No, the only way to compare the revision is to look at each object in a given revision and determine what it is, why it changed, and if you care. Not trivial, but well defined.
Leonard -----Original Message----- From: Emilio Oca [mailto:[email protected]] Sent: Friday, July 24, 2009 11:10 AM To: Post all your questions about iText here Subject: Re: [iText-questions] How to check differences between signed revisions > Oh, you only care about the field values? You don't care about any other > potential changes to the document?? Yes, by now. But I'm looking into check the hole document. Can I compare a hole revision without fiddling with low level objects? > Also, please note that you are have (in this case) an XFA-based form, which > means you may want to use the native XFA information for change detection > INSTEAD OF the "AcroForm mirror"... Yes I feel I dont know enough on XFA-based forms I will look some documentoation on it. Thanks Emilio > > Leonard > > > On 7/23/09 3:06 PM, "Emilio Oca" <[email protected]> wrote: > > Leonard, > > But I actually changed just one of them. Seems to be that the other > tree count as modified too. > Of course is valid, signatures are still valid. But in my workflow I > need to know if all signatures are over the same values. > > So, I was facing to look at each significant field in every revision > and check they value the same. I think I am able to do that. Unless I > am doing this wrong and there is a better way you can suggest me. > > Thanks you very much. > > Emilio > > On Thu, Jul 23, 2009 at 3:38 PM, Leonard Rosenthol<[email protected]> > wrote: >> 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/ >> > > ------------------------------------------------------------------------------ > _______________________________________________ > 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/ ------------------------------------------------------------------------------ _______________________________________________ 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/
