File

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.

local methods = {};
local resolver_mt = { __index = methods };
local unpack = table.unpack or unpack; -- luacheck: ignore 113

-- Find the next target to connect to, and
-- pass it to cb()
function methods:next(cb)
	if #self.targets == 0 then
		cb(nil);
		return;
	end
	local next_target = table.remove(self.targets, 1);
	cb(unpack(next_target, 1, 4));
end

local function new(targets, conn_type, extra)
	return setmetatable({
		conn_type = conn_type;
		extra = extra;
		targets = targets or {};
	}, resolver_mt);
end

return {
	new = new;
};