shameless self-promoting website
»Rejourn root
»LibreOffice Community Blogs

LibreOffice’s user interface prohibited creating multiple signatures by the same author on a document, because there was no semantic meaning of signing the same document multiple times. I’ve recently extended the user interface to be able to provide a signature description: this way it makes sense to allow multiple signatures from the same author, because now each signature can have a different meaning. First, thanks to the Dutch Ministry of Defense who made this work possible.

When the user selects File → Digital Signatures, the dialog lists existing signatures together with their description (if they have any):

When the user clicks on the Sign Document button, the dialog for certificate selection now also asks for an optional description:

Changing the value of the description invalidates the signature. For this feature to work, I have extended LibreOffice’s ODF signature markup to store not only a <dc:date> element as signature metadata, but also the <dc:description>. Given that the metadata of an ODF signature is not part of the ODF specification, it is allowed to extend the metadata with custom child elements, so it was not necessary to submit an ODF enhancement proposal for this file format change at this stage. As usual the commits are in master, so you can try this right now with a 5.2 daily build. :-)