app/api/middleware/security.py

from __future__ import annotations

from fastapi import FastAPI
from starlette.middleware.base import BaseHTTPMiddleware
from starlette.requests import Request
from starlette.responses import Response


class SecurityHeadersMiddleware(BaseHTTPMiddleware):
    async def dispatch(self, request: Request, call_next):
        response: Response = await call_next(request)
        response.headers["X-Content-Type-Options"] = "nosniff"
        response.headers["X-Frame-Options"] = "DENY"
        response.headers["X-XSS-Protection"] = "1; mode=block"
        response.headers["Referrer-Policy"] = "strict-origin-when-cross-origin"
        response.headers["Content-Security-Policy"] = (
            "default-src 'self'; "
            "script-src 'self'; "
            "style-src 'self' 'unsafe-inline'; "
            "img-src 'self' data: https:; "
            "font-src 'self'; "
            "connect-src 'self' https:; "
            "frame-ancestors 'none'; "
        )
        return response


def setup_security_headers(app: FastAPI) -> None:
    app.add_middleware(SecurityHeadersMiddleware)