Secure Coding Practices Every Developer Should Know

# Secure Coding Practices Every Developer Should Know Security is everyone's responsibility. Here are essential practices for writing secure code. ## Input Validation ### Never Trust User Input Validate and sanitize everything: - Type checking - Length limits - Format validation - Encoding ### SQL Injection Prevention Always use parameterized queries, never string concatenation for SQL. ### XSS Prevention - Escape output - Content Security Policy - HTTP-only cookies ## Authentication ### Password Storage - Use bcrypt or argon2 - Never store plaintext - Proper salt handling ### Session Management - Secure session IDs - Proper expiration - HTTPS only ### Multi-Factor Authentication Implement MFA for sensitive operations. ## Authorization ### Principle of Least Privilege Give minimum necessary permissions. ### Access Control - Check permissions on every request - Don't rely on client-side checks ## Data Protection ### Encryption - TLS for transit - AES for storage - Proper key management ### Sensitive Data - Don't log sensitive data - Mask in UI - Proper disposal ## Common Vulnerabilities (OWASP Top 10) 1. Injection 2. Broken Authentication 3. Sensitive Data Exposure 4. XML External Entities 5. Broken Access Control 6. Security Misconfiguration 7. Cross-Site Scripting 8. Insecure Deserialization 9. Components with Known Vulnerabilities 10. Insufficient Logging ## Best Practices 1. **Security reviews**: Include in code review 2. **Dependency scanning**: Check for vulnerabilities 3. **Penetration testing**: Regular testing 4. **Security training**: Keep team updated ## Conclusion Security is a mindset, not a checklist. Build it into your development process.