On Fri, 2010-07-02 at 09:16 -0500, Dustin Kirkland wrote: > On Thu, Jul 1, 2010 at 2:55 PM, Rob King <jk...@deadpixi.com> wrote: > > Hello everyone, > > Ubuntu's encrypted home directory feature is quite useful, and a good way > > of increasing the security and privacy of information. > > However, the scheme is a little "leaky". Applications still use the > > default system-wide temporary directory (/tmp), which is not encrypted. For > > applications that store things in the temporary directory, this can cause > > leaks of sensitive information outside the encrypted home directory. For > > things like Deja Dup, this can cause the entire contents of the home > > directory to be copied into an unencrypted area. > > I would suggest that, when a user enables the encrypted home directory > > feature, the TMPDIR directory is set to a temporary directory inside that > > user's home directory. This could easily be done in desktop sessions by > > modifying ~/.xsessionrc. I'm not sure how easy this would be for > > command-line logins. > > I agree that programs which leak truly sensitive nature to /tmp should > be fixed. Please file a bug in Launchpad for each and every program > you find that leaks sensitive data to /tmp. >
While I agree that any program that writes sensitive data to /tmp is in some way broken, I don't know that fixing them is a good long term solution. For every program that is fixed, another will pop up that's broken. > However, it's worth mentioning that /tmp is wiped on every boot in > Ubuntu. For this reason, I usually put my /tmp in a tmpfs in memory > (on systems where I have a few GB of memory). Add this line to your > /etc/fstab: > tmpfs /tmp tmpfs rw > > This ensures that the data written to /tmp is never actually written > to disk. I think this is an excellent best-practice for the security > conscious. > This is a good solution, except that it only works on systems with sufficient RAM - and even then, the RAM may be swapped to disk. By setting a session-wide TMPDIR variable, temporary data is always written to an area of the disk that is known to be encrypted. Thanks, Rob -- Ubuntu-devel-discuss mailing list Ubuntu-devel-discuss@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel-discuss
