On 09/11/2013 07:09 AM, tangchaojie wrote: > I Forger My password of the Libreoffice file . > Who can tell me how to deal with it ?
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. http://openoffice-password-recovery.en.softonic.com/ offers a tool that they claim: « OpenOffice Password Recovery is a software program to restore any forgotten passwords from any document created with Open Office. This tool supports all Open Office applications including OpenOffice Calc, Impress, Math, Writer and Draw. OpenOffice Password Recovery also features protection removal so you can get rid of the read-only restriction used for protection with some files. » http://openoffice-password-recovery.sharewarejunction.com/ offers an OOo extension for US$79.00 that allegedly recovers passwords from OOo documents. Those tools might work, but I have my doubts. Whilst there are known attacks that result in determining the password faster than using brute force, those attacks require at least a century to complete, using Beowulf Clusters that are currently commercially available. jonathon -- LibreOffice in a Multi-Lingual Environment. -- To unsubscribe e-mail to: [email protected] Problems? http://www.libreoffice.org/get-help/mailing-lists/how-to-unsubscribe/ Posting guidelines + more: http://wiki.documentfoundation.org/Netiquette List archive: http://listarchives.libreoffice.org/global/users/ All messages sent to this list will be publicly archived and cannot be deleted
