Hi !
Every time I'm unlocking the TDE screen it's asking me "Press Ctrl-Alt-Del to begin". First of all it's very annoying, but beside of that, I can't send "ctrl-alt-del" via the VNC connection, so I can't use my computer remotely (a similar problem with Windows OSes can be resolved by manipulating of registry database).
How can I get the password entering dialog directly, without C-A-Del ?
Cheers,
Ilya
Hi !
Every time I'm unlocking the TDE screen it's asking me "Press Ctrl-Alt-Del to begin". First of all it's very annoying, but beside of that, I can't send "ctrl-alt-del" via the VNC connection, so I can't use my computer remotely (a similar problem with Windows OSes can be resolved by manipulating of registry database).
How can I get the password entering dialog directly, without C-A-Del ?
Cheers,
Ilya
Hi Ilya,
The screen you refer to is an enhanced security feature for local logins. If you want to turn it off, simply go to the Control Center-->System Administration-->Login Manager and uncheck the "Enable Secure Attention Key" checkbox.
Tim
Hi Timothy !
01/02/2012 05:32 PM, ext Timothy Pearson пишет:
simply go to the Control Center-->System->Administration-->Login Manager and uncheck the "Enable Secure Attention Key" checkbox.
I did it, but it still appears. Do I have to log off and log in again in order to make "Ctrl-Alt-Del" dialog not appear again after screen lock?
Cheers,
Ilya
On Monday 02 January 2012 15:11:53 Ilya Dogolazky wrote:
Hi !
Every time I'm unlocking the TDE screen it's asking me "Press Ctrl-Alt-Del to begin". First of all it's very annoying, but beside of that, I can't send "ctrl-alt-del" via the VNC connection, so I can't use my computer remotely (a similar problem with Windows OSes can be resolved by manipulating of registry database).
My vnc client (xtightvncserver) will allow me to send ctrl-alt-del. F8 pops up a menu and send ctrl-alt-del is one of the choices. I believe some other VNC clients are similar.
HTH
Neil Youngman
Hi Neil !
01/02/2012 06:05 PM, ext Neil Youngman пишет:
My vnc client (xtightvncserver) will allow me to send ctrl-alt-del. F8 pops up a menu and send ctrl-alt-del is one of the choices. I believe some other VNC clients are similar.
As I mentioned in my original posting, I can do exactly the same (F8->menu->"send Ct-Al-De") with my client (xvnc4viewer) when the server (WinVNC) is running on Windows. Alas, this doesn't work with the same client and the server (x11vnc) running in a TDE session.
Cheers,
Ilya
On Tuesday 03 January 2012 08:43:35 Ilya Dogolazky wrote:
Hi Neil !
01/02/2012 06:05 PM, ext Neil Youngman пишет:
My vnc client (xtightvncserver) will allow me to send ctrl-alt-del. F8 pops up a menu and send ctrl-alt-del is one of the choices. I believe some other VNC clients are similar.
As I mentioned in my original posting, I can do exactly the same (F8->menu->"send Ct-Al-De") with my client (xvnc4viewer) when the server (WinVNC) is running on Windows. Alas, this doesn't work with the same client and the server (x11vnc) running in a TDE session.
So your client can send the CTRL-ALT_DEL, but the server isn't responding to it?
If I am interpreting that right, it wasn't that clear (at least to me) from reading your original message. I hope the other answers have solved your problem.
Neil Youngman
As I mentioned in my original posting, I can do exactly the same (F8->menu->"send Ct-Al-De") with my client (xvnc4viewer) when the server (WinVNC) is running on Windows. Alas, this doesn't work with the same client and the server (x11vnc) running in a TDE session.
Does it work when you run FVWM or TWM instead of TDE?
Nik
Am Dienstag, 3. Januar 2012 schrieb Ilya Dogolazky:
01/03/2012 02:03 PM, ext Mag. Dr. Nikolaus Klepp пишет:
Does it work when you run FVWM or TWM instead of TDE?
No idea, I never used FVWM or TWM as a "real" window manager.
Try it. Or you can try ctrl+alt+del on TDE while the scree is not locked, it should pop up a dialog box. But if I remember right, there was an issue with some xservers and VNC.
Nik
Lieber Herr Mag. Dr. Klepp,
01/03/2012 03:02 PM, ext Mag. Dr. Nikolaus Klepp пишет:
Try it.
Alas, to try it I would have to configure yet another window manager, and learn how to do it something useful by receiving C-A-Del.
Or you can try ctrl+alt+del on TDE while the scree is not locked
That's a good idea, so I did it. After I sent "Ctrl-Alt-Del" from the "F8-menu" of xvnc4viewer (when the screen was *not* locked), TDE opened the "End session for 'ilya'" dialog (with a dragon sleeping on the moon). And that is not the same dialog as I got by pressing C-A-Del physically today.
Should I file a bug about it, or is there any other explanation for this behaviour?
Schöne Grüße,
-- Ilya Dogolazky, dr. rer. nat.
Hello, For people who are interested in testing TDE 3.5.13, I've built an updated Fedora 16 LiveCD .
It contains Fedora 16 for i686 computers, with all available Fedora updates at this time, and TDE 3.5.13 with some applications plus several fixes/patches from bugtracker. The desktop is basically customized to look like an official Fedora 16 desktop environment (background, start button).
The distro is also installable on your hard drive so that you can install Fedora if you like it :-)
The ISO size is 689 MB (721420288 bytes).
It should be available on the mirrors at the following URL, when the mirrors will be synced: http://ppa.quickbuild.pearsoncomputing.net/trinity/trinity/rpm/f16/trinity-3...
And the MD5 file: http://ppa.quickbuild.pearsoncomputing.net/trinity/trinity/rpm/f16/trinity-3...
Have fun with TDE 3.5.13 :-)
Francois Andriot
Le 03/01/2012 18:47, Francois Andriot a écrit :
Hello, For people who are interested in testing TDE 3.5.13, I've built an updated Fedora 16 LiveCD .
It contains Fedora 16 for i686 computers, with all available Fedora updates at this time, and TDE 3.5.13 with some applications plus several fixes/patches from bugtracker. The desktop is basically customized to look like an official Fedora 16 desktop environment (background, start button).
The distro is also installable on your hard drive so that you can install Fedora if you like it :-)
The ISO size is 689 MB (721420288 bytes).
It should be available on the mirrors at the following URL, when the mirrors will be synced: http://ppa.quickbuild.pearsoncomputing.net/trinity/trinity/rpm/f16/trinity-3...
And the MD5 file: http://ppa.quickbuild.pearsoncomputing.net/trinity/trinity/rpm/f16/trinity-3...
Have fun with TDE 3.5.13 :-)
It looks like the mirrors are not synchronized (yet) ... Here is a bittorrent file to help downloading the ISO : http://www.multiupload.com/XNJTI80P3B
Francois Andriot
That's a good idea, so I did it. After I sent "Ctrl-Alt-Del" from the "F8-menu" of xvnc4viewer (when the screen was *not* locked), TDE opened the "End session for 'ilya'" dialog (with a dragon sleeping on the moon). And that is not the same dialog as I got by pressing C-A-Del physically today.
Looks like ctrl+alt+delete of vnc is not ctrl+alt+delete from the keyboard :-)
You can try to figure out what is sent by calling "xev" and analyse the output.
Should I file a bug about it, or is there any other explanation for this behaviour?
Bug in vnc, I'd say ...
Nik
That's a good idea, so I did it. After I sent "Ctrl-Alt-Del" from the "F8-menu" of xvnc4viewer (when the screen was *not* locked), TDE opened the "End session for 'ilya'" dialog (with a dragon sleeping on the moon). And that is not the same dialog as I got by pressing C-A-Del physically today.
Looks like ctrl+alt+delete of vnc is not ctrl+alt+delete from the keyboard :-)
You can try to figure out what is sent by calling "xev" and analyse the output.
Should I file a bug about it, or is there any other explanation for this behaviour?
TDE monitors the first keyboard it finds for the Ctrl-Alt-Del keypress via evdev. The only ways to make this work are: 1.) if vnc registers as a keyboard to evdev somehow (unlikely) 2.) A security hole is opened by monitoring vnc for input 3.) (best) vnc is detected and the ctrl+alt+del input requirement is deactivated
A TDE bug report on this would be a good idea.
Tim
Hi Timothy !
To be honest I don't understand why is this "Ctrl-Alt-Del" dialog window good for security. What kind of attack is prevented by it?
Cheers,
Ilya
Hi Timothy !
To be honest I don't understand why is this "Ctrl-Alt-Del" dialog window good for security. What kind of attack is prevented by it?
Cheers,
Ilya
Hi Ilya,
Login spoofing. http://en.wikipedia.org/wiki/Login_spoofing
In a nutshell TDE intercepts ctrl+alt+del at a very low level, making it impossible for a non-privileged user to ever see the keystroke. Two TDE applications are then granted the ability to see the keystroke, specifically KDM and the desktop locker. Any other application will be oblivious to the fact that ctrl+alt+del was pressed, making it impossible to create a behaviourally accurate copy of the login screen.
Tim
-
Francois Andriot -
Ilya Dogolazky -
Mag. Dr. Nikolaus Klepp -
Neil Youngman -
Timothy Pearson