Caliculate Windows Limited Access Feature Token

calc_laf_token.py

# Caliculate Windows Limited Access Feature Token
# https://firefox-source-docs.mozilla.org/widget/windows/LimitedAccessFeature.html
# term:
#   Limited Access Feature (laf)
#   Package Family Name (pfn)

import winreg
from base64 import b64encode
from hashlib import sha256


def get_laf_token(pfn: str, laf_id: str, laf_key: str) -> str:
    data = f"{laf_id}!{laf_key}!{pfn}".encode()
    return b64encode(sha256(data).digest()[:16]).decode()


def get_laf_attension(pfn: str, laf_id: str) -> str:
    publisher_id = pfn[-13:]
    return f"{publisher_id} has registered their use of {laf_id} with Microsoft and agrees to the terms of use."


def get_laf_key(laf_id: str) -> str:
    key_path = rf"SOFTWARE\Microsoft\Windows\CurrentVersion\AppModel\LimitedAccessFeatures\{laf_id}"
    with winreg.OpenKey(winreg.HKEY_LOCAL_MACHINE, key_path) as key:
        value, _regtype = winreg.QueryValueEx(key, "")
        return value


def main() -> None:
    # set your package family name
    pfn = "win32more_7qdfwf8gx71z8"

    laf_id = "com.microsoft.windows.ai.languagemodel"
    laf_key = get_laf_key(laf_id)
    laf_attension = get_laf_attension(pfn, laf_id)
    laf_token = get_laf_token(pfn, laf_id, laf_key)
    print(f"{laf_key=}")
    print(f"{laf_attension=}")
    print(f"{laf_token=}")

    # Windows.ApplicationModel.LimitedAccessFeatures.TryUnlockFeature(laf_id, laf_token, laf_attension)


if __name__ == "__main__":
    main()