A simple EUDCC verifier implementation with Python CWT: refresh_trustlist

python_cwt_sample_eudcc_03_1.py

def refresh_trustlist(self):
    self._dscs = []
    self._trustlist = []

    # Get a trust-list signer certificate.
    r = requests.get(self._base_url + "/cert")
    if r.status_code != 200:
        raise Exception(f"Received {r.status_code} from /cert")
    key = r.text
    cose_key = COSEKey.from_pem(key)
     # Get DSCs
    r = requests.get(self._base_url + "/trust-list")
    if r.status_code != 200:
        raise Exception(f"Received {r.status_code} from /trust-list")
    decoded = jwt.decode(
        r.text,
        cose_key.key,
        algorithms=["ES256"],
        options={"verify_aud": False},
    )
    for v in decoded["dsc_trust_list"].values():
        for k in v["keys"]:
            if "use" in k and k["use"] == "enc":
                # Workaround for a wrong DSC.
                del k["use"]
            if k["kty"] == "RSA":
                k["alg"] = "PS256"
            self._dscs.append(COSEKey.from_jwk(k))
        self._trustlist.append(k)

    # Update trustlist store.
    with open(self._trustlist_store_path, "w") as f:
        json.dump(self._trustlist, f, indent=4)
    return