浅念
9f556ebe95
- ValidatingBackend：connect_tcp 处 anyio.getaddrinfo 解析→禁段校验→ 只连已验 IP 字面量（anyio 对 IP 字面量跳过 DNS，闭合 rebinding TOCTOU； TLS/SNI 由 httpcore 以原 hostname 包，证书校验不受影响） - 双层防线：fetch URL 层预检（scheme/host/端口白名单+IP 字面量禁段） + 连接层逐跳 DNS 后校验；手动重定向 ≤5 跳每跳重校验 - 私有口（_pool 替换/AnyIOStream/异常映射）由版本探针测试钉位 - tests/test_safe_fetch.py 29 条：禁段参数化/连接层拒绝/重定向私网拦截/ 上限边界/请求真实路由经校验后端（anyio 层打桩离线全链路） Co-Authored-By: Claude Code <noreply@anthropic.com>
188 lines
7.3 KiB
Python
188 lines
7.3 KiB
Python
"""safe_fetch：连接层 SSRF 校验（spec §3.1——防 DNS rebinding）。"""
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import inspect
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import socket
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import httpx
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import pytest
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from app.platform.site_import import safe_fetch
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def _mock_client_factory(handler):
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"""redirect 类测试的打桩口：换掉 _make_client，注入 MockTransport client。"""
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def factory(timeout: float = 10.0) -> httpx.AsyncClient:
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return httpx.AsyncClient(
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transport=httpx.MockTransport(handler), follow_redirects=False)
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return factory
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class _FakeRawSocket:
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def setsockopt(self, *args, **kwargs):
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pass
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class _FakeAnyioStream:
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"""anyio 流替身：吐一条完整 HTTP/1.1 200 响应（经 AnyIOStream 包装喂 httpcore）。"""
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def __init__(self) -> None:
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self._buf = (
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b"HTTP/1.1 200 OK\r\n"
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b"Content-Length: 2\r\n"
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b"Connection: close\r\n"
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b"\r\n"
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b"ok"
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)
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self._raw_socket = _FakeRawSocket()
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async def receive(self, max_bytes: int) -> bytes:
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chunk, self._buf = self._buf[:max_bytes], self._buf[max_bytes:]
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return chunk
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async def send(self, item: bytes) -> None:
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pass
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async def aclose(self) -> None:
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pass
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def extra(self, *args, **kwargs):
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return None
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class TestVersionPin:
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def test_httpx私有口存在(self):
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"""httpx/httpcore 升级破坏私有 API 时立即红（spec 要求的版本钉位）——真断言，禁永真。"""
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import httpcore
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t = httpx.AsyncHTTPTransport()
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assert hasattr(t, "_pool")
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assert "network_backend" in inspect.signature(
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httpcore.AsyncConnectionPool.__init__).parameters
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def test_httpcore私有导出口存在(self):
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"""safe_fetch 消费的 httpcore 私有符号（AnyIOStream 流包装 / 异常映射口）逐个在位。"""
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from httpcore._backends.anyio import AnyIOStream
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from httpcore._exceptions import ConnectError, ConnectTimeout, map_exceptions
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assert callable(map_exceptions)
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assert issubclass(ConnectTimeout, Exception)
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assert issubclass(ConnectError, Exception)
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class TestIsBlockedIp:
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@pytest.mark.parametrize("ip", [
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"127.0.0.1", "10.1.2.3", "172.16.0.1", "172.31.255.255",
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"192.168.1.1", "169.254.1.1", "0.0.0.0", "100.64.0.1",
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"::1", "fd00::1", "fe80::1", "::ffff:127.0.0.1", "::ffff:10.0.0.1",
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])
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def test_私网段全拒(self, ip):
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assert safe_fetch.is_blocked_ip(ip) is True
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@pytest.mark.parametrize("ip", ["8.8.8.8", "1.1.1.1", "47.254.176.10", "2606:4700::1"])
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def test_公网放行(self, ip):
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assert safe_fetch.is_blocked_ip(ip) is False
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def test_非法IP串视为拒(self):
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assert safe_fetch.is_blocked_ip("not-an-ip") is True
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class TestValidatingBackend:
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async def test_connect_tcp_拒绝私网IP字面量(self):
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backend = safe_fetch.ValidatingBackend()
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with pytest.raises(safe_fetch.BlockedAddressError):
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await backend.connect_tcp("127.0.0.1", 80)
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with pytest.raises(safe_fetch.BlockedAddressError):
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await backend.connect_tcp("10.0.0.1", 443)
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# （连接层校验逻辑用 IP 字面量直接钉，不做真实域名 DNS 测试）
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async def test_非法端口拒绝(self):
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backend = safe_fetch.ValidatingBackend()
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with pytest.raises(safe_fetch.BlockedAddressError):
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await backend.connect_tcp("8.8.8.8", 8080)
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class TestFetch:
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async def test_非法端口拒绝(self):
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with pytest.raises(safe_fetch.FetchError):
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await safe_fetch.fetch("http://example.com:8080/")
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async def test_私网URL拒绝(self):
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with pytest.raises(safe_fetch.FetchError):
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await safe_fetch.fetch("http://127.0.0.1/x")
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with pytest.raises(safe_fetch.FetchError):
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await safe_fetch.fetch("http://10.0.0.1/x")
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async def test_非http协议拒绝(self):
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with pytest.raises(safe_fetch.FetchError):
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await safe_fetch.fetch("ftp://example.com/x")
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with pytest.raises(safe_fetch.FetchError):
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await safe_fetch.fetch("file:///etc/passwd")
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async def test_逐跳重定向每跳重校验(self, monkeypatch):
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"""302 → Location 指向私网 IP → 必须以 FetchError 终结（安全关键路径）。"""
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served = []
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def handler(request: httpx.Request) -> httpx.Response:
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served.append(str(request.url))
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return httpx.Response(302, headers={"Location": "http://10.0.0.2/evil"})
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monkeypatch.setattr(safe_fetch, "_make_client", _mock_client_factory(handler))
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with pytest.raises(safe_fetch.FetchError):
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await safe_fetch.fetch("http://example.com/start")
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# 首跳（公网）发生、第二跳（私网 Location）在 URL 层即被拦，未发起
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assert served == ["http://example.com/start"]
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async def test_重定向上限5跳(self, monkeypatch):
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""">5 跳 302 链 → FetchError。"""
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calls = []
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def handler(request: httpx.Request) -> httpx.Response:
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calls.append(request.url.path)
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return httpx.Response(302, headers={"Location": "/next"})
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monkeypatch.setattr(safe_fetch, "_make_client", _mock_client_factory(handler))
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with pytest.raises(safe_fetch.FetchError):
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await safe_fetch.fetch("http://example.com/start")
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# 首跳 + 5 次跟随 = 6 个请求；第 6 个 Location 不再跟
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assert len(calls) == 6
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async def test_五跳内重定向正常返回(self, monkeypatch):
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"""恰好 5 跳 302 + 终点 200 → 正常返回（上限边界正向钉位）。"""
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locations = iter(["/r1", "/r2", "/r3", "/r4", "/final"])
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n_redirects = 0
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def handler(request: httpx.Request) -> httpx.Response:
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nonlocal n_redirects
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loc = next(locations, None)
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if loc is None:
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return httpx.Response(200, text="ok")
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n_redirects += 1
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return httpx.Response(302, headers={"Location": loc})
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monkeypatch.setattr(safe_fetch, "_make_client", _mock_client_factory(handler))
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resp = await safe_fetch.fetch("http://example.com/start")
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assert resp.status_code == 200
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assert resp.text == "ok"
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assert n_redirects == 5
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async def test_请求真实走校验后端(self, monkeypatch):
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"""_make_client 的请求确实路由经 ValidatingBackend（连接层钩子被调用）。"""
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events = []
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async def fake_getaddrinfo(host, port, **kwargs):
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events.append(("resolve", host))
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return [(socket.AF_INET, socket.SOCK_STREAM, 6, "", ("93.184.216.34", port))]
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async def fake_connect_tcp(remote_host, remote_port, **kwargs):
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events.append(("connect", remote_host, remote_port))
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return _FakeAnyioStream()
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monkeypatch.setattr(safe_fetch.anyio, "getaddrinfo", fake_getaddrinfo)
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monkeypatch.setattr(safe_fetch.anyio, "connect_tcp", fake_connect_tcp)
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resp = await safe_fetch.fetch("http://example.com/")
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assert resp.status_code == 200
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assert resp.text == "ok"
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assert ("resolve", "example.com") in events
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# 连接目标是已验 IP 字面量而非原 hostname（DNS rebinding TOCTOU 闭合点）
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assert ("connect", "93.184.216.34", 80) in events
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