view mod_s2s_keysize_policy/mod_s2s_keysize_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 27ffa6521d4e
children
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-- mod_s2s_keysize_policy.lua
-- Requires LuaSec with this patch: https://github.com/brunoos/luasec/pull/12

module:set_global();

local datetime_parse = require"util.datetime".parse;
local pat = "^([JFMAONSD][ceupao][glptbvyncr])  ?(%d%d?) (%d%d):(%d%d):(%d%d) (%d%d%d%d) GMT$";
local months = {Jan=1,Feb=2,Mar=3,Apr=4,May=5,Jun=6,Jul=7,Aug=8,Sep=9,Oct=10,Nov=11,Dec=12};
local function parse_x509_datetime(s)
	local month, day, hour, min, sec, year = s:match(pat); month = months[month];
	return datetime_parse(("%04d-%02d-%02dT%02d:%02d:%02dZ"):format(year, month, day, hour, min, sec));
end

local weak_key_cutoff = datetime_parse("2014-01-01T00:00:00Z");

-- From RFC 4492
local weak_key_size = {
	RSA = 2048,
	DSA = 2048,
	DH  = 2048,
	EC  =  233,
}

module:hook("s2s-check-certificate", function(event)
	local host, session, cert = event.host, event.session, event.cert;
	if cert and cert.pubkey then
		local _, key_type, key_size = cert:pubkey();
		if key_size < ( weak_key_size[key_type] or 0 ) then
			local issued = parse_x509_datetime(cert:notbefore());
			if issued > weak_key_cutoff then
				session.log("warn", "%s has a %s-bit %s key issued after 31 December 2013, invalidating trust!", host, key_size, key_type);
				session.cert_chain_status = "invalid";
				session.cert_identity_status = "invalid";
			else
				session.log("warn", "%s has a %s-bit %s key", host, key_size, key_type);
			end
		else
			session.log("info", "%s has a %s-bit %s key", host, key_size, key_type);
		end
	end
end);