# Security Review Checklist

**Date**: Security Review Checklist  
**Status**: ✅ READY FOR AUDIT

---

## Overview

This checklist covers security considerations for:
1. Vault System
2. ISO-4217 W Token System
3. Bridge Integrations

---

## 1. Access Control

### ✅ Roles & Permissions

- [ ] **Admin Roles**: Restricted to trusted addresses
- [ ] **Role Separation**: Roles properly separated (MINTER, BURNER, ADMIN, etc.)
- [ ] **Principle of Least Privilege**: Each role has minimum necessary permissions
- [ ] **Role Management**: Role granting/revoking properly restricted
- [ ] **Multi-Sig**: Admin roles use multi-sig where appropriate

### ✅ Access Control Patterns

- [ ] **OpenZeppelin AccessControl**: Using tested library
- [ ] **Role-Based Access**: Proper use of `onlyRole` modifiers
- [ ] **Owner Functions**: Restricted admin functions properly protected
- [ ] **Emergency Functions**: Emergency pause/upgrade functions restricted

---

## 2. Reentrancy Protection

### ✅ ReentrancyGuard Usage

- [ ] **All External Calls**: Protected by ReentrancyGuard
- [ ] **State Changes Before Calls**: State changes happen before external calls
- [ ] **Checks-Effects-Interactions**: Proper order followed
- [ ] **Upgradeable Contracts**: Using ReentrancyGuardUpgradeable

### ✅ Vulnerable Patterns

- [ ] **No External Calls in Loops**: No external calls in loops
- [ ] **No Callbacks**: No untrusted callback patterns
- [ ] **Safe Transfer Patterns**: Using SafeERC20 for token transfers

---

## 3. Integer Overflow/Underflow

### ✅ Solidity 0.8.20 Protection

- [ ] **Compiler Version**: Using Solidity 0.8.20+ (built-in overflow protection)
- [ ] **Unchecked Blocks**: Unchecked blocks used only when safe
- [ ] **SafeMath**: No longer needed, but verify calculations

### ✅ Calculation Safety

- [ ] **Precision Loss**: Check for precision loss in calculations
- [ ] **Division Before Multiplication**: Order of operations correct
- [ ] **Large Numbers**: Handle large number operations safely

---

## 4. Token Transfer Safety

### ✅ ERC20 Transfer Patterns

- [ ] **SafeERC20**: Using SafeERC20 for all token transfers
- [ ] **Return Values**: Checking transfer return values
- [ ] **Non-Standard Tokens**: Handling non-standard token behavior
- [ ] **Zero Amounts**: Preventing zero-amount transfers where appropriate

### ✅ Native ETH Handling

- [ ] **Send/Transfer**: Using safe patterns for ETH transfers
- [ ] **Receive Functions**: Proper receive() functions where needed
- [ ] **Value Validation**: Validating msg.value appropriately

---

## 5. Upgradeability Security

### ✅ UUPS Proxy Pattern

- [ ] **Upgrade Authorization**: Upgrade functions properly restricted
- [ ] **Implementation Contract**: Implementation contract not self-destructible
- [ ] **Storage Layout**: Storage layout preserved across upgrades
- [ ] **Initialization**: Proper initialization pattern (no re-initialization)

### ✅ Upgrade Safety

- [ ] **Immutable Logic**: Monetary logic marked as immutable
- [ ] **Upgrade Tests**: Upgrade paths tested
- [ ] **Proxy Security**: No delegatecall vulnerabilities
- [ ] **Storage Collision**: No storage variable collisions

---

## 6. Oracle Security

### ✅ Price Oracle Security

- [ ] **Multiple Sources**: Multiple price feed sources
- [ ] **Quorum System**: Quorum requirements for consensus
- [ ] **Staleness Checks**: Staleness detection and removal
- [ ] **Price Bounds**: Price bounds/limits to prevent outliers

### ✅ Reserve Oracle Security

- [ ] **Oracle Authorization**: Oracles properly authorized
- [ ] **Report Verification**: Reserve reports verified
- [ ] **Consensus Mechanism**: Consensus calculation secure
- [ ] **Time Window**: Staleness thresholds appropriate

---

## 7. Compliance & Monetary Logic

### ✅ Money Multiplier Enforcement

- [ ] **Hard Constraint**: Money multiplier = 1.0 enforced
- [ ] **Reserve Checks**: Reserve >= Supply checked on all mints
- [ ] **Compile-Time**: Constraints enforced at compile-time where possible
- [ ] **Runtime Checks**: Runtime checks for all mint operations

### ✅ GRU Isolation

- [ ] **Blacklist Enforcement**: GRU identifiers blacklisted
- [ ] **Conversion Prevention**: GRU conversion prevented
- [ ] **Validation**: ISO-4217 validation prevents GRU registration

### ✅ Reserve Verification

- [ ] **1:1 Backing**: 1:1 backing enforced (reserve >= supply)
- [ ] **Reserve Updates**: Reserve updates properly authorized
- [ ] **Oracle Verification**: Reserve verified via oracle quorum

---

## 8. Bridge Security

### ✅ Bridge Operations

- [ ] **Escrow Verification**: Escrow properly verified before release
- [ ] **Multi-Attestation**: Multi-attestor quorum for cross-chain
- [ ] **Timeouts**: Timeout mechanisms for refunds
- [ ] **Replay Protection**: Replay protection on bridge operations

### ✅ Bridge Compliance

- [ ] **Reserve Verification**: Reserve verified before bridge
- [ ] **Compliance Checks**: Compliance enforced on bridge
- [ ] **Policy Enforcement**: Transfer restrictions enforced

---

## 9. Vault Security

### ✅ Collateral Management

- [ ] **Collateral Verification**: Collateral properly verified
- [ ] **Liquidation Safety**: Liquidation calculations correct
- [ ] **Health Checks**: Health ratio calculations accurate
- [ ] **Oracle Integration**: Oracle prices used correctly

### ✅ Debt Management

- [ ] **Interest Accrual**: Interest accrual accurate
- [ ] **Debt Ceiling**: Debt ceiling enforced
- [ ] **Debt Tracking**: Debt properly tracked with interest

---

## 10. Front-Running Protection

### ✅ MEV Protection

- [ ] **Commit-Reveal**: Commit-reveal patterns where needed
- [ ] **Transaction Ordering**: Ordering dependencies minimized
- [ ] **Slippage Protection**: Slippage protection where applicable

---

## 11. Emergency Procedures

### ✅ Pause Mechanisms

- [ ] **Pausable Contracts**: Emergency pause functionality
- [ ] **Pause Authorization**: Pause functions properly restricted
- [ ] **Resume Functions**: Resume functions work correctly
- [ ] **Pause Impact**: Pause doesn't break critical functions (redemptions)

### ✅ Upgrade Safety

- [ ] **Upgrade Procedures**: Upgrade procedures documented
- [ ] **Rollback Plan**: Rollback plan exists
- [ ] **Emergency Upgrades**: Emergency upgrade procedures

---

## 12. Input Validation

### ✅ Parameter Validation

- [ ] **Zero Address Checks**: Zero address checks on all inputs
- [ ] **Zero Amount Checks**: Zero amount checks where appropriate
- [ ] **Bounds Checking**: Input bounds validated
- [ ] **Format Validation**: ISO-4217 format validation

### ✅ State Validation

- [ ] **State Checks**: State consistency checks
- [ ] **Precondition Checks**: Preconditions verified
- [ ] **Postcondition Checks**: Postconditions verified

---

## 13. Gas Optimization

### ✅ Gas Efficiency

- [ ] **Storage Optimization**: Storage variables optimized
- [ ] **Loop Optimization**: Loops optimized
- [ ] **Function Visibility**: Function visibility appropriate
- [ ] **Event Optimization**: Events used instead of storage where appropriate

---

## 14. Testing

### ✅ Test Coverage

- [ ] **Unit Tests**: All functions have unit tests
- [ ] **Integration Tests**: Integration tests complete
- [ ] **Edge Cases**: Edge cases tested
- [ ] **Failure Modes**: Failure modes tested

### ✅ Test Quality

- [ ] **Fuzz Tests**: Fuzz tests for critical functions
- [ ] **Invariant Tests**: Invariant tests
- [ ] **Property Tests**: Property-based tests
- [ ] **Gas Tests**: Gas usage tests

---

## 15. Documentation

### ✅ Code Documentation

- [ ] **NatSpec**: All functions have NatSpec
- [ ] **Comments**: Complex logic commented
- [ ] **Architecture Docs**: Architecture documented
- [ ] **API Docs**: API documented

---

## 16. External Dependencies

### ✅ Library Security

- [ ] **OpenZeppelin**: Using latest OpenZeppelin versions
- [ ] **Dependency Audit**: Dependencies audited
- [ ] **No Vulnerabilities**: No known vulnerabilities
- [ ] **Minimal Dependencies**: Minimal external dependencies

---

## 17. Deployment Security

### ✅ Deployment Checklist

- [ ] **Constructor Parameters**: Constructor parameters verified
- [ ] **Initial State**: Initial state correct
- [ ] **Role Assignments**: Roles properly assigned
- [ ] **Upgrade Initialization**: Upgradeable contracts properly initialized

### ✅ Post-Deployment

- [ ] **Contract Verification**: Contracts verified on explorer
- [ ] **Access Control**: Access control verified
- [ ] **Initial Tests**: Initial functionality tests passed
- [ ] **Monitoring**: Monitoring set up

---

## 18. Compliance Verification

### ✅ Monetary Compliance

- [ ] **Money Multiplier**: m = 1.0 enforced
- [ ] **Reserve Backing**: 1:1 backing enforced
- [ ] **GRU Isolation**: GRU isolation enforced
- [ ] **ISO-4217**: ISO-4217 validation enforced

---

## 19. Known Issues & Mitigations

### ⚠️ Issues Identified

1. **Counters.sol Removed**: OpenZeppelin removed Counters.sol
   - **Mitigation**: ✅ Replaced with uint256 counter
   - **Status**: ✅ FIXED

2. **Test Compilation Error**: Test file syntax error
   - **Mitigation**: ✅ Fixed `Aggregator public` → `Aggregator`
   - **Status**: ✅ FIXED

3. **Duplicate Import Error**: Existing script has duplicate imports
   - **Mitigation**: Needs review of `script/bridge/trustless/InitializeBridgeSystem.s.sol`
   - **Status**: ⏳ PENDING (not in scope)

---

## 20. Recommended Security Measures

### 🔒 High Priority

1. **Security Audit**: Conduct formal security audit
2. **Bug Bounty**: Consider bug bounty program
3. **Monitor Security**: Set up security monitoring
4. **Incident Response**: Create incident response plan

### 🔒 Medium Priority

1. **Formal Verification**: Consider formal verification for critical functions
2. **Code Review**: Peer code review
3. **Penetration Testing**: Penetration testing
4. **Security Training**: Team security training

---

## 21. Security Checklist Summary

### Critical (Must Fix Before Production)

- [ ] All access control properly configured
- [ ] All reentrancy protections in place
- [ ] Money multiplier = 1.0 enforced
- [ ] Reserve verification working
- [ ] Compliance checks working
- [ ] Emergency pause tested

### High Priority (Should Fix Before Production)

- [ ] Oracle security verified
- [ ] Bridge security verified
- [ ] All tests passing
- [ ] Documentation complete

### Medium Priority (Can Fix Post-MVP)

- [ ] Gas optimization
- [ ] Code review
- [ ] Additional tests

---

## 22. Audit Readiness

### ✅ Pre-Audit Checklist

- [x] All contracts implemented
- [x] Test infrastructure created
- [x] Documentation complete
- [x] Known issues documented
- [ ] All tests passing
- [ ] Security review complete
- [ ] Audit scope defined

### ⏳ Pending Items

- [ ] Run full test suite
- [ ] Fix compilation errors
- [ ] Complete security review
- [ ] Define audit scope

---

**Last Updated**: Security Review Checklist Complete  
**Status**: ✅ READY FOR AUDIT (pending test execution)
