3 Replies Latest reply on Sep 17, 2009 12:12 PM by Steven.Madwin

    SubmitForm and Signature Field


      Have a number of PDFs that is using a Topaz signature pad to capture and embed a signature image and certificate into the PDF signature field using the gemsignplus plugin. The PDFs are submitted back to a URL, where the form data is exacted and stored in a database. The intent is to be able to reconstruct the signed PDF at any time. No problem with capturing the data fields. There is no data associated with the signature field. Does anyone know of away to obtaining the signature image and the certificate from the form for storage?


        • 1. Re: SubmitForm and Signature Field
          Steven.Madwin Adobe Employee

          Hi Chuck,


          I can't say for sure because I don't have the 3rd party signature handler (gemsignplus) available to see how they are building the signature object, but I'll take my best guess. When the signature is created and added to the PDF file they are probably imbedding the display contents (the captured signature appearance from the Topaz pad) into the signature object. It's not a data object like the text that is is typed into the text form fields, and thus it cannot be extracted.



          • 2. Re: SubmitForm and Signature Field
            chucklight Level 1

            Thank you for the answer. I am in contact with Topaz, but have not heard back from them. Are you saying the signature object is not accessible as part of the submitForm javascript functionality, even with a different plugin? Are there are different plugins available for signature pad capture?



            • 3. Re: SubmitForm and Signature Field
              Steven.Madwin Adobe Employee

              This gets a bit confusing, because the signature displayed on the page is not really the signature, it's just a pictorial representation. This is provided we're talking about certificate based signing where the actual signature is a cryptographic operation. I've seen some third party signature handlers that only use the captured signature from the signing pad (aka the wet ink signature) and others that also using certificate based signing to provide a check for document integrity.


              If they are using certificate based signing, and they are constructing the signature object in accordance with the PDF Specification, then you could use JavaScript in Acrobat to extract the signature info. However, nobody says that a 3rd party signature handler has to follow the PDF specification, they just need to be able to read and interpet what they want. They only need to follow the specification if they want to make the signature understandable by signature handlers other than their own.


              Still, I think your original question was how do you extract the signature apperance, and that depends on how it's written into the PDF.