better checkTor middleware

routes/tor.js

@@ -1,29 +1,15 @@
-var express = require('express');
-var router = express.Router();
-const dns = require('dns').promises;
-
-function isExitNode (ip) {
-    ip = ip.split('.').reverse().join('.');
-    const domain = ip + '.8080.235.126.68.51.ip-port.exitlist.torproject.org'
-    console.log(domain);
-    return dns.lookup(domain, {}).then(ret => {
-	if (ret.address === '127.0.0.2') return true;
-	return false;
-    }).catch( e => false )
+const { promisify } = require('util')
+const dns = require('dns')
+const lookup = promisify(dns.lookup)
+
+// https://www.torproject.org/projects/tordnsel.html.en
+// check if request comes from tor
+module.exports = async (req, res, next) => {
+    const source_ip = req.headers['x-forwarded-for'] || req.connection.remoteAddress
+    const ip = source_ip.split('.').reverse().join('.')
+    const server_ip = '51.68.126.235'.split('.').reverse().join('.')
+    const domain = `${ip}.80.${server_ip}.ip-port.exitlist.torproject.org`
+    const ret = await lookup(domain, {})
+    req.fromTor = (ret.address === '127.0.0.2')
+    next()
 }
-
-
-router.get('/', (req, res) => {
-  const source_ip = req.headers['x-forwarded-for'] || req.connection.remoteAddress;
- 
-  isExitNode(source_ip).then( isExit => {
-	  if (isExit) {
-      res.render('torok');
-	  } else {
-		  res.render('tornook');
-	  }
-  });
-});
-
-
-module.exports = router;