Ask Authelia for sign-in state on the public sign-in host.

Authelia rejects the cluster address. Keep the connection inside the cluster and name login.coulomb.social, which matches the session cookie domain.

Assistant: grok
Assistant-Session: 01a0d25d-d358-7e13-b84a-d007fbb7e34f

src/user_engine/identity_state.py

@@ -18,6 +18,7 @@ from user_engine.oidc import cookie_value
 
 _IDENTITY_NAME = re.compile(r"^[A-Za-z0-9._@+-]{1,200}$")
 _SESSION_TOKEN = re.compile(r"^[A-Za-z0-9._~+/=-]{1,4096}$")
+_PUBLIC_HOST = re.compile(r"[A-Za-z0-9](?:[A-Za-z0-9-]{0,61}[A-Za-z0-9])?(?:\.[A-Za-z0-9](?:[A-Za-z0-9-]{0,61}[A-Za-z0-9])?)+")
 _CLUSTER_HOST = ".svc.cluster.local"
 
 
@@ -51,6 +52,13 @@ def validate_identity_state_url(url: str) -> str:
     return url
 
 
+def validate_identity_state_host(host: str) -> str:
+    """Accept the public sign-in host Authelia uses for its session cookie."""
+    if not _PUBLIC_HOST.fullmatch(host) or host.endswith(_CLUSTER_HOST):
+        raise ValueError("identity state host must be the public sign-in hostname")
+    return host
+
+
 def authelia_session_token(cookie_header: str) -> str | None:
     value = cookie_value(cookie_header, "authelia_session")
     if value is None or _SESSION_TOKEN.fullmatch(value) is None:
@@ -78,15 +86,16 @@ class _RefuseRedirects(HTTPRedirectHandler):
         raise URLError("identity state endpoint must not redirect")
 
 
-def _read_state(url: str, token: str, timeout: float) -> bytes:
+def _read_state(url: str, token: str, timeout: float, *, host: str | None = None) -> bytes:
-    request = Request(
-        url,
     headers = {
         "Accept": "application/json",
         "Cookie": f"authelia_session={token}",
-        },
+    }
-        method="GET",
+    # Authelia rejects the cluster DNS name. The public sign-in host matches
-    )
+    # the session cookie domain, while the connection stays on the cluster URL.
+    if host:
+        headers["Host"] = host
+    request = Request(url, headers=headers, method="GET")
     opener = build_opener(_RefuseRedirects)
     with opener.open(request, timeout=timeout) as response:
         return response.read(8192)
@@ -95,10 +104,18 @@ def _read_state(url: str, token: str, timeout: float) -> bytes:
 class AutheliaIdentityState:
     """Confirm the username on one Authelia session cookie."""
 
-    def __init__(self, state_url: str, *, timeout: float = 2.0, reader=_read_state) -> None:
+    def __init__(
+        self,
+        state_url: str,
+        *,
+        host: str | None = None,
+        timeout: float = 2.0,
+        reader=_read_state,
+    ) -> None:
         if timeout <= 0:
             raise ValueError("identity state timeout must be positive")
         self.state_url = validate_identity_state_url(state_url)
+        self.host = validate_identity_state_host(host) if host else None
         self.timeout = timeout
         self._reader = reader
 
@@ -107,7 +124,12 @@ class AutheliaIdentityState:
         if token is None:
             return None
         try:
-            raw = self._reader(self.state_url, token, self.timeout)
+            raw = self._reader(
+                self.state_url,
+                token,
+                self.timeout,
+                **({"host": self.host} if self.host else {}),
+            )
             payload = json.loads(raw.decode("utf-8"))
         except (HTTPError, URLError, TimeoutError, OSError, UnicodeError, json.JSONDecodeError, ValueError):
             return None

src/user_engine/runtime.py

@@ -120,7 +120,10 @@ def create_application() -> PortalApplication:
             os.environ.get("USER_ENGINE_REGISTRATION_RATE_WINDOW_SECONDS", "60")
         ),
         identity_lookup=(
-            AutheliaIdentityState(os.environ["USER_ENGINE_IDENTITY_STATE_URL"])
+            AutheliaIdentityState(
+                os.environ["USER_ENGINE_IDENTITY_STATE_URL"],
+                host=os.environ.get("USER_ENGINE_IDENTITY_STATE_HOST") or None,
+            )
             if os.environ.get("USER_ENGINE_IDENTITY_STATE_URL")
             else None
         ),

tests/test_identity_state.py

@@ -8,6 +8,7 @@ from user_engine.identity_state import (
     AutheliaIdentityState,
     authelia_session_token,
     username_from_state,
+    validate_identity_state_host,
     validate_identity_state_url,
     _read_state,
 )
@@ -20,6 +21,19 @@ class IdentityStateUrlTests(unittest.TestCase):
         self.assertEqual(cluster, validate_identity_state_url(cluster))
         self.assertEqual(public, validate_identity_state_url(public))
 
+    def test_public_sign_in_host_is_separate_from_the_cluster_address(self):
+        self.assertEqual("login.coulomb.social", validate_identity_state_host("login.coulomb.social"))
+        for host in [
+            "authelia.sso.svc.cluster.local",
+            "login.coulomb.social:443",
+            "https://login.coulomb.social",
+            "login",
+            " login.coulomb.social",
+        ]:
+            with self.subTest(host=host):
+                with self.assertRaises(ValueError):
+                    validate_identity_state_host(host)
+
     def test_rejects_anything_that_could_carry_the_session_cookie_elsewhere(self):
         for url in [
             "http://login.coulomb.social/api/state",
@@ -95,6 +109,24 @@ class IdentityStateParseTests(unittest.TestCase):
         self.assertIsNone(state.username("authelia_session=bad\r\nX"))
         self.assertNotIn("secret", json.dumps(seen))
 
+    def test_lookup_uses_the_public_sign_in_host(self):
+        seen = []
+
+        def reader(url, token, timeout, *, host=None):
+            seen.append((url, token, host))
+            return b'{"status":"OK","data":{"username":"platform-root","authentication_level":1}}'
+
+        state = AutheliaIdentityState(
+            "http://authelia.sso.svc.cluster.local:9091/api/state",
+            host="login.coulomb.social",
+            reader=reader,
+        )
+        self.assertEqual("platform-root", state.username("authelia_session=odd"))
+        self.assertEqual(
+            [("http://authelia.sso.svc.cluster.local:9091/api/state", "odd", "login.coulomb.social")],
+            seen,
+        )
+
 
 class IdentityStateTransportTests(unittest.TestCase):
     def setUp(self):
@@ -103,7 +135,7 @@ class IdentityStateTransportTests(unittest.TestCase):
 
         class Handler(BaseHTTPRequestHandler):
             def do_GET(self):
-                parent.seen.append((self.path, self.headers.get("Cookie")))
+                parent.seen.append((self.path, self.headers.get("Cookie"), self.headers.get("Host")))
                 if self.path == "/api/state":
                     body = json.dumps(
                         {"status": "OK", "data": {"username": "platform-root", "authentication_level": 1}}
@@ -132,10 +164,13 @@ class IdentityStateTransportTests(unittest.TestCase):
 
     def test_transport_sends_one_cookie_and_does_not_follow_redirects(self):
         url = f"http://127.0.0.1:{self.port}/api/state"
-        body = _read_state(url, "opaque-token", 1)
+        body = _read_state(url, "opaque-token", 1, host="login.coulomb.social")
         self.assertIn(b"platform-root", body)
-        self.assertEqual([("/api/state", "authelia_session=opaque-token")], self.seen)
+        self.assertEqual(
+            [("/api/state", "authelia_session=opaque-token", "login.coulomb.social")],
+            self.seen,
+        )
         with self.assertRaises(Exception):
             _read_state(f"http://127.0.0.1:{self.port}/redirect", "opaque-token", 1)
         self.assertEqual("/redirect", self.seen[-1][0])
-        self.assertNotIn("/stolen", [path for path, _cookie in self.seen])
+        self.assertNotIn("/stolen", [item[0] for item in self.seen])