I am facing a very weird and edge-case problem.
I implemented the HS request verification v3 in PHP, it is working fine until the username or any contact data (firstname, lastname, city, street, etc) contains special characters, specifically from German/Nordic/Norwegian/Danish/Finnish/Swedish languages. Examples: őűäå.
In some cases, for unknown reasons, I got a payload that contains a Unicode version of the special characters (u00…)
When the code tries to validate the payload (and we ain’t talking about how poorly designed the entire header validation)
I suspect that there is some trick or encoding/converting required for the payload to have the same as at their side when it gets hashes/signed, but I did not find any official material related to this kind of issue other than “Ask your customers not to use special characters/native characters.”
Has anyone else faced this problem with the request verification?