Input Validation Skill

Purpose

This skill provides systematic approaches to validate, sanitize, and encode all user inputs to prevent injection attacks, XSS, and data corruption. It implements defense-in-depth validation at multiple layers aligned with OWASP best practices and Hack23 ISMS secure coding standards.

When to Use This Skill

Apply this skill when:

• ✅ Processing any user-provided input (forms, APIs, URL parameters)
• ✅ Handling data from external systems (Riksdagen API, World Bank)
• ✅ Constructing database queries or commands
• ✅ Rendering user-generated content in UI
• ✅ Processing file uploads
• ✅ Implementing search functionality
• ✅ Building dynamic SQL, LDAP, or OS commands

Validation Principles