I got a good security one more ya.
Matthew R. Dempsky
mrd at alkemio.org
Fri Mar 31 07:06:42 UTC 2006
On Fri, Mar 31, 2006 at 12:29:34AM -0600, Gromitigo wrote:
> Ok. If I have files saved as a user, and someone takes my hard drive
> out, puts it in another machine, mounts it...could they read that file
> if they we're root? What about if I write the files as root?
They could read it fine.
Similarly, if you were to tar or zip up a directory containing files
with restricted read permissions (e.g. a backup of your home directory
including gpg or ssh keys), anyone with access to your tar/zip file can
easily read the relevant files.
As was said in another post, if someone swiping your hard drive is a
risk you need to account for, you should look into encrypting your hard
drive. These issues are non-trivial, however; dm-crypt, for example,
has (had?) a timing weakness that allows any user to recover the AES key
in a mere 65 *milliseconds*. [1]
You should also realize that if someone has physical access to your
machine, there are quicker ways to access your data than removing the
hard drive: they could simply boot a Live CD or append init=/bin/sh to
your bootloader's boot string. (These can be locked down if you're that
concerned, however.)
[1] http://www.wisdom.weizmann.ac.il/~tromer/papers/cache.pdf
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