Hi all,
On Sat, Nov 18, 2006 at 06:07:14PM +0200, Jari Ruusu wrote:
> String to grep for in v3 losetup is multi-key-v3
> String to grep for in v2 losetup is multi-key
>
> Your code looks for multi-key-v2 string in v2 losetup. That won't work.
On Wed, Nov 22, 2006 at 02:06:11AM +0000, Christian Kujau wrote:
> ...and maybe warn the user, if strings(1) cannot be be found and the
> check cannot be performed?
On Wed, Nov 22, 2006 at 11:07:10PM +0100, Richard Zidlicky wrote:
> why strings? "grep -a" works since ages and saves one command.
Thanks everyone for your fixes and suggestions.
The attached patch changes the script to use grep -a (which is not
in POSIX/SuSv3 or busybox grep, but should generally be available on
normal systems) and fixes the detection of multi-key-v2.
cheers,
Max
Index: loop-aes-keygen
===================================================================
--- loop-aes-keygen (Revision 1326)
+++ loop-aes-keygen (Arbeitskopie)
@@ -139,7 +139,18 @@
check_multikey_support ()
{
- strings /sbin/losetup | grep -q -s multi-key-v$1
+ match=
+ case $1 in
+ 1)
+ return 0;;
+ 2)
+ match="multi-key";;
+ 3)
+ match="multi-key-v3";;
+ *)
+ return 1;;
+ esac
+ grep -q -a "$match" /sbin/losetup
}
keygen()
@@ -153,10 +164,14 @@
# v2.x 64 2880 bytes(45 * 64) AES keys
# v3.x 65 2925 bytes(45 * 65) #65 is md5 seed
case $version in
- 1) nkeys=1 ;;
- 2) nkeys=64 ;;
- 3) nkeys=65 ;;
- *) return 1 ;;
+ 1)
+ nkeys=1;;
+ 2)
+ nkeys=64;;
+ 3)
+ nkeys=65;;
+ *)
+ return 1;;
esac
bytes=$((45*$nkeys))
@@ -179,10 +194,8 @@
exit 1
fi
-if [ "$version" -gt 1 ] && [ -x /usr/bin/strings ]; then
- if ! check_multikey_support $version; then
- echo "Warning: /sbin/losetup too old for v$version keys."
- fi
+if ! check_multikey_support $version; then
+ echo "Warning: /sbin/losetup too old for v$version keys."
fi
if [ -e $keyfile ]; then
#!/bin/sh
#
# loop-aes-keygen - Create loop-AES encryption keys
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; version 2 dated June, 1991.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
#
# Copyright 2005-2006, Max Vozeler <xam@xxxxxxxxxx>
#
# $Id: loop-aes-keygen 1332 2006-11-24 20:21:26Z xam $
#
set -e
umask 077
cipher=
userids=
rnd=/dev/random
version=3
usage()
{
cat << USAGE
usage: loop-aes-keygen [opts] <keyfile>
-v <1|2|3> Key format (Default: $version)
-u userid Encrypt for GnuPG pubkey <userid>
-c cipher Use GnuPG cipher <cipher>
USAGE
}
get_options()
{
while getopts 'v:s:c:u:h' f
do
case $f in
v)
version=$OPTARG
;;
c)
cipher=$OPTARG
;;
s)
rnd=$OPTARG
;;
u)
userids="$userids $OPTARG"
;;
h)
usage
exit 0
;;
esac
done
shift `expr $OPTIND - 1`
keyfile=$1
if [ -z $keyfile ]; then
echo No output file. Aborting
usage
exit 1
fi
if [ $version -lt 1 ] || [ $version -gt 3 ]; then
echo Unsupported key format: $version
exit 1
fi
}
check_safe_loop()
{
loopdev=$1
opts=$(/sbin/losetup $loopdev 2>&1)
if [ $? -ne 0 ]; then
echo "Error: Check for $loopdev failed ($opts)"
exit 1
fi
# If loop entry has an encryption= option assume it's safe
if echo "$opts" | grep -q encryption=; then
return 0
fi
return 1
}
check_safe_swap()
{
if [ ! -r /proc/swaps ]; then
echo Error: Cannot read /proc/swaps
exit 1
fi
unsafe=
while read line
do
set -- $line
case $1 in
/dev/loop*)
if ! check_safe_loop $1; then
unsafe=$1
break
fi
;;
Filename*)
;;
*)
unsafe=$1
break
;;
esac
done < /proc/swaps
if [ $unsafe ]; then
echo Fatal: Unsafe swap detected: $unsafe
exit 1
fi
return 0
}
check_multikey_support ()
{
match=
case $1 in
1)
return 0;;
2)
match="multi-key";;
3)
match="multi-key-v3";;
*)
return 1;;
esac
grep -q -a "$match" /sbin/losetup
}
keygen()
{
version=$1
keyfile=$2
gpgargs=$3
# These are the known loop-AES key formats:
# v1.x 1 45 bytes AES key
# v2.x 64 2880 bytes(45 * 64) AES keys
# v3.x 65 2925 bytes(45 * 65) #65 is md5 seed
case $version in
1)
nkeys=1;;
2)
nkeys=64;;
3)
nkeys=65;;
*)
return 1;;
esac
bytes=$((45*$nkeys))
head -c $bytes $rnd | uuencode -m - | head -n $(($nkeys+1)) | tail -n $nkeys | gpg $gpgargs > $keyfile
}
get_options $*
if ! check_safe_swap; then
exit 1
fi
if ! [ -x /usr/bin/gpg ]; then
echo "Error: gpg not found"
exit 1
fi
if ! [ -x /usr/bin/uuencode ]; then
echo "Error: uuencode not found - see package sharutils"
exit 1
fi
if ! check_multikey_support $version; then
echo "Warning: /sbin/losetup too old for v$version keys."
fi
if [ -e $keyfile ]; then
echo "Keyfile $keyfile exists. Aborting."
exit 1
fi
gpgargs="--armor"
if [ "$userids" ]; then
gpgargs="$gpgargs --encrypt"
for id in $userids; do
gpgargs="$gpgargs --recipient $id"
done
else
gpgargs="$gpgargs --symmetric"
fi
if [ $cipher ]; then
gpgargs="$gpgargs --cipher-algo=$cipher"
fi
if ! keygen $version $keyfile "$gpgargs"; then
echo An error occured while creating the key file.
exit 1
fi
exit 0
