use cookieretry only on presale event pages (Z#23236752) (#6297)

* use cookieretry only on presale event pages

* use csrfcookieretry only on event index page

* include static tag

* include csrfcookieretry in order.html as well

* Update src/pretix/static/pretixpresale/js/csrfcookieretry.js

Co-authored-by: Richard Schreiber <schreiber@pretix.eu>

---------

Co-authored-by: Richard Schreiber <schreiber@pretix.eu>

pyproject.toml

@@ -53,6 +53,7 @@ dependencies = [
   "django-oauth-toolkit==2.3.*",
   "django-otp==1.7.*",
   "django-phonenumber-field==8.4.*",
+  "django-querytagger==0.0.3",
   "django-redis==6.0.*",
   "django-scopes==2.0.*",
   "django-statici18n==2.7.*",
@@ -93,7 +94,7 @@ dependencies = [
   "redis==7.4.*",
   "reportlab==4.5.*",
   "requests==2.32.*",
-  "sentry-sdk==2.63.*",
+  "sentry-sdk==2.64.*",
   "sepaxml==2.7.*",
   "stripe==7.9.*",
   "text-unidecode==1.*",

src/Makefile

@@ -6,8 +6,8 @@ localecompile:
 	./manage.py compilemessages
 
 localegen:
-	./manage.py makemessages --keep-pot --ignore "pretix/static/npm_dir/*" $(LNGS)
-	./manage.py makemessages --keep-pot -e js,ts,vue -d djangojs --ignore "pretix/static/npm_dir/*" --ignore "pretix/helpers/*" --ignore "pretix/static/jsi18n/*" --ignore "pretix/static/jsi18n/*" --ignore "pretix/static.dist/*" --ignore "data/*" --ignore "pretix/static/rrule/*" --ignore "build/*" $(LNGS)
+	./manage.py makemessages --keep-pot --add-location file --ignore "pretix/static/npm_dir/*" $(LNGS)
+	./manage.py makemessages --keep-pot --add-location file -e js,ts,vue -d djangojs --ignore "pretix/static/npm_dir/*" --ignore "pretix/helpers/*" --ignore "pretix/static/jsi18n/*" --ignore "pretix/static/jsi18n/*" --ignore "pretix/static.dist/*" --ignore "data/*" --ignore "pretix/static/rrule/*" --ignore "build/*" $(LNGS)
 
 staticfiles: npminstall npmbuild jsi18n
 	./manage.py collectstatic --noinput

src/pretix/_base_settings.py

@@ -118,6 +118,7 @@ ALL_LANGUAGES = [
     ('sv', _('Swedish')),
     ('es', _('Spanish')),
     ('es-419', _('Spanish (Latin America)')),
+    ('th', _('Thai')),
     ('tr', _('Turkish')),
     ('uk', _('Ukrainian')),
 ]

src/pretix/base/middleware.py

@@ -19,6 +19,8 @@
 # You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
 # <https://www.gnu.org/licenses/>.
 #
+import logging
+import re
 from collections import OrderedDict
 from urllib.parse import urlparse, urlsplit
 from zoneinfo import ZoneInfo, ZoneInfoNotFoundError
@@ -43,6 +45,8 @@ from pretix.multidomain.urlreverse import (
 )
 from pretix.presale.style import get_fonts
 
+logger = logging.getLogger(__name__)
+
 _supported = None
 
 
@@ -223,7 +227,26 @@ def _parse_csp(header):
     return h
 
 
+VALID_CSP_DIRECTIVES = [
+    "child-src", "connect-src", "default-src", "fenced-frame-src", "font-src", "form-action", "frame-src", "img-src",
+    "manifest-src", "media-src", "object-src", "prefetch-src", "report-uri", "script-src", "script-src-elem",
+    "script-src-attr", "style-src", "style-src-elem", "style-src-attr", "worker-src",
+]
+
+CSP_ILLEGAL_CHARS = re.compile(r'[\s,;]')
+
+
+def _sanitize_csp(h):
+    for k, v in h.items():
+        if k not in VALID_CSP_DIRECTIVES:
+            raise ValueError("Invalid CSP directive " + k)
+        if any(CSP_ILLEGAL_CHARS.search(el) for el in v):
+            logger.warning("Stripping invalid component from CSP: %r", h)
+            h[k] = [el for el in v if not CSP_ILLEGAL_CHARS.search(el)]
+
+
 def _render_csp(h):
+    _sanitize_csp(h)
     return "; ".join(k + ' ' + ' '.join(v) for k, v in h.items() if v)
 
 
@@ -243,21 +266,7 @@ def _merge_csp(a, b):
 
 
 class SecurityMiddleware(MiddlewareMixin):
-    CSP_EXEMPT = (
-        '/api/v1/docs/',
-    )
-
     def process_response(self, request, resp):
-        def nested_dict_values(d):
-            for v in d.values():
-                if isinstance(v, dict):
-                    yield from nested_dict_values(v)
-                else:
-                    if isinstance(v, str):
-                        yield v
-
-        url = resolve(request.path_info)
-
         if settings.DEBUG and resp.status_code >= 400:
             # Don't use CSP on debug error page as it breaks of Django's fancy error
             # pages
@@ -268,18 +277,15 @@ class SecurityMiddleware(MiddlewareMixin):
         # https://github.com/pretix/pretix/issues/765
         resp['P3P'] = 'CP=\"ALL DSP COR CUR ADM TAI OUR IND COM NAV INT\"'
 
-        img_src = []
-        gs = global_settings_object(request)
-        if gs.settings.leaflet_tiles:
-            img_src.append(gs.settings.leaflet_tiles[:gs.settings.leaflet_tiles.index("/", 10)].replace("{s}", "*"))
+        if not getattr(resp, '_csp_ignore', False):
+            resp['Content-Security-Policy'] = _render_csp(self._build_csp(request, resp))
+        elif 'Content-Security-Policy' in resp:
+            del resp['Content-Security-Policy']
 
-        font_src = set()
-        if hasattr(request, 'event'):
-            for font in get_fonts(request.event, pdf_support_required=False).values():
-                for path in list(nested_dict_values(font)):
-                    font_location = urlparse(path)
-                    if font_location.scheme and font_location.netloc:
-                        font_src.add('{}://{}'.format(font_location.scheme, font_location.netloc))
+        return resp
+
+    def _build_csp(self, request, resp):
+        url = resolve(request.path_info)
 
         h = {
             'default-src': ["{static}"],
@@ -288,8 +294,8 @@ class SecurityMiddleware(MiddlewareMixin):
             'frame-src': ['{static}'],
             'style-src': ["{static}", "{media}"],
             'connect-src': ["{dynamic}", "{media}"],
-            'img-src': ["{static}", "{media}", "data:"] + img_src,
-            'font-src': ["{static}"] + list(font_src),
+            'img-src': ["{static}", "{media}", "data:"],
+            'font-src': ["{static}"],
             'media-src': ["{static}", "data:"],
             # form-action is not only used to match on form actions, but also on URLs
             # form-actions redirect to. In the context of e.g. payment providers or
@@ -298,6 +304,13 @@ class SecurityMiddleware(MiddlewareMixin):
             'form-action': ["{dynamic}", "https:"] + (['http:'] if settings.SITE_URL.startswith('http://') else []),
         }
 
+        gs = global_settings_object(request)
+        if gs.settings.leaflet_tiles:
+            h['img-src'].append(gs.settings.leaflet_tiles[:gs.settings.leaflet_tiles.index("/", 10)].replace("{s}", "*"))
+
+        if hasattr(request, 'event'):
+            h['font-src'] += list(self._get_font_origins(request.event))
+
         if settings.VITE_DEV_MODE:
             h['script-src'] += ["http://localhost:5173", "ws://localhost:5173"]
             h['style-src'] += ["'unsafe-inline'"]
@@ -309,6 +322,7 @@ class SecurityMiddleware(MiddlewareMixin):
             if not settings.VITE_DEV_MODE:
                 # can't have 'unsafe-inline' and nonce at the same time
                 h['style-src'].append(nonce)
+
         # Only include pay.google.com for wallet detection purposes on the Payment selection page
         if (
                 url.url_name == "event.order.pay.change" or
@@ -317,27 +331,32 @@ class SecurityMiddleware(MiddlewareMixin):
             h['script-src'].append('https://pay.google.com')
             h['frame-src'].append('https://pay.google.com')
             h['connect-src'].append('https://google.com/pay')
+
         if settings.LOG_CSP:
             h['report-uri'] = ["/csp_report/"]
+
         if 'Content-Security-Policy' in resp:
             _merge_csp(h, _parse_csp(resp['Content-Security-Policy']))
+
         if settings.CSP_ADDITIONAL_HEADER:
             _merge_csp(h, _parse_csp(settings.CSP_ADDITIONAL_HEADER))
 
-        staticdomain = "'self'"
-        dynamicdomain = "'self'"
-        mediadomain = "'self'"
+        placeholders = {
+            "{static}": ["'self'"],
+            "{dynamic}": ["'self'"],
+            "{media}": ["'self'"],
+        }
         if settings.MEDIA_URL.startswith('http'):
-            mediadomain += " " + settings.MEDIA_URL[:settings.MEDIA_URL.find('/', 9)]
+            placeholders["{media}"].append(settings.MEDIA_URL[:settings.MEDIA_URL.find('/', 9)])
         if settings.STATIC_URL.startswith('http'):
-            staticdomain += " " + settings.STATIC_URL[:settings.STATIC_URL.find('/', 9)]
+            placeholders["{static}"].append(settings.STATIC_URL[:settings.STATIC_URL.find('/', 9)])
         if settings.SITE_URL.startswith('http'):
             if settings.SITE_URL.find('/', 9) > 0:
-                staticdomain += " " + settings.SITE_URL[:settings.SITE_URL.find('/', 9)]
-                dynamicdomain += " " + settings.SITE_URL[:settings.SITE_URL.find('/', 9)]
+                placeholders["{static}"].append(settings.SITE_URL[:settings.SITE_URL.find('/', 9)])
+                placeholders["{dynamic}"].append(settings.SITE_URL[:settings.SITE_URL.find('/', 9)])
             else:
-                staticdomain += " " + settings.SITE_URL
-                dynamicdomain += " " + settings.SITE_URL
+                placeholders["{static}"].append(settings.SITE_URL)
+                placeholders["{dynamic}"].append(settings.SITE_URL)
 
         if hasattr(request, 'organizer') and request.organizer:
             if hasattr(request, 'event') and request.event:
@@ -348,18 +367,29 @@ class SecurityMiddleware(MiddlewareMixin):
                 siteurlsplit = urlsplit(settings.SITE_URL)
                 if siteurlsplit.port and siteurlsplit.port not in (80, 443):
                     domain = '%s:%d' % (domain, siteurlsplit.port)
-                dynamicdomain += " " + domain
+                placeholders["{dynamic}"].append(domain)
 
-        if request.path not in self.CSP_EXEMPT and not getattr(resp, '_csp_ignore', False):
-            resp['Content-Security-Policy'] = _render_csp(h).format(static=staticdomain, dynamic=dynamicdomain,
-                                                                    media=mediadomain)
-            for k, v in h.items():
-                h[k] = sorted(set(' '.join(v).format(static=staticdomain, dynamic=dynamicdomain, media=mediadomain).split(' ')))
-            resp['Content-Security-Policy'] = _render_csp(h)
-        elif 'Content-Security-Policy' in resp:
-            del resp['Content-Security-Policy']
+        for k, v in h.items():
+            h[k] = sorted(set(result for part in v for result in placeholders.get(part, [part])))
 
-        return resp
+        return h
+
+    def _get_font_origins(self, event):
+        def nested_dict_values(d):
+            for v in d.values():
+                if isinstance(v, dict):
+                    yield from nested_dict_values(v)
+                else:
+                    if isinstance(v, str):
+                        yield v
+
+        font_src = set()
+        for font in get_fonts(event, pdf_support_required=False).values():
+            for path in list(nested_dict_values(font)):
+                font_location = urlparse(path)
+                if font_location.scheme and font_location.netloc:
+                    font_src.add('{}://{}'.format(font_location.scheme, font_location.netloc))
+        return font_src
 
 
 class RejectInvalidInputMiddleware(MiddlewareMixin):

src/pretix/base/models/auth.py

@@ -647,25 +647,22 @@ class User(AbstractBaseUser, PermissionsMixin, LoggingMixin):
             id__in=self.teams.filter(TeamQuerySet.organizer_permission_q(permission)).values_list('organizer', flat=True)
         )
 
-    def has_active_staff_session(self, session_key=None):
+    def has_active_staff_session(self, session_key):
         """
         Returns whether or not a user has an active staff session (formerly known as superuser session)
         with the given session key.
         """
         return self.get_active_staff_session(session_key) is not None
 
-    def get_active_staff_session(self, session_key=None):
-        if not self.is_staff:
+    def get_active_staff_session(self, session_key):
+        if not self.is_staff or not session_key:
             return None
         if not hasattr(self, '_staff_session_cache'):
             self._staff_session_cache = {}
         if session_key not in self._staff_session_cache:
-            qs = StaffSession.objects.filter(
-                user=self, date_end__isnull=True
-            )
-            if session_key:
-                qs = qs.filter(session_key=session_key)
-            sess = qs.first()
+            sess = StaffSession.objects.filter(
+                user=self, date_end__isnull=True, session_key=session_key
+            ).first()
             if sess:
                 if sess.date_start < now() - timedelta(seconds=settings.PRETIX_SESSION_TIMEOUT_ABSOLUTE):
                     sess.date_end = now()

src/pretix/base/settings.py

@@ -1924,8 +1924,6 @@ DEFAULTS = {
         'serializer_class': serializers.BooleanField,
         'form_kwargs': dict(
             label=_("Hide all past dates from calendar"),
-            help_text=_("This option currently only affects the calendar of this event series, not the organizer-wide "
-                        "calendar.")
         )
     },
     'allow_modifications': {

src/pretix/control/middleware.py

@@ -36,6 +36,7 @@ from urllib.parse import quote, urljoin, urlparse
 
 from django.conf import settings
 from django.contrib.auth import REDIRECT_FIELD_NAME, logout
+from django.contrib.auth.views import redirect_to_login
 from django.http import Http404
 from django.shortcuts import get_object_or_404, resolve_url
 from django.template.response import TemplateResponse
@@ -214,12 +215,15 @@ class AuditLogMiddleware:
                 hijack_history = request.session.get('hijack_history', False)
                 hijacker = get_object_or_404(User, pk=hijack_history[0]["user"])
                 ss = hijacker.get_active_staff_session(request.session.get('hijacker_session'))
-                if ss:
-                    ss.logs.create(
-                        url=request.path,
-                        method=request.method,
-                        impersonating=request.user
-                    )
+                if not ss:
+                    # Staff session expired or not found
+                    logout(request)
+                    return redirect_to_login(request.get_full_path())
+                ss.logs.create(
+                    url=request.path,
+                    method=request.method,
+                    impersonating=request.user
+                )
             else:
                 ss = request.user.get_active_staff_session(request.session.session_key)
                 if ss:

src/pretix/control/views/users.py

@@ -31,6 +31,7 @@ from django.contrib.auth import (
 )
 from django.contrib.auth.mixins import LoginRequiredMixin
 from django.contrib.auth.views import redirect_to_login
+from django.core.exceptions import PermissionDenied
 from django.db import transaction
 from django.shortcuts import get_object_or_404, redirect
 from django.urls import reverse
@@ -221,11 +222,13 @@ class UserImpersonateView(AdministratorPermissionRequiredMixin, RecentAuthentica
 
     def post(self, request, *args, **kwargs):
         self.object = get_object_or_404(User, pk=self.kwargs.get("id"))
+        staff_session = request.user.get_active_staff_session(request.session.session_key)
         self.request.user.log_action('pretix.control.auth.user.impersonated',
                                      user=request.user,
                                      data={
                                          'other': self.kwargs.get("id"),
-                                         'other_email': self.object.email
+                                         'other_email': self.object.email,
+                                         'staff_session': staff_session.pk,
                                      })
         oldkey = request.session.session_key
 
@@ -249,6 +252,12 @@ class UserImpersonateView(AdministratorPermissionRequiredMixin, RecentAuthentica
         with signals.no_update_last_login(), keep_session_age(request.session):
             login(request, hijacked, backend=backend)
 
+        request.session.save()
+        staff_session.logs.create(
+            method='(NOTE)',
+            url=f'Begin impersonating user #{hijacked.pk} (request session {oldkey[:8]} -> {request.session.session_key[:8]})',
+        )
+
         request.session["hijack_history"] = hijack_history
 
         signals.hijack_started.send(
@@ -265,13 +274,15 @@ class UserImpersonateView(AdministratorPermissionRequiredMixin, RecentAuthentica
 class UserImpersonateStopView(LoginRequiredMixin, View):
 
     def post(self, request, *args, **kwargs):
-        impersonated = request.user
-
-        hijs = request.session['hijacker_session']
+        staff_session_key = request.session['hijacker_session']
+        prev_session_key = request.session.session_key
         hijack_history = request.session.get("hijack_history", [])
         hijacked = request.user
         prev_session = hijack_history.pop()
         hijacker = get_object_or_404(get_user_model(), pk=prev_session["user"])
+        staff_session = hijacker.get_active_staff_session(staff_session_key)
+        if not staff_session:
+            raise PermissionDenied
 
         expected_hash = salted_hmac(
             key_salt=b"hijack-history-hash",
@@ -299,17 +310,22 @@ class UserImpersonateStopView(LoginRequiredMixin, View):
             hijacked=hijacked,
         )
 
-        ss = request.user.get_active_staff_session(hijs)
-        if ss:
-            request.session.save()
-            ss.session_key = request.session.session_key
-            ss.save()
+        request.session.save()
+        staff_session.session_key = request.session.session_key
+        staff_session.save()
+
+        staff_session.logs.create(
+            method='(NOTE)',
+            url=f'Stop impersonating user #{hijacked.pk} (request session {prev_session_key[:8]}, '
+                f'staff session {staff_session_key[:8]} -> {request.session.session_key[:8]})',
+        )
 
         request.user.log_action('pretix.control.auth.user.impersonate_stopped',
                                 user=request.user,
                                 data={
-                                    'other': impersonated.pk,
-                                    'other_email': impersonated.email
+                                    'other': hijacked.pk,
+                                    'other_email': hijacked.email,
+                                    'staff_session': staff_session.pk,
                                 })
         return redirect(reverse('control:index'))
 

src/pretix/presale/templates/pretixpresale/event/base.html

@@ -9,7 +9,7 @@
 {% load anonymize_email %}
 {% block thetitle %}
     {% if messages %}
-        {{ messages|join:" " }} :: 
+        {{ messages|join:" " }} ::
     {% endif %}
     {% block title %}{% endblock %}{% if request.resolver_match.url_name != "event.index" %} :: {% endif %}{{ event.name }}
 {% endblock %}

src/pretix/presale/templates/pretixpresale/event/index.html

@@ -1,6 +1,7 @@
 {% extends "pretixpresale/event/base.html" %}
 {% load i18n %}
 {% load l10n %}
+{% load static %}
 {% load eventurl %}
 {% load cache_large %}
 {% load money %}
@@ -39,6 +40,7 @@
     {% else %}
         <meta property="og:url" content="{% abseventurl request.event "presale:event.index" %}" />
     {% endif %}
+    <script type="text/javascript" src="{% static "pretixpresale/js/csrfcookieretry.js" %}"></script>
 {% endblock %}
 {% block content %}
 

src/pretix/presale/templates/pretixpresale/event/order.html

@@ -6,6 +6,7 @@
 {% load money %}
 {% load expiresformat %}
 {% load eventurl %}
+{% load static %}
 {% load phone_format %}
 {% load rich_text %}
 {% load getitem %}
@@ -22,6 +23,10 @@
     {% endif %}
     {% trans "Order details" %}
 {% endblock %}
+{% block custom_header %}
+    {{ block.super }}
+     <script type="text/javascript" src="{% static "pretixpresale/js/csrfcookieretry.js" %}"></script>
+{% endblock %}
 {% block content %}
     {% if "thanks" in request.GET or "paid" in request.GET %}
         <div class="thank-you">

src/pretix/presale/templates/pretixpresale/fragment_calendar.html

@@ -21,22 +21,21 @@
                             data-date="{{ day.date|date_fast:"SHORT_DATE_FORMAT" }}">
                             <p>
                             {% if day.events %}
-                                <a href="#selected-day" class="day-label event hidden-sm hidden-md hidden-lg">
+                                <a href="#selected-day" class="day-label event hidden-sm hidden-md hidden-lg" aria-describedby="nr-of-events-{{ day.date|date_fast:"Y-m-d" }}">
                                     <b aria-hidden="true">{{ day.day }}</b>
                                     <time datetime="{{ day.date|date_fast:"Y-m-d" }}" class="sr-only">
                                         {{ day.date|date_fast:"SHORT_DATE_FORMAT" }}
                                     </time>
-                                    <span class="sr-only">
-                                        ({% blocktrans trimmed count count=day.events|length %}
-                                            {{ count }} event
-                                        {% plural %}
-                                            {{ count }} events
-                                        {% endblocktrans %})
-                                    </span>
+                                    <span class="sr-only" id="nr-of-events-{{ day.date|date_fast:"Y-m-d" }}">{% blocktrans trimmed count count=day.events|length %}
+                                        {{ count }} event
+                                    {% plural %}
+                                        {{ count }} events
+                                    {% endblocktrans %}</span>
                                 </a>
                                 <time datetime="{{ day.date|date_fast:"Y-m-d" }}" class="hidden-xs">{{ day.day }}</time>
                             {% else %}
                                 <time datetime="{{ day.date|date_fast:"Y-m-d" }}" class="day-label">{{ day.day }}</time>
+                                <span class="sr-only">{% trans "No events" %}</span>
                             {% endif %}
                             </p>
                             <ul class="events">

src/pretix/presale/views/organizer.py

@@ -650,6 +650,10 @@ def add_subevents_for_days(qs, before, after, ebd, timezones, sales_channel, eve
             if hide:
                 continue
 
+        if s.event_calendar_future_only:
+            if (se.date_to or se.date_from) < time_machine_now():
+                continue
+
         timezones.add(s.timezone)
         tz = ZoneInfo(s.timezone)
         datetime_from = se.date_from.astimezone(tz)

src/pretix/presale/views/widget.py

@@ -123,7 +123,7 @@ def widget_css_etag(request, version, **kwargs):
 
 
 def _use_vite(request):
-    if getattr(settings, 'PRETIX_WIDGET_VITE', False):
+    if getattr(settings, 'PRETIX_WIDGET_VITE', False) or "beta" in request.GET:
         return True
     origin = request.META.get('HTTP_ORIGIN', '')
     gs = GlobalSettingsObject()

src/pretix/settings.py

@@ -440,6 +440,7 @@ CSRF_COOKIE_NAME = 'pretix_csrftoken'
 SESSION_COOKIE_HTTPONLY = True
 
 INSTALLED_APPS += [ # noqa
+    'django_querytagger',
     'django_filters',
     'django_markup',
     'django_otp',
@@ -505,6 +506,7 @@ MIDDLEWARE = [
     'pretix.helpers.logs.RequestIdMiddleware',
     'pretix.api.middleware.IdempotencyMiddleware',
     'pretix.multidomain.middlewares.MultiDomainMiddleware',
+    'django_querytagger.middleware.SetTagMiddleware',  # after MultiDomainMiddleware for correct url resolving
     'pretix.base.middleware.CustomCommonMiddleware',
     'pretix.multidomain.middlewares.SessionMiddleware',
     'pretix.multidomain.middlewares.CsrfViewMiddleware',

src/pretix/static/pretixpresale/js/csrfcookieretry.js

@@ -0,0 +1,15 @@
+document.addEventListener("DOMContentLoaded", () => {
+  const COOKIE_NAME = "__Host-pretix_csrftoken";
+  const RELOAD_FLAG = "csrfReloadPerformed";
+
+  const hasCookie = document.cookie
+    .split("; ")
+    .some((c) => c.startsWith(COOKIE_NAME + "="));
+
+  if (!hasCookie && !sessionStorage.getItem(RELOAD_FLAG)) {
+    sessionStorage.setItem(RELOAD_FLAG, "1");
+    location.reload();
+  } else if (hasCookie && sessionStorage.getItem(RELOAD_FLAG)) {
+      sessionStorage.removeItem(RELOAD_FLAG);
+  }
+});

src/tests/base/test_middleware.py

@@ -126,3 +126,81 @@ class LocaleDeterminationTest(TestCase):
         response = c.get('/dummy/dummy/')
         language = response['Content-Language']
         self.assertEqual(language, 'en')
+
+
+def test_render_csp():
+    from pretix.base.middleware import _render_csp
+
+    assert _render_csp({}) == ""
+    assert _render_csp({'default-src': ["'self'"]}) == "default-src 'self'"
+
+    h = {
+        'default-src': ["'self'"],
+        'script-src': ["'self'"],
+        'object-src': ["'none'"],
+        'frame-src': ["'self'"],
+        'style-src': ["'self'", "'self'"],
+        'connect-src': ["'self'", "'self'"],
+        'img-src': ["'self'", "'self'", "data:"],
+        'font-src': ["'self'"],
+        'media-src': ["'self'", "data:"],
+        'form-action': ["'self'", "https:"],
+    }
+    assert _render_csp(h) == (
+        "default-src 'self'; script-src 'self'; object-src 'none'; frame-src 'self'; style-src 'self' 'self'; "
+        "connect-src 'self' 'self'; img-src 'self' 'self' data:; font-src 'self'; media-src 'self' data:; form-action 'self' https:"
+    )
+
+
+def test_merge_csp():
+    from pretix.base.middleware import _merge_csp, _parse_csp, _render_csp
+
+    h = {
+        'default-src': ["'self'"],
+        'script-src': ["'self'"],
+        'style-src': ["'self'", "'self'"],
+        'form-action': ["'self'", "https:"],
+        'connect-src': ["'self'", "'self'"],
+    }
+    assert _render_csp(h) == (
+        "default-src 'self'; script-src 'self'; style-src 'self' 'self'; form-action 'self' https:; connect-src 'self' 'self'"
+    )
+
+    _merge_csp(h, _parse_csp("style-src 'unsafe-inline'; connect-src https://example.com"))
+    assert _render_csp(h) == (
+        "default-src 'self'; script-src 'self'; style-src 'self' 'self' 'unsafe-inline'; form-action 'self' "
+        "https:; connect-src 'self' 'self' https://example.com"
+    )
+
+
+def test_roundtrip_csp():
+    from pretix.base.middleware import _merge_csp, _parse_csp, _render_csp
+
+    prod_csp = ("default-src 'self' https://pretix.eu https://static.pretix.cloud; script-src 'self' "
+                "'sha256-+tmFggeXIPOAC2UgcQ3LW/gPHTkwyWg3/D6FOJ5BHGo=' 'unsafe-eval' https://matomo.rami.io "
+                "https://pretix.eu https://static.pretix.cloud https://support.rami.io; object-src 'none'; "
+                "frame-src 'self' https://matomo.rami.io https://pretix.eu https://static.pretix.cloud "
+                "https://support.rami.io https://www.youtube-nocookie.com; style-src 'self' 'unsafe-inline' "
+                "data: https://cdn.pretix.cloud https://pretix.eu https://static.pretix…rt.rami.io; connect-src "
+                "'self' https://cdn.pretix.cloud https://matomo.rami.io https://pretix.eu https://static.pretix.cloud "
+                "https://support.rami.io ws://support.rami.io; img-src 'self' data: https://cdn.pretix.cloud "
+                "https://matomo.rami.io https://pretix.eu https://static.pretix.cloud https://support.rami.io; "
+                "font-src 'self' https://pretix.eu https://static.pretix.cloud; media-src 'self' data: "
+                "https://cdn.pretix.cloud https://pretix.eu https://static.pretix.cloud; form-action 'self' "
+                "https: https://pretix.eu")
+    h = _parse_csp(prod_csp)
+    _merge_csp(h, _parse_csp(prod_csp))
+    assert _render_csp(h) == prod_csp
+
+
+def test_sanitize_csp():
+    from pretix.base.middleware import _render_csp
+
+    h = {
+        'style-src': ["'self'", "https://example.com", "https://example.org https://attack.example.net", "https://\fexample.org",
+                      "https://\texample.org", "https://example.org;script-src https://example.org", ],
+        'script-src': ["'self'"],
+    }
+    assert _render_csp(h) == (
+        "style-src 'self' https://example.com; script-src 'self'"
+    )