Files
DECNET/tests/canary/test_worker_http.py
anti fae3e0caa3 feat(canary): worker (HTTP + stdlib DNS callback receivers) + tests
decnet canary worker hosts both callback surfaces in one process:

- HTTP: a tiny FastAPI app on its own port (default 8088). The only
  meaningful route is GET /c/{slug} which looks up the slug, persists
  a CanaryTrigger, publishes canary.<id>.triggered, and returns a 1x1
  transparent GIF. Unknown slugs return the same response (stealth);
  no decnet strings leak in headers/banners; docs/openapi/redoc are
  disabled. X-Forwarded-For is honored.

- DNS: an authoritative UDP server for *.<canary_zone> using
  asyncio.DatagramProtocol with stdlib-only DNS wire-format parsing
  (no dnslib dep). Same lookup -> persist -> publish flow, plus a
  sinkhole A record (192.0.2.1) so the attacker's resolver doesn't
  loop on NXDOMAIN. Single-label slugs only; multi-label probes
  return NXDOMAIN. Pointer loops in malformed queries are caught
  (10-hop cap) so an adversarial packet can't wedge the parser.

Tests cover both surfaces without privileged sockets:
- HTTP via Starlette TestClient: known/unknown slug, headers, XFF,
  stealth-string assertions.
- DNS via direct DatagramProtocol drive: known slug -> ANSWER,
  unknown -> NXDOMAIN, pointer-loop -> ValueError, malformed
  packet -> silent drop.
2026-04-27 13:12:05 -04:00

125 lines
4.3 KiB
Python

"""HTTP surface coverage for the canary worker.
We exercise the FastAPI app via Starlette's TestClient so the test
doesn't need a real socket. Asserts:
* ``GET /c/{slug}`` for a known slug returns 200 + image/gif, persists
a trigger row, bumps the token's counters, and publishes
``canary.<token_id>.triggered`` on the bus.
* ``GET /c/{slug}`` for an unknown slug returns the same 200 (stealth)
but persists nothing.
* The Server header is rewritten to a generic value (``nginx``).
* Bare root returns 404.
* X-Forwarded-For is honored.
"""
from __future__ import annotations
import asyncio
from typing import AsyncIterator
import pytest
import pytest_asyncio
from fastapi.testclient import TestClient
from decnet.bus import topics
from decnet.bus.fake import FakeBus
from decnet.canary.worker import _build_app
from decnet.web.db.sqlite.repository import SQLiteRepository
import decnet.web.db.models # noqa: F401
@pytest_asyncio.fixture
async def repo(tmp_path) -> AsyncIterator[SQLiteRepository]:
r = SQLiteRepository(str(tmp_path / "w.db"))
await r.initialize()
yield r
@pytest_asyncio.fixture
async def bus() -> AsyncIterator[FakeBus]:
b = FakeBus()
await b.connect()
yield b
await b.close()
@pytest.mark.asyncio
async def test_known_slug_records_trigger_and_publishes(
repo: SQLiteRepository, bus: FakeBus,
) -> None:
await repo.create_canary_token({
"uuid": "tok-w1", "kind": "http", "decky_name": "web1",
"generator": "env_file", "placement_path": "/x",
"callback_token": "slug-W1", "secret_seed": "s", "created_by": "u1",
})
sub = bus.subscribe("canary.>")
app = _build_app(repo, bus)
with TestClient(app) as client:
resp = client.get("/c/slug-W1", headers={"User-Agent": "curl/8.0"})
assert resp.status_code == 200
assert resp.headers["content-type"].startswith("image/gif")
assert resp.headers.get("server") == "nginx"
event = await asyncio.wait_for(sub.__anext__(), timeout=2.0)
assert event.topic == topics.canary("tok-w1", topics.CANARY_TRIGGERED)
assert event.payload["src_ip"]
assert event.payload["user_agent"] == "curl/8.0"
triggers = await repo.list_canary_triggers("tok-w1")
assert len(triggers) == 1
assert triggers[0]["request_path"] == "/c/slug-W1"
tok = await repo.get_canary_token("tok-w1")
assert tok["trigger_count"] == 1
@pytest.mark.asyncio
async def test_unknown_slug_returns_same_response_but_persists_nothing(
repo: SQLiteRepository, bus: FakeBus,
) -> None:
app = _build_app(repo, bus)
with TestClient(app) as client:
resp = client.get("/c/unknown-slug")
assert resp.status_code == 200
assert resp.headers["content-type"].startswith("image/gif")
# No tokens, no triggers, no nothing.
assert await repo.list_canary_tokens() == []
@pytest.mark.asyncio
async def test_root_returns_404(repo: SQLiteRepository, bus: FakeBus) -> None:
app = _build_app(repo, bus)
with TestClient(app) as client:
resp = client.get("/")
assert resp.status_code == 404
@pytest.mark.asyncio
async def test_xff_is_honored(repo: SQLiteRepository, bus: FakeBus) -> None:
await repo.create_canary_token({
"uuid": "tok-xff", "kind": "http", "decky_name": "web1",
"generator": "env_file", "placement_path": "/x",
"callback_token": "slug-xff", "secret_seed": "s", "created_by": "u1",
})
app = _build_app(repo, bus)
with TestClient(app) as client:
client.get("/c/slug-xff", headers={"X-Forwarded-For": "9.9.9.9, 10.0.0.1"})
triggers = await repo.list_canary_triggers("tok-xff")
assert triggers[0]["src_ip"] == "9.9.9.9"
@pytest.mark.asyncio
async def test_no_decnet_strings_in_response(repo: SQLiteRepository, bus: FakeBus) -> None:
"""Stealth posture: nothing in the HTTP surface mentions DECNET."""
app = _build_app(repo, bus)
with TestClient(app) as client:
resp = client.get("/c/anything")
body = resp.content.lower()
for v in resp.headers.values():
assert b"decnet" not in v.lower().encode()
assert b"decnet" not in body
# Docs / openapi / redoc are disabled.
assert client.get("/docs").status_code == 404
assert client.get("/openapi.json").status_code == 404
assert client.get("/redoc").status_code == 404