2.6.0-test1 cryptoloop & aes

2.6.0-test1 cryptoloop & aes

[Hielke Christian Braun]

Hello,

i try to test the cryptoloop in 2.6.0-test1. I have enabled:

CONFIG_BLK_DEV_LOOP=y
CONFIG_BLK_DEV_CRYPTOLOOP=y
CONFIG_CRYPTO=y
CONFIG_CRYPTO_HMAC=y
CONFIG_CRYPTO_AES=y

Then i installed the losetup from util-linux-2.12pre. When i setup
the device like this:

/lib/losetup -e aes /dev/loop5 /dev/hda4

I get:

Unsupported encryption type aes

cat /proc/crypto:

name         : aes
module       : kernel
blocksize    : 16
min keysize  : 16
max keysize  : 32
ivsize       : 16


Is the cryptoloop in 2.6.0 not usable yet? 



Regards,
 Christian

Re: 2.6.0-test1 cryptoloop & aes

[Andries Brouwer]

On Sat, Jul 19, 2003 at 05:57:26PM -0700, Hielke Christian Braun wrote:

> Then i installed the losetup from util-linux-2.12pre.

You need util-linux-2.12 or later.

(try ftp://ftp.cwi.nl/pub/aeb/util-linux or so)

Andries

Re: 2.6.0-test1 cryptoloop & aes & xfs

[Hielke Christian Braun]

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 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

Regards,
 Christian.

Re: 2.6.0-test1 cryptoloop & aes & xfs

[Andries Brouwer]

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

Re: 2.6.0-test1 cryptoloop & aes & xfs

[Jeff Sipek]

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On Sunday 20 July 2003 17:38, 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 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

No, you should use

mkfs.xfs /dev/loop5

you want to create a fs on the loop device.

Jeff.

- -- 
bad pun of the week: the formula 1 control computer suffered from a race 
condition
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Re: 2.6.0-test1 cryptoloop & aes & xfs

[Hielke Christian Braun]

Hello,

On Mon, Jul 21, 2003 at 01:12:32PM -0400, Jeff Sipek wrote:
> >
> > So the new cryptoloop in 2.6.0 is incompatible to the one in the
> > international crypto patch?
> >
> > 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
> 
> No, you should use
> 
> mkfs.xfs /dev/loop5
> 
> you want to create a fs on the loop device.
> 

You are right. But i did use the /dev/loop5 device. I just wrote
it wrong in the email. 

I retried today on a different spare machine with the same result.
Then i tried with formating the loopback device with ext2
filesystem. After filling the the device with about 1GB of data, i
umounted it and did a file check. A lot of errors where reported.
Something is not good there too. 


Is anybody using the cryptoloop successful in 2.6.0?

Best regards,
 Christian.

Re: 2.6.0-test1 cryptoloop & aes & xfs

[Jari Ruusu]

Hielke Christian Braun wrote:
> I retried today on a different spare machine with the same result.
> Then i tried with formating the loopback device with ext2
> filesystem. After filling the the device with about 1GB of data, i
> umounted it and did a file check. A lot of errors where reported.
> Something is not good there too.
> 
> Is anybody using the cryptoloop successful in 2.6.0?

loop-AES works fine with 2.6.0-test1, here:

http://loop-aes.sourceforge.net/loop-AES/loop-AES-v1.7d.tar.bz2
http://loop-aes.sourceforge.net/updates/loop-AES-v1.7d-20030714.diff.bz2

Regards,
Jari Ruusu <jari.ruusu@pp.inet.fi>

Re: 2.6.0-test1 cryptoloop & aes

[Bill Davidsen]

On Sunday 20 July 2003 04:38 am, Andries Brouwer wrote:
> On Sat, Jul 19, 2003 at 05:57:26PM -0700, Hielke Christian Braun wrote:
> > Then i installed the losetup from util-linux-2.12pre.
>
> You need util-linux-2.12 or later.
>
> (try ftp://ftp.cwi.nl/pub/aeb/util-linux or so)
>
> Andries

Thank you, that's the missing part. I will say that in limited use I have used 
aes and twofish and they seem to work correctly. I copied a bunch of data 
there, checked it against the md5 contents file and all data was correct, did 
a bunch of renames, slinks, compiles, etc. unmounted and remounted a few 
times. So far so good, this isn't critical data, but I'm leaning that way for 
my laptop.

All this with 2.6.0-test1-ac2.

Now, for the bizarre test case, suppose I did three encrypted losetups, each 
using a different encryption. Then I made a raid-5 array of the three loop 
devices. created a filesystem on the md device, and ran on that. Forget the 
practicality, this is a test to see of the parts are robust, can I do it and 
will it work?

Now make two of those filesystems losetups of NBDs. Now I can recover if any 
one machine is missing, no one can recover the data without compromising at 
least two machines. again, forget practical, this is a test and maybe has 
application to the devout fundamentalist paranoid. If I was going to do it 
I'd loopback mount the md device, too ;-)