ToastSwap - Smart Contract Audit Report

Summary

ToastSwap Audit Report Toast Finance is building a new DeFi ecosystem on the Binance Smart Chain.

For this audit, we analyzed Toast Finance's ToastSwap contract, which contains logic for their token and their MasterChef staking contract. We reviewed the team's code at the following addresses on the BSC mainnet:

ToastSwap Token: 0x7de7177402852b67924e8cc021311be288a875b5

MasterChef Staking: 0x451347862a8d6d8a889b4ab1f604c7d3d0ecbf1c

Notes on the Contracts:
The initial total supply of the ToastSwap token is 500,000 TOAST tokens; currently, held by the team.
More tokens can be minted by the owner of the token contract; and the owner can also burn tokens from any address without prior permission.
The owner of the token contract has been properly set to the MasterChef staking contract for the provision of staking rewards. This also does not allow the team to exercise the function to burn user's tokens.
The token is designed to be a governance token where 1 token = 1 vote.
Token holders can delegate their voting rights to any address. To save gas, users can also do so using an EIP-712 signature.
The transfer function of the token does not properly call _moveDelegates, so when tokens are transferred voting power is not being moved. Governance functions will not be available to users as intended.

Users can stake various tokens in the MasterChef contract to earn rewards in the form of the project's native ToastSwap token.
There is a fee associated with making a deposit to the contract, set by the team upon adding the pool. The fee is directed to the team and its percentage can be updated at any time.
Users can also earn further token rewards by referring others to deposit into the contract. Referral logic is held in a separate contract which was not reviewed as a part of this audit.
The developers will be minted 20% of the tokens issued as rewards to users.
Users can only claim their rewards every set number minutes/hours/days, as determined by the team.
A MasterChefRole contract is present, but it is not used. The unused contract allows the team to add and remove from an array of addresses designed to be MasterChef contracts.
The MasterChef staking contract should not be used with deflationary tokens. If a deflationary token is added as a staking asset, then the contract must be exempt from transfer fees.
The team must also be careful not to add the same token twice for staking.
Two lines perform a multiplication on the result of a division, leading to less accurate results. It is advisable to always do all multiplication prior to division. Applicable lines can be viewed here.
The MasterChef.teamAddress variable could be declared constant to save gas on both storage and each reference.
A number of functions could be declared external instead of public to save some gas on each call. Applicable functions can be viewed here.
Utilization of SafeMath (or similarily safe functions) to prevent overflows; and usage of ReentrancyGuard to prevent reentrancy via ERC777-compliant tokens.

Audit Findings Summary:
No security issues from outside attackers were identified.
Some logical issues exist. The token's governance functionalities will not work as intended.
Ensure trust in the team as they have notable control in the ecosystem.
Date: August 4th, 2021

Combined External Threat Results

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	N/A	PASS
Deprecated Opcodes	N/A	PASS
Ether Thief	N/A	PASS
Exceptions	N/A	PASS
External Calls	N/A	PASS
Integer Over/Underflow	N/A	PASS
Multiple Sends	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

Function Graph

Smart Contract Graph

Inheritence Chart

Smart Contract Inheritance

Functions Overview


 ($) = payable function
 # = non-constant function
 
 Int = Internal
 Ext = External
 Pub = Public

 + [Int] IUniswapV2Factory 
    - [Ext] feeTo
    - [Ext] feeToSetter
    - [Ext] getPair
    - [Ext] allPairs
    - [Ext] allPairsLength
    - [Ext] createPair #
    - [Ext] setFeeTo #
    - [Ext] setFeeToSetter #

 + [Int] IUniswapV2Pair 
    - [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] IUniswapV2Router01 
    - [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] IUniswapV2Router02 (IUniswapV2Router01)
    - [Ext] removeLiquidityETHSupportingFeeOnTransferTokens #
    - [Ext] removeLiquidityETHWithPermitSupportingFeeOnTransferTokens #
    - [Ext] swapExactTokensForTokensSupportingFeeOnTransferTokens #
    - [Ext] swapExactETHForTokensSupportingFeeOnTransferTokens ($)
    - [Ext] swapExactTokensForETHSupportingFeeOnTransferTokens #

 +  ReentrancyGuard 
    - [Int]  #

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

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

 + [Int] IToastReferral 
    - [Ext] recordReferral #
    - [Ext] recordReferralCommission #
    - [Ext] getReferrer

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

 + [Lib] SafeBEP20 
    - [Int] safeTransfer #
    - [Int] safeTransferFrom #
    - [Int] safeApprove #
    - [Int] safeIncreaseAllowance #
    - [Int] safeDecreaseAllowance #
    - [Prv] _callOptionalReturn #

 + [Int] IBEP20 
    - [Ext] totalSupply
    - [Ext] decimals
    - [Ext] symbol
    - [Ext] name
    - [Ext] getOwner
    - [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

 + [Lib] Roles 
    - [Int] add #
    - [Int] remove #
    - [Int] has

 +  MasterChefRole 
    - [Int]  #
    - [Pub] isMasterChef
    - [Pub] addMasterChef #
       - modifiers: onlyMasterChef
    - [Pub] removeMasterChef #
       - modifiers: onlyMasterChef
    - [Pub] renounceMasterChef #
    - [Int] _addMasterChef #
    - [Int] _removeMasterChef #

 +  BEP20 (Context, IBEP20, Ownable)
    - [Pub]  #
    - [Ext] getOwner
    - [Pub] name
    - [Pub] decimals
    - [Pub] symbol
    - [Pub] totalSupply
    - [Pub] balanceOf
    - [Pub] transfer #
    - [Pub] allowance
    - [Pub] approve #
    - [Pub] transferFrom #
    - [Pub] increaseAllowance #
    - [Pub] decreaseAllowance #
    - [Pub] mint #
       - modifiers: onlyOwner
    - [Int] _transfer #
    - [Int] _mint #
    - [Int] _burn #
    - [Int] _approve #
    - [Int] _burnFrom #

 +  ToastToken (BEP20)
    - [Pub]  #
    - [Pub] mint #
       - modifiers: onlyOwner
    - [Pub] burn #
       - modifiers: onlyOwner
    - [Ext] delegates
    - [Ext] delegate #
    - [Ext] delegateBySig #
    - [Ext] getCurrentVotes
    - [Ext] getPriorVotes
    - [Int] _delegate #
    - [Int] _moveDelegates #
    - [Int] _writeCheckpoint #
    - [Int] safe32
    - [Int] getChainId

 +  MasterChef (Ownable, ReentrancyGuard)
    - [Pub]  #
    - [Ext] poolLength
    - [Pub] add #
       - modifiers: onlyOwner
    - [Pub] set #
       - modifiers: onlyOwner
    - [Pub] getMultiplier
    - [Ext] pendingToast #
    - [Pub] canHarvest
    - [Pub] massUpdatePools #
    - [Pub] updatePool #
    - [Pub] deposit #
       - modifiers: nonReentrant
    - [Pub] withdraw #
       - modifiers: nonReentrant
    - [Pub] emergencyWithdraw #
       - modifiers: nonReentrant
    - [Int] payOrLockupPendingToast #
    - [Int] safeToastTransfer #
    - [Pub] setDevAddress #
    - [Pub] setTreasuryAddress #
    - [Pub] updateEmissionRate #
       - modifiers: onlyOwner
    - [Pub] setToastReferral #
       - modifiers: onlyOwner
    - [Pub] setReferralCommissionRate #
       - modifiers: onlyOwner
    - [Int] payReferralCommission #

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