[X2Go-Dev] Bug#459: Bug#459: PolicyKit authentication within apps often fails

Hi Michael,

On So 23 Mär 2014 17:25:58 CET, Michael DePaulo wrote:

Package: x2goserver Version: 4.0.1.13

Notes:

1. I am not sure if this is a bug in x2goserver, x2goserver-xsession, or in nx-libs.

2. PolicyKit depends on ConsoleKit (and on systemd-logind in newer distros.)

3. The behavior seems to be distro-specific and/or app-specific.

4. This bug report differs from 458 because PolicyKit authentication is being called within an app, not when launching the app. This is part of the PolilcyKit architecture: The apps run unprivileged and rely on PolicyKit in order to speak to privileged processes that do the actual task. For example, in test case 2, gpk-application is launched unprivileged. It uses PolicyKit to speak to the PackageKit backend, and the PackageKit backend does the package install.

Test system: Fedora 20 64-bit MATE Desktop 1.6.2.1.fc20 - used for all 3 test cases x2goserver 4.0.1.13.2.fc20 x2goserver-xsession 4.0.1.13.2.fc20 nxlibs 3.5.0.22.1-fc20 (This distro uses logind) (/usr/libexec/polkit-mate-authentication-agent-1 is launched automatically when I login over X2Go. This distro is not affected by bug 457)

Test Case 1: Steps:

1. Launch yumex (from start menu or from console)
2. Switch to the yumex's "history" tab on the left..

Expected result: A policykit authentication window opens up, I select a user to authenticate as (myself or root), enter my password, and then the history is populated within yumex.

Here is an image of that policykit authentication window: http://imgur.com/JUZTBHo

Actual result: The authentication window does not open up and the history is no populated. Instead, I get an error message windows. When I click "Close" on the window, yumex closes.

Error message: Fatal Error: polkit-not-authorized

Could not get polkit autherisation to start backend

Yum Extender will terminate

Here's an image of the error message window http://imgur.com/ABYETM0

From the command-line, I can see this output when I select the history tab: 15:53:07 : INFO - YUM: Error executing command as another user: Not
authorized 15:53:14 : INFO - yum backend process is ended 15:53:14 : INFO - yum backend process is ended

Test Case 2: Steps:

1. Launch gpk-application (GNOME "Software Install" AKA "Add/Remove
   Software")
2. Select to install a single package.
3. Click "Apply Changes"

Expected result: A policykit authentication window opens up, I select a user to authenticate as (myself or root), enter my password, and then the package is downloaded & installed (over the course of at least a few seconds), during which a progress bar is displayed.

Screenshot: http://imgur.com/lLNof08

Actual result: The authentication window does not open up. The progress bar for the install completes in about 1 second. The package is not installed. (Interestingly enough, the package is still selected to be installed, but the "Apply Changes" and "cancel" button are hidden. This is a bug in gpk-application, it does not know how to handle policykit having an error. But this gpk-application bug is besides the point.)

Screenshot: http://i.imgur.com/28lCZF5.png

Also, the command-line does not show any relevant output.

Test Case 3: Steps:

1. Launch virt-manager (AKA "Virtual Machine Manager")

This test case actually passes!

Expected & Actual result: A policykit authentication window opens up, I select a user to authenticate as (e.g., myself or root), enter my password, and then I am connected to the local libvirtd instance and see the VMs running.

Screenshot: http://imgur.com/mZSgdMW

Also, the command-line output does not include any details about PolicyKit (succeeding.)

Note: Test case 3 fails on CentOS 6.5 64-bit. However, CentOS 6.5 64-bit is affected by bug 457, so that precludes running this test case.

I just fixed #458 by exporting $XAUTHORITY in x2goruncommand.

Do you have any clue what this issue may be related to? As I don't
have any of the failing apps on Debian, I cannot reproduce your test
results right away.

Any hint, if this issues also occurs on Debian?

Mike

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