Files
home_control/lib/_zyxel.py
T
2026-08-22 16:12:14 +02:00

185 lines
7.1 KiB
Python

"""Small client for the encrypted Zyxel OPAL/DAL web API."""
from __future__ import annotations
import base64
import json
import os
from dataclasses import dataclass
from typing import Any
from urllib.parse import urlsplit
import requests
from Crypto.Cipher import AES, PKCS1_v1_5
from Crypto.PublicKey import RSA
from Crypto.Util.Padding import pad, unpad
class ZyxelError(RuntimeError):
"""The router rejected a request or returned an unexpected response."""
def normalize_mac(value: str) -> str:
compact = "".join(character for character in value if character.isalnum()).lower()
if len(compact) != 12 or any(character not in "0123456789abcdef" for character in compact):
raise ValueError(f"invalid MAC address: {value!r}")
return ":".join(compact[index : index + 2] for index in range(0, 12, 2))
@dataclass(frozen=True)
class LanHost:
mac: str
active: bool
hostname: str = ""
ip_address: str = ""
class ZyxelRouter:
"""Read-only client for Zyxel routers using the OPAL DAL API."""
def __init__(
self,
host: str,
username: str,
password: str,
*,
timeout: float = 10,
verify_tls: bool = True,
hosts_oid: str = "lanhosts",
) -> None:
if "://" not in host:
host = f"http://{host}"
parsed = urlsplit(host)
if parsed.scheme not in {"http", "https"} or not parsed.netloc:
raise ValueError("zyxel.host must be a hostname/IP, or an http(s) URL")
self.url = host.rstrip("/")
self.username = username
self.password = password
self.timeout = timeout
self.verify_tls = verify_tls
self.hosts_oid = hosts_oid
self.session = requests.Session()
self._aes_key: bytes | None = None
self._session_key: str | None = None
def __enter__(self) -> "ZyxelRouter":
self.login()
return self
def __exit__(self, *_: object) -> None:
self.close()
def _request(self, method: str, path: str, **kwargs: Any) -> requests.Response:
kwargs.setdefault("timeout", self.timeout)
kwargs.setdefault("verify", self.verify_tls)
try:
response = self.session.request(method, f"{self.url}{path}", **kwargs)
response.raise_for_status()
return response
except requests.RequestException as error:
raise ZyxelError(f"Zyxel request failed: {error}") from error
@staticmethod
def _json(response: requests.Response) -> dict[str, Any]:
try:
value = response.json()
except (requests.JSONDecodeError, ValueError) as error:
raise ZyxelError("Zyxel returned a non-JSON response") from error
if not isinstance(value, dict):
raise ZyxelError("Zyxel returned an unexpected JSON response")
return value
def login(self) -> None:
self._request("GET", "/GetInfoNoLogin")
public_key = self._json(self._request("GET", "/getRSAPublickKey")).get("RSAPublicKey")
if not public_key:
raise ZyxelError("Zyxel did not return an RSA public key")
self._aes_key = os.urandom(32)
iv = os.urandom(32)
login = {
"Input_Account": self.username,
"Input_Passwd": base64.b64encode(self.password.encode()).decode(),
"currLang": "en",
"RememberPassword": 0,
}
cipher = AES.new(self._aes_key, AES.MODE_CBC, iv[:16])
content = cipher.encrypt(pad(json.dumps(login, separators=(",", ":")).encode(), 16))
rsa = PKCS1_v1_5.new(RSA.import_key(public_key.encode()))
encrypted_key = rsa.encrypt(base64.b64encode(self._aes_key))
payload = {
"content": base64.b64encode(content).decode(),
"key": base64.b64encode(encrypted_key).decode(),
"iv": base64.b64encode(iv).decode(),
}
result = self._decrypt(self._json(self._request("POST", "/UserLogin", json=payload)))
if result.get("result") != "ZCFG_SUCCESS" or not result.get("sessionkey"):
raise ZyxelError(f"Zyxel login failed: {result.get('result', 'unknown error')}")
self._session_key = str(result["sessionkey"])
def _decrypt(self, envelope: dict[str, Any]) -> dict[str, Any]:
if "content" not in envelope or "iv" not in envelope:
raise ZyxelError(str(envelope.get("result") or "unencrypted Zyxel response"))
if self._aes_key is None:
raise ZyxelError("not logged in")
try:
iv = base64.b64decode(envelope["iv"])[:16]
encrypted = base64.b64decode(envelope["content"])
clear = unpad(AES.new(self._aes_key, AES.MODE_CBC, iv).decrypt(encrypted), 16)
result = json.loads(clear)
except (ValueError, KeyError, json.JSONDecodeError) as error:
raise ZyxelError("could not decrypt Zyxel response") from error
if not isinstance(result, dict):
raise ZyxelError("Zyxel returned an unexpected encrypted response")
return result
def dal_get(self, oid: str) -> dict[str, Any]:
if not self._session_key:
self.login()
response = self._request(
"GET", "/cgi-bin/DAL", params={"oid": oid, "sessionkey": self._session_key}
)
return self._decrypt(self._json(response))
def get_lan_hosts(self) -> list[LanHost]:
result = self.dal_get(self.hosts_oid)
if result.get("result") not in (None, "ZCFG_SUCCESS"):
raise ZyxelError(f"lanhosts query failed: {result.get('result')}")
objects = result.get("Object", [])
if isinstance(objects, dict):
objects = [objects]
hosts: list[LanHost] = []
for item in objects:
if not isinstance(item, dict):
continue
raw_mac = next((item.get(key) for key in ("PhysAddress", "physAddress", "MACAddr", "MacAddress") if item.get(key)), None)
if not raw_mac:
continue
try:
mac = normalize_mac(str(raw_mac))
except ValueError:
continue
raw_active = next((item.get(key) for key in ("Active", "active", "Enable", "enable") if key in item), True)
active = raw_active if isinstance(raw_active, bool) else str(raw_active).lower() in {"1", "true", "yes", "active", "enabled"}
hosts.append(LanHost(
mac=mac,
active=active,
hostname=str(item.get("HostName") or item.get("hostName") or ""),
ip_address=str(item.get("IPAddress") or item.get("ipAddress") or item.get("IPAddr") or ""),
))
return hosts
def is_connected(self, mac: str) -> bool:
wanted = normalize_mac(mac)
return any(host.mac == wanted and host.active for host in self.get_lan_hosts())
def close(self) -> None:
if self._session_key:
try:
self._request("GET", "/cgi-bin/UserLogout", params={"sessionkey": self._session_key})
except ZyxelError:
pass
self._session_key = None
self._aes_key = None
self.session.close()