Authenticate the node dashboard, and the broker connection per node

Two unauthenticated surfaces closed on the edge node.

Dashboard and API: the local dashboard and every /api/* route were open to
anything on the node's LAN. Adds a login page plus session-cookie auth for
the browser, and cookie-or-Basic for the API so scripted callers stay
possible. Passwords are hashed with stdlib scrypt (no new dependency, this
runs on a Pi) and compared in constant time; the salt and session-signing
secret persist in credentials.json. Startup warns while the default password
is still in place. No non-browser callers of the node API exist today
(C2 talks to nodes over MQTT and nodes call C2 outbound), so nothing breaks.

Adds python-multipart, which FastAPI's Form() needs for the login POST and
which was missing from requirements entirely.

MQTT: nodes authenticated with a shared drb-node password, and the broker
ACL keyed off %c — the client-supplied client id — so any holder of that one
password could claim another node's topic namespace. Nodes now connect as
username=<node_id>, password=<their C2-issued api_key>, which mosquitto's
dynamic-security plugin checks, with the ACL keyed off the authenticated %u.
TLS is gated on MQTT_TLS and uses default CA verification.

The old key_request MQTT path stays in place behind TODO(mqtt-cutover)
markers as the fallback until the cutover is proven; a node with no api_key
on disk logs a clear repeated refusal rather than spinning.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

drb-edge-node/tests/test_auth_endpoints.py

@@ -0,0 +1,157 @@
+"""
+HTTP-level tests for the auth-protected dashboard/API surface: login/logout
+flow, session-cookie protection of the HTML pages, and Basic-auth protection
+of the JSON API.
+
+Built as a standalone FastAPI app assembling the real api/ui routers — NOT
+app.main:app, which wires a lifespan that connects to MQTT, starts the
+PulseAudio capture loop, and pings OP25/C2. None of that belongs in a unit
+test, and none of it is needed to exercise the auth layer: the auth
+dependency runs (and short-circuits with a redirect/401) before any route
+body that would touch those services.
+"""
+import base64
+
+import pytest
+from fastapi import FastAPI
+from fastapi.testclient import TestClient
+
+from app.config import settings
+from app.internal import auth, credentials
+from app.routers import api, ui
+
+
+@pytest.fixture(autouse=True)
+def isolated_credentials(tmp_path, monkeypatch):
+    creds_file = tmp_path / "credentials.json"
+    monkeypatch.setattr(credentials, "_CREDS_FILE", creds_file)
+    monkeypatch.setattr(credentials, "_api_key", None)
+    monkeypatch.setattr(credentials, "_auth_salt", None)
+    monkeypatch.setattr(credentials, "_session_secret", None)
+    monkeypatch.setattr(settings, "dashboard_username", "tester")
+    monkeypatch.setattr(settings, "dashboard_password", "s3cret-pass")
+    yield
+
+
+@pytest.fixture
+def client():
+    test_app = FastAPI()
+    test_app.include_router(api.router)
+    test_app.include_router(ui.router)
+    with TestClient(test_app) as c:
+        yield c
+
+
+def _basic_header(username: str, password: str) -> dict:
+    encoded = base64.b64encode(f"{username}:{password}".encode()).decode()
+    return {"Authorization": f"Basic {encoded}"}
+
+
+# ---------------------------------------------------------------------------
+# /api/* — machine-facing JSON API
+# ---------------------------------------------------------------------------
+
+def test_api_route_rejects_unauthenticated_requests(client):
+    r = client.get("/api/status", follow_redirects=False)
+    assert r.status_code == 401
+    assert r.headers["www-authenticate"] == "Basic"
+
+
+def test_api_route_accepts_valid_basic_auth(client):
+    r = client.get("/api/config", headers=_basic_header("tester", "s3cret-pass"))
+    assert r.status_code == 200
+
+
+def test_api_route_rejects_wrong_basic_auth_password(client):
+    r = client.get("/api/config", headers=_basic_header("tester", "wrong"))
+    assert r.status_code == 401
+
+
+def test_api_route_accepts_dashboard_session_cookie(client):
+    login = client.post(
+        "/login", data={"username": "tester", "password": "s3cret-pass"}, follow_redirects=False
+    )
+    assert login.status_code == 303
+    assert auth.SESSION_COOKIE_NAME in login.cookies
+
+    r = client.get("/api/config")  # cookie jar carries the session cookie
+    assert r.status_code == 200
+
+
+def test_every_api_route_is_registered_behind_the_auth_dependency():
+    """Structural guard: catches a future route added to api.py that forgets
+    the router is meant to protect everything in it."""
+    assert any(
+        getattr(dep, "dependency", None) is auth.require_auth
+        for dep in api.router.dependencies
+    )
+
+
+# ---------------------------------------------------------------------------
+# / and /scanner — the HTML dashboard
+# ---------------------------------------------------------------------------
+
+def test_index_redirects_to_login_when_unauthenticated(client):
+    r = client.get("/", follow_redirects=False)
+    assert r.status_code in (302, 307)
+    assert r.headers["location"] == "/login"
+
+
+def test_scanner_redirects_to_login_when_unauthenticated(client):
+    r = client.get("/scanner", follow_redirects=False)
+    assert r.status_code in (302, 307)
+    assert r.headers["location"] == "/login"
+
+
+def test_index_served_with_a_valid_session_cookie(client):
+    client.post("/login", data={"username": "tester", "password": "s3cret-pass"})
+    r = client.get("/")
+    assert r.status_code == 200
+    assert "text/html" in r.headers["content-type"]
+
+
+# ---------------------------------------------------------------------------
+# /login, /logout
+# ---------------------------------------------------------------------------
+
+def test_login_page_loads_without_auth(client):
+    r = client.get("/login")
+    assert r.status_code == 200
+
+
+def test_login_with_correct_credentials_sets_cookie_and_redirects_home(client):
+    r = client.post(
+        "/login", data={"username": "tester", "password": "s3cret-pass"}, follow_redirects=False
+    )
+    assert r.status_code == 303
+    assert r.headers["location"] == "/"
+    cookie = r.cookies.get(auth.SESSION_COOKIE_NAME)
+    assert cookie
+    assert auth._verify_session_token(cookie) == "tester"
+
+
+def test_login_with_wrong_password_redirects_back_with_error_and_no_cookie(client):
+    r = client.post(
+        "/login", data={"username": "tester", "password": "wrong"}, follow_redirects=False
+    )
+    assert r.status_code == 303
+    assert r.headers["location"] == "/login?error=1"
+    assert auth.SESSION_COOKIE_NAME not in r.cookies
+
+
+def test_login_error_banner_renders_on_the_login_page(client):
+    r = client.get("/login?error=1")
+    assert r.status_code == 200
+    assert "Invalid username or password" in r.text
+
+
+def test_logout_clears_the_session_cookie_and_redirects_to_login(client):
+    client.post("/login", data={"username": "tester", "password": "s3cret-pass"})
+    assert client.get("/").status_code == 200  # confirm we were logged in
+
+    r = client.get("/logout", follow_redirects=False)
+    assert r.status_code == 303
+    assert r.headers["location"] == "/login"
+
+    r2 = client.get("/", follow_redirects=False)
+    assert r2.status_code in (302, 307)  # session cookie was cleared