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]
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/

Reply via email to