Allow hidden payment methods on payment method change (#3682)

* Allow hidden payment methods on payment method change

* Save hashes to meta data

src/pretix/base/payment.py

@@ -817,7 +817,7 @@ class BasePaymentProvider:
         """
         return ""
 
-    def order_change_allowed(self, order: Order) -> bool:
+    def order_change_allowed(self, order: Order, request: HttpRequest=None) -> bool:
         """
         Will be called to check whether it is allowed to change the payment method of
         an order to this one.
@@ -835,7 +835,12 @@ class BasePaymentProvider:
             return False
 
         if self.settings.get('_hidden', as_type=bool):
-            return False
+            if request:
+                hashes = set(request.session.get('pretix_unlock_hashes', [])) | set(order.meta_info_data.get('unlock_hashes', []))
+                if hashlib.sha256((self.settings._hidden_seed + self.event.slug).encode()).hexdigest() not in hashes:
+                    return False
+            else:
+                return False
 
         restricted_countries = self.settings.get('_restricted_countries', as_type=list)
         if restricted_countries:

src/pretix/presale/checkoutflow.py

@@ -1515,6 +1515,9 @@ class ConfirmStep(CartMixin, AsyncAction, TemplateFlowStep):
                 str(m) for m in self.confirm_messages.values()
             ]
         }
+        unlock_hashes = request.session.get('pretix_unlock_hashes', [])
+        if unlock_hashes:
+            meta_info['unlock_hashes'] = unlock_hashes
         for receiver, response in order_meta_from_request.send(sender=request.event, request=request):
             meta_info.update(response)
 

src/pretix/presale/views/order.py

@@ -289,9 +289,17 @@ class OrderDetails(EventViewMixin, OrderDetailMixin, CartMixin, TicketPageMixin,
             ctx['can_pay'] = False
 
             for provider in self.request.event.get_payment_providers().values():
-                if provider.is_enabled and provider.order_change_allowed(self.order):
+                if provider.is_enabled:
-                    ctx['can_pay'] = True
+
-                    break
+                    if 'request' in inspect.signature(provider.order_change_allowed).parameters:
+                        if provider.is_enabled and provider.order_change_allowed(self.order, request=self.request):
+                            ctx['can_pay'] = True
+                            break
+
+                    else:
+                        if provider.is_enabled and provider.order_change_allowed(self.order):
+                            ctx['can_pay'] = True
+                            break
 
             if lp and lp.state not in (OrderPayment.PAYMENT_STATE_CONFIRMED, OrderPayment.PAYMENT_STATE_REFUNDED,
                                        OrderPayment.PAYMENT_STATE_CANCELED):
@@ -665,8 +673,16 @@ class OrderPayChangeMethod(EventViewMixin, OrderDetailMixin, TemplateView):
         providers = []
         pending_sum = self.order.pending_sum
         for provider in self.request.event.get_payment_providers().values():
-            if not provider.is_enabled or not provider.order_change_allowed(self.order):
+            if not provider.is_enabled:
                 continue
+
+            if 'request' in inspect.signature(provider.order_change_allowed).parameters:
+                if not provider.order_change_allowed(self.order, request=self.request):
+                    continue
+            else:
+                if not provider.order_change_allowed(self.order):
+                    continue
+
             current_fee = sum(f.value for f in self.open_fees) or Decimal('0.00')
             fee = provider.calculate_fee(pending_sum - current_fee)
             if 'order' in inspect.signature(provider.payment_form_render).parameters: