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AgentLab/backend/app/auth/middleware.py
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"""按请求认出是谁,写进 api/deps 的 contextvar(A7 第 2、4 条)。
纯 ASGI 中间件:HTTP 和 WebSocket 都经过它(Starlette 的 BaseHTTPMiddleware 不管 WebSocket),SSE 流式响应在它的
调用里发完,contextvar 一直有效。
关登录:不拦任何请求,写进 contextvar 的是等同管理员、未认证、署名取自 X-Actor 的身份;actor_of 照旧自己解码请求头,
和加这一层之前一模一样。
开登录:
- 会话 cookie → Principal(认证过的用户名、角色、组);没有会话是匿名(username=None),X-Actor 一律不看;
- /api 下除了登录本身、健康检查、入站钩子,匿名一律 401。各路由的角色要求另由 main.py 的路由级依赖管,这里兜底:
哪个路由忘了挂依赖,也不会对没登录的人敞开;
- 非 GET 的请求必须带 X-AgentLab-Request 头,带了 Origin 的必须是本站或登记的前端地址(CSRF)。自定义请求头跨站发不出来
(要过 CORS 预检,只放行配置里的前端地址),SameSite=Lax 的 cookie 也不随跨站的表单提交带过去;
- WebSocket:没登录的握手前就关掉;登录了的交给路由,按运行判(api/deps.py 的 run_scope:user 角色只能连自己能读、
查询结果在工具边界遮过的运行,也就是自己的问数据运行;应用实例页照旧轮询)。
"""
from __future__ import annotations
import json
from http.cookies import SimpleCookie
from typing import Any
from urllib.parse import urlsplit
from app.core.config import settings
#: 开登录时匿名也能访问的接口
_PUBLIC = frozenset({"/api/health", "/api/auth/me", "/api/auth/login", "/api/auth/logout", "/api/auth/oidc/start",
"/api/auth/oidc/callback", "/api/auth/jwks", "/api/auth/bootstrap"})
#: 只认签名、不走会话的入站钩子(也不查 CSRF:调用方是外部系统,没有浏览器的 Origin)
_HOOKS = "/api/hooks/"
_SAFE_METHODS = frozenset({"GET", "HEAD", "OPTIONS"})
CSRF_HEADER = "x-agentlab-request"
def _headers(scope: dict[str, Any]) -> dict[str, str]:
return {k.decode("latin-1").lower(): v.decode("latin-1") for k, v in scope.get("headers") or []}
def _cookie(headers: dict[str, str], name: str) -> str | None:
raw = headers.get("cookie")
if not raw:
return None
jar = SimpleCookie()
try:
jar.load(raw)
except Exception: # noqa: BLE001 - 坏掉的 cookie 头当没有
return None
morsel = jar.get(name)
return morsel.value if morsel else None
def _origin_ok(origin: str, headers: dict[str, str], scope: dict[str, Any]) -> bool:
allowed = {o.rstrip("/") for o in settings.cors_origins}
if settings.public_url:
parts = urlsplit(settings.public_url)
allowed.add(f"{parts.scheme}://{parts.netloc}")
host = headers.get("x-forwarded-host") or headers.get("host")
if host:
scheme = headers.get("x-forwarded-proto") or scope.get("scheme") or "http"
allowed.add(f"{scheme}://{host}")
return origin.rstrip("/") in allowed
async def _reply(send: Any, status: int, detail: str, code: str) -> None:
body = json.dumps({"detail": detail, "code": code}, ensure_ascii=False).encode()
await send({"type": "http.response.start", "status": status,
"headers": [(b"content-type", b"application/json"), (b"content-length", str(len(body)).encode())]})
await send({"type": "http.response.body", "body": body})
async def resolve(headers: dict[str, str], mode: str) -> Any:
"""cookie → Principal。没有有效会话是匿名(username=None、role 为空)。"""
from app.api.deps import Principal
from app.auth.sessions import COOKIE, principal_of, user_of
from app.db.base import SessionLocal
token = _cookie(headers, COOKIE)
if token:
async with SessionLocal() as session:
user = await user_of(session, token)
if user is not None:
return await principal_of(session, user, mode)
return Principal(username=None, role="", verified=False, mode=mode)
class AuthMiddleware:
def __init__(self, app: Any) -> None:
self.app = app
async def __call__(self, scope: dict[str, Any], receive: Any, send: Any) -> None:
if scope["type"] not in ("http", "websocket"):
await self.app(scope, receive, send)
return
from app.api.deps import reset_principal, set_principal
from app.auth import current_mode
# 登录设置在启动时读进缓存(main.py 的 _platform_startup),改设置的接口改完就刷新;这里不查库
mode = current_mode()
headers = _headers(scope)
if mode == "off":
# 关登录:所有人等同管理员,署名是自报的 X-Actor。actor_of 照旧自己解码请求头,这里写进来只为让审计、
# current_principal() 也拿得到这个署名
from app.api.deps import Principal, decode_actor
actor = decode_actor(headers.get("x-actor"))
token = set_principal(Principal(username=actor, display_name=actor, role="admin", mode="off"))
try:
await self.app(scope, receive, send)
finally:
reset_principal(token)
return
path = scope.get("path") or ""
is_api = path.startswith("/api/")
if scope["type"] == "http" and is_api and not path.startswith(_HOOKS) \
and scope.get("method", "GET").upper() not in _SAFE_METHODS:
if CSRF_HEADER not in headers:
await _reply(send, 403, "请求缺少来源标记,已拒绝。请从 AgentLab 页面操作", "csrf_header")
return
origin = headers.get("origin")
if origin and not _origin_ok(origin, headers, scope):
await _reply(send, 403, "请求来自其他站点,已拒绝", "csrf_origin")
return
principal = await resolve(headers, mode)
if scope["type"] == "websocket" and not principal.username:
# 握手前关闭:服务端回 403,不建立连接。登录了的不在这里一刀切:能不能连哪次运行要看运行(run_scope)
await receive()
await send({"type": "websocket.close", "code": 1008})
return
if (scope["type"] == "http" and is_api and not principal.username and path not in _PUBLIC
and not path.startswith(_HOOKS)):
await _reply(send, 401, "请先登录", "auth_required")
return
token = set_principal(principal)
try:
await self.app(scope, receive, send)
finally:
reset_principal(token)