from django.conf import settings from django.contrib.sessions.backends.base import UpdateError from django.core.exceptions import SuspiciousOperation from django.utils.cache import patch_vary_headers from django.utils.deprecation import MiddlewareMixin from django.utils.http import cookie_date
defprocess_response(self, request, response): """ If request.session was modified, or if the configuration is to save the session every time, save the changes and set a session cookie or delete the session cookie if the session has been emptied. """ try: accessed = request.session.accessed modified = request.session.modified empty = request.session.is_empty() except AttributeError: pass else: # First check if we need to delete this cookie. # The session should be deleted only if the session is entirely empty if settings.SESSION_COOKIE_NAME in request.COOKIES and empty: response.delete_cookie( settings.SESSION_COOKIE_NAME, path=settings.SESSION_COOKIE_PATH, domain=settings.SESSION_COOKIE_DOMAIN, ) else: if accessed: patch_vary_headers(response, ('Cookie',)) if (modified or settings.SESSION_SAVE_EVERY_REQUEST) andnot empty: if request.session.get_expire_at_browser_close(): max_age = None expires = None else: max_age = request.session.get_expiry_age() expires_time = time.time() + max_age expires = cookie_date(expires_time) # Save the session data and refresh the client cookie. # Skip session save for 500 responses, refs #3881. if response.status_code != 500: try: request.session.save() except UpdateError: raise SuspiciousOperation( "The request's session was deleted before the " "request completed. The user may have logged " "out in a concurrent request, for example." ) response.set_cookie( settings.SESSION_COOKIE_NAME, request.session.session_key, max_age=max_age, expires=expires, domain=settings.SESSION_COOKIE_DOMAIN, path=settings.SESSION_COOKIE_PATH, secure=settings.SESSION_COOKIE_SECURE orNone, httponly=settings.SESSION_COOKIE_HTTPONLY orNone, ) return response
The Django sessions framework is entirely, and solely, cookie-based. It does not fall back to putting session IDs in URLs as a last resort, as PHP does. This is an intentional design decision. Not only does that behavior make URLs ugly, it makes your site vulnerable to session-ID theft via the “Referer” header.