Protocol Review

Privileged addresses have authority over many functions that may be used to negatively disrupt the project. Some important privileges include:

• owner can blacklist an address preventing it from swapping ILOTTO tokens. Additionally, the token pair or exchange router could be blacklisted, which would cease trading.
• owner can set isMaxWalletExempt to false for the pair contract, thus halting all trading.
• owner can label an address a teamDivWallet which would instantaneously create more XiLotto dividend tokens and would dilute the future dividends of other holders. Furthermore, this allows the team to to dump on the market without any cooldown.
• owner can toggle tradingStatus to false which would prevent users from transferring funds and cease trading on all exchanges.
• owner can updateClaimWait to an arbitrarily long period, potentially preventing XiLotto holders from ever claiming their dividends.
• Any authorized address can update the router to a potentially malicious contract that causes a denial-of-service via reverting, or siphons funds upon execution of swapBack rather than distributing these funds as dividends.
• owner can set the cooldownTimerInterval to an arbitrarily long length of time, making it so that addresses are potentially only able to buy ILotto2 once. Additionally, owner can combine an extremely long cooldownTimerInterval with adding the exchange’s router as an automatedMarketMakerPair, this way any address can potentially only buy/sell one time.

Currently the owner address is not a multi-sig. Ensure that the privileged addresses are multi-sig and/or introduce timelock for improved community oversight. Optionally introduce require statements to limit the scope of the exploits that can be carried out by the privileged addresses.

Infinity Lotto Team: **

• Contract Ownership is transferred a multi sig wallet

In the function takeFee: uint256 feeAmount = amount.div(feeDenominator * 100).mul(totalFee).mul(multiplier) performs multiplication on the result of division, which leads to a loss in precision.

For example: 100.div(100 * 100).mul(10).mul(100) = 0 but 100.mul(10).mul(100).div(100 * 100) = 10

Change to uint256 feeAmount = (amount * totalFee * multiplier) / (feeDenominator * 100).

Infinity Lotto Team: **

• Acknowledged, but not changed as this doesn’t significantly affect the token and would require a contract migration.

Contract variables such as MAX_INT, RWRD, DEAD, ZERO, _totalSupply, feeDenominator can be declared constant.

Declare the variables constant.

Infinity Lotto Team: **

• Acknowledged, but not changed as this doesn’t significantly affect the token and would require a contract migration.

The WBNB and distributor variables are never modified after they are set in the constructor, and should therefore be declared immutable.

Declare the variables immutable.

Infinity Lotto Team: **

• Acknowledged, but not changed as this doesn’t significantly affect the token and would require a contract migration.

There is no need for add, sub, mul, and div in Solidity version ^0.8.0 as there are already implicit overflow and underflow checks.

Use language provided operators +, -, *, / to save on gas.

Infinity Lotto Team: **

• Acknowledged, but not changed as this doesn’t significantly affect the token and would require a contract migration.

In the XiLotto contract, the tokenHoldersMap is declared as an IterableMapping, but it is only ever used to access the values of the keys. Therefore the use of IterableMapping is gas inefficient and it can be replaced as a list.

Replace the tokenHoldersMap with a list of tokenHolders.

Infinity Lotto Team: **

• Acknowledged, but not changed as this doesn’t significantly affect the token and would require a contract migration.

Internal functions should be denoted with a preceding _: checkTxLimit, shouldTakeFee, takeFee, shouldSwapBack, swapBack, swapAndSendToDiv.

Rename these functions to _checkTxLimit, _shouldTakeFee, _takeFee, _shouldSwapBack, _swapBack, _swapAndSendToDiv.

Infinity Lotto Team: **

• Acknowledged, but not changed as this doesn’t significantly affect the token and would require a contract migration.

Many public functions can be declared external: tradingStatus, cooldownEnabled, enable_blacklist, manage_blacklist, getCirculatingSupply, addTeamDivWallet, setAutomatedMarketMakerPair.

Declare these functions external as they are never called internally.

Infinity Lotto Team: **

• Acknowledged, but not changed as this doesn’t significantly affect the token and would require a contract migration.

Function names should adhere to camelCase: enable_blacklist, manage_blacklist.

Introduce camelCase instead of snake_case.

Infinity Lotto Team: **

• Acknowledged, but not changed as this doesn’t significantly affect the token and would require a contract migration.

withdrawlToken should be withdrawalToken.

Fix spelling for cleaner code.

Infinity Lotto Team: **

• Acknowledged, but not changed as this doesn’t significantly affect the token and would require a contract migration.

When removeBadStakingContract is called, isMaxWalletExempt is not reset to false.

If this is not intended, perform isMaxWalletExempt[badStakingContract] = false; or delete isMaxWalletExempt[badStakingContract].

Infinity Lotto Team: **

• Acknowledged, but not changed as this doesn’t significantly affect the token and would require a contract migration.

In updateRouter the final if statement condition is automatedMarketMakerPairs[pair] != true, but this is redundant since the mapping values are booleans themselves.

Replace the if statement condition with a more gas efficient !automatedMarketMakerPairs[pair].

Infinity Lotto Team: **

• Acknowledged, but not changed as this doesn’t significantly affect the token and would require a contract migration.