search

code-423n4 / 2021-10-tally-findings

0 stars 0 forks source link

Gas: SafeMath is not needed when using Solidity version 0.8 #42

Open code423n4 opened 2 years ago

code423n4 commented 2 years ago

Handle

cmichel

Vulnerability details

The Swap contract uses Solidity version 0.8 which already implements overflow checks by default. At the same time, it uses the SafeMath library which is more gas expensive than the 0.8 overflow checks.

It should just use the built-in checks and remove SafeMath from the dependencies:

// @audit can just normal arithmetic here
uint256 toTransfer = SWAP_FEE_DIVISOR.sub(swapFee).mul(boughtERC20Amount).div(SWAP_FEE_DIVISOR);

// uint256 toTransfer = (SWAP_FEE_DIVISOR - swapFee) * boughtERC20Amount / SWAP_FEE_DIVISOR;

// same with many other computations