Block2Play - Smart Contract Audit Report


Block2Play ($B2P) is a new community-driven DeFi token on the Binance Smart Chain that is an automatic liquidity providing protocol that pays out static rewards to holders.

We reviewed the Block2Play contract at 0xe3A9D3c1174f315ED5c3A8e6C643F2e0AeA58Dff on the Binance Smartchain mainnet.

Notes on the Contract:
  • The total supply of the token is set to 100 million [100,000,000].
  • No minting or burn functions are present; though the circulating supply can be reduced by sending tokens to the 0x..dead address, if desired.
  • At the time of writing this report, 65% of the total supply belongs to the owner.
  • The remaining 35% of the total supply belongs to an unverified contract.

  • Trading is initially set to disabled upon deployment. Only accounts that are excluded from fees are able to trade during this time.
  • The owner must manually enable trading. Once trading is enabled, it can never be disabled.
  • There is a reflection fee, liquidity fee, buyback fee, marketing fee, and operations fee on all transactions for any non-excluded address that participates in a transfer with Pancakeswap. A separate fee structure can be set by the team to apply different fee amounts depending on whether the user is buying or selling during the transfer.
  • Users who hold tokens will automatically benefit from the frictionless fee redistribution at the time of each transaction as the tokens collected through the reflection fee are removed from the circulating supply.
  • The tokens collected from the liquidity fee during transfers are stored in the contract address balance. Once the threshold value of tokens (determined by the owner) is met, a swap will occur for the purpose of funding Pancakeswap liquidity.
  • Liquidity-adds are funded by selling a portion of the tokens collected as fees (after the threshold number of tokens is met), then 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 Burn address.
  • On each transfer that occurs while the minimum threshold (determined by the owner) is met, the protocol will spend 1% of its BNB balance toward buying $B2P tokens that will subsequently be burned.
  • The tokens collected from the operations fee are swapped for BNB and sent to the team's operations wallet.
  • The tokens collected from the marketing fee are sent to the team's marketing wallet.
  • As the contract is implemented with Solidity v0.8.x, it is protected from overflows.

  • Ownership Controls:
  • Ownership has not been renounced.
  • The owner can modify the rfi fee, liquidity fee, buyback fee, marketing fee, and operations fee for each fee structure to any percentages at any time.
  • The owner can exclude and include accounts from transfer fees and reward distribution.
  • The owner can set and update a maximum buy/sell amount at any time, which will impose a limit to the number of tokens that can be transferred during any given transaction with Pancakeswap.
  • The owner can enable/disable automatic liquidity adds and the buyback mechanism at any time.
  • The owner can update the minimum threshold of tokens needed to trigger automatic liquidity adds and the buyback mechanism.
  • The owner can withdraw any BNB or BEP20 tokens from the contract address at any time.
  • The owner can add accounts to a blacklist which will prevent them from being able to participate in transfers.
  • The owner can update the team's marketing wallet and operations wallet at any time.
  • The owner can update the Pancakeswap Router address at any time.
Audit Findings Summary
  • No external threats were identified.
  • Please ensure trust in the team prior to investing as they have substantial control in the ecosystem and control a large portion of the total supply.
  • Date: November 17th, 2021

Audit Results

Vulnerability CategoryNotesResult
Arbitrary Storage WriteN/APASS
Arbitrary JumpN/APASS
Delegate Call to Untrusted ContractN/APASS
Dependence on Predictable VariablesN/APASS
Deprecated OpcodesN/APASS
Ether ThiefN/APASS
External CallsN/APASS
Flash LoansN/APASS
Integer Over/UnderflowN/APASS
Multiple SendsN/APASS
State Change External CallsN/APASS
Unchecked RetvalN/APASS
User Supplied AssertionN/APASS
Critical Solidity CompilerN/APASS
Overall Contract Safety PASS

Function Graph

ERC20 Token Graph

Inheritence Chart

Multi-file Token

Functions Overview

 ($) = payable function
 # = non-constant function
 + [Int] IERC20 
    - [Ext] totalSupply
    - [Ext] balanceOf
    - [Ext] transfer #
    - [Ext] allowance
    - [Ext] approve #
    - [Ext] transferFrom #

 + [Lib] SafeMath 
    - [Int] tryAdd
    - [Int] trySub
    - [Int] tryMul
    - [Int] tryDiv
    - [Int] tryMod
    - [Int] add
    - [Int] sub
    - [Int] mul
    - [Int] div
    - [Int] mod
    - [Int] sub
    - [Int] div
    - [Int] mod

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

 + [Lib] Address 
    - [Int] isContract
    - [Int] sendValue #
    - [Int] functionCall #
    - [Int] functionCall #
    - [Int] functionCallWithValue #
    - [Int] functionCallWithValue #
    - [Int] functionStaticCall
    - [Int] functionStaticCall
    - [Int] functionDelegateCall #
    - [Int] functionDelegateCall #
    - [Prv] _verifyCallResult

 +  Ownable (Context)
    - [Pub]  #
    - [Pub] owner
    - [Pub] renounceOwnership #
       - modifiers: onlyOwner
    - [Pub] transferOwnership #
       - modifiers: onlyOwner
    - [Prv] _setOwner #

 + [Int] IFactory 
    - [Ext] createPair #
    - [Ext] getPair

 + [Int] IRouter 
    - [Ext] factory
    - [Ext] WETH
    - [Ext] addLiquidityETH ($)
    - [Ext] swapExactETHForTokensSupportingFeeOnTransferTokens ($)
    - [Ext] swapExactTokensForETHSupportingFeeOnTransferTokens #

 +  Block2Play (Context, IERC20, Ownable)
    - [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] deliver #
    - [Pub] reflectionFromToken
    - [Ext] startTrading #
       - modifiers: onlyOwner
    - [Pub] tokenFromReflection
    - [Pub] excludeFromReward #
       - modifiers: onlyOwner
    - [Ext] includeInReward #
       - modifiers: onlyOwner
    - [Pub] excludeFromFee #
       - modifiers: onlyOwner
    - [Pub] includeInFee #
       - modifiers: onlyOwner
    - [Pub] isExcludedFromFee
    - [Ext] setFeeRates #
       - modifiers: onlyOwner
    - [Ext] setSellFeeRates #
       - modifiers: onlyOwner
    - [Prv] _reflectRfi #
    - [Prv] _takeOperations #
    - [Prv] _takeBuyback #
    - [Prv] _takeLiquidity #
    - [Prv] _takeMarketing #
    - [Prv] _getValues
    - [Prv] _getTValues
    - [Prv] _getRValues
    - [Prv] _getRate
    - [Prv] _getCurrentSupply
    - [Prv] _approve #
    - [Prv] _transfer #
    - [Prv] _tokenTransfer #
    - [Prv] buyBackTokens #
       - modifiers: lockTheSwap
    - [Prv] swapETHForTokens #
    - [Prv] swapAndLiquify #
       - modifiers: lockTheSwap
    - [Prv] addLiquidity #
    - [Prv] swapTokensForBNB #
    - [Ext] updateMarketingWallet #
       - modifiers: onlyOwner
    - [Ext] updateOperationsWallet #
       - modifiers: onlyOwner
    - [Ext] setMaxBuyAndSellAmount #
       - modifiers: onlyOwner
    - [Ext] updateSwapTokensAtAmount #
       - modifiers: onlyOwner
    - [Ext] updateSwapEnabled #
       - modifiers: onlyOwner
    - [Ext] updateBuybackEnabled #
       - modifiers: onlyOwner
    - [Ext] setAntibot #
       - modifiers: onlyOwner
    - [Ext] setBuybackUpperLimit #
       - modifiers: onlyOwner
    - [Pub] isBot
    - [Ext] rescueBNB #
       - modifiers: onlyOwner
    - [Ext] rescueBEP20Tokens #
       - modifiers: onlyOwner
    - [Ext] setRouterAddress #
       - modifiers: onlyOwner
    - [Ext]  ($)