Implement authentication middleware

core/scripts/webpanel/authentication/auth.py

@@ -0,0 +1,59 @@
+from fastapi import Request, Response, HTTPException
+from fastapi.responses import RedirectResponse
+from starlette.middleware.base import BaseHTTPMiddleware
+from starlette.types import ASGIApp
+from typing import Awaitable, Callable
+from datetime import datetime, timezone
+
+from .session import SessionManager
+
+
+class AuthMiddleware(BaseHTTPMiddleware):
+    '''Middleware that handles session authentication.'''
+
+    def __init__(self, app: ASGIApp, session_manager: SessionManager, api_token: str | None):
+        super().__init__(app)
+        self.__session_manager = session_manager
+        self.__api_token = api_token
+
+    async def dispatch(self, request: Request, call_next: Callable[[Request], Awaitable[Response]]):
+        '''Handles session authentication.'''
+        public_routes = [
+            '/login',
+        ]
+        if request.url.path in public_routes:
+            return await call_next(request)
+
+        is_api_request = '/api/v1/' in request.url.path
+
+        if is_api_request:
+            if self.__api_token:
+                # Attempt to authenticate with API token
+                if auth_header := request.headers.get('Authorization'):
+                    scheme, _, token = auth_header.partition(' ')
+                    if scheme.lower() == 'bearer' and token == self.__api_token:
+                        return await call_next(request)
+
+        # Extract session_id from cookies
+        session_id = request.cookies.get("session_id")
+
+        if not session_id:
+            if is_api_request:
+                raise HTTPException(status_code=401, detail="Unauthorized")
+            return RedirectResponse(url='/login', status_code=302)
+
+        session_data = self.__session_manager.get_session(session_id)
+        
+        if not session_data:
+            if is_api_request:
+                raise HTTPException(status_code=401, detail="The session is invalid.")
+
+            return RedirectResponse(url='/login', status_code=302)
+        
+        if session_data.expires_at < datetime.now(timezone.utc):
+            if is_api_request:
+                raise HTTPException(status_code=401, detail="The session has expired.")
+
+            return RedirectResponse(url='/login', status_code=302)
+
+        return await call_next(request)