InfoPath Dev

Is there anyway to block a user from signing a form if they don't have a signature or pin on file?  Seems the Signature template part allows users without a signature or pin to sign a document.

It also seems you can kind of spoof a signature as well.  If someone isn't setup in the system with a pin or signature you can change the user name to a valid sharepoint user and it will mark it as signed by that user and is just missing the picture signature.

How about querying the current user's username - via the SharePoint UserProfileService web service perhaps? So when the form opens, you'll get the user's login and then you'd populate the Signature template part's username field. The username textbox should be disabled to disallow edits (or use a calculated value). So then the user will just enter his pin to retrieve the signature image.

I think you need to make sure that either the Title or the Description field in the image library matches the user's actual SharePoint username.

Hope that makes sense...

And then add a validation check - if the username is not returned (i.e. blank) which would mean there isn't any signature on file for that user, display a message or something.

I was able to set the "Read-only" on the field no problem so that resolves that issue.

Looks like the current "User Name" field just pulls the current logged in username.  I just need to figure out how to do a validation check with the Signature Admin list and if their name isn't there make it blank or popup a message saying no signature on file.  The problem is I'm fairly new to InfoPath design and was hoping this was an out of the box solution which appears not to be.  For something that deals with Electronic signatures you would think it would be fairly secure and this is not.  There are not enough checks and balances and seem to require a lot of changes to make it legally useable. 

Are you able to access the SharePoint logs and find the correlation id in the error message? There may be more info there. Did you customize the form much? What if you start with a new list and try to customize the form in IP and publish without really making any form changes - do you have the same issue?