#!/bin/sh
#
# BackWatcher, Inc.
# Information Security Solutions
# http://www.backwatcher.com/ 
# support@backwatcher.com
# 813-979-1633
#
# mkcryptfs
#
# Make blowfish(3) encrypted virtual filesystem for use with vnd(4),
# the Vnode Disk Driver, and vnconfig(8), it's configuration utility.
#
# 12/16/01

#
# Get arguments
#

while getopts d:f:s:vh option
do
   case "$option"
   in
      d)   device="$OPTARG"
           ;;
      f)   file="$OPTARG"
           ;;
      s)   size="$OPTARG"
           ;;
      v)   verbose="-v"
           ;;
      h) echo "Usage: mkcryptfs [-vh] -d device -f file -s size"
           echo "   -d device         vnode device (ie. /dev/svnd0c)"  
           echo "   -f file           disk image file"  
           echo "   -s size           size in kilobytes"  
           echo "   -v                verbose"  
           echo "   -h                help" 
           exit 1
           ;;
   esac
done

#
# Check syntax
#

if [ -z "$device" -o -z "$file" -o -z "$size" ]
then
  /bin/echo "syntax error: use -h for help"
  exit
fi

#
# Make sure we are on an OpenBSD system
#

if [ "`/usr/bin/uname -s`" != "OpenBSD" ]
then
  /bin/echo "os error: this must be an OpenBSD system"
  exit
fi

#
# Make sure a "safe" vnd was specified
#

safe="`/bin/echo "$device" | /usr/bin/grep svnd`"
if [ -z "$safe" ]
then
  /bin/echo "device error: you must use a 'safe' vnode device (ie. /dev/svnd0c)"
  exit
fi

#
# Make sure $size does not exceed the maximum
#

if [ "$size" -gt 2097151 ]
then
  /bin/echo "size error: maximum size is 2097151k (approximately 2GB)"
  exit
fi

#
# Create the file with a filesystem on partition c (whole disk)
#

[ $verbose ] && /bin/echo "Creating $file ..."
ddout=`/bin/dd if=/dev/zero of=$file bs=1024 count=$size 2>&1`
[ $verbose ] && /bin/echo "$ddout ..."
/bin/echo

[ $verbose ] && /bin/echo "Associating $file with $device ..."
/usr/sbin/vnconfig -ck $verbose $device $file
/bin/echo

cdevice=`/bin/echo $device | /usr/bin/sed 's/svnd/rsvnd/'`
[ $verbose ] && /bin/echo "Creating filesystem on $cdevice ..."
newfsout=`/sbin/newfs $cdevice`
[ $verbose ] && /bin/echo "$newfsout ..."
/bin/echo

[ $verbose ] && /bin/echo "Disassociating $file from $device ..."
/usr/sbin/vnconfig -u $verbose $device