This question has been asked before, but I cannot find an answer anywhere.
For XFA forms, adobe reader adds a checksum in the <form> tag when saving. I'm trying to automatically fill an xfa form, and I need to calculate that checksum. Is there any documentation about how to perform that calculation?
Oh I see. I am not sure that PDFBox can write XFA data. This checksum must be created by the manipulating software and uses certain parts of the XFA section. I cannot tell you which ones and how you would calculate that. I collected a number of links that might help you:
Yes, I checked those sites but there's no useful info :(. I can write xfa data with pdfbox, I'm actually using it because iText didn't work well for some forms. I can manually write the xfa data and it works perfectly, but the algorithm for calculating the checksum for the <form> tag doesn't seem to be documented, There's even a stackoverflow question about this subject from iText's creator, but no reply: https://stackoverflow.com/questions/27470442/how-to-calculate-the-checksum-in-an-xfa-form
Oh, and just to clarify, this is the tag I'm referring to:
<form xmlns="http://www.xfa.org/schema/xfa-form/2.8/" checksum="vFVrmhPyTqaed06K/Kz2KSlTWbQ=">