All code4rena fixes

contracts/Aura.sol

@@ -1,10 +1,7 @@
 // SPDX-License-Identifier: MIT
-pragma solidity ^0.8.11;
+pragma solidity 0.8.11;
 
-import { IERC20 } from "@openzeppelin/contracts-0.8/token/ERC20/IERC20.sol";
 import { ERC20 } from "@openzeppelin/contracts-0.8/token/ERC20/ERC20.sol";
-import { SafeERC20 } from "@openzeppelin/contracts-0.8/token/ERC20/utils/SafeERC20.sol";
-import { Address } from "@openzeppelin/contracts-0.8/utils/Address.sol";
 import { AuraMath } from "./AuraMath.sol";
 
 interface IStaker {
@@ -18,14 +15,13 @@ interface IStaker {
  *          distirbuted along a supply curve (cliffs etc). Fork of ConvexToken.
  */
 contract AuraToken is ERC20 {
-    using SafeERC20 for IERC20;
-    using Address for address;
     using AuraMath for uint256;
 
     address public operator;
     address public immutable vecrvProxy;
 
     uint256 public constant EMISSIONS_MAX_SUPPLY = 5e25; // 50m
+    uint256 public constant INIT_MINT_AMOUNT = 5e25; // 50m
     uint256 public constant totalCliffs = 500;
     uint256 public immutable reductionPerCliff;
 
@@ -55,20 +51,14 @@ contract AuraToken is ERC20 {
     /**
      * @dev Initialise and mints initial supply of tokens.
      * @param _to        Target address to mint.
-     * @param _amount    Amount of tokens to mint.
      * @param _minter    The minter address.
      */
-    function init(
-        address _to,
-        uint256 _amount,
-        address _minter
-    ) external {
+    function init(address _to, address _minter) external {
         require(msg.sender == operator, "Only operator");
         require(totalSupply() == 0, "Only once");
-        require(_amount > 0, "Must mint something");
         require(_minter != address(0), "Invalid minter");
 
-        _mint(_to, _amount);
+        _mint(_to, INIT_MINT_AMOUNT);
         updateOperator();
         minter = _minter;
         minterMinted = 0;
@@ -80,7 +70,11 @@ contract AuraToken is ERC20 {
      * @dev This can be called if the operator of the voterProxy somehow changes.
      */
     function updateOperator() public {
+        require(totalSupply() != 0, "!init");
+
         address newOperator = IStaker(vecrvProxy).operator();
+        require(newOperator != operator && newOperator != address(0), "!operator");
+
         emit OperatorChanged(operator, newOperator);
         operator = newOperator;
     }
@@ -98,7 +92,7 @@ contract AuraToken is ERC20 {
         }
 
         // e.g. emissionsMinted = 6e25 - 5e25 - 0 = 1e25;
-        uint256 emissionsMinted = totalSupply() - EMISSIONS_MAX_SUPPLY - minterMinted;
+        uint256 emissionsMinted = totalSupply() - INIT_MINT_AMOUNT - minterMinted;
         // e.g. reductionPerCliff = 5e25 / 500 = 1e23
         // e.g. cliff = 1e25 / 1e23 = 100
         uint256 cliff = emissionsMinted.div(reductionPerCliff);

contracts/AuraBalRewardPool.sol

@@ -1,8 +1,7 @@
 // SPDX-License-Identifier: MIT
-pragma solidity ^0.8.11;
+pragma solidity 0.8.11;
 
 import { AuraMath } from "./AuraMath.sol";
-import { SafeMath } from "@openzeppelin/contracts-0.8/utils/math/SafeMath.sol";
 import { IERC20 } from "@openzeppelin/contracts-0.8/token/ERC20/IERC20.sol";
 import { SafeERC20 } from "@openzeppelin/contracts-0.8/token/ERC20/utils/SafeERC20.sol";
 
@@ -21,7 +20,7 @@ import { IAuraLocker } from "./Interfaces.sol";
  *            - Penalty on claim at 20%
  */
 contract AuraBalRewardPool {
-    using SafeMath for uint256;
+    using AuraMath for uint256;
     using SafeERC20 for IERC20;
 
     IERC20 public immutable rewardToken;
@@ -30,7 +29,7 @@ contract AuraBalRewardPool {
 
     address public immutable rewardManager;
 
-    IAuraLocker public immutable auraLocker;
+    IAuraLocker public auraLocker;
     address public immutable penaltyForwarder;
     uint256 public pendingPenalty = 0;
     uint256 public immutable startTime;
@@ -50,6 +49,7 @@ contract AuraBalRewardPool {
     event Withdrawn(address indexed user, uint256 amount);
     event RewardPaid(address indexed user, uint256 reward, bool locked);
     event PenaltyForwarded(uint256 amount);
+    event Rescued();
 
     /**
      * @dev Simple constructoor
@@ -67,14 +67,17 @@ contract AuraBalRewardPool {
         address _penaltyForwarder,
         uint256 _startDelay
     ) {
+        require(_stakingToken != _rewardToken && _stakingToken != address(0), "!tokens");
         stakingToken = IERC20(_stakingToken);
         rewardToken = IERC20(_rewardToken);
+        require(_rewardManager != address(0), "!manager");
         rewardManager = _rewardManager;
+        require(_auraLocker != address(0), "!locker");
         auraLocker = IAuraLocker(_auraLocker);
+        require(_penaltyForwarder != address(0), "!locker");
         penaltyForwarder = _penaltyForwarder;
-        rewardToken.safeApprove(_auraLocker, type(uint256).max);
 
-        require(_startDelay < 2 weeks, "!delay");
+        require(_startDelay > 4 days && _startDelay < 2 weeks, "!delay");
         startTime = block.timestamp + _startDelay;
     }
 
@@ -178,6 +181,7 @@ contract AuraBalRewardPool {
         if (reward > 0) {
             rewards[msg.sender] = 0;
             if (_lock) {
+                rewardToken.safeIncreaseAllowance(address(auraLocker), reward);
                 auraLocker.lock(msg.sender, reward);
             } else {
                 uint256 penalty = (reward * 2) / 10;
@@ -199,6 +203,27 @@ contract AuraBalRewardPool {
         emit PenaltyForwarded(toForward);
     }
 
+    /**
+     * @dev Rescues the reward token provided it hasn't been initiated yet
+     */
+    function rescueReward() public {
+        require(msg.sender == rewardManager, "!rescuer");
+        require(block.timestamp < startTime && rewardRate == 0, "Already started");
+
+        uint256 balance = rewardToken.balanceOf(address(this));
+        rewardToken.transfer(rewardManager, balance);
+
+        emit Rescued();
+    }
+
+    /**
+     * @dev Updates the locker address
+     */
+    function setLocker(address _newLocker) external {
+        require(msg.sender == rewardManager, "!auth");
+        auraLocker = IAuraLocker(_newLocker);
+    }
+
     /**
      * @dev Called once to initialise the rewards based on balance of stakeToken
      */

contracts/AuraClaimZap.sol

@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: MIT
-pragma solidity ^0.8.11;
+pragma solidity 0.8.11;
 
 import { AuraMath } from "./AuraMath.sol";
 import { IAuraLocker, ICrvDepositorWrapper } from "./Interfaces.sol";
@@ -206,15 +206,13 @@ contract AuraClaimZap {
         }
 
         //stake up to given amount of cvx
-        if (depositCvxMaxAmount > 0) {
+        if (depositCvxMaxAmount > 0 && _checkOption(options, uint256(Options.LockCvx))) {
             uint256 cvxBalance = IERC20(cvx).balanceOf(msg.sender).sub(removeCvxBalance);
             cvxBalance = AuraMath.min(cvxBalance, depositCvxMaxAmount);
             if (cvxBalance > 0) {
                 //pull cvx
                 IERC20(cvx).safeTransferFrom(msg.sender, address(this), cvxBalance);
-                if (_checkOption(options, uint256(Options.LockCvx))) {
-                    IAuraLocker(locker).lock(msg.sender, cvxBalance);
-                }
+                IAuraLocker(locker).lock(msg.sender, cvxBalance);
             }
         }
     }

contracts/AuraLocker.sol

@@ -1,6 +1,5 @@
 // SPDX-License-Identifier: MIT
-pragma solidity ^0.8.11;
-pragma experimental ABIEncoderV2;
+pragma solidity 0.8.11;
 
 import { IERC20 } from "@openzeppelin/contracts-0.8/token/ERC20/IERC20.sol";
 import { SafeERC20 } from "@openzeppelin/contracts-0.8/token/ERC20/utils/SafeERC20.sol";
@@ -69,7 +68,7 @@ contract AuraLocker is ReentrancyGuard, Ownable, IAuraLocker {
 
     // Rewards
     address[] public rewardTokens;
-    uint256 public queuedCvxCrvRewards = 0;
+    mapping(address => uint256) public queuedRewards;
     uint256 public constant newRewardRatio = 830;
     //     Core reward data
     mapping(address => RewardData) public rewardData;
@@ -100,6 +99,8 @@ contract AuraLocker is ReentrancyGuard, Ownable, IAuraLocker {
     mapping(address => mapping(uint256 => uint256)) public delegateeUnlocks;
 
     // Config
+    //     Blacklisted smart contract interactions
+    mapping(address => bool) public blacklist;
     //     Tokens
     IERC20 public immutable stakingToken;
     address public immutable cvxCrv;
@@ -130,6 +131,7 @@ contract AuraLocker is ReentrancyGuard, Ownable, IAuraLocker {
     event KickReward(address indexed _user, address indexed _kicked, uint256 _reward);
     event RewardAdded(address indexed _token, uint256 _reward);
 
+    event BlacklistModified(address account, bool blacklisted);
     event KickIncentiveSet(uint256 rate, uint256 delay);
     event Shutdown();
 
@@ -187,14 +189,37 @@ contract AuraLocker is ReentrancyGuard, Ownable, IAuraLocker {
         _;
     }
 
+    modifier notBlacklisted(address _sender, address _receiver) {
+        uint256 csS;
+        uint256 csR;
+        assembly {
+            csS := extcodesize(_sender)
+            csR := extcodesize(_receiver)
+        }
+        if (csS != 0) {
+            require(!blacklist[_sender], "blacklisted");
+        }
+        if (csR != 0) {
+            require(_sender == _receiver || !blacklist[_receiver], "blacklisted");
+        }
+        _;
+    }
+
     /***************************************
                     ADMIN
     ****************************************/
 
+    function modifyBlacklist(address _account, bool _blacklisted) external onlyOwner {
+        blacklist[_account] = _blacklisted;
+        emit BlacklistModified(_account, _blacklisted);
+    }
+
     // Add a new reward token to be distributed to stakers
     function addReward(address _rewardsToken, address _distributor) external onlyOwner {
         require(rewardData[_rewardsToken].lastUpdateTime == 0, "Reward already exists");
         require(_rewardsToken != address(stakingToken), "Cannot add StakingToken as reward");
+        require(rewardTokens.length < 5, "Max rewards length");
+
         rewardTokens.push(_rewardsToken);
         rewardData[_rewardsToken].lastUpdateTime = uint32(block.timestamp);
         rewardData[_rewardsToken].periodFinish = uint32(block.timestamp);
@@ -255,7 +280,7 @@ contract AuraLocker is ReentrancyGuard, Ownable, IAuraLocker {
     }
 
     //lock tokens
-    function _lock(address _account, uint256 _amount) internal {
+    function _lock(address _account, uint256 _amount) internal notBlacklisted(msg.sender, _account) {
         require(_amount > 0, "Cannot stake 0");
         require(!isShutdown, "shutdown");
 
@@ -318,21 +343,35 @@ contract AuraLocker is ReentrancyGuard, Ownable, IAuraLocker {
         }
     }
 
+    function getReward(address _account, bool[] calldata _skipIdx) external nonReentrant updateReward(_account) {
+        uint256 rewardTokensLength = rewardTokens.length;
+        require(_skipIdx.length == rewardTokensLength, "!arr");
+        for (uint256 i; i < rewardTokensLength; i++) {
+            if (_skipIdx[i]) continue;
+            address _rewardsToken = rewardTokens[i];
+            uint256 reward = userData[_account][_rewardsToken].rewards;
+            if (reward > 0) {
+                userData[_account][_rewardsToken].rewards = 0;
+                IERC20(_rewardsToken).safeTransfer(_account, reward);
+                emit RewardPaid(_account, _rewardsToken, reward);
+            }
+        }
+    }
+
     function checkpointEpoch() external {
         _checkpointEpoch();
     }
 
     //insert a new epoch if needed. fill in any gaps
     function _checkpointEpoch() internal {
         uint256 currentEpoch = block.timestamp.div(rewardsDuration).mul(rewardsDuration);
-        uint256 epochindex = epochs.length;
 
         //first epoch add in constructor, no need to check 0 length
         //check to add
-        if (epochs[epochindex - 1].date < currentEpoch) {
-            //fill any epoch gaps until the next epoch date.
-            while (epochs[epochs.length - 1].date != currentEpoch) {
-                uint256 nextEpochDate = uint256(epochs[epochs.length - 1].date).add(rewardsDuration);
+        uint256 nextEpochDate = uint256(epochs[epochs.length - 1].date);
+        if (nextEpochDate < currentEpoch) {
+            while (nextEpochDate != currentEpoch) {
+                nextEpochDate = nextEpochDate.add(rewardsDuration);
                 epochs.push(Epoch({ supply: 0, date: uint32(nextEpochDate) }));
             }
         }
@@ -401,7 +440,7 @@ contract AuraLocker is ReentrancyGuard, Ownable, IAuraLocker {
                 uint256 currentEpoch = block.timestamp.sub(_checkDelay).div(rewardsDuration).mul(rewardsDuration);
                 uint256 epochsover = currentEpoch.sub(uint256(locks[length - 1].unlockTime)).div(rewardsDuration);
                 uint256 rRate = AuraMath.min(kickRewardPerEpoch.mul(epochsover + 1), denominator);
-                reward = uint256(locks[length - 1].amount).mul(rRate).div(denominator);
+                reward = uint256(locked).mul(rRate).div(denominator);
             }
         } else {
             //use a processed index(nextUnlockIndex) to not loop as much
@@ -817,18 +856,20 @@ contract AuraLocker is ReentrancyGuard, Ownable, IAuraLocker {
                 REWARD FUNDING
     ****************************************/
 
-    function queueNewRewards(uint256 _rewards) external nonReentrant {
-        require(rewardDistributors[cvxCrv][msg.sender], "!authorized");
+    function queueNewRewards(address _rewardsToken, uint256 _rewards) external nonReentrant {
+        require(rewardDistributors[_rewardsToken][msg.sender], "!authorized");
         require(_rewards > 0, "No reward");
 
-        RewardData storage rdata = rewardData[cvxCrv];
+        RewardData storage rdata = rewardData[_rewardsToken];
 
-        IERC20(cvxCrv).safeTransferFrom(msg.sender, address(this), _rewards);
+        IERC20(_rewardsToken).safeTransferFrom(msg.sender, address(this), _rewards);
+
+        _rewards = _rewards.add(queuedRewards[_rewardsToken]);
+        require(_rewards < 1e25, "!rewards");
 
-        _rewards = _rewards.add(queuedCvxCrvRewards);
         if (block.timestamp >= rdata.periodFinish) {
-            _notifyReward(cvxCrv, _rewards);
-            queuedCvxCrvRewards = 0;
+            _notifyReward(_rewardsToken, _rewards);
+            queuedRewards[_rewardsToken] = 0;
             return;
         }
 
@@ -838,25 +879,13 @@ contract AuraLocker is ReentrancyGuard, Ownable, IAuraLocker {
         uint256 currentAtNow = rdata.rewardRate * elapsedTime;
         uint256 queuedRatio = currentAtNow.mul(1000).div(_rewards);
         if (queuedRatio < newRewardRatio) {
-            _notifyReward(cvxCrv, _rewards);
-            queuedCvxCrvRewards = 0;
+            _notifyReward(_rewardsToken, _rewards);
+            queuedRewards[_rewardsToken] = 0;
         } else {
-            queuedCvxCrvRewards = _rewards;
+            queuedRewards[_rewardsToken] = _rewards;
         }
     }
 
-    function notifyRewardAmount(address _rewardsToken, uint256 _reward) external {
-        require(_rewardsToken != cvxCrv, "Use queueNewRewards");
-        require(rewardDistributors[_rewardsToken][msg.sender], "Must be rewardsDistributor");
-        require(_reward > 0, "No reward");
-
-        _notifyReward(_rewardsToken, _reward);
-
-        // handle the transfer of reward tokens via `transferFrom` to reduce the number
-        // of transactions required and ensure correctness of the _reward amount
-        IERC20(_rewardsToken).safeTransferFrom(msg.sender, address(this), _reward);
-    }
-
     function _notifyReward(address _rewardsToken, uint256 _reward) internal updateReward(address(0)) {
         RewardData storage rdata = rewardData[_rewardsToken];
 
@@ -868,6 +897,10 @@ contract AuraLocker is ReentrancyGuard, Ownable, IAuraLocker {
             rdata.rewardRate = _reward.add(leftover).div(rewardsDuration).to96();
         }
 
+        // Equivalent to 10 million tokens over a weeks duration
+        require(rdata.rewardRate < 1e20, "!rewardRate");
+        require(lockedSupply >= 1e20, "!balance");
+
         rdata.lastUpdateTime = block.timestamp.to32();
         rdata.periodFinish = block.timestamp.add(rewardsDuration).to32();
 

contracts/AuraMath.sol

@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: MIT
-pragma solidity ^0.8.11;
+pragma solidity 0.8.11;
 
 /// @notice A library for performing overflow-/underflow-safe math,
 /// updated with awesomeness from of DappHub (https://github.com/dapphub/ds-math).