smom-dbis-138/docs/security/SECURITY_AUDIT_CHECKLIST.md

Security Audit Checklist for Refactored Contracts

Overview

This checklist provides security considerations for contracts refactored to remove OpenZeppelin dependencies.

General Security Checklist

Access Control

• Admin Pattern

  • Admin address is set in constructor
  • Admin address is validated (not zero address)
  • Admin functions are protected with onlyAdmin modifier
  • Admin can be changed with changeAdmin function
  • New admin is validated (not zero address)
  • Admin change is logged with event

• Access Control Functions

  • All admin functions use onlyAdmin modifier
  • No public functions with admin privileges
  • No functions that bypass access control
  • Access control is consistent across contract

Token Operations

• ERC20 Token Transfers

  • Token transfers use standard ERC20 calls
  • Transfer return values are checked
  • Transfer failures revert with clear error messages
  • Token addresses are validated (not zero address)
  • Token amounts are validated (greater than zero)

• Token Approvals

  • Token approvals use standard ERC20 calls
  • Approval return values are checked
  • Approval failures revert with clear error messages
  • Approval amounts are validated
  • Approval spender is validated (not zero address)

• Token Balance Checks

  • Balance checks are performed before transfers
  • Balance checks use standard ERC20 calls
  • Balance checks are accurate
  • Balance checks handle edge cases

Input Validation

• Address Validation

  • All addresses are validated (not zero address)
  • Address validation is consistent
  • Address validation has clear error messages
  • Address validation is performed early

• Amount Validation

  • All amounts are validated (greater than zero)
  • Amount validation is consistent
  • Amount validation has clear error messages
  • Amount validation handles overflow/underflow

• Parameter Validation

  • All parameters are validated
  • Parameter validation is consistent
  • Parameter validation has clear error messages
  • Parameter validation is performed early

Error Handling

• Error Messages

  • All error messages are clear and descriptive
  • Error messages follow consistent format
  • Error messages include contract name prefix
  • Error messages are helpful for debugging

• Revert Conditions

  • All revert conditions are explicit
  • Revert conditions use require statements
  • Revert conditions are checked early
  • Revert conditions handle edge cases

Reentrancy Protection

• Reentrancy Guards

  • Reentrancy guards are used where needed
  • Reentrancy guards are consistent
  • Reentrancy guards are effective
  • Reentrancy guards handle all entry points

• External Calls

  • External calls are made after state changes
  • External calls are validated
  • External calls handle failures
  • External calls don't allow reentrancy

State Management

• State Variables

  • State variables are properly initialized
  • State variables are properly updated
  • State variables are properly validated
  • State variables are properly protected

• State Changes

  • State changes are atomic
  • State changes are consistent
  • State changes are validated
  • State changes are logged with events

Events

• Event Logging
  • All important events are logged
  • Events include all relevant parameters
  • Events are indexed where appropriate
  • Events follow consistent naming

Gas Optimization

• Gas Efficiency
  • Contract is gas-efficient
  • Unnecessary operations are avoided
  • Storage operations are optimized
  • External calls are minimized

Code Quality

• Code Structure

  • Code is well-structured
  • Code is well-documented
  • Code follows best practices
  • Code is maintainable

• Code Review

  • Code has been reviewed
  • Code review comments have been addressed
  • Code follows project standards
  • Code is consistent with other contracts

---

Contract-Specific Checklists

CCIP Contracts (CCIPSender, CCIPRouter, CCIPRouterOptimized)

• SafeERC20 Replacement

  • Standard ERC20 calls are used
  • Transfer return values are checked
  • Approval return values are checked
  • Error messages are clear
  • Only standard ERC20 tokens are used

• Fee Token Handling

  • Fee token is validated
  • Fee token transfers are safe
  • Fee token approvals are safe
  • Fee token balance is checked
  • Fee token errors are handled

• CCIP Integration

  • CCIP router is validated
  • CCIP messages are validated
  • CCIP fees are calculated correctly
  • CCIP errors are handled
  • CCIP replay protection is implemented

Governance Contracts (MultiSig, Voting)

• Ownable Replacement

  • Custom admin pattern is used
  • Admin functions are protected
  • Admin can be changed
  • New admin is validated
  • Admin change is logged

• Access Control

  • Access control is consistent
  • Access control is effective
  • Access control handles edge cases
  • Access control is well-tested

• Governance Logic

  • Governance logic is correct
  • Governance logic is secure
  • Governance logic is well-tested
  • Governance logic handles edge cases

---

Testing Checklist

Unit Tests

• Test Coverage

  • All functions are tested
  • All edge cases are tested
  • All error cases are tested
  • Test coverage is high

• Test Quality

  • Tests are comprehensive
  • Tests are well-written
  • Tests are maintainable
  • Tests follow best practices

Integration Tests

• Integration Testing
  • Contracts are tested together
  • Integration tests are comprehensive
  • Integration tests are well-written
  • Integration tests are maintainable

Security Tests

• Security Testing
  • Security tests are performed
  • Security vulnerabilities are tested
  • Security tests are comprehensive
  • Security tests are well-written

---

Deployment Checklist

Pre-Deployment

• Code Review

  • Code has been reviewed
  • Code review comments have been addressed
  • Code follows project standards

• Testing

  • All tests pass
  • Test coverage is high
  • Security tests are performed

• Documentation

  • Documentation is complete
  • Documentation is accurate
  • Documentation is up-to-date

Deployment

• Deployment Scripts

  • Deployment scripts are tested
  • Deployment scripts are secure
  • Deployment scripts are well-documented

• Deployment Verification

  • Contracts are deployed correctly
  • Contract addresses are verified
  • Contract functionality is verified

Post-Deployment

• Monitoring

  • Contracts are monitored
  • Contract events are logged
  • Contract performance is tracked

• Maintenance

  • Contracts are maintained
  • Contract updates are planned
  • Contract security is reviewed

---

References

Contract Examples

• contracts/ccip/CCIPWETH9Bridge.sol - Custom implementation ✅
• contracts/ccip/CCIPWETH10Bridge.sol - Custom implementation ✅
• contracts/tokens/WETH10.sol - Custom implementation ✅

Documentation

• Migration Guide
• Contract Inventory
• OpenZeppelin Usage Analysis
• Dependencies Guide

---

Summary

Key Security Considerations

1. ✅ Access Control: Use custom admin pattern with proper validation
2. ✅ Token Operations: Use standard ERC20 calls with return value checks
3. ✅ Input Validation: Validate all inputs with clear error messages
4. ✅ Error Handling: Use explicit error messages with require statements
5. ✅ Reentrancy Protection: Protect against reentrancy attacks
6. ✅ State Management: Manage state changes safely and atomically
7. ✅ Events: Log all important events
8. ✅ Gas Optimization: Optimize gas usage where possible
9. ✅ Code Quality: Follow best practices and project standards
10. ✅ Testing: Comprehensive testing with high coverage

---

Questions?

For questions about security audit checklists, refer to:

• Migration Guide
• Contract Inventory
• OpenZeppelin Usage Analysis