Subject: Bug#397: Cannot connect when user home folder contains a non-ascii character

From: Néstor Uribe-Patarroyo <[email-masked]>
Date: Wed, 08 Jan 2014 12:05:00 -0500

Package: x2go-server
Version: 4.0.1.12-0~809~ubuntu12.04.1

When the home folder of a user contains a non-ascii character (such as 
"á", or "é") I cannot initiate an x2go session. The error is:

Info: Connecting to remote host 'localhost:31004'.
Info: Connection to remote proxy 'localhost:31004' established.
Error: The remote NX proxy closed the connection.
Error: Failure negotiating the session in stage '7'.
Error: Wrong version or invalid session authentication cookie.
Session: Terminating session at 'Wed Jan 8 09:52:30 2014'.
Session: Session terminated at 'Wed Jan 8 09:52:30 2014'.

Login with ssh works normally.

After changing the home folder of the user to one with only ascii 
characters, initiating an x2go session was possible.

I am using Ubuntu 12.04.3 in the server, Ubuntu 12.10 in the client. 
Client version is 4.0.1.2.Both server and client installed from thePPA 
ppa:x2go/stable

---

From: Mike Gabriel <[email-masked]>
Date: Thu, 09 Jan 2014 08:34:32 +0000

Control: reassign -1 x2goserver
Control: found -1 4.0.1.12
Control: tag -1 moreinfo

Dear Néstor,

On  Mi 08 Jan 2014 18:05:00 CET, Néstor Uribe-Patarroyo wrote:

> When the home folder of a user contains a non-ascii character (such  
> as "á", or "é") I cannot initiate an x2go session. The error is:
>
> Client version is 4.0.1.2.Both server and client installed from  
> thePPA ppa:x2go/stable

Thanks for filing this bug and testing X2Go.

Please note that Posix usernames are not allowed by RFC to contain  
accents on characters. Posix usernames should be ASCII only.

Normally, the home directory's basename should be identical to the  
username, thus also contain ASCII-only characters.

I don't think we will provide a fix for the reported bug, as your  
system does not seem to comply to Posix standards.

If you think I am wrong about this, please give feedback.

Thanks,
Mike
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---

From: Stefan Baur <[email-masked]>
Date: Fri, 10 Jan 2014 12:34:02 +0100

Am 09.01.2014 09:34, schrieb Mike Gabriel:

> I don't think we will provide a fix for the reported bug, as your system
> does not seem to comply to Posix standards.
>

I agree that we shouldn't try to fix what obviously isn't broken on our 
side, however, we could try to check for the issue and provide a clear 
error message as to what is wrong.

I don't know what programming language the particular part of x2goserver 
is written in, but I would hope that something like this is possible in 
it (pseudocode):

StrippedUsername = strip_non_ascii(Username)
if StrippedUsername != Username {
	report_error('Username does not conform to POSIX conventions.')
	exit
}

-Stefan