view mod_sslv3_warn/mod_sslv3_warn.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 37cef218ba20
children
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local st = require"util.stanza";
local host = module.host;

local warning_message = module:get_option_string("sslv3_warning", "Your connection is encrypted using the SSL 3.0 protocol, which has been demonstrated to be insecure and will be disabled soon.  Please upgrade your client.");

module:hook("resource-bind", function (event)
	local session = event.session;
	module:log("debug", "mod_%s sees that %s logged in", module.name, session.username);

	local ok, protocol = pcall(function(session)
		return session.conn:socket():info"protocol";
	end, session);
	if not ok then
		module:log("debug", protocol);
	elseif protocol == "SSLv3" then
		module:add_timer(15, function ()
			if session.type == "c2s" and session.resource then
				session.send(st.message({ from = host, type = "headline", to = session.full_jid }, warning_message));
			end
		end);
	end
end);