# HG changeset patch
# User Matthew Wild <mwild1@gmail.com>
# Date 1667226722 0
# Node ID 24b55f0e2db99fe4a1b8f4746be1443ccbd6129e
# Parent  3835c397b1297a646b5b86211cea41a9292a5361
mod_http: Allow disabling CORS in the http_cors_override option and by default

Fixes #1779.

Due to an oversight in the logic, if the user set 'enabled' to false in an
override, it would disable the item's requested CORS settings, but still apply
Prosody's default CORS policy.

This change ensures that 'enabled = false' will now disable CORS entirely for
the requested item.

Due to the new structure of the code, it was necessary to have a flag to say
whether CORS is to be applied at all. Rather than hard-coding 'true' here, I
chose to add a new option: 'http_default_cors_enabled'. This is a boolean that
allows the operator to disable Prosody's default CORS policy entirely (the one
that is used when a module or config does not override it). This makes it
easier to disable CORS and then selectively enable it only on services you
want it on.

diff -r 3835c397b129 -r 24b55f0e2db9 plugins/mod_http.lua
--- a/plugins/mod_http.lua	Sun Oct 23 16:22:12 2022 +0200
+++ b/plugins/mod_http.lua	Mon Oct 31 14:32:02 2022 +0000
@@ -37,6 +37,7 @@
 local opt_origins = module:get_option_set("access_control_allow_origins");
 local opt_credentials = module:get_option_boolean("access_control_allow_credentials", false);
 local opt_max_age = module:get_option_number("access_control_max_age", 2 * 60 * 60);
+local opt_default_cors = module:get_option_boolean("http_default_cors_enabled", true);
 
 local function get_http_event(host, app_path, key)
 	local method, path = key:match("^(%S+)%s+(.+)$");
@@ -183,7 +184,11 @@
 						app_origins = set.new(cors.origins)._items;
 					end
 				end
+			elseif cors.enabled == false then
+				cors = nil;
 			end
+		else
+			cors = opt_default_cors;
 		end
 
 		local streaming = event.item.streaming_uploads;
@@ -228,12 +233,14 @@
 				if not app_handlers[event_name] then
 					app_handlers[event_name] = {
 						main = handler;
-						cors = cors_handler;
-						options = options_handler;
+						cors = cors and cors_handler;
+						options = cors and options_handler;
 					};
 					module:hook_object_event(server, event_name, handler);
-					module:hook_object_event(server, event_name, cors_handler, 1);
-					module:hook_object_event(server, options_event_name, options_handler, -1);
+					if cors then
+						module:hook_object_event(server, event_name, cors_handler, 1);
+						module:hook_object_event(server, options_event_name, options_handler, -1);
+					end
 				else
 					module:log("warn", "App %s added handler twice for '%s', ignoring", app_name, event_name);
 				end