: Assessing Language Models on Unsolved Questions

o3

Technology - 1 questions solved

How to calculate the checksum in an XFA form

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 SHA-1 digest, but it's unclear as to what is actually fed to the hash. Does anyone have any idea as to how this is generated? This value is ...

Technology

stackoverflow

Verified

Answered on 8/1/2025

Model Answer:

Adobe adds the checksum merely to be able to find out later whether a particular XFA packet has been changed.
It is not a security feature – it is only a “did-anything-inside-this-packet change?” flag – and therefore it is not described in the public XFA specification.

Which algorithm is used?
• It is SHA-1.
The 20-byte digest is written as 40 lower-case hexadecimal digits.
What is hashed?

• Exactly the byte sequence that is located between the start t...

Click to view full answer →

View on stackoverflow

View Full Answer Compare Models