I need to append a pdf file to a digital signed pdf file, keeping valid the signature ...maybe using revision? ...using iTextSharp? How can I do it?
Please help me with some sample.
+2
A:
You can't as that invalidates the whole point of digital signatures, namely to detect when something exactly as you describe occurs and therefore ensure the validity of the original document. To do as you want, you will need to add the extra PDF to the unsigned original PDF and then resign the new conglomerate PDF.
workmad3
2009-10-23 09:14:29
...but is there a way to keep revision insiede pdf?so i will have rev 1 with valid signature...add pdf...rev 2 with invalid signature...I resign...rev 3 with valid signature
Andrea
2009-10-23 09:37:52
No, there is not. Signed PDF documents are tamper proof. Only the original signer can modify the document and resign.
Trumpi
2010-07-27 12:10:28