view mod_flash_policy/mod_flash_policy.lua @ 4651:8231774f5bfd

mod_cloud_notify_encrypted: Ensure body substring remains valid UTF-8 The `body:sub()` call risks splitting the string in the middle of a multi-byte UTF-8 sequence. This should have been caught by util.stanza validation, but that would have caused some havoc, at the very least causing the notification to not be sent. There have been no reports of this happening. Likely because this module isn't widely deployed among users with languages that use many longer UTF-8 sequences. The util.encodings.utf8.valid() function is O(n) where only the last sequence really needs to be checked, but it's in C and expected to be fast.
author Kim Alvefur <zash@zash.se>
date Sun, 22 Aug 2021 13:22:59 +0200
parents 7dbde05b48a9
children
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local filters = require "util.filters";
local config = {}
config.file = module:get_option_string("crossdomain_file", "");
config.string = module:get_option_string("crossdomain_string", [[<?xml version="1.0"?><!DOCTYPE cross-domain-policy SYSTEM "/xml/dtds/cross-domain-policy.dtd"><cross-domain-policy><site-control permitted-cross-domain-policies="master-only"/><allow-access-from domain="*" /></cross-domain-policy>]]);
local string = ''
if not config.file ~= '' then
	local f = assert(io.open(config.file));
	string = f:read("*all");
else
	string = config.string
end

module:log("debug", "crossdomain string: "..string);

module:set_global();

function filter_policy(data, session)
	-- Since we only want to check the first block of data, remove the filter
	filters.remove_filter(session, "bytes/in", filter_policy);
	if data == "<policy-file-request/>\0" then
		session.send(string.."\0");
		return nil; -- Drop data to prevent it reaching the XMPP parser
	else
		return data; -- Pass data through, it wasn't a policy request
	end

end

function filter_session(session)
	if session.type == "c2s_unauthed" then
		filters.add_filter(session, "bytes/in", filter_policy, -1);
	end
end

function module.load()
	filters.add_filter_hook(filter_session);
end

function module.unload()
	filters.remove_filter_hook(filter_session);
end