Thank you for the reply Michael, it was very useful. So I think this is the point to me in the ISO32000 desc:
Table 254 – Entries in the DocMDP transform parameters dictionary " P number (Optional) The access permissions granted for this document. Valid values shall be: 1No changes to the document shall be permitted; any change to the document shall invalidate the signature. 2Permitted changes shall be filling in forms, instantiating page templates, and signing; other changes shall invalidate the signature. 3 Permitted changes shall be the same as for 2, as well as annotation creation, deletion, and modification; other changes shall invalidate the signature. Default value: 2. " *Originally I planned to implement full version history in only one pdf and certify the (any kind of) modifications with signatures. I will search a work around but please confirm that statement the previously panned implementation (*) is impossible with itext (or with pdf at all). The generation number is still not clear for me. You mentioned: "I'm afraid, iText does not itself generate objects with generation numbers greater than 1. Hardly any PDF tool does, by the way." I found these definitions about the generation number and the incremental update. Page 21. about indirect objects: "7.3.10Indirect Objects ... •... •A non-negative integer generation number. In a newly created file, all indirect objects shall have generation numbers of 0. Nonzero generation numbers may be introduced when the file is later updated; see sub-clauses 7.5.4, "Cross-Reference Table" and 7.5.6, "Incremental Updates. Together, the combination of an object number and a generation number shall uniquely identify an indirect object." Page 41. about gereration number: "Except for object number 0, all objects in the cross-reference table shall initially have generation numbers of 0. When an indirect object is deleted, its cross-reference entry shall be marked free and it shall be added to the linked list of free entries. The entry’s generation number shall be incremented by 1 to indicate the generation number to be used the next time an object with that object number is created. Thus, each time the entry is reused, it is given a new generation number. The maximum generation number is 65,535; when a cross-reference entry reaches this value, it shall never be reused." From you: "The generation number does not reflect the document revision the object belongs to. The revision an object belongs to only depends on its position in the file. " So what does it mean? Only the IText does not support the generation higher number than 1 or something else? What is the generation number is used for? Any help still appreciated, Bests, Tamas -- View this message in context: http://old.nabble.com/Append-existing-signed-PDF-with-content-in-such-way-signature-stays-valid.-%28generation-next%29-tp26132337p26157107.html Sent from the iText - General mailing list archive at Nabble.com. ------------------------------------------------------------------------------ Come build with us! The BlackBerry(R) Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9 - 12, 2009. Register now! http://p.sf.net/sfu/devconference _______________________________________________ iText-questions mailing list iText-questions@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/itext-questions Buy the iText book: http://www.1t3xt.com/docs/book.php Check the site with examples before you ask questions: http://www.1t3xt.info/examples/ You can also search the keywords list: http://1t3xt.info/tutorials/keywords/
