Here's a scenario. On SharePoint 2013 in a document library, a user uploads a PDF file with signable fields. Then a workflow kicks off to email another user to go in and review that PDF, and then add his/her digital signature if approved.
Is there a way for that workflow (or another one) to check if a digital signature has been added to the PDF file?
Extra: Is it also possible to check for multiple signatures and verify them specifically with specific fields. For example, there's two signature fields, and the workflow needs to tell which field was signed for two different if/else conditions.