The International crypto patches do not appear to work with the latest
kernels.
The latest patch I can find is one against 2.4.5-ac11, at
http://www.bzimage.org/kernel-patches/v2.4/alan/v2.4.5/patch-2.4.5-ac11-crypto.bz2
. This works when applied to 2.4.5-ac11. However, I tried applying
it to 2.4.6-ac5. It applies all right (a couple of offset hunks, and
the diffs of debian control files obviously fail, because the files
aren't there on my system). But when I boot it and attempt to use
loopback encryption, the mount fails with -EINVAL and the kernel emits
the following messages.
attempt to access beyond end of device
07:02: rw=0, want=10241, limit=10240
EXT2-fs: unable to read group descriptors
Further attempts to fsck the device results in:
e2fsck 1.19, 13-Jul-2000 for EXT2 FS 0.5b, 95/08/09
fsck.ext2: Attempt to read block from filesystem resulted in short read
while trying to open /dev/loop2
Could this be a zero-length partition?
If I losetup -d the device and losetup it again, fsck succeeds, but
mounting still fails.
Here's what I'm doing to make it fail.
CIPHER=aes
KEYSIZE=256
LOOPDEV=/dev/loop2
FILE=/spare/encrypted-image
SIZE=10240 # kbytes
PASSWORD=12345
MOUNTPOINT=/mnt/scratch
FS=ext2
TESTFILE=$MOUNTPOINT/testfile
TESTSTRING="This is a test."
dd if=/dev/zero of=$FILE bs=1k count=$SIZE
echo $PASSWORD |losetup -e $CIPHER -k $KEYSIZE -p 0 $LOOPDEV $FILE
mkfs.$FS $LOOPDEV # works
fsck.$FS -f $LOOPDEV # passes
mount -t $FS $LOOPDEV $MOUNTPOINT # fails as above
echo $TESTSTRING > $TESTFILE # obviously fails
umount $MOUNTPOINT # the same
fsck.$FS -f $LOOPDEV # fails as above
losetup -d $LOOPDEV
echo $PASSWORD |losetup -e $CIPHER -k $KEYSIZE -p 0 $LOOPDEV $FILE
fsck.$FS -f $LOOPDEV # passes
mount -t $FS $LOOPDEV $MOUNTPOINT # still fails
I have also tried with FS=minix, CIPHER=twofish, and KEYSIZE=128, and
I've tried putting FILE on ext2 and reiserfs partitions. None of them
helps.
I think I have gotten the initial mount to succeed in previous tests,
but I can't reproduce it now. In any case, further attempts to mount
fail.
The same patch applied to 2.4.7-ac2 fails similarly.
--
Nate Eldredge
[email protected]