Subject: Bug#1253: [X2Go-Dev] Bug#1253: ssh broker : bad error feedback in interaction mode

From: Mike Gabriel <[email-masked]>
Date: Tue, 15 May 2018 15:32:32 +0000

Control: reassign -1 x2goclient
Control: found -1 4.1.1.1

On  Di 13 Feb 2018 19:29:45 CET, Walid MOGHRABI wrote:

> package: x2gobroker-ssh
> version: 0.0.4.0-0~972~ubuntu16.04.1
> priority: bug
>
> Using the ssh broker is great because it adds the ability for the  
> x2goclient to interact with the auth mechanism such as PAM so that  
> you get notified that you need to renew a password for example.
> This is great but it doesn't always work well.
>
> For example, the user don't get the reason why the access is denied.
>
> Here are different tests I made based on the following setup :  
> x2gobroker in ssh mode with local PAM auth based on Samba  
> Winbind/Kerberos.
>
> I tried both situations to compare :
> * with the x2goclient in broker-ssh mode
> * with a term rying to connect through SSH
>
>
> 1) Account set for password change with temporary password in Active  
> Directory, user type wrong password (neither old or new one)
> * with x2goclient: get message "Access denied. Authentication that  
> can continue: publickey,password,keyboard-interactive"
> * with term : "Your account has been locked. Please contact your  
> System administrator. Password: "
>
>
> 2) Account set for password change with temporary password in Active  
> Directory, user type good password
>
> * with x2goclient: get a new password form in order to type (and  
> confirm) the new password. Reseting password works and you get  
> logged in to the broker with the sessions list displayed.
> However, if you click on the "cancel" button, x2goclient freeze and  
> must be killed, you're not sent back to the login form.
> On the other hand, if you change your password and then be logged  
> in, clicking on the session slot fails because this is the old  
> password that is relayed to the session slot and not the new one.  
> When it fails, you get a new login form to enter your password  
> again, if you type the new password there, it works.
>
> * with term:
>     "Password: ******"
>     "Password expired.  You must change it now."
>     "Enter new password: ******"
>     "Enter it again: ******"
> If you cancel (ctrl+c), nothing happen and you get back to the prompt.
> If you enter the good old password, you're prompted to change it  
> then you're logged in.
> If you enter the wrong password, your prompted to retry 2 times then  
> you get this message "Your account has been locked. Please contact  
> your System administrator" (this is our security policy, this is  
> normal behaviour, 2 fauils then blocked for 10mn.
>
>
> 3) Account disabled in Active Directory
> * with x2goclient: get message "Access denied. Authentication that  
> can continue: publickey,password,keyboard-interactive"
> * with term : "Your account has been locked. Please contact your  
> System administrator. Password: "
>
>
> Would be great to fix the issues in 2) and would be great to  
> retrieve the error message directly from PAM so that we get the  
> reason.

Most of this is unrelated to X2Go Broker. It needs to be worked on in  
X2Go Client.

Mike
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