There are many digital signature products on the market but they appear
to be overkill for a project I have due very soon. The project requires
that a digital signature be applied to an authorization of an e-form
(Request by a non commissioned officer) by his superior or superiors.

By "digital signature", the requirements are:

1) that a physical "mark" appear and
2) that the digital signature protects the document from tampering
(invalidates it if tampered with will do)

When the Request is printed, that mark should also appear.

Adobe PDF would be useable but it does require that a digital signature
be applied manually. This is problematic for the User base, an automated
solution must be sought.

I am wondering if the best approach would be to find an existing, open
source, with code and write the automating functions ourselves.

Comments are appreciated.
--
"You can't trust code that you did not totally create yourself"
Ken Thompson "Reflections on Trusting Trust"
http://www.acm.org/classics/sep95/