Messages in this thread | | | Date | Mon, 21 Jul 2003 00:15:03 +0200 | From | Andries Brouwer <> | Subject | Re: 2.6.0-test1 cryptoloop & aes & xfs |
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On Sun, Jul 20, 2003 at 02:38:03PM -0700, Hielke Christian Braun wrote:
> Thanks for the tip. With util-linux-2.12 i can setup the device. > > So the new cryptoloop in 2.6.0 is incompatible to the one in the > international crypto patch?
I have not investigated. But at least the way to transmit the passphrase is very different. These out-of-kernel patch sets also come with patches for util-linux. Usually the resulting patched losetup uses some cryptographically strong digest algorithm to transform the passphrase into the byte array sent to the kernel.
But I left all crypto out of mount and losetup in util-linux 2.12. On the one hand we already have crypto in the kernel - no need to duplicate that. But on the other hand, the preparation of the passphrase has also been left out. The only handle put into mount/losetup is the ability to read from a specified file descriptor. So, today, you would need something like
% get_passphrase | mount -o loop,encryption=aes -p0 dev dir
where get_passphrase is a separate, to be written, utility that reads the passphrase and digestifies.
Maybe I'll make things a bit friendlier in 2.12a, for example with
% mount -o loop,encryption=aes,getpw=/usr/local/bin/get_passwd dev dir
where mount itself forks off a process that produces the password. Comments (and code) are welcome.
> I could not access my old data. So i created a new one. But when > i copy some data onto it, i get: > > XFS mounting filesystem loop5 > Ending clean XFS mount for filesystem: loop5 > xfs_force_shutdown(loop5,0x8) called from line 1070 of file fs/xfs/xfs_trans.c. Return address = 0xc02071ab > Filesystem "loop5": Corruption of in-memory data detected. Shutting down filesystem: loop5 > Please umount the filesystem, and rectify the problem(s) > > To setup, i did this: > > losetup -e aes /dev/loop5 /dev/hda4 > mkfs.xfs /dev/hda4
Wait! /dev/loop5 is your block device, and /dev/hda4 is the file it is setup on. Now behind the back of loop you fiddle with /dev/hda4. No surprise that fails.
Andries
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