impersonator/docs/security/SECURITY_IMPLEMENTATION_CHECKLIST.md

Security Implementation Checklist

Use this checklist to track security fixes implementation.

Phase 1: Critical Fixes (Week 1) - BLOCK PRODUCTION

Message Security

• Fix postMessage wildcard origin (helpers/communicator.ts:65)
• Add message timestamp validation
• Add message replay protection
• Add origin whitelist validation
• Test: Verify messages only sent to allowed origins

Access Control

• Add owner verification before owner management (contexts/SmartWalletContext.tsx)
• Verify caller is owner for addOwner
• Verify caller is owner for removeOwner
• Verify caller is owner for updateThreshold
• Add on-chain verification for Gnosis Safe
• Test: Unauthorized users cannot modify wallets

Input Validation

• Add contract address detection (components/SmartWallet/OwnerManagement.tsx)
• Add address checksum validation
• Add transaction data validation
• Add value validation (BigNumber, no overflow)
• Add gas limit validation
• Test: All invalid inputs rejected

Race Conditions

• Add approval locking mechanism (contexts/TransactionContext.tsx)
• Make approval updates atomic
• Add duplicate approval prevention
• Test: Concurrent approvals handled correctly

Storage Security

• Implement encrypted storage (utils/encryption.ts)
• Replace all localStorage with SecureStorage
• Generate secure encryption keys
• Test: Data encrypted and decryptable

Transaction Security

• Add nonce management (contexts/TransactionContext.tsx)
• Add transaction deduplication
• Add transaction expiration
• Test: Duplicate transactions prevented

Provider Security

• Add provider verification (contexts/TransactionContext.tsx)
• Verify account matches wallet
• Reject unverified providers
• Test: Fake providers rejected

---

Phase 2: High Priority Fixes (Week 2)

Integer Overflow

• Replace all parseInt with BigNumber (components/Body/index.tsx)
• Fix value parsing in transaction creation
• Fix value display formatting
• Test: Large values handled correctly

Gas Management

• Add maximum gas limit (contexts/TransactionContext.tsx)
• Validate gas prices
• Add gas estimation limits
• Test: Excessive gas rejected

Input Sanitization

• Sanitize all user inputs (components/TransactionExecution/TransactionBuilder.tsx)
• Validate transaction data length
• Prevent XSS in address fields
• Test: Malicious inputs sanitized

API Security

• Move API keys to environment variables (helpers/relayers/index.ts)
• Add API key rotation mechanism
• Add request signing
• Test: API keys not exposed

Transaction Limits

• Add maximum transaction value
• Add daily transaction limits
• Add rate limiting
• Test: Limits enforced

Network Security

• Validate all network IDs (components/SmartWallet/WalletManager.tsx)
• Verify RPC URLs use HTTPS
• Add network whitelist
• Fix Gnosis Safe contract addresses
• Test: Invalid networks rejected

---

Phase 3: Medium Priority Fixes (Week 3-4)

Error Handling

• Add error boundaries (app/layout.tsx)
• Add comprehensive error messages
• Add error logging service
• Test: Errors handled gracefully

Transaction Management

• Add transaction status polling
• Add transaction cancellation
• Add transaction retry mechanism
• Test: Transactions tracked correctly

State Management

• Fix all state update race conditions
• Add state validation
• Add state persistence verification
• Test: State consistency maintained

UI Security

• Add CSP headers
• Sanitize all rendered content
• Add loading states
• Test: No XSS vulnerabilities

Monitoring

• Add security event logging
• Add failed validation tracking
• Add suspicious activity detection
• Test: Events logged correctly

---

Phase 4: Testing & Validation

Unit Tests

• Test all validation functions
• Test security utilities
• Test encryption/decryption
• Test rate limiting
• Coverage: >80%

Integration Tests

• Test complete transaction flow
• Test multi-sig approval flow
• Test wallet management
• Test iframe communication
• All tests passing

Security Tests

• XSS attack tests
• CSRF attack tests
• Replay attack tests
• Race condition tests
• Integer overflow tests
• All security tests passing

Penetration Testing

• External penetration test
• Code review by security expert
• Dependency audit
• All issues resolved

---

Phase 5: Documentation & Deployment

Documentation

• Security architecture documented
• Threat model documented
• Incident response plan
• Security runbook created

Deployment

• Security headers configured
• Monitoring set up
• Alerting configured
• Backup procedures documented

---

Quick Fix Reference

Replace These Patterns:

❌ BAD:

parseInt(value, 16)
Math.random().toString(36).substr(2, 9)
postMessage(msg, "*")
localStorage.setItem(key, JSON.stringify(data))

✅ GOOD:

ethers.BigNumber.from(value)
generateSecureId()
postMessage(msg, specificOrigin)
await secureStorage.setItem(key, JSON.stringify(data))

---

Testing Commands

# Run security tests
npm test -- security.test.ts

# Run linting
npm run lint

# Check dependencies
npm audit
npm audit fix

# Build and check for errors
npm run build

---

Sign-Off

Before production deployment, ensure:

• All CRITICAL issues fixed
• All HIGH issues fixed
• Security tests passing
• Penetration test completed
• Code review approved
• Documentation complete
• Monitoring active
• Incident response plan ready

Security Lead Signature: _________________
Date: _________________

---

Post-Deployment

Week 1

• Monitor security events daily
• Review error logs
• Check for suspicious activity
• Verify monitoring alerts

Month 1

• Security metrics review
• User feedback analysis
• Performance review
• Update threat model

Quarterly

• Full security audit
• Penetration testing
• Dependency updates
• Security training