File

mod_muc_restrict_media/mod_muc_restrict_media.lua @ 5193:2bb29ece216b

mod_http_oauth2: Implement stateless dynamic client registration Replaces previous explicit registration that required either the additional module mod_adhoc_oauth2_client or manually editing the database. That method was enough to have something to test with, but would not probably not scale easily. Dynamic client registration allows creating clients on the fly, which may be even easier in theory. In order to not allow basically unauthenticated writes to the database, we implement a stateless model here. per_host_key := HMAC(config -> oauth2_registration_key, hostname) client_id := JWT { client metadata } signed with per_host_key client_secret := HMAC(per_host_key, client_id) This should ensure everything we need to know is part of the client_id, allowing redirects etc to be validated, and the client_secret can be validated with only the client_id and the per_host_key. A nonce injected into the client_id JWT should ensure nobody can submit the same client metadata and retrieve the same client_secret
author Kim Alvefur <zash@zash.se>
date Fri, 03 Mar 2023 21:14:19 +0100
parent 5171:1682166171ff
line wrap: on
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module:depends"muc";

local restrict_by_default = module:get_option_boolean("muc_room_default_restrict_media", true);

local function should_restrict_media(room)
	local restrict_media = room._data.restrict_media;
	if restrict_media == nil then
		restrict_media = restrict_by_default;
	end
	return restrict_media;
end

module:hook("muc-config-form", function(event)
	local room, form = event.room, event.form;
	table.insert(form, {
		name = "{xmpp:prosody.im}muc#roomconfig_unaffiliated_media",
		type = "boolean",
		label = "Display inline media (images, etc.) from non-members",
		value = not should_restrict_media(room),
	});
end);

module:hook("muc-config-submitted", function(event)
	local room, fields, changed = event.room, event.fields, event.changed;
	local new_restrict_media = not fields["{xmpp:prosody.im}muc#roomconfig_unaffiliated_media"];
	if new_restrict_media ~= should_restrict_media(room) then
		if new_restrict_media == restrict_by_default then
			room._data.restrict_media = nil;
		else
			room._data.restrict_media = new_restrict_media;
		end
		if type(changed) == "table" then
			changed["{xmpp:prosody.im}muc#roomconfig_unaffiliated_media"] = true;
		else
			event.changed = true;
		end
	end
end);

module:hook("muc-disco#info", function (event)
	local room, form, formdata = event.room, event.form, event.formdata;

	local allow_unaffiliated_media = not should_restrict_media(room);
	table.insert(form, {
		name = "{xmpp:prosody.im}muc#roomconfig_unaffiliated_media",
		type = "boolean",
	});
	formdata["{xmpp:prosody.im}muc#roomconfig_unaffiliated_media"] = allow_unaffiliated_media;
end);

local function strip_xhtml_img(tag)
	if tag.attr.xmlns == "http://www.w3.org/1999/xhtml" and tag.name == "img" then
		tag.name = "i";
		tag:text(tag.attr.alt or "<image blocked>");
		tag.attr = { xmlns = tag.attr.xmlns, title = tag.attr.title };
		tag:maptags(strip_xhtml_img);
	else
		tag:maptags(strip_xhtml_img);
	end

	return tag;
end

local function filter_media_tags(tag)
	local xmlns = tag.attr.xmlns;
	if xmlns == "jabber:x:oob" then
		return nil;
	elseif xmlns == "urn:xmpp:reference:0" then
		if tag:get_child("media-sharing", "urn:xmpp:sims:1") then
			return nil;
		end
	elseif xmlns == "http://jabber.org/protocol/xhtml-im" then
		return strip_xhtml_img(tag);
	end
	return tag;
end

module:hook("muc-occupant-groupchat", function (event)
	local stanza = event.stanza;
	if stanza.attr.type ~= "groupchat" then return; end
	if event.room:get_affiliation(stanza.attr.from) then return end
	if should_restrict_media(event.room) then
		stanza:maptags(filter_media_tags);
	end
end, 20);