twain, twain wrote: > But what do you mean with "document appear different"? If I remove an > excluded(from hash computation) pdf dictionary entry the document doesn' > appear more different than if I remove an unsigned attr. > > Pdf dictionary entry doesn't change the "appearance" of a pdf(intended as > visual appearance). If adobe reader allowed other exclusions, the two > techniques would be equivalent.
The actual exclusion of regions from the signed byte range happens based on offsets and lengths of file segments, a mechanism completely unaware of the contents of the non-included file segments. But even something as innocent as a signature dictionary entry might contain something that can be read as an individual PDF object and (if an xref entry points into that entry) give rise to a changed document appearance. Somewhat dirty, but possible. Regards, Michael -- View this message in context: http://itext-general.2136553.n4.nabble.com/Problem-with-preClose-function-and-exclusion-hashmap-tp3903958p3904288.html Sent from the iText - General mailing list archive at Nabble.com. ------------------------------------------------------------------------------ All the data continuously generated in your IT infrastructure contains a definitive record of customers, application performance, security threats, fraudulent activity and more. Splunk takes this data and makes sense of it. Business sense. IT sense. Common sense. http://p.sf.net/sfu/splunk-d2d-oct _______________________________________________ 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
