Re: [libreoffice-users] Lost Pass Word

On 26/11/14 06:39, Isaac Cajina wrote:
> I need to open some documents and I do not remember my pass word. 

LibO 3.4.5 and lower can write files whose password protection relies on
Blowfish;
LibO 3.4.4 and lower can read files whose password protection relies on
Blowfish;
LibO 3.4.5 and higher can read files whose password protection relies on
AES-256;
LibO 3.5.0 and higher can write files whose password protection relies
on AES-256;

The Crypto++ library contains routines for encrypting/decrypting
blowfish, AES-256, and other algorithms for ciphers.

In 2001, four or five firms, worldwide, offered commercial OOo password
recovery services.

One of the firms frankly admitted that they used brute force. The setup
fee paid for the computers used for the "attack". The monthly fee
covered the utility bills that the "attack" generated. FWIW, this firm
now appears to be out of business.

Once upon a time, there was an extension that did password recovery. I
don't know how well it works/worked. I couldn't find it, when I searched
the LibreOffice and Apache OpenOffice archives today.

There are a couple of commercially distributed tools that _might_ work.

The time required to brute force a solution can be reduced if:
* The length of the password is known;
* Part of the password is known;
* Which glyphs the password uses are known;

This issue comes up often enough, that I'm surprised I can't find an
open source tool to brute force ODF passwords. It is a straightforward
algorithm.

Guess_password
Throw_at_document
If fails Guess_password
If success read_document

Guess_password is simply repeat until loops.

jonathon


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