dcrouter/test/suite/rfc-compliance/test.rfc5321-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 '../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 5321 - Server greeting format', async (tools) => {
  const done = tools.defer();
  
  const socket = net.createConnection({
    host: 'localhost',
    port: TEST_PORT,
    timeout: 30000
  });
  
  socket.on('data', (data) => {
    const response = data.toString();
    console.log('Server greeting:', response);
    
    // RFC 5321: Server must provide proper 220 greeting
    const greeting = response.trim();
    const validGreeting = greeting.startsWith('220') && greeting.length > 10;
    
    expect(validGreeting).toBeTrue();
    expect(greeting).toMatch(/^220\s+\S+/); // Should have hostname after 220
    
    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 5321 - EHLO response format', 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')) {
      // RFC 5321: EHLO must return 250 with hostname and extensions
      const ehloLines = dataBuffer.split('\r\n').filter(line => line.startsWith('250'));
      
      expect(ehloLines.length).toBeGreaterThan(0);
      expect(ehloLines[0]).toMatch(/^250[\s-]\S+/); // First line should have hostname
      
      // Check for common extensions
      const extensions = ehloLines.slice(1).map(line => line.substring(4).trim());
      console.log('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 5321 - Command case insensitivity', 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_lowercase';
      // Test lowercase command
      socket.write('ehlo testclient\r\n');
      dataBuffer = '';
    } else if (step === 'ehlo_lowercase' && dataBuffer.includes('250')) {
      step = 'mail_mixed';
      // Test mixed case command
      socket.write('MaIl FrOm:<sender@example.com>\r\n');
      dataBuffer = '';
    } else if (step === 'mail_mixed' && dataBuffer.includes('250')) {
      step = 'rcpt_uppercase';
      // Test uppercase command
      socket.write('RCPT TO:<recipient@example.com>\r\n');
      dataBuffer = '';
    } else if (step === 'rcpt_uppercase' && dataBuffer.includes('250')) {
      // All case variations worked
      console.log('All case variations 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 5321 - Line length limits', 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 = 'long_line';
      // RFC 5321: Command line limit is 512 chars including CRLF
      // Test with a long MAIL FROM command (but within limit)
      const longDomain = 'a'.repeat(400);
      socket.write(`MAIL FROM:<user@${longDomain}.com>\r\n`);
      dataBuffer = '';
    } else if (step === 'long_line') {
      // Should either accept (if within server limits) or reject gracefully
      const accepted = dataBuffer.includes('250');
      const rejected = dataBuffer.includes('501') || dataBuffer.includes('500');
      
      expect(accepted || rejected).toBeTrue();
      console.log(`Long line test ${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 5321 - Standard SMTP verb compliance', async (tools) => {
  const done = tools.defer();
  
  const socket = net.createConnection({
    host: 'localhost',
    port: TEST_PORT,
    timeout: 30000
  });
  
  let dataBuffer = '';
  let step = 'greeting';
  const supportedVerbs: string[] = [];
  
  socket.on('data', (data) => {
    dataBuffer += data.toString();
    console.log('Server response:', data.toString());
    
    if (step === 'greeting' && dataBuffer.includes('220 ')) {
      step = 'help';
      // Try HELP command to see supported verbs
      socket.write('HELP\r\n');
      dataBuffer = '';
    } else if (step === 'help') {
      // Parse HELP response for supported commands
      if (dataBuffer.includes('214') || dataBuffer.includes('502')) {
        // Either help text or command not implemented
        step = 'test_noop';
        socket.write('NOOP\r\n');
        dataBuffer = '';
      }
    } else if (step === 'test_noop') {
      if (dataBuffer.includes('250')) {
        supportedVerbs.push('NOOP');
      }
      step = 'test_rset';
      socket.write('RSET\r\n');
      dataBuffer = '';
    } else if (step === 'test_rset') {
      if (dataBuffer.includes('250')) {
        supportedVerbs.push('RSET');
      }
      step = 'test_vrfy';
      socket.write('VRFY test@example.com\r\n');
      dataBuffer = '';
    } else if (step === 'test_vrfy') {
      // VRFY may be disabled for security (252 or 502)
      if (dataBuffer.includes('250') || dataBuffer.includes('252')) {
        supportedVerbs.push('VRFY');
      }
      
      // Check minimum required verbs
      const requiredVerbs = ['NOOP', 'RSET'];
      const hasRequired = requiredVerbs.every(verb => 
        supportedVerbs.includes(verb) || verb === 'VRFY' // VRFY is optional
      );
      
      console.log('Supported verbs:', supportedVerbs);
      expect(hasRequired).toBeTrue();
      
      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 5321 - Required minimum extensions', 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 ')) {
      socket.write('EHLO testclient\r\n');
      dataBuffer = '';
    } else if (dataBuffer.includes('250')) {
      // Check for 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);
      
      // RFC 5321 recommends these extensions
      const recommendedExtensions = ['8BITMIME', 'SIZE', 'PIPELINING'];
      const hasRecommended = recommendedExtensions.filter(ext => extensions.includes(ext));
      
      console.log('Recommended extensions present:', hasRecommended);
      
      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();