Elias, Elias_iText wrote > Is some like that?
That indeed looks like code with which you extract signature objects from the signature dictionary. Now you have to dig into this signature object to retrieve the hash bytes. Elias_iText wrote > I have a PDF document, with 2 or 3 signatures. I wish externally store the > hash of each signature for future third part validation, if applicable. What third party tools do you have in your mind? What can they do and what not? As you want to extract the hashes for them, they seem to be PDF-agnostic (otherwise they could easily extract those hashes themselves). But what can such a third-party tool do with but a hash value? For checking the hash it would have to know the byte ranges in the PDF the hash was calculated for, but how could a PDF-agnostic tool know those ranges. Or should those third party tools check certificates etc? In that case you would not need the naked hash values but instead at least the signature containers (in case of CMS/CAdES style signatures) or many of the signature dictionary entries (in case of naked PKCS#1 style signatures). If long term validation information also should be taken into account, that information also has to be extracted. If also document or field MDP should be verified, you hardly can use PDF-agnostic tools. So, what do you want to do? Regards, Michael -- View this message in context: http://itext-general.2136553.n4.nabble.com/How-to-get-the-HASH-from-a-signature-tp4655996p4656001.html Sent from the iText - General mailing list archive at Nabble.com. ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ iText-questions mailing list [email protected] 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
