgi?bug=1373 1374: http://bugs.x2go.org/cgi-bin/bugreport.cgi?bug=1374 X2Go Bug Tracking System Contact owner@bugs.x2go.org with problems