On 3/27/12 3:48 AM, Dennis E. Hamilton wrote:
I confirmed my hypothesis. When AOO 3.4 is installed over the top of an existing (i.e.,
OpenOffice.org 3.3.0) installation, it does not updated the registrymodifications.xcu
that is already there. Since there are no settings of options for Save As Password use
of SHA1 and Blowfish there, none are there after the AOO 3.4 install. That means only
the program-set defaults will kick in and the user will be converted to "Save with
Password" using SHA256/K checksums and AES256 CBC encryption.
The update installs over an existing user installation where a user have
made some local changes that we don't overwrite. Everything else would
be probably surprising to the users who have potentially changed a lot
of default values.
I think the behaviour is want the user expect. And the config entries
are read from the configuration anyway independent from the
initialization in the code. So either the default values from Common.xcs
(finallly main.xcd) are used or the overwritten value in the user config
layer.
I don't see a problem here.
Juergen
I verified this with AOO 3.4 r1303653 atop OO.o 3.3.0.
- Dennis
PS: I also confirmed that LibreOffice 3.5.0rc3 is adding chaff to XML files that are
compressed and encrypted, preventing easy access to known plaintexts for attacking
the encryptions in the ODF package. (There is a discussion of chaff, among other
technicalities at<https://issues.apache.org/ooo/show_bug.cgi?id=119090>.)
-----Original Message-----
From: Dennis E. Hamilton [mailto:[email protected]]
Sent: Monday, March 26, 2012 17:16
To: [email protected]
Cc: [email protected]; [email protected]
Subject: RE: [RELEASE,CODE]: Bug 119090 - Default Encryption Fails for
Down-Level Implementations
I did more experiments with AOO-dev 3.4 and LO 3.5.0rc3 which I happened to
have installed where it was easy to test them together.
TEST RESULTS
1. It is possible to change the default behavior of AOO-dev 3.4 and LO
3.5.0rc3 (both of which produce AES 256 CBC and SHA256-1k encryptions by
default) by setting options in registrymodifications.xcu.
2. If registrymodifications.xcu is deleted, a new one is created *but* it has
*no* settings for the SHA1 and Blowfish in ODF12 and these installations
*revert* to AES256 CBC and SHA256-1k even if their last use was with options
set for Blowfish CFB and SHA1/1K.
HYPOTHESIS **CONFIRMED**: If an install is done on top of a previous installation not
supporting AES to update to a later version, no settings for this will be added to the
"legacy" registrymodifications.xcu and the default will go into effect:
encryptions will start being done in AES256, surprise, surprise.
RECOMMENDATION:
1. It looks like registrymodification.xcu is the place where a tool or script
can do the job when it comes to setting/changing the desired option.
2. It looks like there must be code changes to set the default to Blowfish
and SHA1/1K within the application to cover the case where
registrymodification.xcu doesn't specify an option either way.
This last may be in Common.xcs but I am betting that the assured default
setting is in the constructor initial values in savopt.cxx. Why? Because that
class holds the options and setters and getters for them. Other software uses
the setters when processing configuration parameters from elsewhere, with the
default value delivered by the getter when no configuration parameter provides
a change. My money is on that being the place.
- Dennis
-----Original Message-----
From: Dennis E. Hamilton [mailto:[email protected]]
Sent: Sunday, March 25, 2012 18:15
To: [email protected]
Cc: [email protected]
Subject: RE: [RELEASE,CODE]: Bug 119090 - Default Encryption Fails for
Down-Level Implementations
TJ,
I was doing some nosing around and, based on some information on the Community
Forums (thank you Hagar), it looks like the settings are controlled in a file
called registrymodifications.xcu, at least on Windows. The location will vary
with different versions of windows.
On windows, you can find one under the installed-user profile, such as Documents&
Settings\orcmid\Application Data [a hidden file], OpenOffice/3/user/registrymodification.xcu for any
install since the AES256 has been instituted as default. the *.xcu is actually an XML file and you can
find the settings by searching for "blowfish" and for "SHA1".
How this works for Mac, Solaris, OS/2, and the various Linus and BSD builds, I
have no idea.
- Dennis
-----Original Message-----
From: TJ Frazier [mailto:[email protected]]
Sent: Friday, March 23, 2012 11:26
To: [email protected]
Subject: Re: [RELEASE,CODE]: Bug 119090 - Default Encryption Fails for
Down-Level Implementations
[ ... ]
... options to consider:
3. User change to config file, to use the new option.
I have suggested a writeup on this, but such instructions are much
better aimed at the (few?) users who want the "latest and greatest"
security option, and will do a little work to get it. (Does anybody know
what that file name is? Given that, I volunteer to update the Release
Notes.)
4. Macro to toggle the settings.
This could be distributed in a BASIC library (new or existing); no
extension necessary. User instructions to find and run the macro are
simple. I may be able to write this; preliminary investigation is
promising but not certain. I volunteer to try. There are several real
experts on this list, whom I might ask for help.
/tj/
[1] https://issues.apache.org/ooo/show_bug.cgi?id=119090
On 19.03.2012 14:48, Jürgen Schmidt wrote:
On 3/19/12 2:16 PM, TJ Frazier wrote:
On 3/19/2012 08:48, Jürgen Schmidt wrote:
Hi,
I think issue 119090 is no show stopper from my point of view. The new
default provides a better security than before when I understand it
correct. And if people detect potential problems they can save the
document again with other settings.
I agree that this is important for interoperability but no show
stopper.
Any other opinion?
Juergen
Hi, Jürgen,
Like Dennis, I'm nervous about this. Perhaps we can handle it with a
mention in the Release Notes; something like,
PLEASE NOTE: the default options for [technical details here] should
provide your best /individual/ security. However, if you intend to share
the document in secure fashion, the default mode cannot be read by
* previous versions of OpenOffice.org
* current versions of LibreOffice, at least through [version]
* Ms Office [version info]
For compatibility, use the options [details here].
I agree that it make sense to mention it in the release notes.
Any volunteer for updating the release notes?
Juergen
