Convert dangerous PDF files to clean PDF files

[bofrese]

The detection of wether PDF files are dangerous or not may get too many false positives, as it simply detects if the PDF has an openaction.

It should be possible to convert a PDF to a clean PDF via pdf2ps and back...
pdf2ps input.pdf - | ps2pdf - output.pdf

we of course only need to do this if the PDF has been detected as dangerous.

I got the idea on how to clean PDF's from here: https://security.stackexchange.com/questions/171716/how-to-know-if-a-pdf-file-is-infected

I currently do not have the time to do this myself, so I leave the note here in the hope that somebody else will have the time :-)

[Rafiot]

So I tries things similar to that, but it comes with a bunch of issues:

• it simply fails a lot on a lot of legitimate PDFs
• it makes it impossible to copy text out of the PDFs, which is often a requirement

In theory, turning a PDF into PDF/A should/could remove active contents from the file, making it saner. The problem is that pdf to pdf/a converters are not exactly working either (or they weren't last time I checked at least).