Solidity Security Standards
Language Rule
- Always respond in the same language the user is using. If the user asks in Chinese, respond in Chinese. If in English, respond in English.
Private Key Protection
- Store private keys in
.env, load viasource .env— never pass keys as CLI arguments - Never expose private keys in logs, screenshots, conversations, or commits
- Provide
.env.examplewith placeholder values for team reference - Add
.envto.gitignore— verify withgit statusbefore every commit
Security Decision Rules
When writing or reviewing Solidity code, apply these rules:
| Situation | Required Action |
|---|---|
| External ETH/token transfer | Use ReentrancyGuard + Checks-Effects-Interactions (CEI) pattern |
| ERC20 token interaction | Use SafeERC20 — call safeTransfer / safeTransferFrom, never raw transfer / transferFrom |
| Owner-only function | Inherit Ownable2Step (preferred) or Ownable from OZ 4.9.x — Ownable2Step prevents accidental owner loss |
| Multi-role access | Use AccessControl from @openzeppelin/contracts/access/AccessControl.sol |
| Token approval | Use safeIncreaseAllowance / safeDecreaseAllowance from SafeERC20 — never raw approve |
| Price data needed | Use Chainlink AggregatorV3Interface if feed exists; otherwise TWAP with min-liquidity check — never use spot pool price directly |
| Upgradeable contract | Prefer UUPS (UUPSUpgradeable) over TransparentProxy; always use Initializable |
| Solidity version < 0.8.0 | Must use SafeMath — but strongly prefer upgrading to 0.8.20+ |
| Emergency scenario | Inherit Pausable, add whenNotPaused to user-facing functions; keep admin/emergency functions unpaused |
| Whitelist / airdrop | Use MerkleProof for gas-efficient verification — never store full address lists on-chain |
| Signature-based auth | Use ECDSA + EIP712 — never roll custom signature verification |
| Signature content | Signature must bind chainId + nonce + msg.sender + deadline — prevent replay and cross-chain reuse |
| Cross-chain bridge / third-party dependency | Audit all inherited third-party contract code — never assume dependencies are safe |
| Deprecated / legacy contracts | Permanently pause or selfdestruct deprecated contracts — never leave unused contracts callable on-chain |
| UUPS upgrade pattern | _authorizeUpgrade must have onlyOwner; implementation constructor calls _disableInitializers(); retain onlyProxy on upgradeTo — EVMbench/basin H-01 |
| Multi-contract trust boundary | Router/Registry relay calls must verify source contract authorization; never trust caller identity inside flash loan callbacks — EVMbench/noya H-08 |
| Counter/ID + external call | All counter increments and ID assignments must complete before external calls; ETH refunds must be last — EVMbench/phi H-06 |
Reentrancy Protection
- All contracts with external calls: inherit
ReentrancyGuard, addnonReentrantmodifier- Import:
@openzeppelin/contracts/security/ReentrancyGuard.sol(OZ 4.9.x)
- Import:
- Always apply CEI pattern even with
ReentrancyGuard:- Checks — validate all conditions (
require) - Effects — update state variables
- Interactions — external calls last
- Checks — validate all conditions (
Input Validation
- Reject
address(0)for all address parameters - Reject zero amounts for fund transfers
- Validate array lengths match when processing paired arrays
- Bound numeric inputs to reasonable ranges (prevent dust attacks, gas griefing)
Gas Control
- Deployment commands must include
--gas-limit(recommended >= 3,000,000) - Monitor gas with
forge test --gas-report— review before every PR - Configure optimizer in
foundry.toml:optimizer = true,optimizer_runs = 200 - Avoid unbounded loops over dynamic arrays — use pagination or pull patterns
Pre-Audit Checklist
Before submitting code for review or audit, verify:
Access & Control:
- All external/public functions have
nonReentrantwhere applicable - No
tx.originused for authentication (usemsg.sender) - No
delegatecallto untrusted addresses - Owner transfer uses
Ownable2Step(notOwnable) to prevent accidental loss - Contracts with user-facing functions inherit
Pausablewithpause()/unpause() - UUPS
_authorizeUpgradehasonlyOwnermodifier — EVMbench/basin H-01 - Implementation constructor calls
_disableInitializers()— EVMbench/basin H-01 - Router/Registry relay operations verify source contract authorization — EVMbench/noya H-08
Token & Fund Safety:
- All ERC20 interactions use
SafeERC20(safeTransfer/safeTransferFrom) - No raw
token.transfer()orrequire(token.transfer())patterns - Token approvals use
safeIncreaseAllowance, not rawapprove - All
external callreturn values checked
Code Quality:
- Events emitted for every state change
- No hardcoded addresses — use config or constructor params
-
.envis in.gitignore
Oracle & Price (if applicable):
- Price data sourced from Chainlink feed or TWAP — never raw spot price
- Oracle has minimum liquidity check — revert if pool reserves too low
- Price deviation circuit breaker in place
Testing:
-
forge testpasses with zero failures -
forge coverageshows adequate coverage on security-critical paths - Fuzz tests cover arithmetic edge cases (zero, max uint, boundary values)
Security Verification Commands
# Run all tests with gas report
forge test --gas-report
# Fuzz testing with higher runs for critical functions
forge test --fuzz-runs 10000
# Check test coverage
forge coverage
# Dry-run deployment to verify no runtime errors
forge script script/Deploy.s.sol --fork-url $RPC_URL -vvvv
# Static analysis (if slither installed locally)
slither src/
Slither MCP Integration (if available)
When slither MCP is configured, prefer it over the CLI for structured analysis:
| Approach | When to Use |
|---|---|
slither src/ (CLI) | Quick local scan, raw terminal output |
slither MCP get_detector_results | Structured results with impact/confidence filtering, AI can parse and reason about findings |
slither MCP get_contract_metadata | Understanding contract structure before reviewing code |
slither MCP get_function_source | Locating exact function implementations faster than grep |
Recommended: Use slither MCP when working with AI agents (results are structured and actionable). Use CLI for quick local checks during development.
Graceful degradation: If neither slither MCP nor slither CLI is available, rely on the Pre-Audit Checklist above and forge test --fuzz-runs 10000 for coverage.