StampingProperties sp = new StampingProperties() Using (var reader = new PdfReader(input)) Using (MemoryStream input = new MemoryStream(pdfToSign)) Unsigned Pdf document on which the first signature becomes invalid:Ĭode used for signing //Step #1 > prepare pdf for signing (Allocate space for the signature and calculate hash) Question: What can i do in order to keep both signatures valid in the Acrobat Reader? I've found a similar issue on stackoverflow ( multiple signatures invalidate first signature in iTextSharp pdf signing), but it was using iText 5 and i'm not sure it is the same problem. The signatures of the same document are shown as valid in foxit reader. If the pdf was created by combining multiple pdf documents with adobe DC, the first signature is valid but becomes invalid as soon as the seconds signature is applied.ĭocument in Adobe reader after the first signature is applied:ĭocument in Adobe reader after the second signature is applied: created via word, i can apply multiple signatures and all signatures are shown as valid in the adobe acrobat reader. SignDeferred is required since the signature is created PKCS11 hardware token (usb key). Validation is quick process, right? Otherwise it could be started on the background.I'm using iText 7.1.15 and SignDeferred to apply signatures to pdf documents. Ideally the verification should happen automatically once the user clicks on "Manage digital signatures" side tab. " and then click on "Validate Signature" menu item, or search "Validate" button on the toolbar. Now as user I am confused, because I need somehow to guess that I either need to call context menu on node "Certified by. The expanded view has an entry "Signature was not yet verified".", the node is expanded and FoxitReader jumps to the end of the document.Īt this step I see an issue, because as given document does not contain any visible part of the signature, there is no need to jump anywhere. When I doubleclick on the node "Certified by.
Here is the example of PDF document which is only digitally signed. You document contains the visible signature, which in fact is optional in PDF document. When PDF document was signed and afterwards was modified,you also just double click on the signature to validate it.OK, now I see the point of confusion.
0 kommentar(er)
