Assuming you mean "reader-enabled", remember that IT uses digital signature technology. So that you don't want ot remove that signature!
Also, if you make changes to the PDF that are not allowed by the "reader-enabling" signature, then you will end up with a file that requires re-enabling. There is no magic bullet here - you're going to need to understand PDF signatures and permissions to be able to figure out how to "un-sign" without breaking RE, if it's even possible on the documents in question. Leonard From: Wasiq Ashfaq [mailto:[email protected]] Sent: Wednesday, April 28, 2010 6:29 PM To: Post all your questions about iText here Subject: Re: [iText-questions] Clear signature from a Signed field We had previously done the un-signing part using PDFNet library. But once the documents were un-signed it required the PDF form to be re-enabled through the designer. So basically we are looking for a workaround where we can clear the signatures (that we have already done through PDFNet) but in a way that does not render the PDF file unusable without re-enabling it. On Wed, Apr 28, 2010 at 9:16 PM, mkl <[email protected]<mailto:[email protected]>> wrote: Wasiq Ashfaq, Wasiq Ashfaq wrote: > We are automating handling of some our PDF documents based on various > workflows. In certain cases we have to clear the signature from PDF files > and reject the documents so that they can start over from the starting > state. Is there a way to clear signatures from signed fields in a way that > they can be signed again using Acrobat Reader? Thanks. As signing a document essentially means putting a value into a signature field (i.e. setting its V value) and maybe creating some appearances, this can be quite easily undone by removing that V value and resetting the appearances to something neutral. Depending on the exact nature of your workflow and the documents, though, there might be some problems, though. E.g. if you have a document with multiple signatures and only want to clear the newest one, I'm not sure what happens if you do as explained above. Officially (in Adobe products), signing an empty signature field of an already signed document is an allowed operation for a number of certification levels, but "unsigning" as explained above may invalidate remaining signatures as that is not part of the enumeration of allowed changes. In that case you may revert to the revision before the signed revision (essentially cutting the document file at the correct position). This, though, not only removes the signature but also all other changes in that revision. So, the concise answer depends on the nature of the documents you have and the extend the 'unsigning' may and must have. Regards, Michael. -- View this message in context: http://old.nabble.com/Clear-signature-from-a-Signed-field-tp28390524p28390790.html Sent from the iText - General mailing list archive at Nabble.com. ------------------------------------------------------------------------------ _______________________________________________ iText-questions mailing list [email protected]<mailto:[email protected]> https://lists.sourceforge.net/lists/listinfo/itext-questions Buy the iText book: http://www.itextpdf.com/book/ Check the site with examples before you ask questions: http://www.1t3xt.info/examples/ You can also search the keywords list: http://1t3xt.info/tutorials/keywords/
------------------------------------------------------------------------------
_______________________________________________ iText-questions mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/itext-questions Buy the iText book: http://www.itextpdf.com/book/ Check the site with examples before you ask questions: http://www.1t3xt.info/examples/ You can also search the keywords list: http://1t3xt.info/tutorials/keywords/
