ReadMe for Usage of PPDD-Packages for RedHat 8.0
Version 2002-11-10 by DI Walter Haberl

The WHAT

This is a quick readme, intended to make the start easier for "first
time users". I tried to keep it simple so that even Linux-Beginners
are able to get started. I describe the basic install and the simple
functionality of having a container-file and a mounted
loopback-filesystem to use.

The NEED

For a single CPU Machine (most common I guess) you need the following
files (the "*" replaces the Version number):

e2fsprogs-*.ppdd.i386.rpm
ppdd-*.ppdd.i386.rpm
kernel-*.ppdd.i686.rpm
psmisc-*.ppdd.i386.rpm
losetup-*.ppdd.i386.rpm
mount-*.ppdd.i386.rpm

You can, of course, optionally install all *src* for this are sources 
and *devel* - but you do not NEED them to use the stuff.
On SMP Machines you need the kernel-smp* Version. If you do not know
what an SMP Machine is, you do not have one, so why bother? ;-) To 
seriously find out whether you have SMP you type
uname -r
If you find a "smp" at the end, you need to download the kernel-smp* 
instead of the "normal" kernel RPM.
If you have an smp Machine please keep this in mind when reading below
for I will only refer to the "normal" Kernel (Version 2.4.18-14) in my 
examples.

Please note that I only tested with GRUB as bootloader. And please
note that I use sample Filenames and directories. Your desired setup
might be different.

The INSTALLATION

You Linux mars 2.4.18-14.ppdd #1 Tue Oct 1 10:41:07 EEST 2002 i686
i686 i386 GNU/Linux
should be root. Simply type 
su -
on the command prompt and enter root password
then you install
rpm -i kernel-*.ppd.i686.rpm
The rest will be !U!pdated, so please type:
rpm -U e2fsprogs-*.ppdd.i386.rpm
rpm -U losetup-*.ppdd.i386.rpm
rpm -U ppdd-*.ppdd.i386.rpm
rpm -U psmisc-*.ppdd.i386.rpm
rpm -U mount-*.ppdd.i386.rpm

A reboot is needed to activate the new kernel. Please note that GRUB
does not set the new kernel default! If you are unsure which kernel
you booted after the reboot, type
uname -a
and the output should include the "ppdd" like:
Linux localhost 2.4.18-14.ppdd #1 Tue Oct 1 10:41:07 EEST 2002 i686
i686 i386 GNU/Linux

The INITIALISATION

After you have installed the packages successfully, you need to load
the modules:
modprobe cipher-ppdd
modprobe cryptoapi
modprobe cryptoloop

Then you have to set up the cryptodevice first, this example generates
a 600MB File:
dd if=/dev/urandom of=/Data/Container/mars.crypt bs=1024
count=600000

Now associate the file with the loopback device:
losetup /dev/loop0 /Data/Container/mars.crypt

Initialize the Device (aka the file):
ppdncrypt -i /dev/loop0

Disassoziate the Device (better safe than sorry):
losetup -d /dev/loop0

Re-connect the Loopback with the file, using the ppdd cipher:
losetup -e ppdd /dev/loop0 /Data/Container/mars.crypt

Make the Filesystem:
mke2fs /dev/loop0

Mount the Filesystem:
mount /dev/loop0 /Data/Crypted

To safely disconnect the cryptodevice use the following two commands:
umount /Data/Crypted
losetup -d /dev/loop0

The OPERATION
On normal operation, you only have to perform:
modprobe cipher-ppdd
modprobe cryptoapi
modprobe cryptoloop
echo "Mounting Crypted Disk:"
losetup -e ppdd /dev/loop0 /Data/Containers/mars.crypt
mount /dev/loop0 /Data/Crypted

And for dismount:
umount /Data/Crypted
losetup -d /dev/loop0

The BENEFIT
There are two main benefits from using a crypto-device:
First of all if anyone gets hold of your physical equipment, there is
no way to access your data. This is obviously useful for notebooks
but it is also a good feeling in case your PC simply gets stolen.
But aside from that, doing backups on removable media does not render
local security useless. You can push the crypted file to a fileserver
or burn CDs or put it to tape and give it away without worry.

The LINKS

The RPM Packages are taken from
http://ppdd4rhl.sourceforge.net/
The original Package can be found at 
http://linux01.gwdg.de/~alatham/ppdd.html