File

mod_srvinjection/mod_srvinjection.lua @ 5461:06640647d193

mod_http_oauth2: Fix use of arbitrary ports in loopback redirect URIs Per draft-ietf-oauth-v2-1-08#section-8.4.2 > The authorization server MUST allow any port to be specified at the > time of the request for loopback IP redirect URIs, to accommodate > clients that obtain an available ephemeral port from the operating > system at the time of the request. Uncertain if it should normalize the host part, but it also seems harmless to treat IPv6 and IPv4 the same here. One thing is that "localhost" is NOT RECOMMENDED because it can sometimes be pointed to non-loopback interfaces via DNS or hosts file.
author Kim Alvefur <zash@zash.se>
date Wed, 17 May 2023 13:51:30 +0200
parent 1592:47fb4f36dacd
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module:set_global();

local adns = require "net.adns";

local map_config = module:get_option("srvinjection") or {};
local map = module:shared "s2s_map"

for host, mapping in pairs(map_config) do
	if type(mapping) == "table" and type(mapping[1]) == "string" and (type(mapping[2]) == "number") then
		local connecthost, connectport = mapping[1], mapping[2] or 5269;
		map[host] = {{
			srv = {
				target = connecthost..".";
				port = connectport;
				priority = 1;
				weight = 0;
			};
		}};
	else
		module:log("warn", "Ignoring invalid SRV injection for host '%s'", host);
		map[host] = nil;
	end
end

local original_lookup = adns.lookup;
function adns.lookup(handler, qname, qtype, qclass)
	if qtype == "SRV" then
		local host = qname:match("^_xmpp%-server%._tcp%.(.*)%.$");
		local mapping = map[host] or map["*"];
		if mapping then
			handler(mapping);
			return;
		end
	elseif qtype == "A" then
		if (qname == "localhost." or qname == "127.0.0.1.") then
			handler({{ a = "127.0.0.1" }});
			return;
		end
		local ip = qname:match("^(%d+.%d+.%d+.%d+).$");
		if ip then
			handler({{ a = ip }});
			return;
		end
	end
	return original_lookup(handler, qname, qtype, qclass);
end

function module.unload()
	adns.lookup = original_lookup;
end