Precision loss

High MH – 01 |  Invalid

In GGStaking contract the depositReward() function uses the accumulated reward per share, which is stored as an integer with 12 decimal places. This could lead to precision loss if the reward amount or the number of staked tokens is too large.

Recommendation:

Add precision for calculation.

Zero address of claimFeeWallet

Medium MM – 01 |  Resolved

In GGStaking contract the global variable claimFeeWallet allowed to be address 0, when it is set in function setClaimFeeWallet(). At the same a require claimFeeWallet != 0 in function setClaimFee() does not allow to set claimFee variable, if the fee wallet address is zero-address. Hence, in function claim() fee amount can be sent to zero-address claim fee wallet and lost for always.

Recommendation:

Add require condition for setClaimWallet() function and delete one from setClaimFee().

function setClaimFeeWallet(address _claimFeeWallet) external onlyOwner {
       require(
           _claimFeeWallet != address(0),
           "the claimFeeWallet must have a valid address"
       );
       claimFeeWallet = _claimFeeWallet;
       emit SetClaimFeeWallet(_claimFeeWallet);
   }

function setClaimFee(uint256 _claimFee) external onlyOwner {
       require(
           _claimFee > 0 && _claimFee <= 10,
           "setClaimFee: amount should be greater than 0 and smaller than 10"
       );
       claimFee = _claimFee;
       emit SetClaimFee(_claimFee);
   }

Reentrancy

Medium MM – 02 |  Resolved

In GGStaking contract the function depositReward() uses the function transfers tokens to the contract before updating the accumulated reward per share. This could allow an attacker to re-enter the function and claim rewards multiple times before the accumulated reward per share is updated.

Recommendation:

Use checks-effects-interactions pattern; call the transfer function after all rewards updating.

Check pending rewards

Medium MM – 03 |  Invalid

In GGStaking contract unstake() function is not checked if the user has any pending rewards before unstaking. If the user has pending rewards, they should first claim them before unstaking their NFTs. If the user unsatake their NFTs before claiming their rewards, they could lose their pending rewards.

Recommendation:

Add checking for pending rewards before unstake them.

Thrown error

Medium MM – 04 |  Invalid

In GGStaking contract unstake() function is not checked if the user’s depositNumber is less than or equel to the totalDepositCount before calculating the pending rewards. This could cause the function to throw an error if the user’s depositNumber is greater that totalDepositCount.

Recommendation:

Add checking for depositNumber and totalDepositCount.

Invalid event parameter

Medium TM – 01 |  Resolved

The WithdrawUnusedRewardPot event always takes a zero value due to a typo in the code.

Recommendation:

Store the value of unusedRewardPot in a temporary variable before nulling it and use the stored value in the event.

function withdrawUnusedRewardPot() external onlyOwner {
        require(
            unusedRewardPot > 0,
            "withdrawUnusedRewardPot: unusedRewardPot should be greater than 0"
        );
        egToken.transfer(owner(), unusedRewardPot);
        unusedRewardPot = 0;
        emit WithdrawUnusedRewardPot(unusedRewardPot);
    }

Absent require for constructor parameters

Low ML – 01 |  Resolved

In GGStaking contract the constructor parameters are set without checking their addresses. For example, if the address will be zero-address all funds will be lost.

Recommendation:

Add require condition for all variables in constructor.

constructor(IERC721 _nftToken, IERC20 _egToken) {
require(_nftToken != address(0) && _egToken != address(0), “Zero address of token”);
       nftToken = _nftToken;
       egToken = _egToken;
   }

Inappropriate function visibility

Low ML – 02 |  Invalid

In GGStaking smart contract the setTokenInfo function is only called by the contract owner, it is safe to remove the external visibility modifier and replace it with public. This can result in some gas savings.

Recommendation:

 function setTokenInfo(
       uint256[] calldata _ids,
       uint8[] calldata _isLegendaries,
       uint8[] calldata _squadIds
   ) public onlyOwner

Absent indexing in parameters of events

Low ML – 03 |  Resolved

In GGStaking contract events are emitted without indexed parameter, which helps to log parameters in a transaction. The reason it is important to add indexed parameter to events is because it allows for more efficient and selective event filtering. By making certain parameters as indexed, Solidity can create an index of these values, making it easier and faster to search for events with the specific parameter value.

For example, event Staked, Unstaked, Claim, SetClaimWallet need indexed parameter for address staker.

Recommendation:

Add indexed parameter in events.

event Staked(address indexed staker, uint256[] tokenId);
   event UnStaked(address indexed staker, uint256[] tokenId);
   event Claim(address indexed staker, uint256 amount);
   event SetClaimFeeWallet(address indexed_claimFeeWallet);

Initialization with default values

Low TL – 01 |  Resolved

In lines 405, 406, the variable is set to 0. This is a useless step that increases the use of gas.

Recommendation:

Remove initialization of variables.

uint256 requireStakeLegendaryCount = 0;
uint256 requireStakeCommonNFTCount = 0;

Re-Audit:

Please follow the same recommendations as stated in the following issue:  TL - 01.

uint256 requireUnStakeLegendaryCount = 0;
uint256 requireUnStakeCommonNFTCount = 0;

Code optimization

Low TL – 02 |  Resolved

The following line of code can be shortened

if (userSquadTokenFeaturesSum == userSquadTokenFeatures.length) {
        return true;
} else {
        return false;
}

Recommendation:

Write something like this

return userSquadTokenFeaturesSum == userSquadTokenFeatures.length;

Incorrect order of layout, functions

Informational  MI – 01 |  Resolved

In GGStaking smart contract has the order of functions and declared variables not the same as in solidity documentation.

Recommendation:

Layouts, functions, and modifier order should be grouped according to Solidity documentation:

Layouts:

• interfaces;
• libraries;
• contracts.

Functions:

• constructor;
• receive;
• fallback;
• external;
• public;
• internal;
• private;
• view/pure;

Re-audit:

After reordering variables and functions, in new comment lines 77 and 79 should be swapped to have one style.

Add Natspeck

Informational  MI – 02 |  Resolved

GGStaking smart contract has no explanation for functions and variables, that makes it harder to understand the contract’s logic.

Recommendation:

Add Natspeck even for internal and private functions in all contracts that do not have it.

Naming convention

Informational  MI – 03 |  Resolved

Naming conventions in Solidity are important for creating clear, understandable, and maintainable code.

Recommendation:

1. CamelCase: This convention involves starting the first word of a variable name with a lowercase letter and the first letter of each subsequent word with a capital letter, without spaces or underscores. For example, myVariable, myFunction, and myStruct;
2. Uppercase: This convention involves writing the entire name of the constant in uppercase letters, with words separated by underscores. For example, MY_CONSTANT;
3. Underscore: This convention involves separating words in a variable name with an underscore. For example, my_variable;
4. Prefixes: Solidity developers often use prefixes to indicate the type or purpose of a variable. For example, is is used to indicate a boolean value, num for numeric values, str for string values, and add for address values;
5. Verb-noun pairs: When naming functions, it is common to use a verb-noun pair to describe what the function does. For example, transferTokens, approveAccess and setFeeRate.

Gas optimization for setTokenInfo()

Informational  MI – 04 |  Resolved

In GGStaking contract the ‘for’ loop is executed twice for setting the token info. This can be combined into a single loop to optimize gas usage.

In the for loop for checking the _squadIds array, the condition (_squadIds[i] < squadTokenFeatures.length) is used to check if the squid id is valid. However, squadTokenFeatures.length is hardcoded to 8 and does not match the actual length of the squadTokenFeatures array. This can cause the function to fail for valid squad ids. A better way to check the valid squad ids would be to use squadTokenFeatures.contains(_squadIds[i]) instead of the hardcoded length.

Recommendation:

function setTokenInfo(uint256[] calldata _ids, uint8[] calldata _isLegendaries, uint8[] calldata _squadIds) public onlyOwner {
   require(_ids.length > 0, "setTokenInfo: Empty array");
   require(_ids.length == _isLegendaries.length && _ids.length == _squadIds.length, "setTokenInfo: the array lengths should match");

   for (uint256 i = 0; i < _ids.length; i++) {
       require(squadTokenFeatures.contains(_squadIds[i]), "setTokenInfo: invalid squad ID");

       TokenInfo storage tokenInfo = tokenInfos[_ids[i]];
       tokenInfo.isLegendary = _isLegendaries[i] == 0 ? false : true;
       tokenInfo.squadId = _squadIds[i];
   }
}

Constant for 1e12

Informational  MI – 05 |  Resolved

In GGStaking contract the depositReward() function uses a lot 1e12 data, without any explanation what this variable is mean.

Recommendation:

Create and declare the global constant for 1e12.

Storage in read-only function

Informational  MI – 06 |  Resolved

Since the function userStakedNFTs() in GGStaking contract is read-only, it is not necessary to mark the user variable as storage. This variable can be marked as memory to reduce gas costs.

Recommendation:

Use

UserInfo memory user = userInfos[_user];

Re-audit:

In function getPending(), which is also view, is used UserInfo storage user = userInfos[_user];, but user data is not rewrited into struct. Hence, it woulb be better to use memory instead of storage to reguce gast cost.

Gas optimization for getPending()

Informational  MI – 07 |  Resolved

In GGStaking contract function getPending() is possible an optimization - remove the conditional statement if (user.depositNumber < totalDepositCount) because it is always true. Since totalDepositCount is incremented every time a deposit is made, it will always be greater than or equal to user.depositNumber.

Recommendation:

function getPending(address _user) external view returns (uint256) {
   UserInfo storage user = userInfos[_user];
   uint256 pending = user.pendingRewards;
   if (user.depositNumber < totalDepositCount) {
       pending += _getPending(_user) - user.rewardDebt;
   }
   return pending;
}

Gas optimization for unstake()

Informational  MI – 08 |  Invalid

In GGStaking contract function unstake() has the lastTokenIndex variable, which is also unnecessary and can be removed by using the length of the ownedTokens mapping.

The function iterates twice over the tokens array. The first iteration is to validate the tokens, and the second iteration is to unstake them. Instead, the function could combine both interactions into a single loop to reduce gas cost.

Recommendation:

Implement gas optimization advice.

Gas optimization for stake()

Informational  MI – 09 |  Invalid

GGStaking contract function stake() has the use of nested for loops to check duplicates and ownership of each NFT in the input array is a costly operation, especially if the input array contains many elements.

Recommendation:

It would be more gas efficient to use a mapping to keep track of which NFTs have already been checked.

Usage of transferFrom inside the loop

Informational  MI – 10 |  Invalid

The usage of the transferFrom function inside the for loop is not recommended (function stake), as it is a costly operation, and the cost increases with the number of NFTs being transferred.

Recommendation:

It would be more gas efficient to use a single sefeBatchTransferFrom function from the ERC721 contract to transfer all the NFTs at once.

Unnecessary checking

Informational  MI – 11 |  Invalid

In GGStaking contract the function stake has the if statement checking if requireStakeLegendaryCount > 0 is unnecessary since requireStakeLegendaryCount will always be greater than or equal to zero.

Recommendation:

Remove this if statement.

Replace twice call

Informational  MI – 12 |  Resolved

In GGStaking contract the function claim has egToken.balalnceOf(address(this)), that call is made twice, which can be replaced with a single call and stored in a variable for efficiency.

Recommendation:

Create a variable contractBalance = egToken.balalnceOf(address(this)) and use the variable in function.

Gas optimization for _getPending()

Informational  MI – 13 |  Resolved

GGStaking contract function _getPending() has some room for gas optimization. The function performs several divisions by the constant 1e12. These divisions can be avoided by multiplying the final result by 1e12. Additionally, there is no need to declare the pending variable before assigning it a value, as it is only used to store intermediate values. Instead, the function can directly return the final result.

Recommendation:

function _getPending(address _user) public view returns (uint256) {
       UserInfo storage user = userInfos[_user];
       uint256 pending;
       if (user.isLegendaryStaker) {
           pending = user.stakedLegendaryCountForHolder * accLegendaryPerShare;
       }
       if (user.isAllSquadStaker) {
           pending += accAllSquadPerShare;
       }
       if (user.commonNFTHolder) {
           pending += user.commonNFTCountForHolder * accCommonNFTPerShare;
       }
       return pending / 1e12;
   }

Gas optimization for checkAllSquadStaker()

Informational  MI – 14 |  Resolved

The function can be optimized by breaking the loop early if the user has already staked NFTs from all eight squads. This can be done by adding a break statement after the return true statement.

The userSquadTokenFeaturesSum variable can be incremented inside the loop using the += operator instead of the + operator.

Recommendation:

function checkAllSquadStaker() private view returns (bool) {
   UserInfo storage user = userInfos[msg.sender];
   uint8[] memory userSquadTokenFeatures = new uint8[](squadTokenFeatures.length);

   for (uint256 i = 0; i < user.totalNFTCountForHolder; i++) {
       uint256 tokenId = ownedTokens[msg.sender][i];
       if (tokenId == 0) continue; // check if the tokenId is valid
       TokenInfo storage tokenInfo = tokenInfos[tokenId];
       if (tokenInfo.isLegendary) continue;
       userSquadTokenFeatures[tokenInfo.squadId] = 1;
       if (userSquadTokenFeaturesSum == userSquadTokenFeatures.length) {
           return true;
       }
   }
  
   for (uint8 squadId = 0; squadId < userSquadTokenFeatures.length; squadId++) {
       if (userSquadTokenFeatures[squadId] == 0) {
           return false;
       }
   }
  
   return true;
}

Re-audit:

Please follow the recommendations when it is better to use storage data location and when memory.

Memory, is a temporary data location used for storing variables that are only needed during the execution of a particular function. Memory is cheaper to access than storage, but its contents are lost once the function call is completed. Memory is typically used for variables that are only needed within the scope of a single function.

Another recommendation is to save gas-cost. As this contract has pragma version 0.8.17, which has internal SafeMath implementation, math operation can be used +=. Please check all contracts for that.