Power Management and Encryption

[Bill Bogstad]

On Mon, May 17, 2010 at 4:50 PM, Daniel Feenberg <feenberg-fCu/yNAGv6M at public.gmane.org> wrote:
>
> We have a desktop Fedora 12 box with encrypted disks. This satisfies a
> government agency worried about confidential data on the machine, but I
> would like the data to revert to encrypted after X minutes of idle time.
> The gnome-power-management GUI only provides for "sleeping" on idle and I
> can't find the appropriate configuration files to improve on that, such as
> by shutting down. I did test and found that one only needs input the Linux
> password to gain access to the disk after sleeping, although if sleeping
> could suitably unmount the encrypted disks, that would be fine also. (It
> might be hard since it is full disk encryption, including the OS).

It wouldn't surprise me if the power management option to take when
the system is "idle" is hard coded into
the source code.   You might consider doing something involving
writing a program to monitor the screensaver
status instead.

Here are some URLs that might be helpful:

http://coderrr.wordpress.com/2008/04/20/getting-idle-time-in-unix/
http://linux.die.net/man/3/xscreensaverqueryinfo

The first one has some code fragments.

Something that polls XScreenSaverQueryInfo() for how long the screen
has been idle and then
runs shutdown if if has been too long.    I doubt if you need
sub-minute timing of shutdowns
so polling shouldn't be a problem.

Bill Bogstad