Andreas, Elias, Andreas Kuehne-3 wrote > I don't expect any p7s-Viewer to be able to 'verify' an arbitrary hash.
(Actually I had to google around for p7s-viewer as I have never heard that name; if I understood it correctly, it merely describes programs which extract the embedded content of PKCS#7 containers, display them, and probably check the signatures if applicable.) Right, extracting the hashes would do no good here. Extracting the whole signature containers, on the other hand, would allow p7s-viewers to check the signature itself (but obviously not whether the signed PDF file byte ranges were manipulated!); depending on the legal context, the date in the /M signature dictionary entry should also be extracted. Elias_iText wrote > I have a new legal process to follow where the signed PDF document CAN BE > converted to other file standard, like .P7S type. Legal processes demanding generic convertibility of electronically signed material seem a bit weird; signing, after all, is about guaranteeing that the signed data did NOT change, and conversion is a fundamental change. Thus, I think there are additional regulations on the details of these processes. I would surmise that actually after conversion the converter is required to add extra (signed) information to the document indicating a) that it converted a source document without changing the legal content, b) that the original had been signed, and c) which were the original signature. Elias, is this assumption roughly correct? In that case there may be solutions... Elias_iText wrote > PS. About the byte ranges, I get it Elias, here your text stopped. Is there anything missing? Regards, Michael -- View this message in context: http://itext-general.2136553.n4.nabble.com/How-to-get-the-HASH-from-a-signature-tp4655996p4656014.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
