Sherlock contest - Funen's results

Handle

Funen

Vulnerability details

Impact

used i++ instead ++i just because ++i is more gas efficient.

or even better approach is to use unchecked {++i}

Proof of Concept

by seen the disscussion here : https://github.com/ethereum/solidity/issues/10695

Tools Used

Manual Review

Occurences

contracts/Sherlock.sol:106: for (uint256 i; i < _initialstakingPeriods.length; i++) { contracts/SherlockClaimManager.sol:234: for (uint256 i; i < claimCallbacks.length; i++) { contracts/SherlockClaimManager.sol:256: for (uint256 i; i < claimCallbacks.length; i++ { contracts/Sherbuy.sol:186: for (uint256 i; i < _tokens.length; i++) { contracts/Manager.sol:46: for (uint256 i; i < _extraTokens.lengt{h; i++)

Recommended Mitigation Steps

change to using unchecked { ++i }

Handle

Funen

Vulnerability details

Proof of Concept

in this case : https://github.com/code-423n4/2022-01-sherlock/blob/main/contracts/managers/SherlockClaimManager.sol#L197-L198, the gas can be optimazed by using claims instead of claims_[_claimIdentifier]

Tools Used

Manual Review

Recommended Mitigation Steps

if (_state == State.NonExistent) {
      _cleanUpClaim(_claimIdentifier);
    } else {
      claims_[_claimIdentifier].state = _state;
      claims_[_claimIdentifier].updated = block.timestamp;
    }
  }

into

if (_state == State.NonExistent) { _cleanUpClaim(_claimIdentifier); } else { claims.state = _state; claims.updated = block.timestamp; } }