Each time a signature is applied new ids are created. Signing the same PDF twice will never have the same hash.
Paulo ----- Original Message ----- From: "Martin Paljak" <[EMAIL PROTECTED]> To: <iText-questions@lists.sourceforge.net> Sent: Tuesday, August 28, 2007 1:26 PM Subject: [iText-questions] Embedding external signatures inside PDF files > Hello! > > I'd like to know if the following is possible: > 1. User has a PDF file which he/she signs with some external > application. The hash of the original PDF file can not change for the > signature be valid, of course. > 2. The external signature format is embedded inside the PDF as a > custom signature object (doable with itext). > 3. The signature object is extracted&removed from the file done in > step 2. and the PDF file looks the same as in step 1 (meaning that > the SHA1 sum of the PDF file from which the signature object is > removed is the same as for the original file) > > I have successfully implemented the embedding of the external data in > step 2 and extraction of the external data in step 3 but I don't know > if/how it is possible to get the PDF file back to virgin state. > > Is it possible at all? What kind of strategy should I choose to > implement this scenario ? > > Thanks, > -- > Martin Paljak > http://martin.paljak.pri.ee ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ iText-questions mailing list iText-questions@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/itext-questions Buy the iText book: http://itext.ugent.be/itext-in-action/
