Fix FileOpen DRM

[freyta]

Updated the FileOpen DRM so it uses the new URL encryption scheme.

Fixed the computation of the machine and disk keys, so you can decrypt previously opened files from your computer. Previously the machine key was always generating "22222222", and the machine code was slightly off so the last 2 digits were wrong.

[freyta]

If someone else can upload a PDF that wasn't decrypting to try and debug it that would help. I don't know if my changes break previous requests - I haven't got a PDF to test with..

[Chasethedog26]

I have many file open files, mainly Australian standards I've paid for but don't open. how do i send them to you to try. Not sure what to do with that script. does it need compiling to run? I posted the debug out of calibre, is thats of any use. back on the apprentice page. let me know how to get it to you.

[freyta]

You need Python 2.7 installed to run this script - maybe I should update it for Python 3.

These are the modules I have installed:

certifi @ certifi-2019.11.28.tar.gz
pycrypto @ pycrypto-2.6.1.tar.gz
pywin32==225

certifi and pycrypto were both installed as packages downloaded.

Then to run it you an just double click it, or I use the command prompt and type in

C:\Python27\python27.exe "ineptpdf8.6.0.pyw"

[vysmaty]

Idea for improvement. ;)
I had a problem with: "Error: Unexpected EOF"

When I handle lines 2397-2401 it with a try-except block, it works.

        else:
            try:
                self.parser.seek(index)
                (_,objid1) = self.parser.nexttoken() # objid
                (_,genno) = self.parser.nexttoken() # genno
                #assert objid1 == objid, (objid, objid1)
                (_,kwd) = self.parser.nexttoken()
            except Exception as e:
                # Some PDFs specify an out of bounds offset (like 0xFFFFFFFF) for deleted objects
                # instead of properly marking them as free objects in stream. Handle gracefully.
                return None