When you save an XFA form (XFA = XML Forms Architecture) using Adobe software, a checksum attribute is added to the form element. This checksum appears to be a summary of SHA-1, but it is unclear what is actually supplied to the hash. Does anyone know how this happens? This value is needed by Adobe Acrobat to verify that it is actually in the form of XML data, but when I create an XML hash that feeds into the form, Adobe Acrobat does not accept it. This checksum attribute is not described in the XFA specification, so I would really appreciate it if someone could:
- Confirm that it is indeed a hash created using the SHA-1 hash algorithm?
- Explain what data should be used to create this hash.
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