Ghostscript prints question mark when converting digitally signed PDF to image

Ghostscript 9.0 doesn't support validation of the digital signatures in PDF document whe开发者_如何学JAVAn doing PDF to image conversion. Instead, there's a question mark on the digital signature, and Ghostscript reports "Sig is not yet implemented". I'm thinking to modify the source code to get rid of the question mark, but I don't have any ideas to where I should modify in thesource code. Could any one give the hints for that? Any response will be appreciated highly, thanks.

Have you already tested the very latest release (which is v9.02)? If so, have you also tested the current 'HEAD' revision of their source code?

If your problem persists with these versions, the preparatory thing to start with is to download the (current, which is v9.02) Ghostscript source code from here or even check it out from their Git repository.

What you are trying to do can only be located in one of the following two modules of the Ghostscript source code:

• the (PDF) interpreter
• the (image) output devices

So I would first recursively grep the sources for "not yet implemented" or similar expressions, taking into account that there may even be line breaks within the string. (***I doubt the quote you gave in your initial version of the question is accurate, because it contained at least one typo.)

If I didn't find anything in the first step, I'd get into touch with the Ghostscript developers themselves. They usually hang around in IRC on Freenode, channel #ghostscript. In general they are a very friendly and helpful bunch, and they'll surely be able to give you some hints about how to solve your problem if you know how to ask...