Re: Problems encrypting disk partitions in 2.4.3

[Dale Amon <amon@vnl.com>]

On Wed, May 09, 2001 at 04:04:37PM -0400, Tad Truex wrote:
> 
> Greetings,
> 
> I have been trying to get loopback encryption working with the 2.4.3
> patches.  I applied the pathes to a fresh copy of the kernel source and a
> fresh copy of util-linux-2.11b.  Both sets of patches applied cleanly.
> Everything seems to build OK.   When I tested it on a regular file (using
> 128 bit serpent) it seemed to work just fine.  When I attempted it on a
> disk partition, it croaked with the following message.
> 
> [root@bailey mount]# ./mount -t ext2 /dev/loop0 /mnt
> mount: wrong fs type, bad option, bad superblock on /dev/loop0,
>        or too many mounted file systems
> 
> 
> (This is the patched mount from the 2.11b release of util-linux).  Is it
> obvious that I missed something, or is the 2.4 series not quite ready
> (this worked quite reliably under the 2.2.17 kernel I have been using).
> 

There are two things I've noticed. I've on occasion had to
do the mkfs TWICE. 

	      dd if=/dev/zero of=/dev/md0 bs=1k count=17639128
	      losetup -e twofish /dev/loop0 /dev/md0
	      Password:
	      Init (up to 16 hex digits):
	      mkfs -t ext2 /dev/loop0 
	      mount -t ext2 /dev/loop0 /mnt
	      losetup -d /dev/loop0

and redo the losetup and mkfs. Search me...

Also, if you are doing large file systems... I have 
tried to get a patch to a number of people about a problem
with the 2.11b, but no one ever answered.

The patches are missing a very important compiler switch that allows
us to work with files larger than 2GB. Edit the file MCONFIG and
modify the CFLAGS value to include -D_FILE_OFFSET_BITS=64:

           CFLAGS    := -g $(CFLAGS) $(OPT) -I$(LIB) $(WARNFLAGS) \
                                $(CURSESFLAGS) $(SLANGFLAGS) \
                                -DSBINDIR=\"$(SBINDIR)\" \
                                -DUSRSBINDIR=\"$(USRSBINDIR)\" \
                                -DLOGDIR=\"$(LOGDIR)\" \
                                -DVARPATH=\"$(VARPATH)\" \
                                -DLOCALEDIR=\"$(LOCALEDIR)\" \
                                -D_FILE_OFFSET_BITS=64


-- 
------------------------------------------------------
Use Linux: A computer        Dale Amon, CEO/MD
is a terrible thing          Village Networking Ltd
to waste.                    Belfast, Northern Ireland
------------------------------------------------------

Linux-crypto:  cryptography in and on the Linux system
Archive:       http://mail.nl.linux.org/linux-crypto/