titan-iac/services/communication/guest-register-configmap.yaml

# services/communication/guest-register-configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: matrix-guest-register
data:
  server.py: |
    import json
    import os
    from http.server import BaseHTTPRequestHandler, HTTPServer
    from urllib import error, parse, request

    SYNAPSE_BASE = os.environ.get("SYNAPSE_BASE", "http://othrys-synapse-matrix-synapse:8008").rstrip("/")
    GUEST_REGISTER_SHARED_SECRET = os.environ["GUEST_REGISTER_SHARED_SECRET"]
    GUEST_REGISTER_HEADER = os.environ.get("GUEST_REGISTER_HEADER", "x-guest-register-secret")
    GUEST_REGISTER_PATH = os.environ.get("GUEST_REGISTER_PATH", "/_matrix/_guest_register")

    RATE_WINDOW_SEC = int(os.environ.get("RATE_WINDOW_SEC", "60"))
    RATE_MAX = int(os.environ.get("RATE_MAX", "30"))
    _rate = {}  # ip -> [window_start, count]

    def _json(method, url, *, headers=None, body=None, timeout=20):
        hdrs = {"Content-Type": "application/json"}
        if headers:
            hdrs.update(headers)
        data = None
        if body is not None:
            data = json.dumps(body).encode()
        req = request.Request(url, data=data, headers=hdrs, method=method)
        try:
            with request.urlopen(req, timeout=timeout) as resp:
                raw = resp.read()
                payload = json.loads(raw.decode()) if raw else {}
                return resp.status, payload
        except error.HTTPError as e:
            raw = e.read()
            try:
                payload = json.loads(raw.decode()) if raw else {}
            except Exception:
                payload = {}
            return e.code, payload

    def _rate_check(ip, now):
        win, cnt = _rate.get(ip, (now, 0))
        if now - win > RATE_WINDOW_SEC:
            _rate[ip] = (now, 1)
            return True
        if cnt >= RATE_MAX:
            return False
        _rate[ip] = (win, cnt + 1)
        return True

    class Handler(BaseHTTPRequestHandler):
        server_version = "matrix-guest-register"

        def _send_json(self, code, payload):
            body = json.dumps(payload).encode()
            self.send_response(code)
            self.send_header("Content-Type", "application/json")
            self.send_header("Access-Control-Allow-Origin", "*")
            self.send_header("Access-Control-Allow-Methods", "GET, POST, OPTIONS")
            self.send_header("Access-Control-Allow-Headers", "Content-Type, Authorization, X-Requested-With")
            self.send_header("Content-Length", str(len(body)))
            self.end_headers()
            self.wfile.write(body)

        def do_OPTIONS(self):  # noqa: N802
            self.send_response(204)
            self.send_header("Access-Control-Allow-Origin", "*")
            self.send_header("Access-Control-Allow-Methods", "GET, POST, OPTIONS")
            self.send_header("Access-Control-Allow-Headers", "Content-Type, Authorization, X-Requested-With")
            self.end_headers()

        def do_GET(self):  # noqa: N802
            parsed = parse.urlparse(self.path)
            if parsed.path in ("/healthz", "/"):
                return self._send_json(200, {"ok": True})
            if parsed.path in ("/_matrix/client/v3/register", "/_matrix/client/r0/register"):
                return self._send_json(200, {"flows": [{"stages": []}]})
            return self._send_json(404, {"errcode": "M_NOT_FOUND", "error": "not_found"})

        def do_POST(self):  # noqa: N802
            parsed = parse.urlparse(self.path)
            if parsed.path not in ("/_matrix/client/v3/register", "/_matrix/client/r0/register"):
                return self._send_json(404, {"errcode": "M_NOT_FOUND", "error": "not_found"})

            qs = parse.parse_qs(parsed.query)
            kind = (qs.get("kind") or ["user"])[0]
            if kind != "guest":
                return self._send_json(
                    403,
                    {
                        "errcode": "M_FORBIDDEN",
                        "error": "Registration is disabled; use https://bstein.dev/request-access for accounts.",
                    },
                )

            xfwd = self.headers.get("x-forwarded-for", "")
            ip = (xfwd.split(",")[0].strip() if xfwd else "") or self.client_address[0]
            now = __import__("time").time()
            if not _rate_check(ip, now):
                return self._send_json(429, {"errcode": "M_LIMIT_EXCEEDED", "error": "rate_limited"})

            length = int(self.headers.get("content-length", "0") or "0")
            raw = self.rfile.read(length) if length else b"{}"
            try:
                body = json.loads(raw.decode()) if raw else {}
                if not isinstance(body, dict):
                    body = {}
            except Exception:
                body = {}

            status, payload = _json(
                "POST",
                f"{SYNAPSE_BASE}{GUEST_REGISTER_PATH}",
                headers={GUEST_REGISTER_HEADER: GUEST_REGISTER_SHARED_SECRET},
                body=body,
                timeout=20,
            )
            if "refresh_token" in payload:
                payload.pop("refresh_token", None)
            return self._send_json(status, payload)

    def main():
        port = int(os.environ.get("PORT", "8080"))
        HTTPServer(("0.0.0.0", port), Handler).serve_forever()

    if __name__ == "__main__":
        main()