For reasons easy to imagine I have had a look at the greenpass QR-code and managed to reasonably decode the thing using common tools and a few Python modules. I figured it should be easy enough to roll that into a Python script.
Then I did a quick web search and found that someone (turns out a student and Linux user from Innsbruck) had already done that.
The reasoning given for the encoding seems weak to me though, seems very much written after the fact.
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