This document outlines the security measures implemented in Paper Circle and best practices for developers.

• NEVER log environment variables in production or development
• All sensitive credentials are in .env file (git-ignored)
• .env.example provided for reference without actual values
• Supabase client validates env vars without logging them

• Custom error handling utility (src/lib/errorHandling.ts)
• Errors are sanitized to remove sensitive data
• Production logs minimal information
• Development logs are filtered for sensitive keys (password, token, key, secret, auth, session, cookie)

• All database tables have RLS enabled
• Policies enforce:
  • Authentication requirements
  • Community membership checks
  • Role-based access control (member, presenter, admin)
• Security definer functions used for safe public operations (invitation viewing)

• SECURITY DEFINER functions bypass RLS for specific safe operations
• Only expose necessary data
• Validate permissions within function logic
• Used for: invitation details, invitation acceptance

• No sensitive data in client-side code
• Authentication tokens handled by Supabase SDK
• No hardcoded credentials
• API keys are anon keys (safe for client-side use with RLS)

• ✅ Use logError() from errorHandling.ts instead of console.error()
• ✅ Use getUserFriendlyErrorMessage() for user-facing errors
• ✅ Keep .env file git-ignored
• ✅ Update .env.example when adding new env vars
• ✅ Test RLS policies thoroughly
• ✅ Validate user input on both client and server
• ✅ Use parameterized queries (Supabase handles this)
• ✅ Implement proper authentication checks
• ✅ Use HTTPS in production
• ✅ Keep dependencies updated

• ❌ NEVER log environment variables
• ❌ NEVER log full error objects with sensitive data
• ❌ NEVER expose database internals in error messages
• ❌ NEVER commit .env file
• ❌ NEVER use console.log/error for production errors
• ❌ NEVER trust client-side data without validation
• ❌ NEVER expose admin functions without proper checks
• ❌ NEVER store sensitive data in localStorage without encryption
• ❌ NEVER use any type for sensitive operations

• Supabase Auth handles user authentication
• JWT tokens for session management
• Auto-refresh tokens for long sessions
• Session persistence with secure cookies

• Database-level permission enforcement
• Every query checked against RLS policies
• Cannot be bypassed from client
• Policies check:
  • User authentication
  • Community membership
  • User roles
  • Resource ownership

• Input validation
• Sanitized error messages
• Secure error logging
• XSS prevention via React's default escaping

• HTTPS in production (enforced by hosting)
• Secure WebSocket connections
• CORS configured properly
• No sensitive data in URLs

• User passwords (handled by Supabase Auth)
• Session tokens
• Database credentials
• API keys (except public anon key)
• User email addresses (handle carefully)
• Private user data

1. Passwords: Never stored or handled by app (Supabase Auth)
2. Tokens: Auto-managed by Supabase SDK, stored securely
3. Database Creds: Only in .env, never logged
4. API Keys: Only anon key in client (designed for client-side use)
5. Emails: Protected by RLS, only shown to authorized users
6. Private Data: RLS policies enforce access control

If you discover a security issue:

1. DO NOT open a public GitHub issue
2. DO NOT commit a fix without review
3. DO contact the maintainers privately
4. DO document the vulnerability clearly
5. DO wait for coordinated disclosure

• Review new dependencies for vulnerabilities
• Check error logs for suspicious patterns
• Test authentication flows

• Update dependencies
• Review RLS policies
• Audit user permissions
• Check for exposed secrets in code

• Full security audit
• Penetration testing
• Review access logs
• Update security documentation

• ESLint security rules
• TypeScript strict mode
• Supabase RLS policy tester
• Browser DevTools Security tab

• Supabase Auth logs
• Error tracking (development only)
• Access logs
• Failed authentication attempts

• RLS policy unit tests
• Authentication flow tests
• Permission boundary tests
• SQL injection prevention tests (Supabase handles this)

Before merging:

• No console.log of sensitive data
• Error handling uses secure utility
• No hardcoded credentials
• RLS policies tested
• Input validation present
• Authentication checks in place
• User-facing errors don't expose internals
• New env vars in .env.example
• TypeScript types prevent sensitive data leaks

• Risk: LOW
• Mitigation: Supabase uses parameterized queries
• Action: Always use Supabase query builder

• Risk: LOW
• Mitigation: React escapes by default
• Action: Never use dangerouslySetInnerHTML without sanitization

• Risk: LOW
• Mitigation: Supabase JWT tokens, SameSite cookies
• Action: Use Supabase SDK for all API calls

• Risk: LOW
• Mitigation: RLS enforced at database level
• Action: Test all RLS policies thoroughly

• Risk: MEDIUM (if errors not handled properly)
• Mitigation: Secure error handling utility
• Action: Use getUserFriendlyErrorMessage()

• Risk: LOW
• Mitigation: RLS + role checks
• Action: Test permission boundaries

• Supabase Security Best Practices
• OWASP Top 10
• React Security Best Practices

Last Updated: 2025-11-29 Security Contact: [Your contact method here]