I wonder if Microsoft uses encryption compatible with javax.crypto.*. If yes, we have a chance to decode it. Otherwise it is not worth the trouble.
Yegor NB> On Tue, 17 Apr 2007, Justin Warren wrote: >> I should mention that the exceptions don't really tell if the files are >> password protected or not. For word, I catch an >> ArrayIndexOutOfBoundsException, or java.lang.NegativeArraySizeException. >> I'm guessing that is not the expected behaviour. NB> With powerpoint, we did find one record we could look for early on that NB> indicates if the file is encrypted or not. For the others, we haven't NB> spotted anything suitable. NB> The problem is that if the file is encrypted, lots of the core records are NB> there, but there data is encrytped, and hence garbage if you try to read NB> it as if it wasn't. Unless we can tell very early on that a file is NB> encrypted, we can't just look through the record list looking for the NB> encrypted record flag, since the parent records can't be read properly. NB> Instead, we must find either a absolute offset to an indicator, or one NB> non encrypted record at a given location that'll have a child that tells NB> you it's encrypted. NB> If someone encrypts both the properties and the document, it's easy, as NB> you can tell at the poifs level. If they just encrypt the document, it's NB> hard. See EncryptedSlideShow in hslf for an example of how to do it for NB> powerpoint. Any suggestions for a similar way to do it for word or excel NB> gratefully received :) NB> Nick NB> --------------------------------------------------------------------- NB> To unsubscribe, e-mail: [EMAIL PROTECTED] NB> Mailing List: http://jakarta.apache.org/site/mail2.html#poi NB> The Apache Jakarta Poi Project: http://jakarta.apache.org/poi/ --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] Mailing List: http://jakarta.apache.org/site/mail2.html#poi The Apache Jakarta Poi Project: http://jakarta.apache.org/poi/
