Guys lets stay away from encryption. We'd have to do all this
registering with the government and a whole lot of hassle for not much
benefit. Lame encryption to boot.
Nick Burch wrote:
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.
With powerpoint, we did find one record we could look for early on
that indicates if the file is encrypted or not. For the others, we
haven't spotted anything suitable.
The problem is that if the file is encrypted, lots of the core records
are there, but there data is encrytped, and hence garbage if you try
to read it as if it wasn't. Unless we can tell very early on that a
file is encrypted, we can't just look through the record list looking
for the encrypted record flag, since the parent records can't be read
properly. Instead, we must find either a absolute offset to an
indicator, or one non encrypted record at a given location that'll
have a child that tells you it's encrypted.
If someone encrypts both the properties and the document, it's easy,
as you can tell at the poifs level. If they just encrypt the document,
it's hard. See EncryptedSlideShow in hslf for an example of how to do
it for powerpoint. Any suggestions for a similar way to do it for word
or excel gratefully received :)
Nick
---------------------------------------------------------------------
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/
--
From Windows/Exchange to Linux/Meldware
Buni Meldware Communication Suite
Email, Calendaring, ease of configuration/administration
http://buni.org
---------------------------------------------------------------------
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/
