I have a question regarding the features I’m looking for. We have two scenarios:
1) Checking for existing digital signatures:
A PDF document is uploaded to our solution (it’s a server side solution)
We then have to check if it has a digital signature or not
If it has a digital signature, we have to validate the signature and extract basic info (name etc.) regarding the person who own the signature
2) Adding signatures to a new PDF document:
The user select a PDF file for signing
The users existing X509-based certificate is used (the user is queried for a password to use the signature)
The document is signed