On Thu, 3 Apr 2008, Borisoff, Victor wrote:
While on this topic, we have Excel document and want to protect it from
modification. POI provides something to mart each cell "protected". But
this can be easily changed back. Is there is something to make excel
document un-modifiable with the password?
You can write protect a workbook without encrypting it:
http://poi.apache.org/apidocs/org/apache/poi/hssf/usermodel/HSSFWorkbook.html#writeProtectWorkbook(java.lang.String,%20java.lang.String)
The last time I looked at it, document encryption stuff was just a mess.
There was a dozen different algorithms to select from, and all but one
were microsoft proprietary algorithms / proprietary versions of standard
algorithms.
It might be possible to decrypt / encrypt documents that are really stored
as rc4, and not as one of the microsoft nobbled rc4s, assuming we knew how
to turn the password string into key bytes. Page 119 of the excel binary
specs talks about a FilePass record (2fh), and bizarely points you at the
ooxml specs for more information. If someone was interested in adding
support, that would seem to be the place to start
Nick
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
