This is a pretty simple to use component:
After importing the dependencies just use the 'GetPdfDigitalSignatures' action and assign the PDF you want to check for signatures in the 'Pdf' input parameter:
The time it takes depends on the number of signatures and the size of the PDF file.
After the document is processed we parse the certificate for readability:
A more complete (but less readable) method called 'GetAllSignatureElements' is available where you can see each of the certificate properties with each key value pair: