This document outlines the comprehensive security measures implemented in the SkillSwap application to protect against various types of attacks and vulnerabilities.

• Input Sanitization: All user inputs are automatically sanitized to remove SQL injection patterns
• Parameterized Queries: Using Supabase client which automatically prevents SQL injection
• Input Validation: Strict validation of all input data before processing
• Pattern Blocking: Blocks common SQL injection patterns like ', ;, --, /*, etc.

• Rate Limiting:
  • Authentication endpoints: 5 attempts per 15 minutes
  • General API: 100 requests per 15 minutes
  • Swap requests: 20 requests per 15 minutes
• Account Locking: Accounts are locked after 5 failed login attempts for 15 minutes
• Progressive Delays: Increasing delays between failed attempts
• IP-based Tracking: Monitors failed attempts by IP address

• Input Sanitization: Removes HTML tags and dangerous scripts
• Content Security Policy (CSP): Strict CSP headers to prevent script execution
• XSS-Clean Middleware: Automatic XSS protection for all inputs
• Output Encoding: All user-generated content is properly encoded

• CSRF Tokens: Generated and validated for all state-changing operations
• SameSite Cookies: Strict cookie policies
• Token Validation: Server-side validation of all CSRF tokens

• JWT Tokens: Secure JSON Web Tokens with expiration
• Password Hashing: Bcrypt with 12 salt rounds
• Strong Password Policy: Minimum 8 characters with complexity requirements
• Session Management: Secure session handling with automatic expiration

• Email Validation: Strict email format validation
• Password Strength: Enforces strong password requirements
• Input Length Limits: Prevents buffer overflow attacks
• Type Validation: Ensures data types match expectations

• Request Throttling: Limits requests per IP address
• Endpoint Protection: Different limits for different types of endpoints
• Automatic Blocking: Temporarily blocks IPs that exceed limits

• Helmet.js: Comprehensive security headers
• HSTS: HTTP Strict Transport Security
• X-Frame-Options: Prevents clickjacking
• X-Content-Type-Options: Prevents MIME type sniffing
• X-XSS-Protection: Additional XSS protection

• Encryption: Sensitive data is encrypted at rest
• Secure Storage: Uses secure storage utilities for sensitive information
• Data Sanitization: All data is sanitized before storage and retrieval

• Security Logs: Comprehensive logging of security events
• Failed Attempt Tracking: Logs all failed authentication attempts
• Audit Trail: Maintains audit logs for sensitive operations

// Security middleware stack
app.use(helmet());                    // Security headers
app.use(cors(corsOptions));           // CORS protection
app.use(xss());                       // XSS protection
app.use(hpp());                       // Parameter pollution protection
app.use(mongoSanitize());             // NoSQL injection protection
app.use(validateAndSanitizeInput);    // Input sanitization
app.use(securityHeaders);             // Custom security headers

// Authentication rate limiting
const authRateLimit = createRateLimit(15 * 60 * 1000, 5, 
  'Too many authentication attempts. Please try again later.');

// General API rate limiting
const generalRateLimit = createRateLimit(15 * 60 * 1000, 100, 
  'Too many requests. Please slow down.');

// SQL injection pattern removal
const sanitizeString = (str) => {
  return str
    .replace(/['";]/g, '')           // Remove SQL delimiters
    .replace(/--/g, '')              // Remove SQL comments
    .replace(/\/\*/g, '')            // Remove SQL comment start
    .replace(/\*\//g, '')            // Remove SQL comment end
    .replace(/xp_/gi, '')            // Remove dangerous procedures
    .replace(/<[^>]*>/g, '')         // Remove HTML tags
    .trim();
};

# Security Configuration
JWT_SECRET=your-super-secret-jwt-key
BCRYPT_SALT_ROUNDS=12
RATE_LIMIT_WINDOW_MS=900000
MAX_LOGIN_ATTEMPTS=5
ACCOUNT_LOCK_DURATION_MS=900000

const corsOptions = {
  origin: process.env.ALLOWED_ORIGINS?.split(',') || 
    ['http://localhost:3000', 'http://localhost:8080'],
  credentials: true,
  methods: ['GET', 'POST', 'PUT', 'DELETE', 'OPTIONS'],
  allowedHeaders: ['Content-Type', 'Authorization', 'X-Requested-With']
};

• Input Validation Tests: Ensures all inputs are properly validated
• Rate Limiting Tests: Verifies rate limiting functionality
• Authentication Tests: Tests authentication security measures
• XSS Prevention Tests: Validates XSS protection mechanisms

• SQL Injection Tests: Attempts various SQL injection patterns
• XSS Tests: Tests cross-site scripting vulnerabilities
• CSRF Tests: Validates CSRF protection
• Brute Force Tests: Tests brute force protection mechanisms

• Failed Login Attempts: Track failed authentication attempts
• Rate Limit Violations: Monitor rate limiting effectiveness
• Security Events: Log and monitor security-related events
• Performance Impact: Measure security measures' performance impact

• Suspicious Activity: Alerts for unusual patterns
• Rate Limit Exceeded: Notifications when limits are exceeded
• Account Lockouts: Alerts for account security events
• Failed Authentication: Monitoring of authentication failures

1. Immediate Response: Isolate affected systems
2. Assessment: Evaluate the scope and impact
3. Containment: Prevent further damage
4. Investigation: Analyze the root cause
5. Recovery: Restore normal operations
6. Post-Incident: Document lessons learned

• Security Team: security@skillswap.com
• Emergency Contact: +1-XXX-XXX-XXXX
• Bug Bounty: security@skillswap.com

• Monthly: Security configuration review
• Quarterly: Penetration testing
• Annually: Comprehensive security audit
• Continuous: Automated security monitoring

• Weekly: Security dependency updates
• Monthly: Major version updates
• Immediate: Critical security patches

1. Never trust user input
2. Always validate and sanitize data
3. Use parameterized queries
4. Implement proper authentication
5. Follow security coding guidelines

1. Use strong, unique passwords
2. Enable two-factor authentication
3. Keep software updated
4. Be cautious with links and downloads
5. Report suspicious activity

• OWASP: Open Web Application Security Project
• Security Headers: Security headers testing tool
• Mozilla Observatory: Security scanning tool
• Snyk: Vulnerability scanning

• Security Guidelines: Internal security coding standards
• API Security: API security best practices
• Authentication: Authentication implementation guide
• Data Protection: Data protection and privacy guide

Last Updated: December 2024
Version: 1.0.0
Maintained By: SkillSwap Security Team