#!/bin/bash
#
# simple_dl1.sh: A simple demo script for simple automactic downloading (without explicit proxy),
# without encryption, steganography etc., but optional with a little hiding, confuscation/deniability and
# optional self-destruction to remove traces.
#
# Dr. Rolf Freitag 2010
#
# Version 2010-07-22

# set -u : Stop the script when a variable isn't set (add -x for debugging)
set -u

# go to the download directory
#cd /tmp/
cd /mnt-system/tmp

# wait while not online
while [ ! -f /home/knoppix/Desktop/online ]
do
  sleep 1
done

# now we are online; download with the biggest file at last, because the return value of that single download will be checked
USER_AGENT=Mozilla/4.0\ \(compatible\;\ MSIE\ 7.0\;\ Windows\ NT\ 6.0\;\ SLCC1\;\ .NET\ CLR\ 2.0.50727\;\ .NET\ CLR\ 3.0.04506\)
OTHER_WGET_OPTIONS="-c -v -np -e robots=off --cache=off -T 20 --quota=2345M --tries=2 --restrict-file-names=unix --ignore-length --no-passive-ftp --retry-connrefused"
# download the current version of damnsmalllinux (DSL) with a checksum (about 50 MB)
URLS="http://ftp.belnet.be/packages/damnsmalllinux/current/current.iso.md5.txt http://ftp.belnet.be/packages/damnsmalllinux/current/current.iso"
typeset -i retval=1
while [ $retval -ne 0 ] ; do  # retry while the dowload is not finished
  for URL in $URLS ; do
    wget --user-agent="$USER_AGENT" $OTHER_WGET_OPTIONS --header="Accept-Encoding: deflate, gzip" $URL
    retval=$?
  done
done

# Optional: Move the download to an unsuspicious place, reverse it and set it's times to the ones
# from this script for confuscation/deniability
#mkdir -p /mnt-system/found.000
#perl -e 'print reverse <>' current.iso > /mnt-system/found.000/file0000.chk
#perl -e 'print reverse <>' current.iso.md5.txt > /mnt-system/found.000/file0001.chk
#touch -r $0 /mnt-system/found.000
#touch -r $0 /mnt-system/found.000/file*.chk
#rm -f current.iso* &

# after the download the job is done, so shutdown
poweroff &

# Optional: Simple self-destruction to remove traces
#shred -u "$0"