fix: fixed SRS issues

helpers/check-srs.js

@@ -21,7 +21,26 @@ function checkSRS(address, shouldThrow = false, ignoreHook = false) {
   if (!REGEX_SRS0.test(address) && !REGEX_SRS1.test(address)) return address;
 
   try {
-    const reversed = srs.reverse(address);
+    //
+    // sometimes senders send to a lowercase version of the MAIL FROM
+    // which is going to mess things up here because case sensitivity is needed
+    // therefore we will do a rewrite here if necessary
+    //
+    const index = address.indexOf('@');
+    const local = address.slice(0, index).split('=');
+    const domain = address.slice(index + 1);
+
+    //
+    // > local.split('=')
+    // [ 'srs0', '4f4d', 't7', 'example.com', 'john' ]
+    // and we need
+    // SRS0=4f4d=T7=example.com=john
+    // therefore keys 0 and 2 need capitalized
+    //
+    if (local[0]) local[0] = local[0].toUpperCase(); // SRS0
+    if (local[2]) local[2] = local[2].toUpperCase(); // T7
+    const srsAddress = `${local.join('=')}@${domain}`;
+    const reversed = srs.reverse(srsAddress);
     if (_.isNull(reversed)) throw new Error('Bad signature');
     return reversed;
   } catch (_err) {

helpers/get-forwarding-addresses.js

@@ -229,7 +229,7 @@ async function getForwardingAddresses(
   if (!isSANB(record) && !hasIMAP)
     throw new SMTPError(
       `${address} is not yet configured with its email service provider ${config.urls.web} ;`,
-      { responseCode: 421, ignore_hook: true }
+      { responseCode: 421, ignore_hook: true, notConfigured: true }
     );
 
   // e.g. user@example.com => [email protected]
@@ -557,7 +557,7 @@ async function getForwardingAddresses(
   if (forwardingAddresses.length === 0 && !hasIMAP) {
     throw new SMTPError(
       `${address} is not yet configured with its email service provider ${config.urls.web} ;`,
-      { responseCode: 421, ignore_hook: true }
+      { responseCode: 421, ignore_hook: true, notConfigured: true }
     );
   }
 

helpers/get-recipients.js

@@ -332,6 +332,19 @@ async function getRecipients(session, scan) {
           webhookKey
         };
       } catch (err) {
+        if (err.notConfigured && to.srs) {
+          return {
+            address: to.address,
+            addresses: [to.address],
+            port: 25,
+            hasIMAP: false,
+            aliasPublicKey: false,
+            vacationResponder: false,
+            // TODO: only do this if MX server of sender used our service
+            srs: true
+          };
+        }
+
         logger.warn(err, { session });
         err.responseCode = getErrorCode(err);
         bounces.push({
@@ -609,7 +622,8 @@ async function getRecipients(session, scan) {
         port: recipient.port,
         recipient: recipient.address,
         to: [address.to],
-        replacements
+        replacements,
+        ...(recipient.srs ? { srs: true } : {})
       });
     }
   }

helpers/on-data-mx.js

@@ -1690,9 +1690,6 @@ async function onDataMX(session, headers, body) {
     }
   }
 
-  // TODO: fix the SRS0 thing (not rewriting properly. e.g. RCD)
-  // TODO: if it was SRS rewritten then it shouldn't 421 it should deliver to the address still
-
   //
   // send vacation responders if necessary in series
   //

helpers/on-data.js

@@ -100,7 +100,9 @@ async function onData(stream, _session, fn) {
               //       however because srs0 was rewritten from SRS0
               //       and because tv was rewritten from TV it is not being delivered correctly
               //
+              const original = to.address;
               to.address = checkSRS(to.address, shouldThrow);
+              if (original !== to.address) to.srs = true;
               return to;
             }),
             async (to) => {

test/mx/index.js

@@ -18,6 +18,7 @@ const pWaitFor = require('p-wait-for');
 const pify = require('pify');
 const test = require('ava');
 const { SMTPServer } = require('smtp-server');
+const { SRS } = require('sender-rewriting-scheme');
 
 const utils = require('../utils');
 
@@ -40,6 +41,7 @@ import('@ava/get-port').then((obj) => {
 const asyncMxConnect = pify(mxConnect);
 const IP_ADDRESS = ip.address();
 const tls = { rejectUnauthorized: false };
+const srs = new SRS(config.srs);
 
 test.before(utils.setupMongoose);
 test.before(utils.setupRedisClient);
@@ -333,7 +335,14 @@ test('imap/forward/webhook', async (t) => {
       transporter.sendMail({
         envelope: {
           from: '[email protected]',
-          to: `test@${domain.name}`
+          to: [
+            `test@${domain.name}`,
+            //
+            // NOTE: this is purposely formatted incorrectly
+            //       to test when mail servers send to lowercase version of MAIL FROM
+            //       (we have logic that accounts for this, see `#helpers/check-srs`)
+            srs.forward(`test@${domain.name}`, env.WEB_HOST).toLowerCase()
+          ]
         },
         raw: `
 To: test@${domain.name}