[Owncloud] help needed with encryption and corruped files

[Victor Dubiniuk]

Hi all,

I used 4.0.  and found that the problem is in the  *OC_Crypt::decrypt*
it strips all 0x00 characters at the block boundary.
Please check with the attached files.
One has 32 of 0x00 inside and another one -

When I change *apps/files_encryption/lib/crypt.php*  line *#136*
return rtrim($data, "\0");
to
return $data;

the file is decrypted correctly except the fact that it's last block is
padded with 0x00.

I hope that it will be helpful.


---
Victor Dubiniuk

On Wed, Jun 13, 2012 at 4:45 AM, Michael Gapczynski <mtgap at owncloud.com>wrote:

> On Tuesday, June 12, 2012 12:52:06 PM Klaas Freitag wrote:
> > On 04.06.2012 18:33, Klaas Freitag wrote:
> > > On 04.06.2012 18:13, Frank Karlitschek wrote:
> > >> Hi,
> > >>
> > >> we have a very evil bug report about corrupted files together with the
> > >> encryption app.
> > >>
> > >> http://bugs.owncloud.org/thebuggenie/owncloud/issues/oc-912
> > >> http://forum.owncloud.org/viewtopic.php?f=3&t=2726
> > >>
> > >> Everything works for me and I can´t find the problem
> > >> Can someone help me with reproducing it?
> > >
> > > I can reproduce it with a Firefox on Linux and on Windows 7. I have
> > > master running from this morning.
> >
> > Frank, do you think that
> > http://bugs.owncloud.org/thebuggenie/owncloud/issues/oc-669
> > can be related to this problem? Is there a fix already for #912?
> >
> > Thanks,
> >
> > Klaas
>
> It seems that binary data has problems going through the encryption. I did
> some research and read that base64_encode()/decode() should allow binary
> files
> to be encrypted. My attempts to encode and decode the data with base64
> still
> result in corrupted binary files.
>
> http://bytes.com/topic/php/answers/8958-binary-encryption
>
>
> http://stackoverflow.com/questions/6033972/encrypting-files-with-php-mcrypt-
> is-corrupting-docx-and-other-microsoft-office<http://stackoverflow.com/questions/6033972/encrypting-files-with-php-mcrypt-is-corrupting-docx-and-other-microsoft-office>
>
> http://www.itnewb.com/tutorial/PHP-Encryption-Decryption-Using-the-MCrypt-
> Library-libmcrypt<http://www.itnewb.com/tutorial/PHP-Encryption-Decryption-Using-the-MCrypt-Library-libmcrypt>
>
>
>
> Michael
> _______________________________________________
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> Owncloud at kde.org
> https://mail.kde.org/mailman/listinfo/owncloud
>
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