Ubuntu
evince package

  1. Bug #1085526
  2. Comment #111

Comment 111 for bug 1085526

Revision history for this message
In , Markus Kilås (markuskilas) wrote :

(In reply to Markus Wernig from comment #104)
> I think the correct statement to issue in this case would be that a part
> ("revision") of the PDF has been signed and to show the validation result
> for that revision, ideally giving the user a chance to view only the signed
> part.
>
> This might even be indispensable when there are multiple signatures applied
> to the document.

So one idea could be to also use the first offset when checking the signature and in case it is not zero instead of return the status as SIGNATURE_VALID say something like "SIGNATURE_PARTLY_VALID".

The pdfsig tool already implements support for multiple signatures/"revisions" but it seems the API does not expose the ByteRange for which the signature covers nor provides an other way to obtain that revision of the document (?).