Linux Lite Forums

Software - Support => Installing Software => Topic started by: pab49162 on October 14, 2018, 11:22:17 AM

Title: Admin Rights Problems When Accessing PC Over VNC Connection
Post by: pab49162 on October 14, 2018, 11:22:17 AM
I recently installed Linux Lite 4.0 (release 18.04) on an older PC with a plan to run the PC headless and access it over my local home network via a VNC connection.

So I installed vnc4server and was able to successfully connect to it using a TigerVNC client on a Windows10 PC.  However, as I started doing things over the VNC connection, I noticed that programs requiring admin rights did not work.

For example, the File Manager works just fine until I try to do an "Open as Administrator".  When I do try that, nothing happens when I use the VNC connection.  However, this works just fine when I use a monitor and keyword connected directly to the PC.

This issue also exists with other things like System --> Install/Remove Software and Settings --> Firewall Configuration.  For all of these, I never see the Authenticate popup window to enter a password when connected via VNC.

Finally, I have experimented using x11vnc on this PC and I do not see the same issue when accessing the PC over that VNC connection.  I assume that is because x11vnc is sharing the existing X session rather than opening a separate session like other VNC servers.

Any comments/suggestions/alternatives to resolve this admin rights issue would be greatly appreciated.

Thanks in advance, Paul
Title: Re: Admin Rights Problems When Accessing PC Over VNC Connection
Post by: trinidad on October 14, 2018, 01:04:06 PM
Generally, and really generally because Windows 10 has been finally integrating SSH into the 1800 series builds, pretty much breaking most of the traditional solutions for what you are trying to do like TightVNC, PuTTY, even Teamviewer, etc., yes TigerVNC generates a new xserver instance for each user, thus in your case user  and root, and I believe you must have two ports enabled, 5900 and 5901 to the client and an SSL or SSH tunnel. That setting is defaulted on x11vnc. I do believe x11vnc is the best solution via an SSH tunnel, given that you can obtain a secure shell now from Windows SSH and start and stop x11vnc server remotely. Make sure the LL machine is set to autologin and it's SSH server is on. The old problems with older hardware running modern Windows 10 builds are still there however, like RAM hogging when using VNC, 4gig is almost not enough these days. You can use an alternative x server on Windows 10 that is more RAM efficient like xming but I haven't configured one since the 1600 build series and even that may not work correctly. Of course Linux to Linux, and Linux to Windows RDP servers work flawlessly most of the time, but Windows to Linux VNC is fraught with problems as always, on the Windows client side of the connection. I would run x11vnc server and SSH server on the Linux side, and check the most recent documentation on Windows 10 SSH client, and TightVNC, not Tiger VNC, using an SSH tunnel to get a secure shell on the Linux side from Windows. I would probably wait until after the problematic fall update to Windows 10 installs though.

https://www.zdnet.com/article/openssh-arrives-in-windows-10-spring-update/
https://blogs.windows.com/windowsexperience/2018/10/09/updated-version-of-windows-10-october-2018-update-released-to-windows-insiders/

TC
Title: Re: Admin Rights Problems When Accessing PC Over VNC Connection
Post by: pab49162 on October 15, 2018, 09:53:51 AM
Thank you for the reply concerning my issues with VNC.  After thinking about the things you mentioned, I decide to try an RDP approach.  From my initial testing, that looks like it might be a better solution to the way I want to access the PC.

To assist other people that might run into an Admin right issue with VNC, I thought I would share what I ended up doing relative to RPD.

Given that I loaded 3 or 4 different VNC servers and did a lot of hacking along the way, I decide to start over with a fresh load of Linux Lite.  Once I had all of the updates applied, I loaded XRDP following the steps outlined here

https://www.linuxliteos.com/forums/installing-software/how-do-i-get-xrdp-working/msg43511/#msg43511 (https://www.linuxliteos.com/forums/installing-software/how-do-i-get-xrdp-working/msg43511/#msg43511)

After doing that, I was able to access the PC using the standard RDC application on my Windows 10 PC.  I found that almost all of the applications needing Administrator rights worked as expected except for Thunar which had two separate issues.   :(

First, when I opened it up using the User Files launcher on the desktop, it gave me an error that said something about access problems to my home thinclient_drives.  After a bit of research, I followed the solution outlined here

http://catch22cats.blogspot.com/2018/05/xrdp-creates-strange-directory-called.html (http://catch22cats.blogspot.com/2018/05/xrdp-creates-strange-directory-called.html)

After that fix, I could access the User Files without an issue but the  File --> Open as Administrator still did not work.   :(   Basically, nothing happened when I did it.

I found several postings and such from other people that had somwhat related issues with Thunar.  After reading through them, I decided the easiest solution was to make a copy of the “User Files” launch, rename that copy of “Root” and edit its properties to change the launcher command to “gksudo thunar /”. 

This approach worked great and I like it even better than using the File --> Open as Administrator option.

Hope this explanation might be helpful to anyone faced with a similar problem.
Title: Re: Admin Rights Problems When Accessing PC Over VNC Connection
Post by: trinidad on October 15, 2018, 11:35:26 AM
Actually all you need is to use an SSH tunnel (SSH client Windows, SSH server LL) and login via SSH secure shell with the same user name and password that is the sudo account of your Linux Lite system, and run whatever VNC client you can get to work on your Windows machine. This passes authentication to SSH and eliminates issues with administrator access. To make it really simple have the same user name and password on the Windows 10 administrator account.

TC