Security Summary for Draw Winner Reveal Feature

Changes Made

This feature adds a countdown mechanism for revealing draw winners, with the following security considerations:

Security Analysis

1. Input Validation ✅

• reveal_at parameter: Properly typed as *time.Time in Go, validated through JSON unmarshal
• Frontend validation: Minimum date validation prevents setting past dates
• Database constraints: Uses PostgreSQL timestamptz type with proper timezone handling

2. Authorization & Access Control ✅

• Admin endpoints: All admin endpoints (PUT /admin/draws/:id/status, GET /admin/draws/:id/winner) require Firebase authentication
• Mobile endpoint protection: GET /mobile/draws/:id/winner returns 403 Forbidden for non-revealed draws
• Proper status checks: Draw status verified before allowing operations

3. SQL Injection Protection ✅

• All database queries use sqlc generated code with parameterized queries
• No raw SQL string concatenation
• Proper type safety with Go structs

4. Data Exposure Controls ✅

• Winner details (user info) only accessible to:
  • Admins at any time (via dedicated admin endpoint)
  • Mobile users only after reveal time
• Winning ticket number only returned for revealed draws to mobile
• Completed draws show reveal timestamp but hide winner details

5. Race Conditions ✅

• Status transitions use atomic database operations
• Idempotent operations (e.g., completing an already completed draw is safe)
• Cron jobs use SELECT FOR UPDATE where appropriate in winner selection

6. No Vulnerabilities Introduced ✅

• No new external dependencies added
• No hardcoded credentials or secrets
• No execution of user-provided code
• No file system operations with user input
• No reflection or dynamic code execution

Recommendations for Production

1. Rate Limiting: Consider adding rate limiting to the mobile winner endpoint to prevent abuse
2. Logging: Ensure all status transitions are logged for audit purposes (already implemented)
3. Monitoring: Monitor cron job execution for failures
4. Database Indexes: Consider adding an index on (status, reveal_at) for efficient cron queries

Conclusion

The implementation follows security best practices:

• ✅ Proper authentication and authorization
• ✅ Input validation and type safety
• ✅ SQL injection protection
• ✅ Appropriate access controls
• ✅ No sensitive data leakage

No security vulnerabilities were introduced by this feature.