Subject: Bug#1374: [X2Go-Dev] Bug#1373: kex error : no match for method mac algo

From: Antenore <[email-masked]>
Date: Mon, 18 Feb 2019 11:22:16 +0100

Package: client

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 18 February 2019 10:07:37 CET, Danie de Jager <[email-masked]> 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 [email-masked]
>,ecdh-sha2-nistp521,ecdh-sha2-nistp384,ecdh-sha2-nistp256,diffie-hellman-group-exchange-sha256
>Ciphers [email-masked],[email-masked],
>[email-masked],aes256-ctr,aes192-ctr,aes128-ctr
>MACs [email-masked],[email-masked],
>[email-masked],hmac-sha2-512,hmac-sha2-256,[email-masked]
>
>Client sshd config:
>Client using default sshd config
>
>or
>
>HashKnownHosts yes
>HostKeyAlgorithms [email-masked],
>[email-masked],ssh-ed25519,ssh-rsa,
>[email-masked],
>[email-masked],
>[email-masked]
>,ecdsa-sha2-nistp521,ecdsa-sha2-nistp384,ecdsa-sha2-nistp256
>KexAlgorithms [email-masked]
>,ecdh-sha2-nistp521,ecdh-sha2-nistp384,ecdh-sha2-nistp256,diffie-hellman-group-exchange-sha256
>MACs [email-masked],[email-masked],
>[email-masked],hmac-sha2-512,hmac-sha2-256,[email-masked]
>Ciphers [email-masked],[email-masked],
>[email-masked],aes256-ctr,aes192-ctr,aes128-ctr
>
>Error:
>"kex error : no match for method mac algo client->server: server [
>[email-masked],[email-masked],
>[email-masked],hmac-sha2-512,hmac-sha2-256,[email-masked]],
>client [hmac-sha1]"
>
>or sometimes
>
>"crypt_set_algorithms2: no crypto algorithm function found for
>[email-masked]"
>
>Let me know if I can provide more information.
>
>Regards,
>*Danie de Jager*