[Pkg-cryptsetup-devel] Bug#430158: uswsusp and cryptoswap

[Helmut Grohne]

Package: cryptsetup
Version: 2:1.0.4+svn29-1
Severity: wishlist

(a similar mail already went to pkg-cryptsetup-devel at lists.alioth.debian.org)

I tried to use luks to encrypt swapspace for uswsusp, because this will
also encrypt normal swapping activity and not only hibernation. After
reading and experimenting with cryptsetup's initramfs hooks I found some
things:

The initramfs tries to limit the rate at which passwords can be entered
by invoking sleep 3 on failures. I generally appreciate this behaviour,
but in this case it would be cool if there was an easy way to disable
this feature (easy means not editing files under /usr).

In contrast to this high security the initramfs proposes normal booting
after several password failures. I don't see any advantage in this
behaviour. Assuming the user doesn't use cryptoroot this leads to an
easier way to get a running system as an attacker. If one really does
not want to resume there is an easier way than pressing enter all the
time: append noresume to kernel command line. This also has the
advantage, that a boot loader can be configured not to accept these
modifications without a password. I therefore suggest asking for
passwords until it is valid or a configurable behaviour.

Otherwise uswsusp seems to work great with cryptsetup and luks (i.e.
roughly out of the box with some googling, documentation would be
great[1]).

Greetings

Helmut

[1] I filled in a bit of the documentation gap:
    http://subdivi.de/~helmut/luks-uswsusp.html