Detailed Instructions

This initial phase establishes the audit's foundation. The auditor and client agree on the specific contracts to be reviewed, the depth of analysis (e.g., automated tools only vs. full manual review), and the project timeline. A formal scope document is created, detailing the repository commit hash (e.g., 0xabc123...), the specific Solidity files, and any excluded components like legacy or forked libraries.

• Sub-step 1: Client provides the repository link and target commit hash for the audit.
• Sub-step 2: Auditor reviews the codebase size and complexity to estimate effort.
• Sub-step 3: Both parties agree on a testing environment, such as forking mainnet at block 18,500,000 or using a custom Hardhat configuration.

Tip: Clearly document any out-of-scope elements, like admin multisig contracts, to prevent scope creep later.

Detailed Instructions

Auditors employ a suite of automated security tools to perform an initial, broad sweep of the code. This includes static analysis with Slither or Mythril to detect common patterns like reentrancy, and formal verification tools for mathematical proof of certain properties. Dynamic analysis involves running the test suite and fuzzing with Echidna or Foundry's forge fuzz, specifying invariant tests like totalSupply() never decreasing.

• Sub-step 1: Execute Slither with custom detectors: slither . --detect reentrancy-eth,unchecked-transfer.
• Sub-step 2: Run a Foundry fuzzer for 100,000 runs on a core swap function.
• Sub-step 3: Analyze tool outputs, triaging false positives (e.g., benign unused return values) from true issues.

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// Example invariant test in Foundry
function test_supply_invariant() public {
    assertEq(vault.totalSupply(), vault.totalAssets());
}

Tip: Automated tools are a starting point; they cannot reason about business logic flaws, which require manual review.

Detailed Instructions

The core of the audit is the line-by-line manual review. Auditors examine the code's architecture, data flow, and adherence to the intended specification or whitepaper. They focus on business logic errors, privilege escalation, economic incentives, and integration risks. This involves tracing function calls, checking access controls (e.g., onlyOwner modifiers), and verifying that state changes are handled correctly under all conditions, including edge cases like zero-value transfers or maximum uint256 values.

• Sub-step 1: Map out all state variables and their mutability, noting which functions are public/external.
• Sub-step 2: Review mathematical operations for overflow/underflow and precision loss, even with Solidity 0.8.x.
• Sub-step 3: Analyze external calls to other contracts (e.g., Oracle feeds, LP tokens) for trust assumptions.

Tip: Create a mental or documented model of the contract's intended state machine and challenge it with unexpected user flows.

Detailed Instructions

Findings are compiled into a detailed audit report. Each issue is categorized by severity level (Critical, High, Medium, Low, Informational) following a standardized framework like the DASP Top 10 or SWC Registry. The report includes a clear description, code snippets with line numbers, a proof-of-concept exploit where possible, and a recommended fix. The client then addresses the issues, and the auditor performs a remediation review on the updated code (e.g., commit 0xdef456...) to verify the fixes are correct and do not introduce new vulnerabilities.

• Sub-step 1: For a Critical reentrancy bug, provide a PoC showing how to drain the contract.
• Sub-step 2: Client deploys fixes and provides a diff for the auditor's review.
• Sub-step 3: Auditor re-runs targeted tests and manual review on the patched functions.

solidityCopy
// Example of a mitigated reentrancy guard
function withdraw() external nonReentrant { // Using OpenZeppelin's ReentrancyGuard
    // ... safe logic
}

Tip: A good report is actionable, providing specific code changes rather than just describing the problem.

Detailed Instructions

Review the audit report and classify each finding based on its severity level (Critical, High, Medium, Low, Informational). Create a remediation plan that addresses Critical and High-severity issues first, as they pose the greatest risk to user funds or contract logic. For each finding, assign a developer and set a target resolution date.

• Sub-step 1: Map each finding to its corresponding function and line numbers in your codebase.
• Sub-step 2: Assess the complexity and potential side effects of each fix. Some fixes may require architectural changes.
• Sub-step 3: Log all decisions in a tracking document (e.g., spreadsheet or project management tool) to maintain accountability.

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// Example: A Critical reentrancy finding in a withdrawal function
function withdraw() public {
    // Vulnerable original code
    (bool success, ) = msg.sender.call{value: balances[msg.sender]}("");
    require(success, "Transfer failed");
    balances[msg.sender] = 0; // State update AFTER external call
}

Tip: Engage the auditing team to clarify any ambiguous findings before beginning implementation to avoid misinterpretation.

Detailed Instructions

Apply the specific code changes required to mitigate each vulnerability. This often involves implementing established security patterns. For reentrancy, use the Checks-Effects-Interactions pattern or ReentrancyGuard. For access control issues, implement explicit role checks with modifiers. For integer overflows/underflows, use SafeMath libraries or Solidity 0.8.x's built-in checks.

• Sub-step 1: Apply the fix in a dedicated feature branch, making minimal, focused changes.
• Sub-step 2: Add comprehensive NatSpec comments explaining the security fix and referencing the audit finding ID.
• Sub-step 3: Ensure the fix does not break existing contract functionality or introduce new gas inefficiencies.

solidityCopy
// Example: Fixed withdrawal function using Checks-Effects-Interactions
function withdraw() public nonReentrant { // Added modifier
    uint256 amount = balances[msg.sender];
    require(amount > 0, "No balance");
    // Effects: Update state BEFORE external call
    balances[msg.sender] = 0;
    // Interactions: Perform the call last
    (bool success, ) = msg.sender.call{value: amount}("");
    require(success, "Transfer failed");
}

Tip: Use git diff to generate a patch file of all changes for easy review by auditors during verification.

Detailed Instructions

After implementing fixes, you must update your test suite. Write new tests that specifically target the patched vulnerabilities to prove they are resolved. Also, run the full existing test suite to ensure no regressions were introduced. Use a framework like Foundry or Hardhat with high coverage goals.

• Sub-step 1: Create a test for each audit finding that simulates the exploit path and asserts it now fails.
• Sub-step 2: Run fuzz tests (e.g., with Foundry's forge fuzz) on modified functions to uncover edge cases.
• Sub-step 3: Execute invariant tests to ensure core contract properties (e.g., "total supply is constant") still hold.

solidityCopy
// Foundry test example for the fixed reentrancy vulnerability
function test_ReentrancyAttackFails() public {
    AttackerContract attacker = new AttackerContract(address(vault));
    vm.deal(address(attacker), 1 ether);
    attacker.deposit{value: 1 ether}();
    // The attack function attempts a reentrant call during withdrawal
    vm.expectRevert(); // Expect the transaction to revert
    attacker.attack();
    // Assert the attacker did not drain extra funds
    assertEq(address(vault).balance, 1 ether);
}

Tip: Aim for 100% branch coverage on the modified code paths. Use coverage reports to identify untested lines.

Detailed Instructions

Formally submit the patched codebase to the original auditing team for verification. The deliverable should include the updated source code, the diff/patch file, the updated test suite, and a detailed document mapping each audit finding to its resolution. The auditors will perform a focused review to confirm fixes are correct and complete.

• Sub-step 1: Provide clear access to the code repository (e.g., a specific git tag or branch) and deployment artifacts.
• Sub-step 2: Include a summary of all changes made and any decisions not to fix certain findings (e.g., acknowledged informational issues).
• Sub-step 3: The auditors will re-run their static analysis, manual review, and possibly custom exploit scripts against the new code.

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# Example command auditors might run for differential analysis
# Compare the pre-audit and post-remediation bytecode
diff <(solc --bin OldContract.sol) <(solc --bin NewContract.sol)

Tip: A successful verification typically results in an updated audit report or a formal letter stating all critical/high issues are resolved, which is crucial for community trust.

Detailed Instructions

Once verification is complete, proceed with deployment. Use a staged rollout if possible, deploying to a testnet first for final community testing. For mainnet deployment, employ a multisig wallet or timelock controller for the deployer address. After deployment, implement monitoring and incident response plans.

• Sub-step 1: Deploy the verified contracts to a testnet (e.g., Sepolia) and run a final suite of on-chain integration tests.
• Sub-step 2: For mainnet, execute the deployment transaction from a multisig wallet requiring multiple signatures.
• Sub-step 3: Set up monitoring tools (e.g., Tenderly, OpenZeppelin Defender) to alert on unusual transactions, function failures, or gas usage spikes.

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// Example: Hardhat deployment script using a multisig executor
async function main() {
  const MyContract = await ethers.getContractFactory("MyContract");
  // The 'multisig' signer is configured in hardhat.config.js
  const contract = await MyContract.connect(multisig).deploy();
  await contract.deployed();
  console.log("Contract deployed to:", contract.address);
  // Propose ownership transfer to a timelock contract
  await contract.proposeTransferOwnership(timelockAddress);
}

Tip: Consider engaging a bug bounty program (e.g., on Immunefi) post-deployment as an additional continuous security layer.