Petras, Petras wrote > Our national PDF-based electronic document specification defines metadata > which may be included into signature dictionary.
Can you share (a link to) that specification, so we are sure what we are talking about? Given that there is an English version of that document, that is... The national specification probably overrides certain parts of ISO 32000-1. This would not be a wise thing to do (interoperability-wise) but would not be unheard of either... In the following text I answer in a way favoring ISO 32000-1 conformance. > ISO 32000-1 section "14.3.2 Metadata Streams" states, that "Metadata, both > for an entire document and for components within a document, may be stored > in PDF streams called metadata streams". Therefore as a component, > signature dictionary may contain metadata entry. > Section "7.3.8 Stream Objects" states, that "All streams shall be indirect > objects", but this requirement clashes with the requirement for signature > dictionary entries in "12.8 Digital Signatures", which states: "When a > byte range digest is present, all values in the signature dictionary shall > be direct objects." So you have essentially found all the relevant information yourself: The signature dictionary itself is not allowed to reference indirect objects. In particular, therefore, it is not allowed to reference metadata streams. Thus, > Does that mean that metadata stream may not be included in signature > dictionary? Indeed, no metadata stream can immediately be attached to a signature dictionary with a byte range digest (i.e. any interoperable signature dictionary) in a completely ISO 32000-1 conform way. But the specification in section 14.3.2 also says "When there is ambiguity about exactly which stream or dictionary may bear the Metadata entry, the metadata shall be attached as close as possible to the object that actually stores the data resource described." As close as possible in the case at hand may be the signature field dictionary the signature dictionary is the value of. Regards, Michael PS: You had better ask on stackoverflow tagging your question with pdf and digital-signature tags; this mailing list is pretty inactive... -- View this message in context: http://itext.2136553.n4.nabble.com/Metadata-in-signature-dictionary-tp4661089p4661091.html Sent from the iText mailing list archive at Nabble.com. ------------------------------------------------------------------------------ What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic patterns at an interface-level. Reveals which users, apps, and protocols are consuming the most bandwidth. Provides multi-vendor support for NetFlow, J-Flow, sFlow and other flows. Make informed decisions using capacity planning reports. http://sdm.link/zohodev2dev _______________________________________________ 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
