Submission Details
Severity:
Use variables instead of magic numbers
Summary
You should use descriptive variables rather than magic numbers in your code.
Vulnerability Details
This function uses magic numbers for the fee split:
function selectWinner() external {
require(block.timestamp >= raffleStartTime + raffleDuration, "PuppyRaffle: Raffle not over");
require(players.length >= 4, "PuppyRaffle: Need at least 4 players");
uint256 winnerIndex =
uint256(keccak256(abi.encodePacked(msg.sender, block.timestamp, block.difficulty))) % players.length;
address winner = players[winnerIndex];
uint256 totalAmountCollected = players.length * entranceFee;
uint256 prizePool = (totalAmountCollected * 80) / 100;
uint256 fee = (totalAmountCollected * 20) / 100;
totalFees = totalFees + uint64(fee);
uint256 tokenId = totalSupply();
// We use a different RNG calculate from the winnerIndex to determine rarity
uint256 rarity = uint256(keccak256(abi.encodePacked(msg.sender, block.difficulty))) % 100;
if (rarity <= COMMON_RARITY) {
tokenIdToRarity[tokenId] = COMMON_RARITY;
} else if (rarity <= COMMON_RARITY + RARE_RARITY) {
tokenIdToRarity[tokenId] = RARE_RARITY;
} else {
tokenIdToRarity[tokenId] = LEGENDARY_RARITY;
}
Impact
Your code is not as readable and easy to parse. Also, you use variables for the rarities so it is more consistent to also use variables for the fee split.
Tools Used
Manual review
Recommendations
Use variables for the fee split...add the following variables and then use these in selectWinner. Also please see my submission with regard to multiplying and dividing in selectWinner.
uint256 internal constant PLAYERFEESPLIT == 80;
uint256 internal constant PROTOCOLFEESPLIT == 100;
Rewards breakdown
nSLOC
143This contest has a flat reward structure with the following payouts:
100 EXP
20 EXP
2 EXP
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