Actually FOUR fields were modified between the revisions (according to Acrobat 9's modification list).
And under what criteria do you consider it "spoiled"? Under many workflows, it is perfectly valid, since the second signature "resigned" the original plus the changes. However, if you wish to determine what has changed between revisions you need to look at the LOW LEVEL OBJECTS in the PDF file to see what objects exist in the update table and whether they are significant to you or not. Leonard -----Original Message----- From: Emilio Oca [mailto:[email protected]] Sent: Thursday, July 23, 2009 12:18 PM To: Post all your questions about iText here Subject: Re: [iText-questions] How to check differences between signed revisions Hi, Attached is a pdf with two signatures. One of the fields had it's contents modified between the first and the second signing How can I get to know and reject this as a spoiled document? Shall I get each revision and check every signed field? Can you enlighten me how? Best. Emilio On Wed, Jul 22, 2009 at 3:43 PM, Emilio Oca<[email protected]> wrote: > Yes, I meant that each signature covers the hole present document at > the signing moment. > To check that I use: > > PdfReader reader = new PdfReader( acroFiledsf.extractRevision( > revision ) ); > boolean covers = > reader.getAcroFields().signatureCoversWholeDocument( revision ); > reader.close(); > > where revision is each signature associated revision. > > Sorry for asking, but shall I sent the document here? > > Best. > > Emilio > > On Wed, Jul 22, 2009 at 3:25 PM, Leonard Rosenthol<[email protected]> wrote: >> Sure you can. >> >> The first signature covers the original document while the second covers the >> original PLUS the additions. Assuming no other changes other than signing, >> both should be valid. >> >> If the first signature is a certifying signature, then you could potentially >> have other operations as well between signatures and they could both still >> be valid. >> >> Leonard >> >> -----Original Message----- >> From: Paulo Soares [mailto:[email protected]] >> Sent: Wednesday, July 22, 2009 2:06 PM >> To: Post all your questions about iText here >> Subject: Re: [iText-questions] How to check differences between >> signed revisions >> >> You can't have two valid signatures covering the whole document. Show >> us the PDF. >> >> Paulo >> >> ----- Original Message ----- >> From: "Emilio Oca" <[email protected]> >> To: <[email protected]> >> Sent: Wednesday, July 22, 2009 6:41 PM >> Subject: [iText-questions] How to check differences between signed >> revisions >> >> >> Could someone explain me (or point me where to find) how to check if >> differents signatures on a document where made over differents >> contents? >> I am trying to check if a document containing acrofields signed for >> first time where later modified when signed again. >> Both signatures seems to be valid and cover the hole document. >> >> Best >> >> Emilio >> >> >> --------------------------------------------------------------------- >> --------- _______________________________________________ >> iText-questions mailing list >> [email protected] >> 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/ >> >> --------------------------------------------------------------------- >> --------- _______________________________________________ >> iText-questions mailing list >> [email protected] >> 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/ >> > ------------------------------------------------------------------------------ _______________________________________________ iText-questions mailing list [email protected] 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/
