Vulnerability Development mailing list archives
RE: PDF modifications?
From: Javier Otero <jotero () smartekh com>
Date: Thu, 16 May 2002 16:07:16 -0500
If you look in astalavista.box.sk you can find a pdf decrypter program Javier Otero Grupo Smartekh Antivirus Expertos Business Continuity Inftegrity Investigación y Desarrollo 5243-4782/83/84 México, D.F. -----Mensaje original----- De: Mika Boström [mailto:bostik () lut fi] Enviado el: jueves, 16 de mayo de 2002 15:07 Para: vuln-dev () securityfocus com Asunto: 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.
If the PDF document is protected against printing/text extraction, it is nonetheless viewable. I have made a trivial patch for my own use, against the sources of xpdf 0.93 to bypass such restrictions. As long as the document and format allow viewing, it's practically impossible to deny the ability to fix the viewer client from exporting it to some other format. I won't go into details as to what exactly is required to modify in xpdf sources, but it's not a lot. I'm by no means what you would call a "good" programmer and it took me less than 10 minutes to find and patch the section of code that does the checking. On the other hand, if the entire document has been protected with password (even against viewing), then it's another story. I will let the experts speak on that subject. Take care. -- Mika Boström +358-40-525-7347 \-/ "The Hell is empty, Bostik () lut fi www.lut.fi/~bostik X and all the devils Security freak, and proud of it. /-\ are here." -W.S.
Current thread:
- RE: PDF modifications?, (continued)
- RE: PDF modifications? Elan Hasson (May 16)
- Re: PDF modifications? Kurt Seifried (May 15)
- Re: PDF modifications? Sumit Dhar (May 16)
- Re: PDF modifications? Mika Boström (May 16)
- Re: PDF modifications? Matthew Leeds (May 16)
- RE: PDF modifications? Elan Hasson (May 16)
- Re: PDF modifications? Sumit Dhar (May 16)
- Re: PDF modifications? Marukka (May 15)
- RE: PDF modifications? security (May 16)
- Re: PDF modifications? Bogdan Tomchuk (May 17)
- RE: PDF modifications? Tziortzis,George (May 16)
- RE: PDF modifications? Javier Otero (May 16)
- RE: PDF modifications? Dawes, Rogan (ZA - Johannesburg) (May 17)
- Re: PDF modifications? Valdis . Kletnieks (May 17)
- RE: PDF modifications? João Sobral (May 17)
- RE: PDF modifications? Matthew Leeds (May 17)
- Re: PDF modifications? Valdis . Kletnieks (May 17)