CryptoAgainstCancer - Smart Contract Audit Report

Summary

CryptoAgainstCancer is a new token with frictionless fee redistribution and charity contribution on each transfer featuring liquidity adds, BNB rewards, and a lottery system.

We audited CryptoAgainstCancer's token contract at 0x6fbFf934ec9D724450E66d9AcE621cb7E67CeB5A on the Binance Smart Chain mainnet.

Overview of the Contract:
The total supply of the token is set to one quadrillion.
No mint or burn functions are present; though the circulating supply can be reduced by sending tokens to the 0x..dead address, if desired.
The token is designed to be a governance token where 1 token = 1 vote.
Another contract will be needed to collect votes and execute transactions on behalf of the governance token holders.
Token holders can delegate their voting rights to any address. To save gas, users can also do so using an EIP-712 signature.
Pancakeswap holds ~65.6% of the token's supply as liquidity.
96.6% of liquidity has been locked in an unverified contract.
7% is held in the contract to be used for swap and liquify.

Fees are collected by the project team and are sent to the charity wallet and the dev marketing wallet.
Users who hold tokens will automatically receive a portion of the fees from a transaction tax on each transfer.
A portion of the fee charged on transactions is stored in the contract and, once a threshold value is met, used to fund PancakeSwap liqudity.
Liquidity-adds are funded by selling half of the tokens collected as fees, pairing the received BNB with the token, and adding it as liquidity to the BNB pair.
The recipient of the newly created LP tokens is the owner. We recommend that this liquidity is locked at the time of acquisition.
A final portion of the fees charged on transfers is used to fund BNB rewards, which will be claimable by token holders. This is also used to fund a lottery system, allowing users to win extra rewards on a psuedo-random basis.

Claims for BNB rewards are disabled for 3 days after launch, and the owner can disable claims for these rewards for 2 weeks at a time at will.
The owner of the contract can exclude and include users from transfer fees, set the maximum transfer amount, and update the fee percentages at any time.
The randomness function, to an extent, relies on predictable environment variables. This is common, albiet not best practice; but the probability of miners maliciously changing these variables is extremley low.
Some state variables could have been declared constant to save some gas.
Some functions could have been declared external instead of public to save some gas.
BNB claiming logic is properly structured to prevent reentrancy attacks.
The contract utilizes SafeMath libraries to prevent overflows along with following the BEP20 standard.

Audit Findings Summary
No security threats were identified.
Ensure trust in the team as they have some power in the ecosystem and will receive the LP tokens from liquidity-adds.
Date: June 22nd, 2021

Vulnerability Category	Notes	Result
Arbitrary Storage Write	N/A	PASS
Arbitrary Jump	N/A	PASS
Delegate Call to Untrusted Contract	N/A	PASS
Dependence on Predictable Variables	Randomness relies on a series of environmental variables. Probability of a negative impact is very low.	WARNING
Deprecated Opcodes	N/A	PASS
Ether Thief	N/A	PASS
Exceptions	N/A	PASS
External Calls	N/A	PASS
Flash Loans	N/A	PASS
Integer Over/Underflow	N/A	PASS
Multiple Sends	N/A	PASS
Oracles	N/A	PASS
Suicide	N/A	PASS
State Change External Calls	N/A	PASS
Unchecked Retval	N/A	PASS
User Supplied Assertion	N/A	PASS
Critical Solidity Compiler	N/A	PASS
Overall Contract Safety		PASS

BEP20 Token Graph

Multi-file Token

												
($) = payable function
 # = non-constant function

 + [Int] IBEP20 
    - [Ext] totalSupply
    - [Ext] balanceOf
    - [Ext] transfer #
    - [Ext] allowance
    - [Ext] approve #
    - [Ext] transferFrom #

 + [Lib] SafeMath 
    - [Int] add
    - [Int] sub
    - [Int] sub
    - [Int] mul
    - [Int] div
    - [Int] div
    - [Int] mod
    - [Int] mod

 +  Context 
    - [Int] _msgSender
    - [Int] _msgData

 + [Lib] Address 
    - [Int] isContract
    - [Int] sendValue #
    - [Int] functionCall #
    - [Int] functionCall #
    - [Int] functionCallWithValue #
    - [Int] functionCallWithValue #
    - [Prv] _functionCallWithValue #

 +  Ownable (Context)
    - [Int]  #
    - [Pub] owner
    - [Pub] renounceOwnership #
       - modifiers: onlyOwner
    - [Pub] transferOwnership #
       - modifiers: onlyOwner
    - [Pub] geUnlockTime
    - [Pub] lock #
       - modifiers: onlyOwner
    - [Pub] unlock #

 + [Int] IPancakeFactory 
    - [Ext] feeTo
    - [Ext] feeToSetter
    - [Ext] getPair
    - [Ext] allPairs
    - [Ext] allPairsLength
    - [Ext] createPair #
    - [Ext] setFeeTo #
    - [Ext] setFeeToSetter #

 + [Int] IPancakePair 
    - [Ext] name
    - [Ext] symbol
    - [Ext] decimals
    - [Ext] totalSupply
    - [Ext] balanceOf
    - [Ext] allowance
    - [Ext] approve #
    - [Ext] transfer #
    - [Ext] transferFrom #
    - [Ext] DOMAIN_SEPARATOR
    - [Ext] PERMIT_TYPEHASH
    - [Ext] nonces
    - [Ext] permit #
    - [Ext] MINIMUM_LIQUIDITY
    - [Ext] factory
    - [Ext] token0
    - [Ext] token1
    - [Ext] getReserves
    - [Ext] price0CumulativeLast
    - [Ext] price1CumulativeLast
    - [Ext] kLast
    - [Ext] mint #
    - [Ext] burn #
    - [Ext] swap #
    - [Ext] skim #
    - [Ext] sync #
    - [Ext] initialize #

 + [Int] IPancakeRouter01 
    - [Ext] factory
    - [Ext] WETH
    - [Ext] addLiquidity #
    - [Ext] addLiquidityETH ($)
    - [Ext] removeLiquidity #
    - [Ext] removeLiquidityETH #
    - [Ext] removeLiquidityWithPermit #
    - [Ext] removeLiquidityETHWithPermit #
    - [Ext] swapExactTokensForTokens #
    - [Ext] swapTokensForExactTokens #
    - [Ext] swapExactETHForTokens ($)
    - [Ext] swapTokensForExactETH #
    - [Ext] swapExactTokensForETH #
    - [Ext] swapETHForExactTokens ($)
    - [Ext] quote
    - [Ext] getAmountOut
    - [Ext] getAmountIn
    - [Ext] getAmountsOut
    - [Ext] getAmountsIn

 + [Int] IPancakeRouter02 (IPancakeRouter01)
    - [Ext] removeLiquidityETHSupportingFeeOnTransferTokens #
    - [Ext] removeLiquidityETHWithPermitSupportingFeeOnTransferTokens #
    - [Ext] swapExactTokensForTokensSupportingFeeOnTransferTokens #
    - [Ext] swapExactETHForTokensSupportingFeeOnTransferTokens ($)
    - [Ext] swapExactTokensForETHSupportingFeeOnTransferTokens #

 +  ReentrancyGuard 
    - [Pub]  #

 +  CryptoAgainstCancer (Context, IBEP20, Ownable, ReentrancyGuard)
    - [Pub]  #
    - [Pub] name
    - [Pub] symbol
    - [Pub] decimals
    - [Pub] totalSupply
    - [Pub] balanceOf
    - [Pub] transfer #
    - [Pub] allowance
    - [Pub] approve #
    - [Pub] transferFrom #
    - [Pub] increaseAllowance #
    - [Pub] decreaseAllowance #
    - [Pub] isExcludedFromReward
    - [Pub] totalFees
    - [Pub] deliver #
    - [Pub] reflectionFromToken
    - [Pub] tokenFromReflection
    - [Pub] excludeFromReward #
       - modifiers: onlyOwner
    - [Ext] includeInReward #
       - modifiers: onlyOwner
    - [Prv] _getTxAmountMinusFee
    - [Prv] _getTValues
    - [Prv] _getRValues
    - [Pub] excludeFromFee #
       - modifiers: onlyOwner
    - [Pub] includeInFee #
       - modifiers: onlyOwner
    - [Ext] setTaxFeePercent #
       - modifiers: onlyOwner
    - [Ext] setLiquidityFeePercent #
       - modifiers: onlyOwner
    - [Ext] setDevMarketingFeePercentTenths #
       - modifiers: onlyOwner
    - [Ext] setCharityPercent #
       - modifiers: onlyOwner
    - [Pub] setSwapAndLiquifyEnabled #
       - modifiers: onlyOwner
    - [Ext]  ($)
    - [Prv] _reflectFee #
    - [Prv] _getValues
    - [Prv] _getRValues
    - [Prv] _getRate
    - [Prv] _getCurrentSupply
    - [Prv] _takeDevMarketingFee #
    - [Prv] _takeLiquidity #
    - [Pub] isExcludedFromFee
    - [Prv] _approve #
    - [Prv] _transfer #
    - [Prv] _tokenTransfer #
    - [Prv] _transferBothExcluded #
    - [Prv] _transferStandard #
    - [Prv] _transferToExcluded #
    - [Prv] _transferFromExcluded #
    - [Pub] setMaxTxPercent #
       - modifiers: onlyOwner
    - [Pub] setExcludeFromMaxTx #
       - modifiers: onlyOwner
    - [Pub] calculateBNBReward
    - [Pub] getRewardCycleBlock
    - [Pub] claimBNBReward #
       - modifiers: isHuman,nonReentrant
    - [Pub] toggleClaims #
       - modifiers: onlyOwner
    - [Prv] topUpClaimCycleAfterTransfer #
    - [Prv] ensureMaxTxAmount
    - [Pub] disruptiveTransfer ($)
    - [Prv] swapAndLiquify #
    - [Prv] calculateFeeTenth
    - [Prv] removeAllFee #
    - [Prv] restoreAllFee #
    - [Prv] _takeCharityFee #
    - [Pub] activateContract #
       - modifiers: onlyOwner
    - [Ext] delegates
    - [Ext] delegate #
    - [Ext] delegateBySig #
    - [Ext] getCurrentVotes
    - [Ext] getPriorVotes
    - [Int] _delegate #
    - [Int] _moveDelegates #
    - [Int] _writeCheckpoint #
    - [Int] safe32
    - [Int] getChainId
    - [Prv] random
    - [Prv] isLotteryWon
    - [Prv] calculateBNBReward
    - [Prv] calculateTopUpClaim
    - [Prv] swapTokensForEth #
    - [Prv] swapETHForTokens #
    - [Prv] addLiquidity #

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CryptoAgainstCancer - Smart Contract Audit Report

Summary

External Threat Results

Function Graph

Inheritence Chart

Functions Overview