cryptoloop-source: init file to allow use of encrypted swap

[Vincent Bernat <bernat@free.fr>]

Package: cryptoloop-source
Version: 0.0.0+0.0.1-pre1-8
Followup-For: Bug #203538

Hello,

Here is an init script which aims at providing encrypted swap support
via cryptoloop. It is largely inspired by current Mandrake scripts (so
credits need to be added). It assumes that aes support is in the kernel
(or loaded), it may be launched only as a start script. It could be
extended to support encrypted partition as well, but this needs to
modify /etc/init.d/mountall.sh.

I suggest to put it as S36 in /etc/rcS.d

#! /bin/sh
# Emacs ! This is a -*- sh -*- file

encrypted_swap=$(awk '($0 !~ /^#/ && $3 == "swap" && $4 == "encrypted") {print $1}' /etc/fstab)

if [[ -n $encrypted_swap ]];then
    loop=NONE
    modprobe loop
    if [ $? == 0 ]; then
        for (( s = 1; s <= 10; s++ )); do
            if [ -b /dev/loop0 ]; then
                loop=OK
                s=11
            else
                sleep 1
            fi
	done
    fi
    if [ $loop == OK ]; then
        for swdev in ${encrypted_swap}; do
            loop=NONE
            for l in $(echo /dev/loop[0-9]); do
                if [ $loop == NONE ] && ! grep -q $l /proc/mounts && ! { losetup $l &> /dev/null; }; then
                    loop=$l
                fi
            done
            if [ $loop != NONE ]; then
                # echo "Found available loop device" $loop
                swapoff $swdev > /dev/null 2>&1
                dd if=$swdev bs=1024 count=40 2>/dev/null |\
                mcookie -f /dev/stdin | losetup -p 0 -e aes -k 128 $loop $swdev 
                if [ $? == 0 ]; then
                    echo "Mounting" $swdev "on encrypted" $loop "with random key"
                    dd if=/dev/zero of=$loop bs=1024 count=40 > /dev/null 2>&1
                    if [ $? == 0 ]; then
                       echo "Activating encrypted swap on" $swdev "using" $loop
		       mkswap $loop
		       swapon -p 0 $loop
                    fi
                else
                    echo "Failed to mount" $swdev "on encrypted" $loop "with random key"
                fi
            else
                echo "Could not find any available loop device for encrypted swap!"
            fi
        done
    fi
fi



-- System Information:
Debian Release: testing/unstable
Architecture: powerpc
Kernel: Linux guybrush 2.4.21-ben2-guybrush.45 #1 mer jui 30 19:55:47 CEST 2003 ppc
Locale: LANG=fr_FR@euro, LC_CTYPE=fr_FR@euro

Versions of packages cryptoloop-source depends on:
ii  bash                          2.05b-8.1  The GNU Bourne Again SHell
ii  build-essential               9.4        informational list of build-essent
ii  cryptoapi-core-source         0.1.0-3    CryptoAPI core kernel module
ii  grep-dctrl                    1.100      Grep Debian package information
ii  kernel-patch-scripts          0.99.27    Scripts to help dealing with packa
ii  patch                         2.5.9-1    Apply a diff file to an original

-- no debconf information