[poppler] Encrypt with Revision 6 and AES256

[Brad Hards]

On Mon, 21 Oct 2013 12:29:17 AM Albert Astals Cid wrote:
> Does anyone have any clue where the spec that mentions Encrypt with Revision
> 6 and AES256 is?
> 
> There's such a file at https://bugs.freedesktop.org/show_bug.cgi?id=70704
> but I can't find anything newer than ISO_PDF32000_2008.pdf and it's not
> mentioned in there.
http://www.pdflib.com/knowledge-base/pdf-security/encryption/ (via wikipedia) 
discusses this a bit, but not enough to implement it, and my google foo can't 
find Extension Level 8 documentation.


WARNING: Link below is reverse engineered code from acroread binary!

There is documentation on this algorithm at:
http://esec-lab.sogeti.com/post/The-undocumented-password-validation-algorithm-of-Adobe-Reader-X
but it is not from a specification, but instead from adobe object code.

Brad