update

test/suite/smtpserver_security/test.sec-11.bounce-management.ts

@@ -0,0 +1,363 @@
+import { tap, expect } from '@git.zone/tstest/tapbundle';
+import * as plugins from '../../../ts/plugins.js';
+import * as net from 'net';
+import { startTestServer, stopTestServer } from '../../helpers/server.loader.js'
+import type { ITestServer } from '../../helpers/server.loader.js';
+
+const TEST_PORT = 2525;
+let testServer: ITestServer;
+
+// Helper to wait for SMTP response
+const waitForResponse = (socket: net.Socket, expectedCode?: string, timeout = 5000): Promise<string> => {
+  return new Promise((resolve, reject) => {
+    let buffer = '';
+    const timer = setTimeout(() => {
+      socket.removeListener('data', handler);
+      reject(new Error(`Timeout waiting for ${expectedCode || 'any'} response`));
+    }, timeout);
+    
+    const handler = (data: Buffer) => {
+      buffer += data.toString();
+      const lines = buffer.split('\r\n');
+      
+      for (const line of lines) {
+        if (expectedCode) {
+          if (line.startsWith(expectedCode + ' ')) {
+            clearTimeout(timer);
+            socket.removeListener('data', handler);
+            resolve(buffer);
+            return;
+          }
+        } else {
+          // Look for any complete response
+          if (line.match(/^\d{3} /)) {
+            clearTimeout(timer);
+            socket.removeListener('data', handler);
+            resolve(buffer);
+            return;
+          }
+        }
+      }
+    };
+    
+    socket.on('data', handler);
+  });
+};
+
+tap.test('setup - start test server', async (toolsArg) => {
+  testServer = await startTestServer({ port: TEST_PORT });
+  await toolsArg.delayFor(1000);
+});
+
+tap.test('Bounce Management - Invalid recipient domain', async (tools) => {
+  const socket = net.createConnection({
+    host: 'localhost',
+    port: TEST_PORT,
+    timeout: 30000
+  });
+  
+  try {
+    // Wait for greeting
+    await waitForResponse(socket, '220');
+    
+    // Send EHLO
+    socket.write('EHLO testclient\r\n');
+    await waitForResponse(socket, '250');
+    
+    // Send MAIL FROM
+    socket.write('MAIL FROM:<sender@example.com>\r\n');
+    await waitForResponse(socket, '250');
+    
+    // Send to non-existent domain
+    socket.write('RCPT TO:<nonexistent@invalid-domain-that-does-not-exist.com>\r\n');
+    const rcptResponse = await waitForResponse(socket);
+    
+    if (rcptResponse.startsWith('550') || rcptResponse.startsWith('551') || rcptResponse.startsWith('553')) {
+      console.log('Bounce management active - invalid recipient properly rejected');
+      expect(true).toEqual(true);
+    } else if (rcptResponse.startsWith('250')) {
+      // Server accepted, may generate bounce later
+      console.log('Invalid recipient accepted - bounce may be generated later');
+      
+      // Send DATA
+      socket.write('DATA\r\n');
+      await waitForResponse(socket, '354');
+      
+      const email = [
+        `From: sender@example.com`,
+        `To: nonexistent@invalid-domain-that-does-not-exist.com`,
+        `Subject: Bounce Management Test`,
+        `Return-Path: <bounce@example.com>`,
+        `Date: ${new Date().toUTCString()}`,
+        `Message-ID: <bounce-test-${Date.now()}@example.com>`,
+        '',
+        'This email is designed to test bounce management functionality.',
+        '.',
+        ''
+      ].join('\r\n');
+      
+      socket.write(email);
+      const dataResponse = await waitForResponse(socket, '250');
+      
+      console.log('Email accepted for processing - bounce will be generated');
+      expect(dataResponse.startsWith('250')).toEqual(true);
+    }
+    
+    socket.write('QUIT\r\n');
+    await waitForResponse(socket, '221').catch(() => {});
+  } finally {
+    socket.destroy();
+  }
+});
+
+tap.test('Bounce Management - Empty return path (null sender)', async (tools) => {
+  const socket = net.createConnection({
+    host: 'localhost',
+    port: TEST_PORT,
+    timeout: 30000
+  });
+  
+  try {
+    // Wait for greeting
+    await waitForResponse(socket, '220');
+    
+    // Send EHLO
+    socket.write('EHLO testclient\r\n');
+    await waitForResponse(socket, '250');
+    
+    // Empty return path (null sender) - used for bounce messages
+    socket.write('MAIL FROM:<>\r\n');
+    const mailResponse = await waitForResponse(socket);
+    
+    if (mailResponse.startsWith('250')) {
+      console.log('Null sender accepted (for bounce messages)');
+      
+      // Send RCPT TO
+      socket.write('RCPT TO:<recipient@example.com>\r\n');
+      await waitForResponse(socket, '250');
+      
+      // Send DATA
+      socket.write('DATA\r\n');
+      const dataCommandResponse = await waitForResponse(socket);
+      
+      if (dataCommandResponse.startsWith('354')) {
+        // Bounce message format
+        const email = [
+          `From: MAILER-DAEMON@example.com`,
+          `To: recipient@example.com`,
+          `Subject: Mail delivery failed: returning message to sender`,
+          `Date: ${new Date().toUTCString()}`,
+          `Message-ID: <bounce-${Date.now()}@example.com>`,
+          `Auto-Submitted: auto-replied`,
+          '',
+          'This message was created automatically by mail delivery software.',
+          '',
+          'A message that you sent could not be delivered to one or more recipients.',
+          '.',
+          ''
+        ].join('\r\n');
+        
+        socket.write(email);
+        const dataResponse = await waitForResponse(socket, '250');
+        
+        console.log('Bounce message with null sender accepted');
+        expect(dataResponse.startsWith('250')).toEqual(true);
+      } else if (dataCommandResponse.startsWith('503')) {
+        // Server rejects DATA for null sender
+        console.log('Server rejects DATA command for null sender (strict policy)');
+        expect(dataCommandResponse.startsWith('503')).toEqual(true);
+      }
+    } else {
+      console.log('Null sender rejected');
+      expect(true).toEqual(true);
+    }
+    
+    socket.write('QUIT\r\n');
+    await waitForResponse(socket, '221').catch(() => {});
+  } finally {
+    socket.destroy();
+  }
+});
+
+tap.test('Bounce Management - DSN headers', async (tools) => {
+  const socket = net.createConnection({
+    host: 'localhost',
+    port: TEST_PORT,
+    timeout: 30000
+  });
+  
+  try {
+    // Wait for greeting
+    await waitForResponse(socket, '220');
+    
+    // Send EHLO
+    socket.write('EHLO testclient\r\n');
+    await waitForResponse(socket, '250');
+    
+    // Send MAIL FROM
+    socket.write('MAIL FROM:<sender@example.com>\r\n');
+    await waitForResponse(socket, '250');
+    
+    // Send RCPT TO
+    socket.write('RCPT TO:<recipient@example.com>\r\n');
+    await waitForResponse(socket, '250');
+    
+    // Send DATA
+    socket.write('DATA\r\n');
+    await waitForResponse(socket, '354');
+    
+    // Email with DSN request headers
+    const email = [
+      `From: sender@example.com`,
+      `To: recipient@example.com`,
+      `Subject: DSN Test`,
+      `Return-Path: <bounce-handler@example.com>`,
+      `Disposition-Notification-To: sender@example.com`,
+      `Return-Receipt-To: sender@example.com`,
+      `Date: ${new Date().toUTCString()}`,
+      `Message-ID: <dsn-test-${Date.now()}@example.com>`,
+      '',
+      'This email requests delivery status notifications.',
+      '.',
+      ''
+    ].join('\r\n');
+    
+    socket.write(email);
+    const dataResponse = await waitForResponse(socket, '250');
+    
+    console.log('Email with DSN headers accepted');
+    expect(dataResponse.startsWith('250')).toEqual(true);
+    
+    socket.write('QUIT\r\n');
+    await waitForResponse(socket, '221').catch(() => {});
+  } finally {
+    socket.destroy();
+  }
+});
+
+tap.test('Bounce Management - Bounce loop prevention', async (tools) => {
+  const socket = net.createConnection({
+    host: 'localhost',
+    port: TEST_PORT,
+    timeout: 30000
+  });
+  
+  try {
+    // Wait for greeting
+    await waitForResponse(socket, '220');
+    
+    // Send EHLO
+    socket.write('EHLO testclient\r\n');
+    await waitForResponse(socket, '250');
+    
+    // Null sender (bounce message)
+    socket.write('MAIL FROM:<>\r\n');
+    await waitForResponse(socket, '250');
+    
+    // To another mailer-daemon (potential loop)
+    socket.write('RCPT TO:<mailer-daemon@another-server.com>\r\n');
+    const rcptResponse = await waitForResponse(socket);
+    
+    if (rcptResponse.startsWith('550') || rcptResponse.startsWith('553')) {
+      console.log('Bounce loop prevented - mailer-daemon recipient rejected');
+      expect(true).toEqual(true);
+    } else if (rcptResponse.startsWith('250')) {
+      console.log('Mailer-daemon recipient accepted - check for loop prevention');
+      
+      // Send DATA
+      socket.write('DATA\r\n');
+      const dataCommandResponse = await waitForResponse(socket);
+      
+      if (dataCommandResponse.startsWith('354')) {
+        const email = [
+          `From: MAILER-DAEMON@example.com`,
+          `To: mailer-daemon@another-server.com`,
+          `Subject: Delivery Status Notification (Failure)`,
+          `Date: ${new Date().toUTCString()}`,
+          `Message-ID: <bounce-loop-${Date.now()}@example.com>`,
+          `Auto-Submitted: auto-replied`,
+          `X-Loop: example.com`,
+          '',
+          'This is a bounce of a bounce - potential loop.',
+          '.',
+          ''
+        ].join('\r\n');
+        
+        socket.write(email);
+        const dataResponse = await waitForResponse(socket);
+        
+        const result = dataResponse.startsWith('250') ? 'accepted' : 'rejected';
+        console.log(`Bounce loop test: ${result}`);
+        expect(true).toEqual(true);
+      } else if (dataCommandResponse.startsWith('503')) {
+        // Server rejects DATA for null sender
+        console.log('Bounce loop prevented at DATA stage (null sender rejection)');
+        expect(dataCommandResponse.startsWith('503')).toEqual(true);
+      }
+    }
+    
+    socket.write('QUIT\r\n');
+    await waitForResponse(socket, '221').catch(() => {});
+  } finally {
+    socket.destroy();
+  }
+});
+
+tap.test('Bounce Management - Valid email (control test)', async (tools) => {
+  const socket = net.createConnection({
+    host: 'localhost',
+    port: TEST_PORT,
+    timeout: 30000
+  });
+  
+  try {
+    // Wait for greeting
+    await waitForResponse(socket, '220');
+    
+    // Send EHLO
+    socket.write('EHLO testclient\r\n');
+    await waitForResponse(socket, '250');
+    
+    // Send MAIL FROM
+    socket.write('MAIL FROM:<sender@example.com>\r\n');
+    await waitForResponse(socket, '250');
+    
+    // Send RCPT TO
+    socket.write('RCPT TO:<valid@example.com>\r\n');
+    await waitForResponse(socket, '250');
+    
+    // Send DATA
+    socket.write('DATA\r\n');
+    await waitForResponse(socket, '354');
+    
+    const email = [
+      `From: sender@example.com`,
+      `To: valid@example.com`,
+      `Subject: Valid Email Test`,
+      `Return-Path: <sender@example.com>`,
+      `Date: ${new Date().toUTCString()}`,
+      `Message-ID: <valid-email-${Date.now()}@example.com>`,
+      '',
+      'This is a valid email that should not trigger bounce.',
+      '.',
+      ''
+    ].join('\r\n');
+    
+    socket.write(email);
+    const dataResponse = await waitForResponse(socket, '250');
+    
+    console.log('Valid email accepted - no bounce expected');
+    expect(dataResponse.startsWith('250')).toEqual(true);
+    
+    socket.write('QUIT\r\n');
+    await waitForResponse(socket, '221').catch(() => {});
+  } finally {
+    socket.destroy();
+  }
+});
+
+tap.test('cleanup - stop test server', async () => {
+  await stopTestServer(testServer);
+});
+
+tap.start();