Re: Encrypted loopback filesystem

[Klein Moebius <klein.moebius@gmail.com>]

* Michael S. Peek <peek@tiem.utk.edu> [2007-05-25 10:43:26 -0400]:

> Hi gurus,
> 
> I thought I would experiment with creating an encrypted loopback 
> filesystem.  I've generated a file of random numbers, but I can't attack 
> it to /dev/loop0:
> 
> # losetup -e serpent /dev/loop0 $(pwd)/file.bin
> Password:
> ioctl: LOOP_SET_STATUS: Invalid argument
> 
> I did a quick google search, but what I've found refers to making sure 
> that you have the modules and util-linux installed, and I 've got those 
> (using Debian/Etch), and the loop and serpent modules are loaded.
> 
> What else can I check for?
> 
packages:

loop-aes-modules-XXX (looks like you have them)
loop-aes-utils
loop-aes-testsuite
sharutils

after install of loop-aes-modules, module loop must be removed and then
reloaded in the kernel to get to the new loop-aes module (only once if
you haven't rebooted since install:

rmmod loop
modprobe loop

command would be:

losetup -e serpent[128,192, or 256] /dev/loop[1,2,3,4,5,6,7, or 8]\
 ~/file.bin

 file.bin must have a physical size already, example:

 dd if=/dev/urandom of=~/file.bin bs=1024 count=1000

 will block out a working space for the file... change the count to vary
 the size...

Look here:

<http://www.debian-administration.org/articles/81>

And here:

<http://www.hermann-uwe.de/blog/howto-encrypted-usb-thumb-drives-and-usb-hard-disks-using-loop-aes>

Good place to start.  Good luck!

Regards,
Klein

-- 
... In Brooklyn, we had such great pennant races, it made the World Series
    just something that came later.
		    -- Walter O'Malley, Dodgers owner