Note the document I sent has also two chapters called 
        "Allowed actions for signed but uncertified documents".
        "Limitations on adding signature fields to signed but uncertified 
documents"

No, I don't know any new document, similar to this one, for newer versions 
of Adobe Reader.

Enric



From:   "Federico Kircheis" <federico.kirch...@openlimit.com>
To:     podofo-users@lists.sourceforge.net
Date:   31/08/2018 08:58
Subject:        Re: [Podofo-users] Signing document a second time



>From Adobe Reader version 9, Adobe added some restrictions to 
>signatures,
>other than merely cryptographic ones (I mean checking the signature CMS
>and the byterange). For instance, if you add a new blank page, the
>previous signature becomes invalid for Adobe Reader version 9 or later
>(Adobe Reader 8 said it was ok).

Thank you, this is a very important piece of information.

>Take a look at readercomp_digitalsignatures.pdf (I attach it since the
>link I had from adobe.com is broken).
>Maybe it can help.

I just gave a look, but my document is not certified just signed.

Is there any cli tools from the PoDoFo suite (or some other suite) that 
I can use to check my claims just to be sure?
It would also be useful in the case in future I need to work with 
another file with a similar issue.

Since it is signed, but uncertified, adding fields and signing should be 
fine.
I've also tried to manipulate the PDF file by removing the updated 
`INFO` object for example.
Of course the second signature got invalidated, but I simply overwrote 
it so that it would be valid again, but unfortunately the first was 
still invalid.

Of course it could be that in the meantime Adobe checks other properties 
too, do you know if there is an updated version of this document?

For the moment I was not even able to find the one you attached.

Federico

------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________
Podofo-users mailing list
Podofo-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/podofo-users


------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________
Podofo-users mailing list
Podofo-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/podofo-users

Reply via email to