File

util/pluginloader.lua @ 12181:783056b4e448 0.11 0.11.12

util.xml: Do not allow doctypes, comments or processing instructions Yes. This is as bad as it sounds. CVE pending. In Prosody itself, this only affects mod_websocket, which uses util.xml to parse the <open/> frame, thus allowing unauthenticated remote DoS using Billion Laughs. However, third-party modules using util.xml may also be affected by this. This commit installs handlers which disallow the use of doctype declarations and processing instructions without any escape hatch. It, by default, also introduces such a handler for comments, however, there is a way to enable comments nontheless. This is because util.xml is used to parse human-facing data, where comments are generally a desirable feature, and also because comments are generally harmless.
author Jonas Schäfer <jonas@wielicki.name>
date Mon, 10 Jan 2022 18:23:54 +0100
parent 8382:e5d00bf4a4d5
child 10205:ff8de86b75f0
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-- Prosody IM
-- Copyright (C) 2008-2010 Matthew Wild
-- Copyright (C) 2008-2010 Waqas Hussain
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--
-- luacheck: ignore 113/CFG_PLUGINDIR

local dir_sep, path_sep = package.config:match("^(%S+)%s(%S+)");
local plugin_dir = {};
for path in (CFG_PLUGINDIR or "./plugins/"):gsub("[/\\]", dir_sep):gmatch("[^"..path_sep.."]+") do
	path = path..dir_sep; -- add path separator to path end
	path = path:gsub(dir_sep..dir_sep.."+", dir_sep); -- coalesce multiple separaters
	plugin_dir[#plugin_dir + 1] = path;
end

local io_open = io.open;
local envload = require "util.envload".envload;

local function load_file(names)
	local file, err, path;
	for i=1,#plugin_dir do
		for j=1,#names do
			path = plugin_dir[i]..names[j];
			file, err = io_open(path);
			if file then
				local content = file:read("*a");
				file:close();
				return content, path;
			end
		end
	end
	return file, err;
end

local function load_resource(plugin, resource)
	resource = resource or "mod_"..plugin..".lua";

	local names = {
		"mod_"..plugin..dir_sep..plugin..dir_sep..resource; -- mod_hello/hello/mod_hello.lua
		"mod_"..plugin..dir_sep..resource;                  -- mod_hello/mod_hello.lua
		plugin..dir_sep..resource;                          -- hello/mod_hello.lua
		resource;                                           -- mod_hello.lua
	};

	return load_file(names);
end

local function load_code(plugin, resource, env)
	local content, err = load_resource(plugin, resource);
	if not content then return content, err; end
	local path = err;
	local f, err = envload(content, "@"..path, env);
	if not f then return f, err; end
	return f, path;
end

local function load_code_ext(plugin, resource, extension, env)
	local content, err = load_resource(plugin, resource.."."..extension);
	if not content then
		content, err = load_resource(resource, resource.."."..extension);
		if not content then
			return content, err;
		end
	end
	local path = err;
	local f, err = envload(content, "@"..path, env);
	if not f then return f, err; end
	return f, path;
end

return {
	load_file = load_file;
	load_resource = load_resource;
	load_code = load_code;
	load_code_ext = load_code_ext;
};