deer-flow/backend/app/gateway/csrf_middleware.py
greatmengqi 27b66d6753 feat(auth): authentication module with multi-tenant isolation (RFC-001)
Introduce an always-on auth layer with auto-created admin on first boot,
multi-tenant isolation for threads/stores, and a full setup/login flow.

Backend
- JWT access tokens with `ver` field for stale-token rejection; bump on
  password/email change
- Password hashing, HttpOnly+Secure cookies (Secure derived from request
  scheme at runtime)
- CSRF middleware covering both REST and LangGraph routes
- IP-based login rate limiting (5 attempts / 5-min lockout) with bounded
  dict growth and X-Forwarded-For bypass fix
- Multi-worker-safe admin auto-creation (single DB write, WAL once)
- needs_setup + token_version on User model; SQLite schema migration
- Thread/store isolation by owner; orphan thread migration on first admin
  registration
- thread_id validated as UUID to prevent log injection
- CLI tool to reset admin password
- Decorator-based authz module extracted from auth core

Frontend
- Login and setup pages with SSR guard for needs_setup flow
- Account settings page (change password / email)
- AuthProvider + route guards; skips redirect when no users registered
- i18n (en-US / zh-CN) for auth surfaces
- Typed auth API client; parseAuthError unwraps FastAPI detail envelope

Infra & tooling
- Unified `serve.sh` with gateway mode + auto dep install
- Public PyPI uv.toml pin for CI compatibility
- Regenerated uv.lock with public index

Tests
- HTTP vs HTTPS cookie security tests
- Auth middleware, rate limiter, CSRF, setup flow coverage
2026-04-08 00:31:43 +08:00

113 lines
3.5 KiB
Python

"""CSRF protection middleware for FastAPI.
Per RFC-001:
State-changing operations require CSRF protection.
"""
import secrets
from collections.abc import Callable
from fastapi import Request, Response
from starlette.middleware.base import BaseHTTPMiddleware
from starlette.responses import JSONResponse
from starlette.types import ASGIApp
CSRF_COOKIE_NAME = "csrf_token"
CSRF_HEADER_NAME = "X-CSRF-Token"
CSRF_TOKEN_LENGTH = 64 # bytes
def is_secure_request(request: Request) -> bool:
"""Detect whether the original client request was made over HTTPS."""
return request.headers.get("x-forwarded-proto", request.url.scheme) == "https"
def generate_csrf_token() -> str:
"""Generate a secure random CSRF token."""
return secrets.token_urlsafe(CSRF_TOKEN_LENGTH)
def should_check_csrf(request: Request) -> bool:
"""Determine if a request needs CSRF validation.
CSRF is checked for state-changing methods (POST, PUT, DELETE, PATCH).
GET, HEAD, OPTIONS, and TRACE are exempt per RFC 7231.
"""
if request.method not in ("POST", "PUT", "DELETE", "PATCH"):
return False
path = request.url.path.rstrip("/")
# Exempt /api/v1/auth/me endpoint
if path == "/api/v1/auth/me":
return False
return True
_AUTH_EXEMPT_PATHS: frozenset[str] = frozenset(
{
"/api/v1/auth/login/local",
"/api/v1/auth/logout",
"/api/v1/auth/register",
}
)
def is_auth_endpoint(request: Request) -> bool:
"""Check if the request is to an auth endpoint.
Auth endpoints don't need CSRF validation on first call (no token).
"""
return request.url.path.rstrip("/") in _AUTH_EXEMPT_PATHS
class CSRFMiddleware(BaseHTTPMiddleware):
"""Middleware that implements CSRF protection using Double Submit Cookie pattern."""
def __init__(self, app: ASGIApp) -> None:
super().__init__(app)
async def dispatch(self, request: Request, call_next: Callable) -> Response:
_is_auth = is_auth_endpoint(request)
if should_check_csrf(request) and not _is_auth:
cookie_token = request.cookies.get(CSRF_COOKIE_NAME)
header_token = request.headers.get(CSRF_HEADER_NAME)
if not cookie_token or not header_token:
return JSONResponse(
status_code=403,
content={"detail": "CSRF token missing. Include X-CSRF-Token header."},
)
if not secrets.compare_digest(cookie_token, header_token):
return JSONResponse(
status_code=403,
content={"detail": "CSRF token mismatch."},
)
response = await call_next(request)
# For auth endpoints that set up session, also set CSRF cookie
if _is_auth and request.method == "POST":
# Generate a new CSRF token for the session
csrf_token = generate_csrf_token()
is_https = is_secure_request(request)
response.set_cookie(
key=CSRF_COOKIE_NAME,
value=csrf_token,
httponly=False, # Must be JS-readable for Double Submit Cookie pattern
secure=is_https,
samesite="strict",
)
return response
def get_csrf_token(request: Request) -> str | None:
"""Get the CSRF token from the current request's cookies.
This is useful for server-side rendering where you need to embed
token in forms or headers.
"""
return request.cookies.get(CSRF_COOKIE_NAME)