[pkg-cryptsetup-devel] Bug#652497: cryptdisks: danger in swap

[A Mennucc]

Package: cryptsetup
Version: 2:1.3.0-3
Severity: important
File: cryptdisks

hi

'cryptdisks' eases the use of crypted swap partitions,
the instructions in  /usr/share/doc/cryptsetup/README.Debian.gz
are very easy; but there is an intrinsic danger.

Indeed, if there is a line such as 

   cswap1          /dev/sdaXX       /dev/urandom    swap,cipher=aes-cbc-essiv:sha256,size=256,hash=sha256

in /etc/crypttab, then , at boot, the OS will happily overwrite 
whatever is contained in /dev/sdaXX .

So if for any reason the partion /dev/sdaXX , after a reboot,
points to a different partition/disk, it will be wiped out.
(This does happen sometimes: when the user repartitions the disk,
or has many disks and swaps them, or the BIOS
discover them in different order).

I tried to use

   cswap1          UUID=....       /dev/urandom    swap,cipher=aes-cbc-essiv:sha256,size=256,hash=sha256

but it works only once, the UUID is destroyed during use

a.

-- System Information:
Debian Release: wheezy/sid
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 3.1.0-1-amd64 (SMP w/2 CPU cores)
Locale: LANG=it_IT.utf8, LC_CTYPE=it_IT.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages cryptsetup depends on:
ii  debconf [debconf-2.0]  1.5.41
ii  dmsetup                2:1.02.67-2
ii  libc6                  2.13-21
ii  libcryptsetup1         2:1.3.0-3
ii  libpopt0               1.16-1

cryptsetup recommends no packages.

Versions of packages cryptsetup suggests:
ii  busybox                                 1:1.19.3-4
ii  dosfstools                              3.0.12-1
ii  initramfs-tools [linux-initramfs-tool]  0.99
ii  liblocale-gettext-perl                  1.05-7+b1
ii  udev                                    175-3

-- debconf information excluded

-- 
Andrea Mennucc
 "E' un mondo difficile. Che vita intensa!" (Tonino Carotone)