pdfbox-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Tilman Hausherr <THaush...@t-online.de>
Subject Re: Detect modifications between signatures
Date Wed, 02 Nov 2016 19:10:23 GMT
Am 29.10.2016 um 18:47 schrieb Jonathan Barbero:
> Hi,
>
>   How could I detect any modification between two signatures (visibles or
> not) ?
>
> For example:
>
>   An application signs a PDF with PDFbox. A user downloads it, and should
> sign it (visible signature). I would like to check that the user didn't add
> any modification after the app signature (except it's own user signature).
>
> How could I check it? I guess it's different between a visible signature
> and not visible.

I assume that what you want is to have something similar to Adobe 
Reader, which can detect whether users did more than just add a 
signature, and then tells "page X was changed".

I can't think of a way to do this out of the box. Maybe compare the COS 
tree of both PDF structures.

Tilman

---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscribe@pdfbox.apache.org
For additional commands, e-mail: users-help@pdfbox.apache.org


Mime
View raw message