Gas Optimizations

[code423n4]

Issue: Require message is too long
Explanation: The require messages below can be shortened to 32 characters or fewer (as shown) to save gas

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraLocker.sol#L197

        require(_rewardsToken != address(stakingToken), "Cannot add StakingToken as reward");

Change message to Can't add StakingToken as reward

Issue: Should use != 0 instead of > 0 in a require statement if variable is an unsigned integer (uint)
Explanation: != 0 should be used where possible since > 0 costs more gas

require(_amount > 0 occurs in all 7 lines below:

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/Aura.sol#L68

        require(_amount > 0, "Must mint something");

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraBalRewardPool.sol#L121

        require(_amount > 0, "RewardPool : Cannot stake 0");

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraBalRewardPool.sol#L139

        require(_amount > 0, "RewardPool : Cannot stake 0");

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraLocker.sol#L259

        require(_amount > 0, "Cannot stake 0");

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraMerkleDrop.sol#L122

        require(_amount > 0, "!amount");

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/CrvDepositor.sol#L169

        require(_amount > 0,"!>0");

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/BaseRewardPool.sol#L211

        require(_amount > 0, 'RewardPool : Cannot stake 0');

Change _amount > 0 to _amount != 0 in each case

require(amount > 0 occurs in both lines below:

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraBalRewardPool.sol#L157

        require(amount > 0, "RewardPool : Cannot withdraw 0");

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/BaseRewardPool.sol#L227

        require(amount > 0, 'RewardPool : Cannot withdraw 0');

Change amount > 0 to amount != 0 in both cases

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraBalRewardPool.sol#L210

        require(rewardsAvailable > 0, "!balance");

Change rewardsAvailable > 0 to rewardsAvailable != 0

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraLocker.sol#L359

        require(amt > 0, "Nothing locked");

Change amt > 0 to amt != 0

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraLocker.sol#L385

        require(length > 0, "no locks");

Change length > 0 to length != 0

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraLocker.sol#L431

        require(locked > 0, "no exp locks");

Change locked > 0 to locked != 0

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraLocker.sol#L471

        require(len > 0, "Nothing to delegate");

Change len > 0 to len != 0

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraPenaltyForwarder.sol#L52

        require(bal > 0, "!empty");

Change bal > 0 to bal != 0

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/BalLiquidityProvider.sol#L70

        require(balAfter > 0, "!mint");

Change balAfter > 0 to balAfter != 0

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/PoolManagerSecondaryProxy.sol#L104

        require(weight > 0, "must have weight");

Change weight > 0 to weight != 0

Issue: Use of '&&' within a require function
Explanation: Dividing the require into separate requires instead of using '&&' will save gas

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraStakingProxy.sol#L90

        require(_outputBps > 9000 && _outputBps < 10000, "Invalid output bps");

Recommendation:

        require(_outputBps > 9000, "Invalid output bps");
        require( _outputBps < 10000, "Invalid output bps");

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraStakingProxy.sol#L159

        require(_token != crv && _token != cvx && _token != cvxCrv, "not allowed");

Recommendation:

        require(_token != crv, "not allowed");
        require( _token != cvx, "not allowed");
        require( _token != cvxCrv, "not allowed");

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraStakingProxy.sol#L203

        require(address(_token) != crv && address(_token) != cvxCrv, "not allowed");

Recommendation:

        require(address(_token) != crv, "not allowed");
        require(address(_token) != cvxCrv, "not allowed");

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/BalLiquidityProvider.sol#L48

        require(_request.assets.length == 2 && _request.maxAmountsIn.length == 2, "!valid");

Recommendation:

        require(_request.assets.length == 2, "!valid");
        require(_request.maxAmountsIn.length == 2, "!valid");

There are two opportunities to save gas in the require below:

1. Use != 0 instead of > 0
2. Divide the require into two separate requires instead of using '&&'

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/BalLiquidityProvider.sol#L57

            require(bal > 0 && bal == _request.maxAmountsIn[i], "!bal");

Recommendation:

            require(bal != 0, "!bal");
            require(bal == _request.maxAmountsIn[i], "!bal");

There are similar opportunities to save gas in the require below:

1. Use != 0 instead of > 0
2. Divide the require into two separate requires instead of using '&&'

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/ExtraRewardsDistributor.sol#L171

        require(_index > 0 && _index < rewardEpochs[_token].length - 1, "!past");

Recommendation:

        require(_index != 0, "!past");
        require( _index < rewardEpochs[_token].length - 1, "!past");

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/Booster.sol#L220

        require(lockRewards != address(0) && rewardFactory != address(0), "!initialised");

Recommendation:

        require(lockRewards != address(0), "!initialised");
        require(rewardFactory != address(0), "!initialised");

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/Booster.sol#L222

        require(_feeToken != address(0) && _feeDistro != address(0), "!addresses");

Recommendation:

        require(_feeToken != address(0), "!addresses");
        require( _feeDistro != address(0), "!addresses");

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/Booster.sol#L278

        require(_lockFees >= 300 && _lockFees <= 1500, "!lockFees");

Recommendation:

        require(_lockFees >= 300, "!lockFees");
        require( _lockFees <= 1500, "!lockFees");

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/Booster.sol#L279

        require(_stakerFees >= 300 && _stakerFees <= 1500, "!stakerFees");

Recommendation:

        require(_stakerFees >= 300, "!stakerFees");
        require( _stakerFees <= 1500, "!stakerFees");

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/Booster.sol#L280

        require(_callerFees >= 10 && _callerFees <= 100, "!callerFees");

Recommendation:

        require(_callerFees >= 10, "!callerFees");
        require( _callerFees <= 100, "!callerFees");

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/Booster.sol#L313

        require(msg.sender==poolManager && !isShutdown, "!add");

Recommendation:

        require(msg.sender==poolManager, "!add");
        require(!isShutdown, "!add");

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/Booster.sol#L314

        require(_gauge != address(0) && _lptoken != address(0),"!param");

Recommendation:

        require(_gauge != address(0),"!param");
        require( _lptoken != address(0),"!param");

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/PoolManagerSecondaryProxy.sol#L111

        require(!usedMap[_lptoken] && !usedMap[_gauge], "cant force used pool");

Recommendation:

        require(!usedMap[_lptoken], "cant force used pool");
        require(!usedMap[_gauge], "cant force used pool");

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/StashFactoryV2.sol#L83

        require(!isV1 && !isV2 && !isV3,"stash version mismatch");

Recommendation:

        require(!isV1,"stash version mismatch");
        require(!isV2,"stash version mismatch");
        require(!isV3,"stash version mismatch");

Issue: Variables should not be initialized to their default values
Explanation: For example, initializing uint variables to their default value of 0 is unnecessary and costs gas

public pendingPenalty is initialized to zero in both lines below:

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraBalRewardPool.sol#L35

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraMerkleDrop.sol#L29

    uint256 public pendingPenalty = 0;

Change to uint256 public pendingPenalty;

public periodFinish is initialized to zero in all three lines below:

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraBalRewardPool.sol#L38

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraMerkleDrop.sol#L29

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/VirtualBalanceRewardPool.sol#L89

    uint256 public periodFinish = 0;

Change to uint256 public periodFinish;

public rewardRate is initialized to zero in all three lines below:

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraBalRewardPool.sol#L39

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/VirtualBalanceRewardPool.sol#L90

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/VirtualBalanceRewardPool.sol#L90

    uint256 public rewardRate = 0;

Change to uint256 public rewardRate;

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraLocker.sol#L72

    uint256 public queuedCvxCrvRewards = 0;

Change to uint256 public queuedCvxCrvRewards;

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraLocker.sol#L540

                    uint256 unlocksSinceLatestCkpt = 0;

Change to uint256 unlocksSinceLatestCkpt;

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraLocker.sol#L114

    bool public isShutdown = false;

Change to bool public isShutdown;

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraLocker.sol#L381

        uint256 reward = 0;

Change to uint256 reward;

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraLocker.sol#L485

        uint256 futureUnlocksSum = 0;

Change to uint256 futureUnlocksSum;

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraLocker.sol#L630

        uint256 low = 0;

Change to uint256 low;

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraVestedEscrow.sol#L33

    bool public initialised = false;

Change to bool public initialised;

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraVestedEscrow.sol#L99

        uint256 totalAmount = 0;

Change to uint256 totalAmount;

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/ExtraRewardsDistributor.sol#L231

        uint256 claimableTokens = 0;

Change to uint256 claimableTokens;

public queuedRewards is initialized to zero in both lines below:

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/BaseRewardPool.sol#L75

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/VirtualBalanceRewardPool.sol#L93

    uint256 public queuedRewards = 0;

Change to uint256 public queuedRewards;

public currentRewards is initialized to zero in both lines below:

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/BaseRewardPool.sol#L76

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/VirtualBalanceRewardPool.sol#L94

    uint256 public currentRewards = 0;

Change to uint256 public currentRewards;

public historicalRewards is initialized to zero in both lines below:

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/BaseRewardPool.sol#L77

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/VirtualBalanceRewardPool.sol#L95

    uint256 public historicalRewards = 0;

Change to uint256 public historicalRewards;

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/Booster.sol#L29

    uint256 public platformFee = 0; //possible fee to build treasury

Change to uint256 public platformFee; //possible fee to build treasury

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/ConvexMasterChef.sol#L63

    uint256 public totalAllocPoint = 0;

Change to uint256 public totalAllocPoint;

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/CrvDepositor.sol#L36

    uint256 public incentiveCrv = 0;

Change to uint256 public incentiveCrv;

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/VoterProxy.sol#L308

        uint256 _balance = 0;

Change to uint256 _balance;