dcrouter/test/suite/rfc-compliance/test.rfc3461-dsn-compliance.ts

import { tap, expect } from '@git.zone/tstest/tapbundle';
import * as plugins from '../plugins.js';
import * as net from 'net';
import { startTestServer, stopTestServer, TEST_PORT, sendEmailWithRawSocket } from '../../helpers/server.loader.js';
import type { SmtpServer } from '../../../ts/mail/delivery/smtpserver/index.js';

let testServer: SmtpServer;

tap.test('setup - start test server', async () => {
  testServer = await startTestServer();
  await plugins.smartdelay.delayFor(1000);
});

tap.test('RFC 3461 DSN - DSN extension advertised', async (tools) => {
  const done = tools.defer();
  
  const socket = net.createConnection({
    host: 'localhost',
    port: TEST_PORT,
    timeout: 30000
  });
  
  let dataBuffer = '';
  
  socket.on('data', (data) => {
    dataBuffer += data.toString();
    console.log('Server response:', data.toString());
    
    if (dataBuffer.includes('220 ') && !dataBuffer.includes('EHLO')) {
      // Initial greeting received
      socket.write('EHLO testclient\r\n');
      dataBuffer = '';
    } else if (dataBuffer.includes('250')) {
      // Check if DSN extension is advertised
      const advertisesDsn = dataBuffer.toLowerCase().includes('dsn');
      
      console.log('DSN extension advertised:', advertisesDsn);
      
      // Parse extensions
      const lines = dataBuffer.split('\r\n');
      const extensions = lines
        .filter(line => line.startsWith('250-') || (line.startsWith('250 ') && lines.indexOf(line) > 0))
        .map(line => line.substring(4).split(' ')[0].toUpperCase());
      
      console.log('Server extensions:', extensions);
      
      socket.write('QUIT\r\n');
      socket.end();
      done.resolve();
    }
  });
  
  socket.on('error', (err) => {
    console.error('Socket error:', err);
    done.reject(err);
  });
  
  await done.promise;
});

tap.test('RFC 3461 DSN - MAIL FROM with DSN parameters', async (tools) => {
  const done = tools.defer();
  
  const socket = net.createConnection({
    host: 'localhost',
    port: TEST_PORT,
    timeout: 30000
  });
  
  let dataBuffer = '';
  let step = 'greeting';
  
  socket.on('data', (data) => {
    dataBuffer += data.toString();
    console.log('Server response:', data.toString());
    
    if (step === 'greeting' && dataBuffer.includes('220 ')) {
      step = 'ehlo';
      socket.write('EHLO testclient\r\n');
      dataBuffer = '';
    } else if (step === 'ehlo' && dataBuffer.includes('250')) {
      step = 'mail_dsn';
      // Test MAIL FROM with DSN parameters (RFC 3461)
      socket.write('MAIL FROM:<sender@example.com> RET=FULL ENVID=test-envelope-123\r\n');
      dataBuffer = '';
    } else if (step === 'mail_dsn') {
      // Server should either accept (250) or reject with proper error
      const accepted = dataBuffer.includes('250');
      const properlyRejected = dataBuffer.includes('501') || dataBuffer.includes('555');
      
      expect(accepted || properlyRejected).toEqual(true);
      console.log(`DSN parameters in MAIL FROM ${accepted ? 'accepted' : 'rejected'}`);
      
      if (accepted) {
        // Reset to test other parameters
        socket.write('RSET\r\n');
        step = 'reset1';
      } else {
        socket.write('QUIT\r\n');
        socket.end();
        done.resolve();
      }
      dataBuffer = '';
    } else if (step === 'reset1' && dataBuffer.includes('250')) {
      step = 'mail_dsn_hdrs';
      // Test with RET=HDRS
      socket.write('MAIL FROM:<sender@example.com> RET=HDRS\r\n');
      dataBuffer = '';
    } else if (step === 'mail_dsn_hdrs') {
      const accepted = dataBuffer.includes('250');
      console.log(`RET=HDRS parameter ${accepted ? 'accepted' : 'rejected'}`);
      
      socket.write('QUIT\r\n');
      socket.end();
      done.resolve();
    }
  });
  
  socket.on('error', (err) => {
    console.error('Socket error:', err);
    done.reject(err);
  });
  
  await done.promise;
});

tap.test('RFC 3461 DSN - RCPT TO with DSN parameters', async (tools) => {
  const done = tools.defer();
  
  const socket = net.createConnection({
    host: 'localhost',
    port: TEST_PORT,
    timeout: 30000
  });
  
  let dataBuffer = '';
  let step = 'greeting';
  
  socket.on('data', (data) => {
    dataBuffer += data.toString();
    console.log('Server response:', data.toString());
    
    if (step === 'greeting' && dataBuffer.includes('220 ')) {
      step = 'ehlo';
      socket.write('EHLO testclient\r\n');
      dataBuffer = '';
    } else if (step === 'ehlo' && dataBuffer.includes('250')) {
      step = 'mail';
      socket.write('MAIL FROM:<sender@example.com>\r\n');
      dataBuffer = '';
    } else if (step === 'mail' && dataBuffer.includes('250')) {
      step = 'rcpt_dsn';
      // Test RCPT TO with DSN parameters
      socket.write('RCPT TO:<recipient@example.com> NOTIFY=SUCCESS,FAILURE ORCPT=rfc822;recipient@example.com\r\n');
      dataBuffer = '';
    } else if (step === 'rcpt_dsn') {
      // Server should either accept (250) or reject with proper error
      const accepted = dataBuffer.includes('250');
      const properlyRejected = dataBuffer.includes('501') || dataBuffer.includes('555');
      
      expect(accepted || properlyRejected).toEqual(true);
      console.log(`DSN parameters in RCPT TO ${accepted ? 'accepted' : 'rejected'}`);
      
      if (accepted) {
        // Reset to test other notify values
        socket.write('RSET\r\n');
        step = 'reset1';
      } else {
        socket.write('QUIT\r\n');
        socket.end();
        done.resolve();
      }
      dataBuffer = '';
    } else if (step === 'reset1' && dataBuffer.includes('250')) {
      step = 'mail2';
      socket.write('MAIL FROM:<sender@example.com>\r\n');
      dataBuffer = '';
    } else if (step === 'mail2' && dataBuffer.includes('250')) {
      step = 'rcpt_never';
      // Test NOTIFY=NEVER
      socket.write('RCPT TO:<recipient@example.com> NOTIFY=NEVER\r\n');
      dataBuffer = '';
    } else if (step === 'rcpt_never') {
      const accepted = dataBuffer.includes('250');
      console.log(`NOTIFY=NEVER parameter ${accepted ? 'accepted' : 'rejected'}`);
      
      socket.write('QUIT\r\n');
      socket.end();
      done.resolve();
    }
  });
  
  socket.on('error', (err) => {
    console.error('Socket error:', err);
    done.reject(err);
  });
  
  await done.promise;
});

tap.test('RFC 3461 DSN - Complete DSN-enabled email', async (tools) => {
  const done = tools.defer();
  
  const socket = net.createConnection({
    host: 'localhost',
    port: TEST_PORT,
    timeout: 30000
  });
  
  let dataBuffer = '';
  let step = 'greeting';
  
  socket.on('data', (data) => {
    dataBuffer += data.toString();
    console.log('Server response:', data.toString());
    
    if (step === 'greeting' && dataBuffer.includes('220 ')) {
      step = 'ehlo';
      socket.write('EHLO testclient\r\n');
      dataBuffer = '';
    } else if (step === 'ehlo' && dataBuffer.includes('250')) {
      step = 'mail';
      // Try with DSN parameters, fallback to regular if not supported
      socket.write('MAIL FROM:<sender@example.com> RET=FULL ENVID=test123\r\n');
      dataBuffer = '';
    } else if (step === 'mail') {
      if (dataBuffer.includes('250')) {
        step = 'rcpt';
        socket.write('RCPT TO:<recipient@example.com> NOTIFY=SUCCESS,FAILURE,DELAY\r\n');
      } else if (dataBuffer.includes('501') || dataBuffer.includes('555')) {
        // DSN not supported, try without parameters
        console.log('DSN parameters not supported, using plain MAIL FROM');
        step = 'mail_plain';
        socket.write('MAIL FROM:<sender@example.com>\r\n');
      }
      dataBuffer = '';
    } else if (step === 'mail_plain' && dataBuffer.includes('250')) {
      step = 'rcpt';
      socket.write('RCPT TO:<recipient@example.com>\r\n');
      dataBuffer = '';
    } else if (step === 'rcpt') {
      if (dataBuffer.includes('250')) {
        step = 'data';
        socket.write('DATA\r\n');
      } else if (dataBuffer.includes('501') || dataBuffer.includes('555')) {
        // DSN RCPT parameters not supported, try plain
        console.log('DSN RCPT parameters not supported, using plain RCPT TO');
        socket.write('RCPT TO:<recipient@example.com>\r\n');
        step = 'rcpt_plain';
      }
      dataBuffer = '';
    } else if (step === 'rcpt_plain' && dataBuffer.includes('250')) {
      step = 'data';
      socket.write('DATA\r\n');
      dataBuffer = '';
    } else if (step === 'data' && dataBuffer.includes('354')) {
      const email = [
        `From: sender@example.com`,
        `To: recipient@example.com`,
        `Subject: RFC 3461 DSN Compliance Test`,
        `Date: ${new Date().toUTCString()}`,
        `Message-ID: <dsn-test-${Date.now()}@example.com>`,
        '',
        'This email tests RFC 3461 DSN (Delivery Status Notification) compliance.',
        'The server should handle DSN parameters according to RFC 3461.',
        '.',
        ''
      ].join('\r\n');
      
      socket.write(email);
      dataBuffer = '';
    } else if (dataBuffer.includes('250 ') && dataBuffer.includes('Message accepted')) {
      console.log('DSN-enabled email accepted');
      
      socket.write('QUIT\r\n');
      socket.end();
      done.resolve();
    }
  });
  
  socket.on('error', (err) => {
    console.error('Socket error:', err);
    done.reject(err);
  });
  
  await done.promise;
});

tap.test('RFC 3461 DSN - Invalid DSN parameter handling', async (tools) => {
  const done = tools.defer();
  
  const socket = net.createConnection({
    host: 'localhost',
    port: TEST_PORT,
    timeout: 30000
  });
  
  let dataBuffer = '';
  let step = 'greeting';
  
  socket.on('data', (data) => {
    dataBuffer += data.toString();
    console.log('Server response:', data.toString());
    
    if (step === 'greeting' && dataBuffer.includes('220 ')) {
      step = 'ehlo';
      socket.write('EHLO testclient\r\n');
      dataBuffer = '';
    } else if (step === 'ehlo' && dataBuffer.includes('250')) {
      step = 'mail_invalid';
      // Test with invalid RET value
      socket.write('MAIL FROM:<sender@example.com> RET=INVALID\r\n');
      dataBuffer = '';
    } else if (step === 'mail_invalid') {
      // Should reject with 501 or similar
      const properlyRejected = dataBuffer.includes('501') || 
                              dataBuffer.includes('555') ||
                              dataBuffer.includes('500');
      
      if (properlyRejected) {
        console.log('Invalid RET parameter properly rejected');
        expect(true).toEqual(true);
      } else if (dataBuffer.includes('250')) {
        // Server ignores unknown parameters (also acceptable)
        console.log('Server ignores invalid DSN parameters');
      }
      
      // Reset and test invalid NOTIFY
      socket.write('RSET\r\n');
      step = 'reset';
      dataBuffer = '';
    } else if (step === 'reset' && dataBuffer.includes('250')) {
      step = 'mail2';
      socket.write('MAIL FROM:<sender@example.com>\r\n');
      dataBuffer = '';
    } else if (step === 'mail2' && dataBuffer.includes('250')) {
      step = 'rcpt_invalid';
      // Test with invalid NOTIFY value
      socket.write('RCPT TO:<recipient@example.com> NOTIFY=INVALID\r\n');
      dataBuffer = '';
    } else if (step === 'rcpt_invalid') {
      const properlyRejected = dataBuffer.includes('501') || 
                              dataBuffer.includes('555') ||
                              dataBuffer.includes('500');
      
      if (properlyRejected) {
        console.log('Invalid NOTIFY parameter properly rejected');
      } else if (dataBuffer.includes('250')) {
        console.log('Server ignores invalid NOTIFY parameter');
      }
      
      socket.write('QUIT\r\n');
      socket.end();
      done.resolve();
    }
  });
  
  socket.on('error', (err) => {
    console.error('Socket error:', err);
    done.reject(err);
  });
  
  await done.promise;
});

tap.test('cleanup - stop test server', async () => {
  await stopTestServer(testServer);
});

tap.start();