Yes Manesh, it seems that OpenOffice can open a password protected Excel spredsheet file - at least one created using Excel 2003, so in the binary BIFF8 format. Bearing in mind David's advice however, it does not seem wise to focus on reverse engineering OpenOffice's implementation too closely.
It is possible now to get your hands on a lot of information about the Excel file format. I have a copy of the OpenOffice Excel File Format document that Andrew contributed to some time ago. It focuses on the binary file formats but - against my expectations - includes a lot of information about password protection; this ranges from explaining which records are involved and progresses through detailed descriptions - including pseudo code - of how to decrypt the data stream. I do not know how this information would relate to the OpenXML file formats or if it would be wise - legal - to use this information to develop a patch for HSSF/XSSF. Perhaps David could let us know his thoughts on this matter. Mahesh Ganapathy wrote: > > Can Open Office open password protected excel files? If it can, then the > algorithm could be leveraged by POI. I do not have access to Oo right this > moment, hence the question. If this is feasible, I can spend some time > developing the necessary code with some guidance from the masters. > Sent via BlackBerry by AT&T > > -----Original Message----- > From: MSB <[email protected]> > > Date: Wed, 22 Apr 2009 10:09:42 > To: <[email protected]> > Subject: Re: How to read password-protected XLSX file? > > > > I hung back from answering because I do not have mucg experience with XSSF > and the OpenXML file format. However, with regard to the older binary file > format, I know that HSSF could not open password protected spreadsheet > files. The reason is that they are encrypted and the algorithm is not - at > least as far as I am aware - in the public domain. As I said, I cannot be > certain but I would expect that the same is true of the xlsx, xlsm and > xlsb > files that Office 2007 can produce. > > Just as an aside, I know that OpenOffice can read and write xlsx files. It > also has a programming interface - UNO - that allows you to control an > instance of OpenOffice and manipulate files; abit like OLE but it is > platform independent. It may - and this is another guess on my part - be > the > case that you could use this API to process password protected spreadsheet > files using Java code. No promises though. > > > J Keller wrote: >> >> Can anyone please point me to some docs and/or examples that show how to >> read a password-protected spreadsheet? Thanks. >> > > -- > View this message in context: > http://www.nabble.com/How-to-read-password-protected-XLSX-file--tp23161302p23175636.html > Sent from the POI - User mailing list archive at Nabble.com. > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > > > -- View this message in context: http://www.nabble.com/How-to-read-password-protected-XLSX-file--tp23161302p23191289.html Sent from the POI - User mailing list archive at Nabble.com. --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
