Source code for oioioi.su.middleware

from django.core.exceptions import ImproperlyConfigured, PermissionDenied
from django.http.response import HttpResponseForbidden
from django.shortcuts import redirect

from oioioi.base.utils.middleware import was_response_generated_by_exception
from oioioi.su import SU_BACKEND_SESSION_KEY, SU_UID_SESSION_KEY
from oioioi.su.utils import get_user

REDIRECTION_AFTER_SU_KEY = "redirection_after_su"


class SuAuthenticationMiddleware(object):
    """Middleware overriding current request.user object with that switched to.

    User object representing real user privileges are stored in
    ``request.real_user``.
    """

    def __init__(self, get_response):
        self.get_response = get_response

    def __call__(self, request):
        self._process_request(request)

        return self.get_response(request)

    def _process_request(self, request):
        if not hasattr(request, 'user'):
            raise ImproperlyConfigured(
                "The SuAuthenticationMiddleware requires the"
                " 'django.contrib.auth.middleware.AuthenticationMiddleware'"
                " earlier in MIDDLEWARE."
            )

        request.real_user = request.user
        if SU_UID_SESSION_KEY in request.session:
            request.user = get_user(
                request,
                request.session[SU_UID_SESSION_KEY],
                request.session[SU_BACKEND_SESSION_KEY],
            )


class SuFirstTimeRedirectionMiddleware(object):
    """Middleware used for silent redirection on 403 after su'ing."""

    def __init__(self, get_response):
        self.get_response = get_response

    def __call__(self, request):
        response = self.get_response(request)

        return self._process_response(request, response)

    def process_exception(self, request, exception):
        if REDIRECTION_AFTER_SU_KEY in request.session:
            del request.session[REDIRECTION_AFTER_SU_KEY]

            if isinstance(exception, PermissionDenied):
                return redirect('index')

    def _process_response(self, request, response):
        if REDIRECTION_AFTER_SU_KEY in request.session:
            if was_response_generated_by_exception(response):
                del request.session[REDIRECTION_AFTER_SU_KEY]

                if isinstance(response, HttpResponseForbidden):
                    return redirect('index')

            elif request.session[REDIRECTION_AFTER_SU_KEY] == 'PRE_SU':
                request.session[REDIRECTION_AFTER_SU_KEY] = 'POST_SU'

            else:
                del request.session[REDIRECTION_AFTER_SU_KEY]

        return response