pdfresurrect

PDFResurrect is a tool aimed at analyzing PDF documents. The PDF format allows for previous document changes to be retained in a more recent version of the document, thereby creating a running history of changes for the document. This tool attempts to modify the PDF so that a reading utility will be presented with the previous versions of the PDF. The modified "versions" will be generated as new PDF files leaving the original PDF unmodified.

Usage: pdfresurrect <file.pdf> [-i] [-w] [-q]
-i   Display PDF creator information (DocInfo dictionary)
-w   Write the PDF versions and summary to disk
-q   Display only the number of versions contained in the PDF

And if built with #define PDFRESURRECT_EXPERIMENTAL:

-s Scrub the previous history data from the specified PDF

Key changes in fork https://github.com/petervwyatt/pdfresurrect

Support for Windows builds (x64 and x86) using Microsoft VisualStudio 2022 (common C code)
Bug fixes to ensure PDFs are always treated as binary files
Bug fixes to avoid crashes (i.e. fix codified assumptions about validity of some PDF structures)
Code cleanup for more modern C compilers that whinge more
Switch to MarkDown for this README
Some code polishing

Notes

If built with #define PDFRESURRECT_EXPERIMENTAL, the scrubbing feature (-s) should not be trusted for any serious security uses. After using this experimental feature, please verify that it in fact zero'd all of the objects that were of concern (those objects that were to be zero'd). Currently this feature will likely not render a working pdf.

This tool relies on the application reading the pdfresurrect extracted versions to treat the last xref table as the most recent in the document. This should typically be the case.

The verbose output, which tries to deduce the PDF object type (e.g. stream, page), is not always accurate, and the object counts might not be 100% accurate. However, this should not prevent the extraction of the versions. This output is merely to provide a hint for the user as to what might be different between the documents.

Object counts might appear off in linearized PDF documents. That is not truly the case, the reason for this is that each version of the PDF consists of the objects that compose the linear portion of the PDF plus all of the objects that compose the version in question. Suppose there is a linearized PDF with 59 objects in its linear portion, and suppose the PDF has a second version that consists of 21 objects. The total number of objects in "version 2" would be 59 + 21 or 80 objects.

Building

Linux

From the top-level directory of pdfresurrect run:

./configure
make

To install/uninstall the resulting binary to a specific path the --prefix= flag can be used:

./configure --prefix=/my/desired/path/

Debugging mode can be enabled when configuring by using the following option:

./configure --enable-debug

The resulting binary can be placed anywhere, however it can also be installed/uninstalled to the configured path automatically. If no path was specified at configure time, the default is /usr/local/bin. To install/uninstall:

make install

make uninstall

Windows

Either compile from within the Microsoft VisualStudio 2022 IDE or use a Developer command prompt:

devenv pdfresurrect.sln /build "Debug|x64"
devenv pdfresurrect.sln /build "Debug|x86"

Build configurations are Debug|x64, Release|x64, Debug|x86 and Release|x86.

Thanks

The rest of the 757/757Labs crew.
GNU (https://www.gnu.org).
All of the contributors: See AUTHORS file.

Contact / Project URL

mattdavis9@gmail.com

https://github.com/enferex/pdfresurrect