When talking about certified PDFs Adobe is pretty near to the PDF standard here. PS: I always stressed in the eyes of Adobe software in this post. You find details on the signing process in the whitepaper Digital Signatures for PDF documents C# samples equivalent to the Java samples in that white paper can be found here on sourceforge. ![]() Then you add your signature as usual, either creating a new signature field or using an empty one. The iText in Action - 2nd Edition sample TimetableAnnotations3.java / TimetableAnnotations3.cs illustrates how to add annotations with PdfStampers. Using this PdfStamper you add your image on the document pages by means of annotations. you must work in append mode to not invalidate the initial signature). Where the final bool parameter value must be true (i.e. If these requirements are fulfilled, you can use a PdfStamper you retrieve from the static PdfStamper method public static PdfStamper CreateSignature(PdfReader reader, Stream os, char pdfVersion, string tempFile, bool append) (Furthermore I assume the PDF neither is encrypted nor does contain dynamic XFA forms that would complicate things even more.) If that signed pdf already contains multiple signatures, neither of them by means of Locking information shall have added any additional restrictions. ![]() the initial signature is a certification signature with those types of changes allowed) and have an empty signature field for you to put your signature into. Or be Certified with annotations, form fill-in, and digital signatures, allowed (i.e. the initial signature is merely an approval signature) Thus, to take a signed pdf and stamp an image on all pages and also add another signature and not invalidate (in the eyes of Adobe software) the initial signature in the process, that signed pdf mustĮither be uncertified (i.e. Have a look at this answer for information on "Allowed and disallowed changes" as considered by Adobe since version 9 of its Acrobat & Reader. ![]() In that case you first of all must be aware that the allowed and disallowed changes depend on the first signature itself. When you require that the first signature on the document must be valid when open the file, I assume you foremost talk about opening in a current Adobe Reader version.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |