RE: PDF modifications?

["Dawes, Rogan (ZA - Johannesburg)" <rdawes () deloitte co za>]

There are a couple of issues with PDF "protection".

If the PDF requires a password to open, I'm not sure you can do anything
about cracking it, other than brute forcing the password (haven't looked for
any tools for this)

If the PDF is openable and viewable, but is "protected", so that you can't
select or print or annotate, that is easily bypassed with almost any
non-Adobe PDF viewer, such as xpdf, which simply elects not to honour that
setting in the PDF. The data is all there, because you can view it, it is
simply a case of the software choosing to not let you select it. Find some
software that doesn't honour those document settings, and you are on your
way.

As I recall, there was some discussion about this issue on the xpdf lists,
or somewhere, about whether xpdf should honour the document requests or not,
but it is really moot, since the source is there, just modify it to suit. I
think that was the conclusion by the xpdf developers, so they simply didn't
bother honouring the setting.

Rogan

> -----Original Message-----
> From: Sumit Dhar [mailto:dhar () dexponet com]
> Sent: 16 May 2002 08:36
> To: Kurt Seifried
> Cc: bad bob; vuln-dev
> Subject: Re: PDF modifications?
>
>
> > PDF encryption is a joke, xpdf/etc will bypass it most 
> trivially. Adobe
> > makes some tools to modify PDF's and then there's also 
> emacs or your text
> > editor of choice.
>
> I am not sure we are on the same page here.. but are you 
> telling me that
> a document that is password protected (for printing/text 
> extraction etc)
> is not really that secure. Or are you talking about some 
> other encryption.
>
> I had performed an intensive search on google to locate ways of
> bypassing that protection, and found.. well nothing.
>
> But if we are on the same page, which tools can I use to read password
> protected documents. I wasn't able to use xpdf to do the same.
>
> Regards,
> Dhar