wangweiandCopilot
49ee50c104
Critical: the MCP SDK auto-enables DNS-rebinding protection when its host parameter is left at the 127.0.0.1 default, hard-coding a loopback-only Host allow-list. Every remote client (the only deployment this feature targets) was refused with HTTP 421 before auth or the tool ran. Now driven by a new MCP_ALLOWED_HOSTS setting, with '*' as an explicit, logged opt-out. Also bounds query/top_k to match AskRequest (top_k is amplified 4x downstream, so an unbounded value was a resource-exhaustion vector), decodes the Authorization header as latin-1 per the ASGI spec instead of raising a 500 on malformed bytes, and returns WWW-Authenticate on 401 per RFC 7235. Moves the psycopg2 import guard into backend/tests/conftest.py: duplicated across four test modules, it only worked because of alphabetical collection order, and any earlier-sorting package would have reintroduced a live connection attempt against the production database. Registers the mcp module in the authoritative backend architecture doc. 84 backend tests pass. Verified against a live server: allowed remote Host returns a valid initialize result, unknown Host returns 421, missing token returns 401 with WWW-Authenticate. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
94 lines
3.8 KiB
Python
94 lines
3.8 KiB
Python
"""Unit tests for MCPAuthMiddleware.
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Wraps a minimal dummy ASGI app (not the real MCP app) so these tests exercise
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only the auth gate, not the MCP protocol itself — keeps the test fast and
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independent of FastMCP internals.
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"""
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from __future__ import annotations
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from unittest.mock import patch
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from starlette.applications import Starlette
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from starlette.responses import PlainTextResponse
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from starlette.routing import Route
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from starlette.testclient import TestClient
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from app.mcp.server import MCPAuthMiddleware
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def _dummy_app() -> Starlette:
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"""Build a minimal Starlette app that MCPAuthMiddleware can wrap."""
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async def _ok(request):
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"""Return a fixed 200 response so tests can assert pass-through."""
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return PlainTextResponse("ok")
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app = Starlette(routes=[Route("/ping", _ok)])
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app.add_middleware(MCPAuthMiddleware)
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return app
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def test_missing_token_rejected_when_auth_enabled():
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"""No Authorization header + auth_enabled=True -> 401."""
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with patch("app.mcp.server.settings") as fake_settings:
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fake_settings.auth_enabled = True
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client = TestClient(_dummy_app())
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response = client.get("/ping")
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assert response.status_code == 401
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def test_invalid_token_rejected_when_auth_enabled():
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"""A token that fails decode_token() -> 401, request never reaches the app."""
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fake_handler = type("H", (), {"decode_token": lambda self, t: (_ for _ in ()).throw(ValueError("bad token"))})()
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with patch("app.mcp.server.settings") as fake_settings, \
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patch("app.mcp.server.get_jwt_handler", return_value=fake_handler):
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fake_settings.auth_enabled = True
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client = TestClient(_dummy_app())
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response = client.get("/ping", headers={"Authorization": "Bearer garbage"})
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assert response.status_code == 401
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def test_valid_token_passes_through_when_auth_enabled():
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"""A token that decodes successfully -> request reaches the wrapped app."""
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fake_handler = type("H", (), {"decode_token": lambda self, t: object()})()
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with patch("app.mcp.server.settings") as fake_settings, \
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patch("app.mcp.server.get_jwt_handler", return_value=fake_handler):
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fake_settings.auth_enabled = True
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client = TestClient(_dummy_app())
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response = client.get("/ping", headers={"Authorization": "Bearer good"})
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assert response.status_code == 200
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assert response.text == "ok"
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def test_auth_disabled_always_passes_through():
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"""auth_enabled=False (dev mode) -> no token needed, matches get_current_user's dev bypass."""
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with patch("app.mcp.server.settings") as fake_settings:
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fake_settings.auth_enabled = False
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client = TestClient(_dummy_app())
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response = client.get("/ping")
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assert response.status_code == 200
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def test_401_includes_www_authenticate_header():
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"""RFC 7235 requires WWW-Authenticate on 401 so clients can tell why they failed."""
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with patch("app.mcp.server.settings") as fake_settings:
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fake_settings.auth_enabled = True
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client = TestClient(_dummy_app())
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response = client.get("/ping")
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assert response.status_code == 401
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assert response.headers["WWW-Authenticate"] == "Bearer"
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def test_non_utf8_authorization_header_is_rejected_not_crashed():
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"""A non-UTF-8 header byte must yield a clean 401, not an unhandled 500.
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ASGI header values are latin-1 bytes, so any remote client could otherwise
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trigger a UnicodeDecodeError inside the middleware at will.
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"""
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with patch("app.mcp.server.settings") as fake_settings:
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fake_settings.auth_enabled = True
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client = TestClient(_dummy_app(), raise_server_exceptions=False)
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# Bypass the http client's own header encoding by writing raw bytes.
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response = client.get("/ping", headers={"Authorization": b"Bearer \xff\xfe"})
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assert response.status_code == 401
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