xyz babe, xyzbabe wrote > I would like to figure out if there is a way to detect with iText whether > or not a document is reader enabled (extended features enabled) and more > importantly if the document has not been modified after that.
Being reader for a PDF depends on two factors: 1) does it have a valid usage rights digital signature (by Adobe) and 2) are later changes appended to it accepted by Adobe Reader as allowed changes. Before starting you should really study the basics of usage rights signatures in the PDF specification (http://www.adobe.com/content/dam/Adobe/en/devnet/acrobat/pdfs/PDF32000_2008.pdf section 12.8, especially subsection 12.8.2.3). Concerning 1): As iText handles normal integrated digital signatures quite proficiently, it brings along code which you can use for this test without too many changes. Some changes will be necessary, though, usage rights are special in certain ways, see the spec. Concerning 2): This might be the harder part as in case such appended changes exist, you must analyze them and determine whether Adobe Reader would allow them or not. I'm not aware of them being documented anywhere in detail, I only know the abstract definitions as listed in table 255 of the spec. Thus, while the feature surely can be implemented, it is quite something to do. And as new Adobe Reader version may allow other changes, you'll have a neverending task at your hands. Regards, Michael -- View this message in context: http://itext-general.2136553.n4.nabble.com/Way-to-detect-if-document-is-reader-enabled-and-still-valid-tp4656930p4656932.html Sent from the iText - General mailing list archive at Nabble.com. ------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_d2d_nov _______________________________________________ iText-questions mailing list iText-questions@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/itext-questions iText(R) is a registered trademark of 1T3XT BVBA. Many questions posted to this list can (and will) be answered with a reference to the iText book: http://www.itextpdf.com/book/ Please check the keywords list before you ask for examples: http://itextpdf.com/themes/keywords.php
