Transaction Hash:
Block:
17201112 at May-06-2023 10:59:59 AM +UTC
Transaction Fee:
0.004951381586072496 ETH
$12.49
Gas Used:
46,544 Gas / 106.380663159 Gwei
Emitted Events:
349 |
BananaClubToken.Approval( owner=[Sender] 0xeb2a81e229b68c1c22b6683275c00945f9872d90, spender=0x00000000...43aC78BA3, value=115792089237316195423570985008687907853269984665640564039457584007913129639935 )
|
Account State Difference:
Address | Before | After | State Difference | ||
---|---|---|---|---|---|
0x350D3f0f...55562150a | |||||
0x690B9A9E...Db4FaC990
Miner
| (builder0x69) | 3.630995406669419606 Eth | 3.630999781805419606 Eth | 0.000004375136 | |
0xeB2a81e2...5f9872D90 |
0.03387855798976174 Eth
Nonce: 1469
|
0.028927176403689244 Eth
Nonce: 1470
| 0.004951381586072496 |
Execution Trace
BananaClubToken.approve( spender=0x000000000022D473030F116dDEE9F6B43aC78BA3, amount=115792089237316195423570985008687907853269984665640564039457584007913129639935 ) => ( True )
// SPDX-License-Identifier: MIT import "./Ownable.sol"; import "./LazyMath.sol"; import "./BananaFactory.sol"; import "./BananaRouter.sol"; import "./BANANA20.sol"; import "./draft-ERC20Permit.sol"; import "./ERC20Votes.sol"; pragma solidity 0.8.2; //File: BananaToken.sol /* * */ contract BananaClubToken is ERC20, ERC20Permit, ERC20Votes, Ownable { using SafeMath for uint256; IUniswapV2Router02 public uniswapV2Router; address public uniswapV2Pair; bool private _swapping; address public treasury; address public buyBack; uint256 public maxTransactionAmount; uint256 public swapTokensAtAmount; uint256 public maxWallet; bool public limitsInEffect = true; bool public tradingActive = false; uint256 public buyTotalFees; uint256 private _buyTreasuryFee; uint256 private _buyLiquidityFee; uint256 private _buyBuyBackFee; uint256 public sellTotalFees; uint256 private _sellTreasuryFee; uint256 private _sellLiquidityFee; uint256 private _sellBuyBackFee; uint256 private _tokensForTreasury; uint256 private _tokensForLiquidity; uint256 private _tokensForBuyBack; /******************/ // exclude from fees and max transaction amount mapping (address => bool) private _isExcludedFromFees; mapping (address => bool) public _isExcludedMaxTransactionAmount; // store addresses that a automatic market maker pairs. Any transfer *to* these addresses // could be subject to a maximum transfer amount mapping (address => bool) public automatedMarketMakerPairs; event ExcludeFromFees(address indexed account, bool isExcluded); event SetAutomatedMarketMakerPair(address indexed pair, bool indexed value); event TreasuryUpdated(address newAddress); event BuyBackUpdated(address newAddress); event LPSwap(uint256 tokensSwapped, uint256 ethReceived, uint256 tokensIntoLiquidity); event tradingEnabled(bool tradingActive); event MaxTxnUpdated(uint256 newNum); event MaxWalletAmount(uint256 newNum); event MaxTxnExcluded(address updAds); event BuyFeeUpdated(uint256 marketingFee, uint256 liquidityFee, uint256 buyBackFee); event SellFeeUpdated(uint256 marketingFee, uint256 liquidityFee, uint256 buyBackFee); event ExcludedFromFee(address account, bool excluded); event limitsRemoved(bool limitsInEffect); event swapTokensAt(uint newAmount); event feesCollected(bool); constructor() ERC20("BananaClubToken", "BCT") ERC20Permit("BananaClubToken") { IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D); excludeFromMaxTransaction(address(_uniswapV2Router), true); uniswapV2Router = _uniswapV2Router; uniswapV2Pair = IUniswapV2Factory(_uniswapV2Router.factory()).createPair(address(this), _uniswapV2Router.WETH()); excludeFromMaxTransaction(address(uniswapV2Pair), true); _setAutomatedMarketMakerPair(address(uniswapV2Pair), true); uint256 buyTreasuryFee = 1; uint256 buyLiquidityFee = 0; uint256 buyBuyBackFee = 1; uint256 sellTreasuryFee = 1; uint256 sellLiquidityFee = 1; uint256 sellBuyBackFee = 1; uint256 totalSupply = 1e8 * 1e9; // 100 million 1e8 = 1(00,000,000) * 1e9 ((9).000000000 decimals) // Initial Deployed settings maybe be changed later with individual functions - Set all fees, Max AMTs maxTransactionAmount = totalSupply * 3 / 1000; // 0.3% maxTransactionAmountTxn 300,000 Tokens maxWallet = totalSupply * 2 / 100; // 2% maxWallet 2,000,000 Tokens swapTokensAtAmount = totalSupply * 3 / 10000; // 0.03% swap wallet 30,000 tokens _buyTreasuryFee = buyTreasuryFee; _buyLiquidityFee = buyLiquidityFee; _buyBuyBackFee = buyBuyBackFee; buyTotalFees = _buyTreasuryFee + _buyLiquidityFee + _buyBuyBackFee; _sellTreasuryFee = sellTreasuryFee; _sellLiquidityFee = sellLiquidityFee; _sellBuyBackFee = sellBuyBackFee; sellTotalFees = _sellTreasuryFee + _sellLiquidityFee + _sellBuyBackFee; treasury = address(owner()); // set owner as treasury at launch. Change it after Launch with the Update Function buyBack = address(owner()); // set owner as buyBack at launch. Change it after Launch with the Update Function // exclude from paying fees or having max transaction amount Owner/this/dead excludeFromFees(owner(), true); excludeFromFees(address(this), true); excludeFromFees(address(0xdead), true); excludeFromMaxTransaction(owner(), true); excludeFromMaxTransaction(address(this), true); excludeFromMaxTransaction(address(0xdead), true); /* _mint is an internal function in ERC20.sol that is only called here, and CANNOT be called ever again, this is used to Issue the initial Supply */ _mint(msg.sender, totalSupply); } // three required checks in solidity function _afterTokenTransfer(address from, address to, uint256 amount) internal override(ERC20, ERC20Votes) { super._afterTokenTransfer(from, to, amount); } function _mint(address to, uint256 amount) internal override(ERC20, ERC20Votes) { super._mint(to, amount); } function _burn(address account, uint256 amount) internal override(ERC20, ERC20Votes) { super._burn(account, amount); } /** * @dev Enables Trading on Uniswap */ function enableTrading() external onlyOwner { tradingActive = true; emit tradingEnabled(tradingActive); } /** * @dev Removes Max txn, and wallet limits if and when its Needed * cannot be turned back on. */ function removeLimits() external onlyOwner returns (bool) { limitsInEffect = false; emit limitsRemoved(limitsInEffect); return true; } /** * @dev Update how many tokens to Swap&Liquify at */ function updateSwapTokensAtAmount(uint256 newAmount) external onlyOwner returns (bool) { \t require(newAmount >= totalSupply() * 1 / 100000, "Swap amount cannot be lower than 0.001% total supply."); \t require(newAmount <= totalSupply() * 5 / 1000, "Swap amount cannot be higher than 0.5% total supply."); \t swapTokensAtAmount = newAmount; emit swapTokensAt(newAmount); \t return true; \t} /** * @dev Update MaxTransaction */ function updateMaxTxnAmount(uint256 newNum) external onlyOwner { require(newNum >= (totalSupply() * 1 / 1000) / 1e9, "Cannot set maxTransactionAmount lower than 0.1%"); maxTransactionAmount = newNum * 1e9; emit MaxTxnUpdated(newNum); } /** * @dev Update MaxWallet */ function updateMaxWalletAmount(uint256 newNum) external onlyOwner { require(newNum >= (totalSupply() * 5 / 1000)/1e9, "Cannot set maxWallet lower than 0.5%"); maxWallet = newNum * 1e9; emit MaxWalletAmount(newNum); } /** * @dev exclude Address from MaxTxn */ function excludeFromMaxTransaction(address updAds, bool isEx) public onlyOwner { _isExcludedMaxTransactionAmount[updAds] = isEx; emit MaxTxnExcluded(updAds); } /** * @dev Update Buy Tax */ function updateBuyFees(uint256 treasuryFee, uint256 liquidityFee, uint256 buyBackFee) external onlyOwner { _buyTreasuryFee = treasuryFee; _buyLiquidityFee = liquidityFee; _buyBuyBackFee = buyBackFee; buyTotalFees = _buyTreasuryFee + _buyLiquidityFee + _buyBuyBackFee; require(buyTotalFees <= 10, "Must keep fees at 10% or less"); emit BuyFeeUpdated(treasuryFee, liquidityFee, buyBackFee); } /** * @dev Update Sell Tax */ function updateSellFees(uint256 treasuryFee, uint256 liquidityFee, uint256 buyBackFee) external onlyOwner { _sellTreasuryFee = treasuryFee; _sellLiquidityFee = liquidityFee; _sellBuyBackFee = buyBackFee; sellTotalFees = _sellTreasuryFee + _sellLiquidityFee + _sellBuyBackFee; require(sellTotalFees <= 15, "Must keep fees at 15% or less"); emit SellFeeUpdated(treasuryFee, liquidityFee, buyBackFee); } /** * @dev Exclude Address from Tax */ function excludeFromFees(address account, bool excluded) public onlyOwner { _isExcludedFromFees[account] = excluded; emit ExcludeFromFees(account, excluded); } // function for setting AMM Pairs in the future function setAutomatedMarketMakerPair(address pair, bool value) external onlyOwner { require(pair != uniswapV2Pair, "The pair cannot be removed from automatedMarketMakerPairs"); _setAutomatedMarketMakerPair(pair, value); } function _setAutomatedMarketMakerPair(address pair, bool value) private { automatedMarketMakerPairs[pair] = value; emit SetAutomatedMarketMakerPair(pair, value); } /** * @dev Update Treasury Address */ function updateTreasury(address newAddress) external onlyOwner { treasury = newAddress; require(newAddress != address(0),"Address cannot be Zero address"); emit TreasuryUpdated(newAddress); } /** * @dev Update BuyBack Address */ function updateBuyBack(address newAddress) external onlyOwner { buyBack = newAddress; require(newAddress != address(0),"Address cannot be Zero address"); emit BuyBackUpdated(newAddress); } function isExcludedFromFees(address account) public view returns(bool) { return _isExcludedFromFees[account]; } // transfer function with required checks function _transfer( address from, address to, uint256 amount ) internal override { require(from != address(0), "ERC20: transfer from the zero address"); require(to != address(0), "ERC20: transfer to the zero address"); if (amount == 0) { super._transfer(from, to, 0); return; } if (limitsInEffect) { if ( from != owner() && to != owner() && to != address(0) && to != address(0xdead) && !_swapping ) { if (!tradingActive) { require(_isExcludedFromFees[from] || _isExcludedFromFees[to], "Trading is not active."); } // when buy if (automatedMarketMakerPairs[from] && !_isExcludedMaxTransactionAmount[to]) { require(amount <= maxTransactionAmount, "Buy transfer amount exceeds the maxTransactionAmount."); require(amount + balanceOf(to) <= maxWallet, "Max wallet exceeded"); } // when sell else if (automatedMarketMakerPairs[to] && !_isExcludedMaxTransactionAmount[from]) { require(amount <= maxTransactionAmount, "Sell transfer amount exceeds the maxTransactionAmount."); } else if (!_isExcludedMaxTransactionAmount[to]){ require(amount + balanceOf(to) <= maxWallet, "Max wallet exceeded"); } } } \t\tuint256 contractTokenBalance = balanceOf(address(this)); bool canSwap = contractTokenBalance >= swapTokensAtAmount; if ( canSwap && !_swapping && !automatedMarketMakerPairs[from] && !_isExcludedFromFees[from] && !_isExcludedFromFees[to] ) { _swapping = true; swapBack(); _swapping = false; } bool takeFee = !_swapping; // if any account belongs to _isExcludedFromFee account then remove the fee if (_isExcludedFromFees[from] || _isExcludedFromFees[to]) { takeFee = false; } uint256 fees = 0; // only take fees on buys/sells, do not take on wallet transfers if (takeFee) { // on sell if (automatedMarketMakerPairs[to] && sellTotalFees > 0) { fees = amount.mul(sellTotalFees).div(100); _tokensForLiquidity += fees * _sellLiquidityFee / sellTotalFees; _tokensForTreasury += fees * _sellTreasuryFee / sellTotalFees; _tokensForBuyBack += fees * _sellBuyBackFee / sellTotalFees; } // on buy else if (automatedMarketMakerPairs[from] && buyTotalFees > 0) { \t fees = amount.mul(buyTotalFees).div(100); \t _tokensForLiquidity += fees * _buyLiquidityFee / buyTotalFees; _tokensForTreasury += fees * _buyTreasuryFee / buyTotalFees; _tokensForBuyBack += fees * _buyBuyBackFee / buyTotalFees; } if (fees > 0) { super._transfer(from, address(this), fees); } \t \tamount -= fees; } super._transfer(from, to, amount); } function _swapTokensForEth(uint256 tokenAmount) private { // generate the uniswap pair path of token -> weth address[] memory path = new address[](2); path[0] = address(this); path[1] = uniswapV2Router.WETH(); _approve(address(this), address(uniswapV2Router), tokenAmount); // make the swap uniswapV2Router.swapExactTokensForETHSupportingFeeOnTransferTokens( tokenAmount, 0, // accept any amount of ETH path, address(this), block.timestamp ); } function _addLiquidity(uint256 tokenAmount, uint256 ethAmount) private { // approve token transfer to cover all possible scenarios _approve(address(this), address(uniswapV2Router), tokenAmount); // add the liquidity uniswapV2Router.addLiquidityETH{value: ethAmount}( address(this), tokenAmount, 0, // slippage is unavoidable 0, // slippage is unavoidable owner(), block.timestamp ); } function swapBack() private { uint256 contractBalance = balanceOf(address(this)); uint256 totalTokensToSwap = _tokensForLiquidity + _tokensForTreasury + _tokensForBuyBack; bool success; if (contractBalance == 0 || totalTokensToSwap == 0) return; if (contractBalance > swapTokensAtAmount * 20) { contractBalance = swapTokensAtAmount * 20; } // Halve the amount of liquidity tokens uint256 liquidityTokens = contractBalance * _tokensForLiquidity / totalTokensToSwap / 2; uint256 amountToSwapForETH = contractBalance.sub(liquidityTokens); uint256 initialETHBalance = address(this).balance; _swapTokensForEth(amountToSwapForETH); uint256 ethBalance = address(this).balance.sub(initialETHBalance); uint256 ethForTreasury = ethBalance.mul(_tokensForTreasury).div(totalTokensToSwap); uint256 ethForLiquidity = ethBalance.mul(_tokensForLiquidity).div(totalTokensToSwap); uint256 ethForBuyBack = ethBalance - ethForLiquidity - ethForTreasury; _tokensForLiquidity = 0; _tokensForTreasury = 0; _tokensForBuyBack = 0; if (liquidityTokens > 0 && ethForLiquidity > 0) { _addLiquidity(liquidityTokens, ethForLiquidity); emit LPSwap(amountToSwapForETH, ethForLiquidity, _tokensForLiquidity); } if (ethForTreasury > 0) { (success,) = address(treasury).call{value: ethForTreasury}(""); } if (ethForBuyBack > 0) { (success,) = address(buyBack).call{value: ethForBuyBack}(""); } } /** * @dev manually collect any eth from contract to treasury */ function manualCollectFees() external onlyOwner { bool success; (success,) = address(treasury).call{value: address(this).balance}(""); require(success, "Error on transfer, reverted"); emit feesCollected(success); } /** * @dev Fallback function for contract to recieve. */ receive() external payable {} } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/ERC20Votes.sol) pragma solidity ^0.8.0; import "./draft-ERC20Permit.sol"; import "./Math.sol"; import "./SafeCast.sol"; import "./ECDSA.sol"; /** * @dev Extension of ERC20 to support Compound-like voting and delegation. This version is more generic than Compound's, * and supports token supply up to 2^224^ - 1, while COMP is limited to 2^96^ - 1. * * NOTE: If exact COMP compatibility is required, use the {ERC20VotesComp} variant of this module. * * This extension keeps a history (checkpoints) of each account's vote power. Vote power can be delegated either * by calling the {delegate} function directly, or by providing a signature to be used with {delegateBySig}. Voting * power can be queried through the public accessors {getVotes} and {getPastVotes}. * * By default, token balance does not account for voting power. This makes transfers cheaper. The downside is that it * requires users to delegate to themselves in order to activate checkpoints and have their voting power tracked. * * _Available since v4.2._ */ abstract contract ERC20Votes is ERC20Permit { struct Checkpoint { uint32 fromBlock; uint224 votes; } bytes32 private constant _DELEGATION_TYPEHASH = keccak256("Delegation(address delegatee,uint256 nonce,uint256 expiry)"); mapping(address => address) private _delegates; mapping(address => Checkpoint[]) private _checkpoints; Checkpoint[] private _totalSupplyCheckpoints; /** * @dev Emitted when an account changes their delegate. */ event DelegateChanged(address indexed delegator, address indexed fromDelegate, address indexed toDelegate); /** * @dev Emitted when a token transfer or delegate change results in changes to an account's voting power. */ event DelegateVotesChanged(address indexed delegate, uint256 previousBalance, uint256 newBalance); /** * @dev Get the `pos`-th checkpoint for `account`. */ function checkpoints(address account, uint32 pos) public view virtual returns (Checkpoint memory) { return _checkpoints[account][pos]; } /** * @dev Get number of checkpoints for `account`. */ function numCheckpoints(address account) public view virtual returns (uint32) { return SafeCast.toUint32(_checkpoints[account].length); } /** * @dev Get the address `account` is currently delegating to. */ function delegates(address account) public view virtual returns (address) { return _delegates[account]; } /** * @dev Gets the current votes balance for `account` */ function getVotes(address account) public view returns (uint256) { uint256 pos = _checkpoints[account].length; return pos == 0 ? 0 : _checkpoints[account][pos - 1].votes; } /** * @dev Retrieve the number of votes for `account` at the end of `blockNumber`. * * Requirements: * * - `blockNumber` must have been already mined */ function getPastVotes(address account, uint256 blockNumber) public view returns (uint256) { require(blockNumber < block.number, "ERC20Votes: block not yet mined"); return _checkpointsLookup(_checkpoints[account], blockNumber); } /** * @dev Retrieve the `totalSupply` at the end of `blockNumber`. Note, this value is the sum of all balances. * It is but NOT the sum of all the delegated votes! * * Requirements: * * - `blockNumber` must have been already mined */ function getPastTotalSupply(uint256 blockNumber) public view returns (uint256) { require(blockNumber < block.number, "ERC20Votes: block not yet mined"); return _checkpointsLookup(_totalSupplyCheckpoints, blockNumber); } /** * @dev Lookup a value in a list of (sorted) checkpoints. */ function _checkpointsLookup(Checkpoint[] storage ckpts, uint256 blockNumber) private view returns (uint256) { // We run a binary search to look for the earliest checkpoint taken after `blockNumber`. // // During the loop, the index of the wanted checkpoint remains in the range [low-1, high). // With each iteration, either `low` or `high` is moved towards the middle of the range to maintain the invariant. // - If the middle checkpoint is after `blockNumber`, we look in [low, mid) // - If the middle checkpoint is before or equal to `blockNumber`, we look in [mid+1, high) // Once we reach a single value (when low == high), we've found the right checkpoint at the index high-1, if not // out of bounds (in which case we're looking too far in the past and the result is 0). // Note that if the latest checkpoint available is exactly for `blockNumber`, we end up with an index that is // past the end of the array, so we technically don't find a checkpoint after `blockNumber`, but it works out // the same. uint256 high = ckpts.length; uint256 low = 0; while (low < high) { uint256 mid = Math.average(low, high); if (ckpts[mid].fromBlock > blockNumber) { high = mid; } else { low = mid + 1; } } return high == 0 ? 0 : ckpts[high - 1].votes; } /** * @dev Delegate votes from the sender to `delegatee`. */ function delegate(address delegatee) public virtual { _delegate(_msgSender(), delegatee); } /** * @dev Delegates votes from signer to `delegatee` */ function delegateBySig( address delegatee, uint256 nonce, uint256 expiry, uint8 v, bytes32 r, bytes32 s ) public virtual { require(block.timestamp <= expiry, "ERC20Votes: signature expired"); address signer = ECDSA.recover( _hashTypedDataV4(keccak256(abi.encode(_DELEGATION_TYPEHASH, delegatee, nonce, expiry))), v, r, s ); require(nonce == _useNonce(signer), "ERC20Votes: invalid nonce"); _delegate(signer, delegatee); } /** * @dev Maximum token supply. Defaults to `type(uint224).max` (2^224^ - 1). */ function _maxSupply() internal view virtual returns (uint224) { return type(uint224).max; } /** * @dev Snapshots the totalSupply after it has been increased. */ function _mint(address account, uint256 amount) internal virtual override { super._mint(account, amount); require(totalSupply() <= _maxSupply(), "ERC20Votes: total supply risks overflowing votes"); _writeCheckpoint(_totalSupplyCheckpoints, _add, amount); } /** * @dev Snapshots the totalSupply after it has been decreased. */ function _burn(address account, uint256 amount) internal virtual override { super._burn(account, amount); _writeCheckpoint(_totalSupplyCheckpoints, _subtract, amount); } /** * @dev Move voting power when tokens are transferred. * * Emits a {DelegateVotesChanged} event. */ function _afterTokenTransfer( address from, address to, uint256 amount ) internal virtual override { super._afterTokenTransfer(from, to, amount); _moveVotingPower(delegates(from), delegates(to), amount); } /** * @dev Change delegation for `delegator` to `delegatee`. * * Emits events {DelegateChanged} and {DelegateVotesChanged}. */ function _delegate(address delegator, address delegatee) internal virtual { address currentDelegate = delegates(delegator); uint256 delegatorBalance = balanceOf(delegator); _delegates[delegator] = delegatee; emit DelegateChanged(delegator, currentDelegate, delegatee); _moveVotingPower(currentDelegate, delegatee, delegatorBalance); } function _moveVotingPower( address src, address dst, uint256 amount ) private { if (src != dst && amount > 0) { if (src != address(0)) { (uint256 oldWeight, uint256 newWeight) = _writeCheckpoint(_checkpoints[src], _subtract, amount); emit DelegateVotesChanged(src, oldWeight, newWeight); } if (dst != address(0)) { (uint256 oldWeight, uint256 newWeight) = _writeCheckpoint(_checkpoints[dst], _add, amount); emit DelegateVotesChanged(dst, oldWeight, newWeight); } } } function _writeCheckpoint( Checkpoint[] storage ckpts, function(uint256, uint256) view returns (uint256) op, uint256 delta ) private returns (uint256 oldWeight, uint256 newWeight) { uint256 pos = ckpts.length; oldWeight = pos == 0 ? 0 : ckpts[pos - 1].votes; newWeight = op(oldWeight, delta); if (pos > 0 && ckpts[pos - 1].fromBlock == block.number) { ckpts[pos - 1].votes = SafeCast.toUint224(newWeight); } else { ckpts.push(Checkpoint({fromBlock: SafeCast.toUint32(block.number), votes: SafeCast.toUint224(newWeight)})); } } function _add(uint256 a, uint256 b) private pure returns (uint256) { return a + b; } function _subtract(uint256 a, uint256 b) private pure returns (uint256) { return a - b; } }// SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-ERC20Permit.sol) pragma solidity ^0.8.0; import "./draft-IERC20Permit.sol"; import "./BANANA20.sol"; import "./draft-EIP712.sol"; import "./ECDSA.sol"; import "./Counters.sol"; /** * @dev Implementation of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612]. * * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by * presenting a message signed by the account. By not relying on `{IERC20-approve}`, the token holder account doesn't * need to send a transaction, and thus is not required to hold Ether at all. * * _Available since v3.4._ */ abstract contract ERC20Permit is ERC20, IERC20Permit, EIP712 { using Counters for Counters.Counter; mapping(address => Counters.Counter) private _nonces; // solhint-disable-next-line var-name-mixedcase bytes32 private immutable _PERMIT_TYPEHASH = keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)"); /** * @dev Initializes the {EIP712} domain separator using the `name` parameter, and setting `version` to `"1"`. * * It's a good idea to use the same `name` that is defined as the ERC20 token name. */ constructor(string memory name) EIP712(name, "1") {} /** * @dev See {IERC20Permit-permit}. */ function permit( address owner, address spender, uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s ) public virtual override { require(block.timestamp <= deadline, "ERC20Permit: expired deadline"); bytes32 structHash = keccak256(abi.encode(_PERMIT_TYPEHASH, owner, spender, value, _useNonce(owner), deadline)); bytes32 hash = _hashTypedDataV4(structHash); address signer = ECDSA.recover(hash, v, r, s); require(signer == owner, "ERC20Permit: invalid signature"); _approve(owner, spender, value); } /** * @dev See {IERC20Permit-nonces}. */ function nonces(address owner) public view virtual override returns (uint256) { return _nonces[owner].current(); } /** * @dev See {IERC20Permit-DOMAIN_SEPARATOR}. */ // solhint-disable-next-line func-name-mixedcase function DOMAIN_SEPARATOR() external view override returns (bytes32) { return _domainSeparatorV4(); } /** * @dev "Consume a nonce": return the current value and increment. * * _Available since v4.1._ */ function _useNonce(address owner) internal virtual returns (uint256 current) { Counters.Counter storage nonce = _nonces[owner]; current = nonce.current(); nonce.increment(); } }// SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (token/ERC20/ERC20.sol) pragma solidity ^0.8.0; import "./IERC20.sol"; import "./IERC20MetaData.sol"; import "./Context.sol"; /** * @dev Implementation of the {IERC20} interface. * * This implementation is agnostic to the way tokens are created. This means * that a supply mechanism has to be added in a derived contract using {_mint}. * For a generic mechanism see {ERC20PresetMinterPauser}. * * TIP: For a detailed writeup see our guide * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How * to implement supply mechanisms]. * * We have followed general OpenZeppelin Contracts guidelines: functions revert * instead returning `false` on failure. This behavior is nonetheless * conventional and does not conflict with the expectations of ERC20 * applications. * * Additionally, an {Approval} event is emitted on calls to {transferFrom}. * This allows applications to reconstruct the allowance for all accounts just * by listening to said events. Other implementations of the EIP may not emit * these events, as it isn't required by the specification. * * Finally, the non-standard {decreaseAllowance} and {increaseAllowance} * functions have been added to mitigate the well-known issues around setting * allowances. See {IERC20-approve}. */ contract ERC20 is Context, IERC20, IERC20Metadata { mapping(address => uint256) private _balances; mapping(address => mapping(address => uint256)) private _allowances; uint256 private _totalSupply; string private _name; string private _symbol; /** * @dev Sets the values for {name} and {symbol}. * * The default value of {decimals} is 18. To select a different value for * {decimals} you should overload it. * * All two of these values are immutable: they can only be set once during * construction. */ constructor(string memory name_, string memory symbol_) { _name = name_; _symbol = symbol_; } /** * @dev Returns the name of the token. */ function name() public view virtual override returns (string memory) { return _name; } /** * @dev Returns the symbol of the token, usually a shorter version of the * name. */ function symbol() public view virtual override returns (string memory) { return _symbol; } /** * @dev Returns the number of decimals used to get its user representation. * For example, if `decimals` equals `2`, a balance of `505` tokens should * be displayed to a user as `5.05` (`505 / 10 ** 2`). * * Tokens usually opt for a value of 18, imitating the relationship between * Ether and Wei. This is the value {ERC20} uses, unless this function is * overridden; * * NOTE: This information is only used for _display_ purposes: it in * no way affects any of the arithmetic of the contract, including * {IERC20-balanceOf} and {IERC20-transfer}. */ function decimals() public view virtual override returns (uint8) { return 9; } /** * @dev See {IERC20-totalSupply}. */ function totalSupply() public view virtual override returns (uint256) { return _totalSupply; } /** * @dev See {IERC20-balanceOf}. */ function balanceOf(address account) public view virtual override returns (uint256) { return _balances[account]; } /** * @dev See {IERC20-transfer}. * * Requirements: * * - `recipient` cannot be the zero address. * - the caller must have a balance of at least `amount`. */ function transfer(address recipient, uint256 amount) public virtual override returns (bool) { _transfer(_msgSender(), recipient, amount); return true; } /** * @dev See {IERC20-allowance}. */ function allowance(address owner, address spender) public view virtual override returns (uint256) { return _allowances[owner][spender]; } /** * @dev See {IERC20-approve}. * * Requirements: * * - `spender` cannot be the zero address. */ function approve(address spender, uint256 amount) public virtual override returns (bool) { _approve(_msgSender(), spender, amount); return true; } /** * @dev See {IERC20-transferFrom}. * * Emits an {Approval} event indicating the updated allowance. This is not * required by the EIP. See the note at the beginning of {ERC20}. * * Requirements: * * - `sender` and `recipient` cannot be the zero address. * - `sender` must have a balance of at least `amount`. * - the caller must have allowance for ``sender``'s tokens of at least * `amount`. */ function transferFrom( address sender, address recipient, uint256 amount ) public virtual override returns (bool) { _transfer(sender, recipient, amount); uint256 currentAllowance = _allowances[sender][_msgSender()]; require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance"); unchecked { _approve(sender, _msgSender(), currentAllowance - amount); } return true; } /** * @dev Atomically increases the allowance granted to `spender` by the caller. * * This is an alternative to {approve} that can be used as a mitigation for * problems described in {IERC20-approve}. * * Emits an {Approval} event indicating the updated allowance. * * Requirements: * * - `spender` cannot be the zero address. */ function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) { _approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue); return true; } /** * @dev Atomically decreases the allowance granted to `spender` by the caller. * * This is an alternative to {approve} that can be used as a mitigation for * problems described in {IERC20-approve}. * * Emits an {Approval} event indicating the updated allowance. * * Requirements: * * - `spender` cannot be the zero address. * - `spender` must have allowance for the caller of at least * `subtractedValue`. */ function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) { uint256 currentAllowance = _allowances[_msgSender()][spender]; require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero"); unchecked { _approve(_msgSender(), spender, currentAllowance - subtractedValue); } return true; } /** * @dev Moves `amount` of tokens from `sender` to `recipient`. * * This internal function is equivalent to {transfer}, and can be used to * e.g. implement automatic token fees, slashing mechanisms, etc. * * Emits a {Transfer} event. * * Requirements: * * - `sender` cannot be the zero address. * - `recipient` cannot be the zero address. * - `sender` must have a balance of at least `amount`. */ function _transfer( address sender, address recipient, uint256 amount ) internal virtual { require(sender != address(0), "ERC20: transfer from the zero address"); require(recipient != address(0), "ERC20: transfer to the zero address"); _beforeTokenTransfer(sender, recipient, amount); uint256 senderBalance = _balances[sender]; require(senderBalance >= amount, "ERC20: transfer amount exceeds balance"); unchecked { _balances[sender] = senderBalance - amount; } _balances[recipient] += amount; emit Transfer(sender, recipient, amount); _afterTokenTransfer(sender, recipient, amount); } /** @dev Creates `amount` tokens and assigns them to `account`, increasing * the total supply. * * Emits a {Transfer} event with `from` set to the zero address. * * Requirements: * * - `account` cannot be the zero address. */ function _mint(address account, uint256 amount) internal virtual { require(account != address(0), "ERC20: mint to the zero address"); _beforeTokenTransfer(address(0), account, amount); _totalSupply += amount; _balances[account] += amount; emit Transfer(address(0), account, amount); _afterTokenTransfer(address(0), account, amount); } /** * @dev Destroys `amount` tokens from `account`, reducing the * total supply. * * Emits a {Transfer} event with `to` set to the zero address. * * Requirements: * * - `account` cannot be the zero address. * - `account` must have at least `amount` tokens. */ function _burn(address account, uint256 amount) internal virtual { require(account != address(0), "ERC20: burn from the zero address"); _beforeTokenTransfer(account, address(0), amount); uint256 accountBalance = _balances[account]; require(accountBalance >= amount, "ERC20: burn amount exceeds balance"); unchecked { _balances[account] = accountBalance - amount; } _totalSupply -= amount; emit Transfer(account, address(0), amount); _afterTokenTransfer(account, address(0), amount); } /** * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens. * * This internal function is equivalent to `approve`, and can be used to * e.g. set automatic allowances for certain subsystems, etc. * * Emits an {Approval} event. * * Requirements: * * - `owner` cannot be the zero address. * - `spender` cannot be the zero address. */ function _approve( address owner, address spender, uint256 amount ) internal virtual { require(owner != address(0), "ERC20: approve from the zero address"); require(spender != address(0), "ERC20: approve to the zero address"); _allowances[owner][spender] = amount; emit Approval(owner, spender, amount); } /** * @dev Hook that is called before any transfer of tokens. This includes * minting and burning. * * Calling conditions: * * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens * will be transferred to `to`. * - when `from` is zero, `amount` tokens will be minted for `to`. * - when `to` is zero, `amount` of ``from``'s tokens will be burned. * - `from` and `to` are never both zero. * * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks]. */ function _beforeTokenTransfer( address from, address to, uint256 amount ) internal virtual {} /** * @dev Hook that is called after any transfer of tokens. This includes * minting and burning. * * Calling conditions: * * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens * has been transferred to `to`. * - when `from` is zero, `amount` tokens have been minted for `to`. * - when `to` is zero, `amount` of ``from``'s tokens have been burned. * - `from` and `to` are never both zero. * * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks]. */ function _afterTokenTransfer( address from, address to, uint256 amount ) internal virtual {} }// SPDX-License-Identifier: MIT pragma solidity ^0.8.0; /* * * Uniswap Router 01 and 02 Interfaces. Needed with Factory * and pair to swap tokens for eth supporting * the fees of the Token * */ interface IUniswapV2Router01 { function factory() external pure returns (address); function WETH() external pure returns (address); function addLiquidity( address tokenA, address tokenB, uint amountADesired, uint amountBDesired, uint amountAMin, uint amountBMin, address to, uint deadline ) external returns (uint amountA, uint amountB, uint liquidity); function addLiquidityETH( address token, uint amountTokenDesired, uint amountTokenMin, uint amountETHMin, address to, uint deadline ) external payable returns (uint amountToken, uint amountETH, uint liquidity); function removeLiquidity( address tokenA, address tokenB, uint liquidity, uint amountAMin, uint amountBMin, address to, uint deadline ) external returns (uint amountA, uint amountB); function removeLiquidityETH( address token, uint liquidity, uint amountTokenMin, uint amountETHMin, address to, uint deadline ) external returns (uint amountToken, uint amountETH); function removeLiquidityWithPermit( address tokenA, address tokenB, uint liquidity, uint amountAMin, uint amountBMin, address to, uint deadline, bool approveMax, uint8 v, bytes32 r, bytes32 s ) external returns (uint amountA, uint amountB); function removeLiquidityETHWithPermit( address token, uint liquidity, uint amountTokenMin, uint amountETHMin, address to, uint deadline, bool approveMax, uint8 v, bytes32 r, bytes32 s ) external returns (uint amountToken, uint amountETH); function swapExactTokensForTokens( uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline ) external returns (uint[] memory amounts); function swapTokensForExactTokens( uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline ) external returns (uint[] memory amounts); function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline) external payable returns (uint[] memory amounts); function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline) external returns (uint[] memory amounts); function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline) external returns (uint[] memory amounts); function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline) external payable returns (uint[] memory amounts); function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB); function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut); function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn); function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts); function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts); } interface IUniswapV2Router02 is IUniswapV2Router01 { function removeLiquidityETHSupportingFeeOnTransferTokens( address token, uint liquidity, uint amountTokenMin, uint amountETHMin, address to, uint deadline ) external returns (uint amountETH); function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens( address token, uint liquidity, uint amountTokenMin, uint amountETHMin, address to, uint deadline, bool approveMax, uint8 v, bytes32 r, bytes32 s ) external returns (uint amountETH); function swapExactTokensForTokensSupportingFeeOnTransferTokens( uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline ) external; function swapExactETHForTokensSupportingFeeOnTransferTokens( uint amountOutMin, address[] calldata path, address to, uint deadline ) external payable; function swapExactTokensForETHSupportingFeeOnTransferTokens( uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline ) external; }// SPDX-License-Identifier: MIT pragma solidity ^0.8.0; /* * * UniswapV2 Pair and Factory Interfaces Needed with Router to swap tokens * for eth supporting the fees of the Token * * */ interface IUniswapV2Pair { event Approval(address indexed owner, address indexed spender, uint value); event Transfer(address indexed from, address indexed to, uint value); function name() external pure returns (string memory); function symbol() external pure returns (string memory); function decimals() external pure returns (uint8); function totalSupply() external view returns (uint); function balanceOf(address owner) external view returns (uint); function allowance(address owner, address spender) external view returns (uint); function approve(address spender, uint value) external returns (bool); function transfer(address to, uint value) external returns (bool); function transferFrom(address from, address to, uint value) external returns (bool); function DOMAIN_SEPARATOR() external view returns (bytes32); function PERMIT_TYPEHASH() external pure returns (bytes32); function nonces(address owner) external view returns (uint); function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external; event Mint(address indexed sender, uint amount0, uint amount1); event Burn(address indexed sender, uint amount0, uint amount1, address indexed to); event Swap( address indexed sender, uint amount0In, uint amount1In, uint amount0Out, uint amount1Out, address indexed to ); event Sync(uint112 reserve0, uint112 reserve1); function MINIMUM_LIQUIDITY() external pure returns (uint); function factory() external view returns (address); function token0() external view returns (address); function token1() external view returns (address); function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast); function price0CumulativeLast() external view returns (uint); function price1CumulativeLast() external view returns (uint); function kLast() external view returns (uint); function mint(address to) external returns (uint liquidity); function burn(address to) external returns (uint amount0, uint amount1); function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external; function skim(address to) external; function sync() external; function initialize(address, address) external; } // Uniswap V2 Factory interface IUniswapV2Factory { event PairCreated(address indexed token0, address indexed token1, address pair, uint); function feeTo() external view returns (address); function feeToSetter() external view returns (address); function getPair(address tokenA, address tokenB) external view returns (address pair); function allPairs(uint) external view returns (address pair); function allPairsLength() external view returns (uint); function createPair(address tokenA, address tokenB) external returns (address pair); function setFeeTo(address) external; function setFeeToSetter(address) external; }// SPDX-License-Identifier: MIT pragma solidity ^0.8.0; /* * A tweaked version of SafeMath from Openzeppelin. * In the jungle we call it LazyMath * * * */ library SafeMath { function add(uint256 a, uint256 b) internal pure returns (uint256) { uint256 c = a + b; require(c >= a, "SafeMath: addition overflow"); return c; } function sub(uint256 a, uint256 b) internal pure returns (uint256) { return sub(a, b, "SafeMath: subtraction overflow"); } function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { require(b <= a, errorMessage); uint256 c = a - b; return c; } function mul(uint256 a, uint256 b) internal pure returns (uint256) { if (a == 0) { return 0; } uint256 c = a * b; require(c / a == b, "SafeMath: multiplication overflow"); return c; } function div(uint256 a, uint256 b) internal pure returns (uint256) { return div(a, b, "SafeMath: division by zero"); } function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { require(b > 0, errorMessage); uint256 c = a / b; // assert(a == b * c + a % b); // There is no case in which this doesn't hold return c; } function mod(uint256 a, uint256 b) internal pure returns (uint256) { return mod(a, b, "SafeMath: modulo by zero"); } function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { require(b != 0, errorMessage); return a % b; } } // Safemath Int256 library SafeMathInt { int256 private constant MIN_INT256 = int256(1) << 255; int256 private constant MAX_INT256 = ~(int256(1) << 255); function mul(int256 a, int256 b) internal pure returns (int256) { int256 c = a * b; require(c != MIN_INT256 || (a & MIN_INT256) != (b & MIN_INT256)); require((b == 0) || (c / b == a)); return c; } function div(int256 a, int256 b) internal pure returns (int256) { require(b != -1 || a != MIN_INT256); return a / b; } function sub(int256 a, int256 b) internal pure returns (int256) { int256 c = a - b; require((b >= 0 && c <= a) || (b < 0 && c > a)); return c; } function add(int256 a, int256 b) internal pure returns (int256) { int256 c = a + b; require((b >= 0 && c >= a) || (b < 0 && c < a)); return c; } function abs(int256 a) internal pure returns (int256) { require(a != MIN_INT256); return a < 0 ? -a : a; } function toUint256Safe(int256 a) internal pure returns (uint256) { require(a >= 0); return uint256(a); } } library SafeMathUint { function toInt256Safe(uint256 a) internal pure returns (int256) { int256 b = int256(a); require(b >= 0); return b; } }// SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (access/Ownable.sol) pragma solidity ^0.8.0; import "./Context.sol"; /** * @dev Contract module which provides a basic access control mechanism, where * there is an account (an owner) that can be granted exclusive access to * specific functions. * * By default, the owner account will be the one that deploys the contract. This * can later be changed with {transferOwnership}. * * This module is used through inheritance. It will make available the modifier * `onlyOwner`, which can be applied to your functions to restrict their use to * the owner. */ abstract contract Ownable is Context { address private _owner; event OwnershipTransferred(address indexed previousOwner, address indexed newOwner); /** * @dev Initializes the contract setting the deployer as the initial owner. */ constructor() { _transferOwnership(_msgSender()); } /** * @dev Returns the address of the current owner. */ function owner() public view virtual returns (address) { return _owner; } /** * @dev Throws if called by any account other than the owner. */ modifier onlyOwner() { require(owner() == _msgSender(), "Ownable: caller is not the owner"); _; } /** * @dev Leaves the contract without owner. It will not be possible to call * `onlyOwner` functions anymore. Can only be called by the current owner. * * NOTE: Renouncing ownership will leave the contract without an owner, * thereby removing any functionality that is only available to the owner. */ function renounceOwnership() public virtual onlyOwner { _transferOwnership(address(0)); } /** * @dev Transfers ownership of the contract to a new account (`newOwner`). * Can only be called by the current owner. */ function transferOwnership(address newOwner) public virtual onlyOwner { require(newOwner != address(0), "Ownable: new owner is the zero address"); _transferOwnership(newOwner); } /** * @dev Transfers ownership of the contract to a new account (`newOwner`). * Internal function without access restriction. */ function _transferOwnership(address newOwner) internal virtual { address oldOwner = _owner; _owner = newOwner; emit OwnershipTransferred(oldOwner, newOwner); } }// SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (utils/Counters.sol) pragma solidity ^0.8.0; /** * @title Counters * @author Matt Condon (@shrugs) * @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number * of elements in a mapping, issuing ERC721 ids, or counting request ids. * * Include with `using Counters for Counters.Counter;` */ library Counters { struct Counter { // This variable should never be directly accessed by users of the library: interactions must be restricted to // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add // this feature: see https://github.com/ethereum/solidity/issues/4637 uint256 _value; // default: 0 } function current(Counter storage counter) internal view returns (uint256) { return counter._value; } function increment(Counter storage counter) internal { unchecked { counter._value += 1; } } function decrement(Counter storage counter) internal { uint256 value = counter._value; require(value > 0, "Counter: decrement overflow"); unchecked { counter._value = value - 1; } } function reset(Counter storage counter) internal { counter._value = 0; } }// SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (utils/cryptography/ECDSA.sol) pragma solidity ^0.8.0; import "./Strings.sol"; /** * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations. * * These functions can be used to verify that a message was signed by the holder * of the private keys of a given address. */ library ECDSA { enum RecoverError { NoError, InvalidSignature, InvalidSignatureLength, InvalidSignatureS, InvalidSignatureV } function _throwError(RecoverError error) private pure { if (error == RecoverError.NoError) { return; // no error: do nothing } else if (error == RecoverError.InvalidSignature) { revert("ECDSA: invalid signature"); } else if (error == RecoverError.InvalidSignatureLength) { revert("ECDSA: invalid signature length"); } else if (error == RecoverError.InvalidSignatureS) { revert("ECDSA: invalid signature 's' value"); } else if (error == RecoverError.InvalidSignatureV) { revert("ECDSA: invalid signature 'v' value"); } } /** * @dev Returns the address that signed a hashed message (`hash`) with * `signature` or error string. This address can then be used for verification purposes. * * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures: * this function rejects them by requiring the `s` value to be in the lower * half order, and the `v` value to be either 27 or 28. * * IMPORTANT: `hash` _must_ be the result of a hash operation for the * verification to be secure: it is possible to craft signatures that * recover to arbitrary addresses for non-hashed data. A safe way to ensure * this is by receiving a hash of the original message (which may otherwise * be too long), and then calling {toEthSignedMessageHash} on it. * * Documentation for signature generation: * - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js] * - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers] * * _Available since v4.3._ */ function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError) { // Check the signature length // - case 65: r,s,v signature (standard) // - case 64: r,vs signature (cf https://eips.ethereum.org/EIPS/eip-2098) _Available since v4.1._ if (signature.length == 65) { bytes32 r; bytes32 s; uint8 v; // ecrecover takes the signature parameters, and the only way to get them // currently is to use assembly. assembly { r := mload(add(signature, 0x20)) s := mload(add(signature, 0x40)) v := byte(0, mload(add(signature, 0x60))) } return tryRecover(hash, v, r, s); } else if (signature.length == 64) { bytes32 r; bytes32 vs; // ecrecover takes the signature parameters, and the only way to get them // currently is to use assembly. assembly { r := mload(add(signature, 0x20)) vs := mload(add(signature, 0x40)) } return tryRecover(hash, r, vs); } else { return (address(0), RecoverError.InvalidSignatureLength); } } /** * @dev Returns the address that signed a hashed message (`hash`) with * `signature`. This address can then be used for verification purposes. * * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures: * this function rejects them by requiring the `s` value to be in the lower * half order, and the `v` value to be either 27 or 28. * * IMPORTANT: `hash` _must_ be the result of a hash operation for the * verification to be secure: it is possible to craft signatures that * recover to arbitrary addresses for non-hashed data. A safe way to ensure * this is by receiving a hash of the original message (which may otherwise * be too long), and then calling {toEthSignedMessageHash} on it. */ function recover(bytes32 hash, bytes memory signature) internal pure returns (address) { (address recovered, RecoverError error) = tryRecover(hash, signature); _throwError(error); return recovered; } /** * @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately. * * See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures] * * _Available since v4.3._ */ function tryRecover( bytes32 hash, bytes32 r, bytes32 vs ) internal pure returns (address, RecoverError) { bytes32 s; uint8 v; assembly { s := and(vs, 0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff) v := add(shr(255, vs), 27) } return tryRecover(hash, v, r, s); } /** * @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately. * * _Available since v4.2._ */ function recover( bytes32 hash, bytes32 r, bytes32 vs ) internal pure returns (address) { (address recovered, RecoverError error) = tryRecover(hash, r, vs); _throwError(error); return recovered; } /** * @dev Overload of {ECDSA-tryRecover} that receives the `v`, * `r` and `s` signature fields separately. * * _Available since v4.3._ */ function tryRecover( bytes32 hash, uint8 v, bytes32 r, bytes32 s ) internal pure returns (address, RecoverError) { // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines // the valid range for s in (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): v ∈ {27, 28}. Most // signatures from current libraries generate a unique signature with an s-value in the lower half order. // // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept // these malleable signatures as well. if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) { return (address(0), RecoverError.InvalidSignatureS); } if (v != 27 && v != 28) { return (address(0), RecoverError.InvalidSignatureV); } // If the signature is valid (and not malleable), return the signer address address signer = ecrecover(hash, v, r, s); if (signer == address(0)) { return (address(0), RecoverError.InvalidSignature); } return (signer, RecoverError.NoError); } /** * @dev Overload of {ECDSA-recover} that receives the `v`, * `r` and `s` signature fields separately. */ function recover( bytes32 hash, uint8 v, bytes32 r, bytes32 s ) internal pure returns (address) { (address recovered, RecoverError error) = tryRecover(hash, v, r, s); _throwError(error); return recovered; } /** * @dev Returns an Ethereum Signed Message, created from a `hash`. This * produces hash corresponding to the one signed with the * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`] * JSON-RPC method as part of EIP-191. * * See {recover}. */ function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) { // 32 is the length in bytes of hash, // enforced by the type signature above return keccak256(abi.encodePacked("\\x19Ethereum Signed Message:\ 32", hash)); } /** * @dev Returns an Ethereum Signed Message, created from `s`. This * produces hash corresponding to the one signed with the * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`] * JSON-RPC method as part of EIP-191. * * See {recover}. */ function toEthSignedMessageHash(bytes memory s) internal pure returns (bytes32) { return keccak256(abi.encodePacked("\\x19Ethereum Signed Message:\ ", Strings.toString(s.length), s)); } /** * @dev Returns an Ethereum Signed Typed Data, created from a * `domainSeparator` and a `structHash`. This produces hash corresponding * to the one signed with the * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`] * JSON-RPC method as part of EIP-712. * * See {recover}. */ function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32) { return keccak256(abi.encodePacked("\\x19\\x01", domainSeparator, structHash)); } }// SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (utils/cryptography/draft-EIP712.sol) pragma solidity ^0.8.0; import "./ECDSA.sol"; /** * @dev https://eips.ethereum.org/EIPS/eip-712[EIP 712] is a standard for hashing and signing of typed structured data. * * The encoding specified in the EIP is very generic, and such a generic implementation in Solidity is not feasible, * thus this contract does not implement the encoding itself. Protocols need to implement the type-specific encoding * they need in their contracts using a combination of `abi.encode` and `keccak256`. * * This contract implements the EIP 712 domain separator ({_domainSeparatorV4}) that is used as part of the encoding * scheme, and the final step of the encoding to obtain the message digest that is then signed via ECDSA * ({_hashTypedDataV4}). * * The implementation of the domain separator was designed to be as efficient as possible while still properly updating * the chain id to protect against replay attacks on an eventual fork of the chain. * * NOTE: This contract implements the version of the encoding known as "v4", as implemented by the JSON RPC method * https://docs.metamask.io/guide/signing-data.html[`eth_signTypedDataV4` in MetaMask]. * * _Available since v3.4._ */ abstract contract EIP712 { /* solhint-disable var-name-mixedcase */ // Cache the domain separator as an immutable value, but also store the chain id that it corresponds to, in order to // invalidate the cached domain separator if the chain id changes. bytes32 private immutable _CACHED_DOMAIN_SEPARATOR; uint256 private immutable _CACHED_CHAIN_ID; address private immutable _CACHED_THIS; bytes32 private immutable _HASHED_NAME; bytes32 private immutable _HASHED_VERSION; bytes32 private immutable _TYPE_HASH; /* solhint-enable var-name-mixedcase */ /** * @dev Initializes the domain separator and parameter caches. * * The meaning of `name` and `version` is specified in * https://eips.ethereum.org/EIPS/eip-712#definition-of-domainseparator[EIP 712]: * * - `name`: the user readable name of the signing domain, i.e. the name of the DApp or the protocol. * - `version`: the current major version of the signing domain. * * NOTE: These parameters cannot be changed except through a xref:learn::upgrading-smart-contracts.adoc[smart * contract upgrade]. */ constructor(string memory name, string memory version) { bytes32 hashedName = keccak256(bytes(name)); bytes32 hashedVersion = keccak256(bytes(version)); bytes32 typeHash = keccak256( "EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)" ); _HASHED_NAME = hashedName; _HASHED_VERSION = hashedVersion; _CACHED_CHAIN_ID = block.chainid; _CACHED_DOMAIN_SEPARATOR = _buildDomainSeparator(typeHash, hashedName, hashedVersion); _CACHED_THIS = address(this); _TYPE_HASH = typeHash; } /** * @dev Returns the domain separator for the current chain. */ function _domainSeparatorV4() internal view returns (bytes32) { if (address(this) == _CACHED_THIS && block.chainid == _CACHED_CHAIN_ID) { return _CACHED_DOMAIN_SEPARATOR; } else { return _buildDomainSeparator(_TYPE_HASH, _HASHED_NAME, _HASHED_VERSION); } } function _buildDomainSeparator( bytes32 typeHash, bytes32 nameHash, bytes32 versionHash ) private view returns (bytes32) { return keccak256(abi.encode(typeHash, nameHash, versionHash, block.chainid, address(this))); } /** * @dev Given an already https://eips.ethereum.org/EIPS/eip-712#definition-of-hashstruct[hashed struct], this * function returns the hash of the fully encoded EIP712 message for this domain. * * This hash can be used together with {ECDSA-recover} to obtain the signer of a message. For example: * * ```solidity * bytes32 digest = _hashTypedDataV4(keccak256(abi.encode( * keccak256("Mail(address to,string contents)"), * mailTo, * keccak256(bytes(mailContents)) * ))); * address signer = ECDSA.recover(digest, signature); * ``` */ function _hashTypedDataV4(bytes32 structHash) internal view virtual returns (bytes32) { return ECDSA.toTypedDataHash(_domainSeparatorV4(), structHash); } } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-IERC20Permit.sol) pragma solidity ^0.8.0; /** * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612]. * * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't * need to send a transaction, and thus is not required to hold Ether at all. */ interface IERC20Permit { /** * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens, * given ``owner``'s signed approval. * * IMPORTANT: The same issues {IERC20-approve} has related to transaction * ordering also apply here. * * Emits an {Approval} event. * * Requirements: * * - `spender` cannot be the zero address. * - `deadline` must be a timestamp in the future. * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner` * over the EIP712-formatted function arguments. * - the signature must use ``owner``'s current nonce (see {nonces}). * * For more information on the signature format, see the * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP * section]. */ function permit( address owner, address spender, uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s ) external; /** * @dev Returns the current nonce for `owner`. This value must be * included whenever a signature is generated for {permit}. * * Every successful call to {permit} increases ``owner``'s nonce by one. This * prevents a signature from being used multiple times. */ function nonces(address owner) external view returns (uint256); /** * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}. */ // solhint-disable-next-line func-name-mixedcase function DOMAIN_SEPARATOR() external view returns (bytes32); }// SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (utils/Context.sol) pragma solidity ^0.8.0; /** * @dev Provides information about the current execution context, including the * sender of the transaction and its data. While these are generally available * via msg.sender and msg.data, they should not be accessed in such a direct * manner, since when dealing with meta-transactions the account sending and * paying for execution may not be the actual sender (as far as an application * is concerned). * * This contract is only required for intermediate, library-like contracts. */ abstract contract Context { function _msgSender() internal view virtual returns (address) { return msg.sender; } function _msgData() internal view virtual returns (bytes calldata) { return msg.data; } }// SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (utils/math/SafeCast.sol) pragma solidity ^0.8.0; /** * @dev Wrappers over Solidity's uintXX/intXX casting operators with added overflow * checks. * * Downcasting from uint256/int256 in Solidity does not revert on overflow. This can * easily result in undesired exploitation or bugs, since developers usually * assume that overflows raise errors. `SafeCast` restores this intuition by * reverting the transaction when such an operation overflows. * * Using this library instead of the unchecked operations eliminates an entire * class of bugs, so it's recommended to use it always. * * Can be combined with {SafeMath} and {SignedSafeMath} to extend it to smaller types, by performing * all math on `uint256` and `int256` and then downcasting. */ library SafeCast { /** * @dev Returns the downcasted uint224 from uint256, reverting on * overflow (when the input is greater than largest uint224). * * Counterpart to Solidity's `uint224` operator. * * Requirements: * * - input must fit into 224 bits */ function toUint224(uint256 value) internal pure returns (uint224) { require(value <= type(uint224).max, "SafeCast: value doesn't fit in 224 bits"); return uint224(value); } /** * @dev Returns the downcasted uint128 from uint256, reverting on * overflow (when the input is greater than largest uint128). * * Counterpart to Solidity's `uint128` operator. * * Requirements: * * - input must fit into 128 bits */ function toUint128(uint256 value) internal pure returns (uint128) { require(value <= type(uint128).max, "SafeCast: value doesn't fit in 128 bits"); return uint128(value); } /** * @dev Returns the downcasted uint96 from uint256, reverting on * overflow (when the input is greater than largest uint96). * * Counterpart to Solidity's `uint96` operator. * * Requirements: * * - input must fit into 96 bits */ function toUint96(uint256 value) internal pure returns (uint96) { require(value <= type(uint96).max, "SafeCast: value doesn't fit in 96 bits"); return uint96(value); } /** * @dev Returns the downcasted uint64 from uint256, reverting on * overflow (when the input is greater than largest uint64). * * Counterpart to Solidity's `uint64` operator. * * Requirements: * * - input must fit into 64 bits */ function toUint64(uint256 value) internal pure returns (uint64) { require(value <= type(uint64).max, "SafeCast: value doesn't fit in 64 bits"); return uint64(value); } /** * @dev Returns the downcasted uint32 from uint256, reverting on * overflow (when the input is greater than largest uint32). * * Counterpart to Solidity's `uint32` operator. * * Requirements: * * - input must fit into 32 bits */ function toUint32(uint256 value) internal pure returns (uint32) { require(value <= type(uint32).max, "SafeCast: value doesn't fit in 32 bits"); return uint32(value); } /** * @dev Returns the downcasted uint16 from uint256, reverting on * overflow (when the input is greater than largest uint16). * * Counterpart to Solidity's `uint16` operator. * * Requirements: * * - input must fit into 16 bits */ function toUint16(uint256 value) internal pure returns (uint16) { require(value <= type(uint16).max, "SafeCast: value doesn't fit in 16 bits"); return uint16(value); } /** * @dev Returns the downcasted uint8 from uint256, reverting on * overflow (when the input is greater than largest uint8). * * Counterpart to Solidity's `uint8` operator. * * Requirements: * * - input must fit into 8 bits. */ function toUint8(uint256 value) internal pure returns (uint8) { require(value <= type(uint8).max, "SafeCast: value doesn't fit in 8 bits"); return uint8(value); } /** * @dev Converts a signed int256 into an unsigned uint256. * * Requirements: * * - input must be greater than or equal to 0. */ function toUint256(int256 value) internal pure returns (uint256) { require(value >= 0, "SafeCast: value must be positive"); return uint256(value); } /** * @dev Returns the downcasted int128 from int256, reverting on * overflow (when the input is less than smallest int128 or * greater than largest int128). * * Counterpart to Solidity's `int128` operator. * * Requirements: * * - input must fit into 128 bits * * _Available since v3.1._ */ function toInt128(int256 value) internal pure returns (int128) { require(value >= type(int128).min && value <= type(int128).max, "SafeCast: value doesn't fit in 128 bits"); return int128(value); } /** * @dev Returns the downcasted int64 from int256, reverting on * overflow (when the input is less than smallest int64 or * greater than largest int64). * * Counterpart to Solidity's `int64` operator. * * Requirements: * * - input must fit into 64 bits * * _Available since v3.1._ */ function toInt64(int256 value) internal pure returns (int64) { require(value >= type(int64).min && value <= type(int64).max, "SafeCast: value doesn't fit in 64 bits"); return int64(value); } /** * @dev Returns the downcasted int32 from int256, reverting on * overflow (when the input is less than smallest int32 or * greater than largest int32). * * Counterpart to Solidity's `int32` operator. * * Requirements: * * - input must fit into 32 bits * * _Available since v3.1._ */ function toInt32(int256 value) internal pure returns (int32) { require(value >= type(int32).min && value <= type(int32).max, "SafeCast: value doesn't fit in 32 bits"); return int32(value); } /** * @dev Returns the downcasted int16 from int256, reverting on * overflow (when the input is less than smallest int16 or * greater than largest int16). * * Counterpart to Solidity's `int16` operator. * * Requirements: * * - input must fit into 16 bits * * _Available since v3.1._ */ function toInt16(int256 value) internal pure returns (int16) { require(value >= type(int16).min && value <= type(int16).max, "SafeCast: value doesn't fit in 16 bits"); return int16(value); } /** * @dev Returns the downcasted int8 from int256, reverting on * overflow (when the input is less than smallest int8 or * greater than largest int8). * * Counterpart to Solidity's `int8` operator. * * Requirements: * * - input must fit into 8 bits. * * _Available since v3.1._ */ function toInt8(int256 value) internal pure returns (int8) { require(value >= type(int8).min && value <= type(int8).max, "SafeCast: value doesn't fit in 8 bits"); return int8(value); } /** * @dev Converts an unsigned uint256 into a signed int256. * * Requirements: * * - input must be less than or equal to maxInt256. */ function toInt256(uint256 value) internal pure returns (int256) { // Note: Unsafe cast below is okay because `type(int256).max` is guaranteed to be positive require(value <= uint256(type(int256).max), "SafeCast: value doesn't fit in an int256"); return int256(value); } } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (utils/math/Math.sol) pragma solidity ^0.8.0; /** * @dev Standard math utilities missing in the Solidity language. */ library Math { /** * @dev Returns the largest of two numbers. */ function max(uint256 a, uint256 b) internal pure returns (uint256) { return a >= b ? a : b; } /** * @dev Returns the smallest of two numbers. */ function min(uint256 a, uint256 b) internal pure returns (uint256) { return a < b ? a : b; } /** * @dev Returns the average of two numbers. The result is rounded towards * zero. */ function average(uint256 a, uint256 b) internal pure returns (uint256) { // (a + b) / 2 can overflow. return (a & b) + (a ^ b) / 2; } /** * @dev Returns the ceiling of the division of two numbers. * * This differs from standard division with `/` in that it rounds up instead * of rounding down. */ function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) { // (a + b - 1) / b can overflow on addition, so we distribute. return a / b + (a % b == 0 ? 0 : 1); } }// SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol) pragma solidity ^0.8.0; import "./IERC20.sol"; /** * @dev Interface for the optional metadata functions from the ERC20 standard. * * _Available since v4.1._ */ interface IERC20Metadata is IERC20 { /** * @dev Returns the name of the token. */ function name() external view returns (string memory); /** * @dev Returns the symbol of the token. */ function symbol() external view returns (string memory); /** * @dev Returns the decimals places of the token. */ function decimals() external view returns (uint8); }// SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (token/ERC20/IERC20.sol) pragma solidity ^0.8.0; /** * @dev Interface of the ERC20 standard as defined in the EIP. */ interface IERC20 { /** * @dev Returns the amount of tokens in existence. */ function totalSupply() external view returns (uint256); /** * @dev Returns the amount of tokens owned by `account`. */ function balanceOf(address account) external view returns (uint256); /** * @dev Moves `amount` tokens from the caller's account to `recipient`. * * Returns a boolean value indicating whether the operation succeeded. * * Emits a {Transfer} event. */ function transfer(address recipient, uint256 amount) external returns (bool); /** * @dev Returns the remaining number of tokens that `spender` will be * allowed to spend on behalf of `owner` through {transferFrom}. This is * zero by default. * * This value changes when {approve} or {transferFrom} are called. */ function allowance(address owner, address spender) external view returns (uint256); /** * @dev Sets `amount` as the allowance of `spender` over the caller's tokens. * * Returns a boolean value indicating whether the operation succeeded. * * IMPORTANT: Beware that changing an allowance with this method brings the risk * that someone may use both the old and the new allowance by unfortunate * transaction ordering. One possible solution to mitigate this race * condition is to first reduce the spender's allowance to 0 and set the * desired value afterwards: * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729 * * Emits an {Approval} event. */ function approve(address spender, uint256 amount) external returns (bool); /** * @dev Moves `amount` tokens from `sender` to `recipient` using the * allowance mechanism. `amount` is then deducted from the caller's * allowance. * * Returns a boolean value indicating whether the operation succeeded. * * Emits a {Transfer} event. */ function transferFrom( address sender, address recipient, uint256 amount ) external returns (bool); /** * @dev Emitted when `value` tokens are moved from one account (`from`) to * another (`to`). * * Note that `value` may be zero. */ event Transfer(address indexed from, address indexed to, uint256 value); /** * @dev Emitted when the allowance of a `spender` for an `owner` is set by * a call to {approve}. `value` is the new allowance. */ event Approval(address indexed owner, address indexed spender, uint256 value); }// SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (utils/Strings.sol) pragma solidity ^0.8.0; /** * @dev String operations. */ library Strings { bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef"; /** * @dev Converts a `uint256` to its ASCII `string` decimal representation. */ function toString(uint256 value) internal pure returns (string memory) { // Inspired by OraclizeAPI's implementation - MIT licence // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol if (value == 0) { return "0"; } uint256 temp = value; uint256 digits; while (temp != 0) { digits++; temp /= 10; } bytes memory buffer = new bytes(digits); while (value != 0) { digits -= 1; buffer[digits] = bytes1(uint8(48 + uint256(value % 10))); value /= 10; } return string(buffer); } /** * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation. */ function toHexString(uint256 value) internal pure returns (string memory) { if (value == 0) { return "0x00"; } uint256 temp = value; uint256 length = 0; while (temp != 0) { length++; temp >>= 8; } return toHexString(value, length); } /** * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length. */ function toHexString(uint256 value, uint256 length) internal pure returns (string memory) { bytes memory buffer = new bytes(2 * length + 2); buffer[0] = "0"; buffer[1] = "x"; for (uint256 i = 2 * length + 1; i > 1; --i) { buffer[i] = _HEX_SYMBOLS[value & 0xf]; value >>= 4; } require(value == 0, "Strings: hex length insufficient"); return string(buffer); } }