dcrouter/test/suite/smtpserver_rfc-compliance/test.rfc-01.rfc5321-compliance.ts

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 function 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');
      
      // Check if we have a complete response
      for (const line of lines) {
        if (expectedCode) {
          if (line.startsWith(expectedCode + ' ')) {
            clearTimeout(timer);
            socket.removeListener('data', handler);
            resolve(buffer);
            return;
          }
        } else {
          // Any complete response line
          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('RFC 5321 - Server greeting format', async (tools) => {
  const done = tools.defer();
  
  const socket = net.createConnection({
    host: 'localhost',
    port: TEST_PORT,
    timeout: 30000
  });
  
  socket.on('error', (err) => {
    console.error('Socket error:', err);
    done.reject(err);
  });
  
  socket.on('connect', async () => {
    try {
      // Wait for initial greeting
      const greeting = await waitForResponse(socket, '220');
      console.log('Server greeting:', greeting.trim());
      
      // RFC 5321: Server must provide proper 220 greeting
      const greetingLine = greeting.trim();
      const validGreeting = greetingLine.startsWith('220') && greetingLine.length > 10;
      
      expect(validGreeting).toEqual(true);
      expect(greetingLine).toMatch(/^220\s+\S+/); // Should have hostname after 220
      
      // Send QUIT
      socket.write('QUIT\r\n');
      await waitForResponse(socket, '221');
      
      socket.end();
      done.resolve();
    } catch (err) {
      console.error('Test error:', err);
      socket.end();
      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
  });
  
  socket.on('error', (err) => {
    console.error('Socket error:', err);
    done.reject(err);
  });
  
  socket.on('connect', async () => {
    try {
      // Wait for greeting
      await waitForResponse(socket, '220');
      
      // Send EHLO
      socket.write('EHLO testclient\r\n');
      const ehloResponse = await waitForResponse(socket, '250');
      console.log('Server response:', ehloResponse);
      
      // RFC 5321: EHLO must return 250 with hostname and extensions
      const ehloLines = ehloResponse.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);
      
      // Send QUIT
      socket.write('QUIT\r\n');
      await waitForResponse(socket, '221');
      
      socket.end();
      done.resolve();
    } catch (err) {
      console.error('Test error:', err);
      socket.end();
      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
  });
  
  socket.on('error', (err) => {
    console.error('Socket error:', err);
    done.reject(err);
  });
  
  socket.on('connect', async () => {
    try {
      // Wait for greeting
      await waitForResponse(socket, '220');
      
      // Test lowercase command
      socket.write('ehlo testclient\r\n');
      await waitForResponse(socket, '250');
      
      // Test mixed case command
      socket.write('MaIl FrOm:<sender@example.com>\r\n');
      await waitForResponse(socket, '250');
      
      // Test uppercase command  
      socket.write('RCPT TO:<recipient@example.com>\r\n');
      await waitForResponse(socket, '250');
      
      // All case variations worked
      console.log('All case variations accepted');
      
      // Send QUIT
      socket.write('QUIT\r\n');
      await waitForResponse(socket, '221');
      
      socket.end();
      done.resolve();
    } catch (err) {
      console.error('Test error:', err);
      socket.end();
      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
  });
  
  socket.on('error', (err) => {
    console.error('Socket error:', err);
    done.reject(err);
  });
  
  socket.on('connect', async () => {
    try {
      // Wait for greeting
      await waitForResponse(socket, '220');
      
      // Send EHLO
      socket.write('EHLO testclient\r\n');
      await waitForResponse(socket, '250');
      
      // 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`);
      const response = await waitForResponse(socket);
      
      // Should either accept (if within server limits) or reject gracefully
      const accepted = response.includes('250');
      const rejected = response.includes('501') || response.includes('500');
      
      expect(accepted || rejected).toEqual(true);
      console.log(`Long line test ${accepted ? 'accepted' : 'rejected'}`);
      
      // Send QUIT
      socket.write('QUIT\r\n');
      await waitForResponse(socket, '221');
      
      socket.end();
      done.resolve();
    } catch (err) {
      console.error('Test error:', err);
      socket.end();
      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
  });
  
  socket.on('error', (err) => {
    console.error('Socket error:', err);
    done.reject(err);
  });
  
  socket.on('connect', async () => {
    try {
      const supportedVerbs: string[] = [];
      
      // Wait for greeting
      await waitForResponse(socket, '220');
      
      // Try HELP command to see supported verbs
      socket.write('HELP\r\n');
      const helpResponse = await waitForResponse(socket);
      
      // Parse HELP response for supported commands
      if (helpResponse.includes('214') || helpResponse.includes('502')) {
        // Either help text or command not implemented
      }
      
      // Test NOOP
      socket.write('NOOP\r\n');
      const noopResponse = await waitForResponse(socket);
      if (noopResponse.includes('250')) {
        supportedVerbs.push('NOOP');
      }
      
      // Test RSET
      socket.write('RSET\r\n');
      const rsetResponse = await waitForResponse(socket);
      if (rsetResponse.includes('250')) {
        supportedVerbs.push('RSET');
      }
      
      // Test VRFY
      socket.write('VRFY test@example.com\r\n');
      const vrfyResponse = await waitForResponse(socket);
      // VRFY may be disabled for security (252 or 502)
      if (vrfyResponse.includes('250') || vrfyResponse.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).toEqual(true);
      
      // Send QUIT
      socket.write('QUIT\r\n');
      await waitForResponse(socket, '221');
      
      socket.end();
      done.resolve();
    } catch (err) {
      console.error('Test error:', err);
      socket.end();
      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
  });
  
  socket.on('error', (err) => {
    console.error('Socket error:', err);
    done.reject(err);
  });
  
  socket.on('connect', async () => {
    try {
      // Wait for greeting
      await waitForResponse(socket, '220');
      
      // Send EHLO
      socket.write('EHLO testclient\r\n');
      const ehloResponse = await waitForResponse(socket, '250');
      
      // Check for extensions
      const lines = ehloResponse.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);
      
      // Send QUIT
      socket.write('QUIT\r\n');
      await waitForResponse(socket, '221');
      
      socket.end();
      done.resolve();
    } catch (err) {
      console.error('Test error:', err);
      socket.end();
      done.reject(err);
    }
  });
  
  await done.promise;
});

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

tap.start();