A compilation of patterns and best practices for the smart contract programming language Solidity

Solidity/EVM smart contract security auditor — 104 vulnerability patterns, 8 tools, 100% CTF + EVMBench benchmark (120/120)

📝 Patterns found in smart contract oriented language Solidity.

Architectural pattern for writing dynamic smart contracts in Solidity.

Smart Contracts Design Patterns in the Ethereum Ecosystem and Solidity Code

Smart-Contract Patterns written in Solidity, collated for community good

Common Solidity contract patterns, based on OpenZeppelin's contract library, implemented in the Huff language

Call graph-based analysis tools for Solidity smart contracts. Visualize contract interactions, generate Foundry tests, analyze storage patterns, and trace execution paths.

A Smart Contract implementing the escrow blockchain design pattern. Written in Solidity and deployed in the Ethereum network.

A lightweight static analysis engine for Solidity smart contracts. Extracts code features, detects dangerous patterns (delegatecall, tx.origin, call.value), computes heuristic risk scores, and classifies contracts into Low/Medium/High risk levels. Includes multiple example vulnerabilities and a clean CLI for rapid security assessment.

A deep technical article exploring how AI, feature engineering, and static smart-contract analysis uncover rugpull risks before humans detect them. Covers Solidity pattern mining, mint abuse detection, blacklist/fee manipulation signals, ML-inspired scoring models, and how to quantify ERC-20 token scam probability.

A practical, research-friendly toolkit demonstrating how Python can read, parse, and analyze Solidity smart contracts using feature-engineering techniques. Extracts structural and security-relevant signals from Solidity code, detects risky patterns, builds interpretable features, and forms the basis for heuristic or ML-driven security analysis.

A hybrid Solidity + Python security toolkit that analyzes ERC-20 token contracts using static pattern extraction and ML-inspired scoring. Detects mint backdoors, blacklist controls, fee manipulation, trading locks, and rugpull mechanics. Outputs interpretable risk scores, labels, and structured features for deeper analysis.

Initial Coin Offering (ICO) smart contract written in Solidity. This repository budling with hardhat and openzeppelin with best practice code pattern.

Solidity upgradeable contracts proxy based on unstructured storage pattern

A collection of best practices and design patterns for writing secure and efficient Solidity smart contracts. Covers upgradeability, proxy patterns, and gas optimization.

/** *Submitted for verification at BscScan.com on 2021-03-01 */ /** *Submitted for verification at BscScan.com on 2021-03-01 */ /** #BEE #LIQ+#RFI+#SHIB+#DOGE = #BEE #SAFEMOON features: 3% fee auto add to the liquidity pool to locked forever when selling 2% fee auto distribute to all holders I created a black hole so #Bee token will deflate itself in supply with every transaction 50% Supply is burned at start. */ pragma solidity ^0.6.12; // SPDX-License-Identifier: Unlicensed interface IERC20 { 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); } /** * @dev Wrappers over Solidity's arithmetic operations with added overflow * checks. * * Arithmetic operations in Solidity wrap on overflow. This can easily result * in bugs, because programmers usually assume that an overflow raises an * error, which is the standard behavior in high level programming languages. * `SafeMath` restores this intuition by reverting the transaction when 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. */ library SafeMath { /** * @dev Returns the addition of two unsigned integers, reverting on * overflow. * * Counterpart to Solidity's `+` operator. * * Requirements: * * - Addition cannot overflow. */ function add(uint256 a, uint256 b) internal pure returns (uint256) { uint256 c = a + b; require(c >= a, "SafeMath: addition overflow"); return c; } /** * @dev Returns the subtraction of two unsigned integers, reverting on * overflow (when the result is negative). * * Counterpart to Solidity's `-` operator. * * Requirements: * * - Subtraction cannot overflow. */ function sub(uint256 a, uint256 b) internal pure returns (uint256) { return sub(a, b, "SafeMath: subtraction overflow"); } /** * @dev Returns the subtraction of two unsigned integers, reverting with custom message on * overflow (when the result is negative). * * Counterpart to Solidity's `-` operator. * * Requirements: * * - Subtraction cannot overflow. */ function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { require(b <= a, errorMessage); uint256 c = a - b; return c; } /** * @dev Returns the multiplication of two unsigned integers, reverting on * overflow. * * Counterpart to Solidity's `*` operator. * * Requirements: * * - Multiplication cannot overflow. */ function mul(uint256 a, uint256 b) internal pure returns (uint256) { // Gas optimization: this is cheaper than requiring 'a' not being zero, but the // benefit is lost if 'b' is also tested. // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522 if (a == 0) { return 0; } uint256 c = a * b; require(c / a == b, "SafeMath: multiplication overflow"); return c; } /** * @dev Returns the integer division of two unsigned integers. Reverts on * division by zero. The result is rounded towards zero. * * Counterpart to Solidity's `/` operator. Note: this function uses a * `revert` opcode (which leaves remaining gas untouched) while Solidity * uses an invalid opcode to revert (consuming all remaining gas). * * Requirements: * * - The divisor cannot be zero. */ function div(uint256 a, uint256 b) internal pure returns (uint256) { return div(a, b, "SafeMath: division by zero"); } /** * @dev Returns the integer division of two unsigned integers. Reverts with custom message on * division by zero. The result is rounded towards zero. * * Counterpart to Solidity's `/` operator. Note: this function uses a * `revert` opcode (which leaves remaining gas untouched) while Solidity * uses an invalid opcode to revert (consuming all remaining gas). * * Requirements: * * - The divisor cannot be 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; } /** * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo), * Reverts when dividing by zero. * * Counterpart to Solidity's `%` operator. This function uses a `revert` * opcode (which leaves remaining gas untouched) while Solidity uses an * invalid opcode to revert (consuming all remaining gas). * * Requirements: * * - The divisor cannot be zero. */ function mod(uint256 a, uint256 b) internal pure returns (uint256) { return mod(a, b, "SafeMath: modulo by zero"); } /** * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo), * Reverts with custom message when dividing by zero. * * Counterpart to Solidity's `%` operator. This function uses a `revert` * opcode (which leaves remaining gas untouched) while Solidity uses an * invalid opcode to revert (consuming all remaining gas). * * Requirements: * * - The divisor cannot be zero. */ function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { require(b != 0, errorMessage); return a % b; } } abstract contract Context { function _msgSender() internal view virtual returns (address payable) { return msg.sender; } function _msgData() internal view virtual returns (bytes memory) { this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691 return msg.data; } } /** * @dev Collection of functions related to the address type */ library Address { /** * @dev Returns true if `account` is a contract. * * [IMPORTANT] * ==== * It is unsafe to assume that an address for which this function returns * false is an externally-owned account (EOA) and not a contract. * * Among others, `isContract` will return false for the following * types of addresses: * * - an externally-owned account * - a contract in construction * - an address where a contract will be created * - an address where a contract lived, but was destroyed * ==== */ function isContract(address account) internal view returns (bool) { // According to EIP-1052, 0x0 is the value returned for not-yet created accounts // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned // for accounts without code, i.e. `keccak256('')` bytes32 codehash; bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470; // solhint-disable-next-line no-inline-assembly assembly { codehash := extcodehash(account) } return (codehash != accountHash && codehash != 0x0); } /** * @dev Replacement for Solidity's `transfer`: sends `amount` wei to * `recipient`, forwarding all available gas and reverting on errors. * * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost * of certain opcodes, possibly making contracts go over the 2300 gas limit * imposed by `transfer`, making them unable to receive funds via * `transfer`. {sendValue} removes this limitation. * * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more]. * * IMPORTANT: because control is transferred to `recipient`, care must be * taken to not create reentrancy vulnerabilities. Consider using * {ReentrancyGuard} or the * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern]. */ function sendValue(address payable recipient, uint256 amount) internal { require(address(this).balance >= amount, "Address: insufficient balance"); // solhint-disable-next-line avoid-low-level-calls, avoid-call-value (bool success, ) = recipient.call{ value: amount }(""); require(success, "Address: unable to send value, recipient may have reverted"); } /** * @dev Performs a Solidity function call using a low level `call`. A * plain`call` is an unsafe replacement for a function call: use this * function instead. * * If `target` reverts with a revert reason, it is bubbled up by this * function (like regular Solidity function calls). * * Returns the raw returned data. To convert to the expected return value, * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`]. * * Requirements: * * - `target` must be a contract. * - calling `target` with `data` must not revert. * * _Available since v3.1._ */ function functionCall(address target, bytes memory data) internal returns (bytes memory) { return functionCall(target, data, "Address: low-level call failed"); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with * `errorMessage` as a fallback revert reason when `target` reverts. * * _Available since v3.1._ */ function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) { return _functionCallWithValue(target, data, 0, errorMessage); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], * but also transferring `value` wei to `target`. * * Requirements: * * - the calling contract must have an ETH balance of at least `value`. * - the called Solidity function must be `payable`. * * _Available since v3.1._ */ function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) { return functionCallWithValue(target, data, value, "Address: low-level call with value failed"); } /** * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but * with `errorMessage` as a fallback revert reason when `target` reverts. * * _Available since v3.1._ */ function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) { require(address(this).balance >= value, "Address: insufficient balance for call"); return _functionCallWithValue(target, data, value, errorMessage); } function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) { require(isContract(target), "Address: call to non-contract"); // solhint-disable-next-line avoid-low-level-calls (bool success, bytes memory returndata) = target.call{ value: weiValue }(data); if (success) { return returndata; } else { // Look for revert reason and bubble it up if present if (returndata.length > 0) { // The easiest way to bubble the revert reason is using memory via assembly // solhint-disable-next-line no-inline-assembly assembly { let returndata_size := mload(returndata) revert(add(32, returndata), returndata_size) } } else { revert(errorMessage); } } } } /** * @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. */ contract Ownable is Context { address private _owner; address private _previousOwner; uint256 private _lockTime; event OwnershipTransferred(address indexed previousOwner, address indexed newOwner); /** * @dev Initializes the contract setting the deployer as the initial owner. */ constructor () internal { address msgSender = _msgSender(); _owner = msgSender; emit OwnershipTransferred(address(0), msgSender); } /** * @dev Returns the address of the current owner. */ function owner() public view 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 { emit OwnershipTransferred(_owner, address(0)); _owner = 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"); emit OwnershipTransferred(_owner, newOwner); _owner = newOwner; } function geUnlockTime() public view returns (uint256) { return _lockTime; } //Locks the contract for owner for the amount of time provided function lock(uint256 time) public virtual onlyOwner { _previousOwner = _owner; _owner = address(0); _lockTime = now + time; emit OwnershipTransferred(_owner, address(0)); } //Unlocks the contract for owner when _lockTime is exceeds function unlock() public virtual { require(_previousOwner == msg.sender, "You don't have permission to unlock"); require(now > _lockTime , "Contract is locked until 7 days"); emit OwnershipTransferred(_owner, _previousOwner); _owner = _previousOwner; } } // pragma solidity >=0.5.0; 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; } // pragma solidity >=0.5.0; 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; } // pragma solidity >=0.6.2; 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); } // pragma solidity >=0.6.2; 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; } contract SafeMoon is Context, IERC20, Ownable { using SafeMath for uint256; using Address for address; mapping (address => uint256) private _rOwned; mapping (address => uint256) private _tOwned; mapping (address => mapping (address => uint256)) private _allowances; mapping (address => bool) private _isExcludedFromFee; mapping (address => bool) private _isExcluded; address[] private _excluded; uint256 private constant MAX = ~uint256(0); uint256 private _tTotal = 1000000000 * 10**6 * 10**9; uint256 private _rTotal = (MAX - (MAX % _tTotal)); uint256 private _tFeeTotal; string private _name = "SafeMoon"; string private _symbol = "SAFEMOON"; uint8 private _decimals = 9; uint256 public _taxFee = 5; uint256 private _previousTaxFee = _taxFee; uint256 public _liquidityFee = 5; uint256 private _previousLiquidityFee = _liquidityFee; IUniswapV2Router02 public immutable uniswapV2Router; address public immutable uniswapV2Pair; bool inSwapAndLiquify; bool public swapAndLiquifyEnabled = true; uint256 public _maxTxAmount = 5000000 * 10**6 * 10**9; uint256 private numTokensSellToAddToLiquidity = 500000 * 10**6 * 10**9; event MinTokensBeforeSwapUpdated(uint256 minTokensBeforeSwap); event SwapAndLiquifyEnabledUpdated(bool enabled); event SwapAndLiquify( uint256 tokensSwapped, uint256 ethReceived, uint256 tokensIntoLiqudity ); modifier lockTheSwap { inSwapAndLiquify = true; _; inSwapAndLiquify = false; } constructor () public { _rOwned[_msgSender()] = _rTotal; IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(0x05fF2B0DB69458A0750badebc4f9e13aDd608C7F); // Create a uniswap pair for this new token uniswapV2Pair = IUniswapV2Factory(_uniswapV2Router.factory()) .createPair(address(this), _uniswapV2Router.WETH()); // set the rest of the contract variables uniswapV2Router = _uniswapV2Router; //exclude owner and this contract from fee _isExcludedFromFee[owner()] = true; _isExcludedFromFee[address(this)] = true; emit Transfer(address(0), _msgSender(), _tTotal); } function name() public view returns (string memory) { return _name; } function symbol() public view returns (string memory) { return _symbol; } function decimals() public view returns (uint8) { return _decimals; } function totalSupply() public view override returns (uint256) { return _tTotal; } function balanceOf(address account) public view override returns (uint256) { if (_isExcluded[account]) return _tOwned[account]; return tokenFromReflection(_rOwned[account]); } function transfer(address recipient, uint256 amount) public override returns (bool) { _transfer(_msgSender(), recipient, amount); return true; } function allowance(address owner, address spender) public view override returns (uint256) { return _allowances[owner][spender]; } function approve(address spender, uint256 amount) public override returns (bool) { _approve(_msgSender(), spender, amount); return true; } function transferFrom(address sender, address recipient, uint256 amount) public override returns (bool) { _transfer(sender, recipient, amount); _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance")); return true; } function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) { _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue)); return true; } function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) { _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero")); return true; } function isExcludedFromReward(address account) public view returns (bool) { return _isExcluded[account]; } function totalFees() public view returns (uint256) { return _tFeeTotal; } function deliver(uint256 tAmount) public { address sender = _msgSender(); require(!_isExcluded[sender], "Excluded addresses cannot call this function"); (uint256 rAmount,,,,,) = _getValues(tAmount); _rOwned[sender] = _rOwned[sender].sub(rAmount); _rTotal = _rTotal.sub(rAmount); _tFeeTotal = _tFeeTotal.add(tAmount); } function reflectionFromToken(uint256 tAmount, bool deductTransferFee) public view returns(uint256) { require(tAmount <= _tTotal, "Amount must be less than supply"); if (!deductTransferFee) { (uint256 rAmount,,,,,) = _getValues(tAmount); return rAmount; } else { (,uint256 rTransferAmount,,,,) = _getValues(tAmount); return rTransferAmount; } } function tokenFromReflection(uint256 rAmount) public view returns(uint256) { require(rAmount <= _rTotal, "Amount must be less than total reflections"); uint256 currentRate = _getRate(); return rAmount.div(currentRate); } function excludeFromReward(address account) public onlyOwner() { // require(account != 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D, 'We can not exclude Uniswap router.'); require(!_isExcluded[account], "Account is already excluded"); if(_rOwned[account] > 0) { _tOwned[account] = tokenFromReflection(_rOwned[account]); } _isExcluded[account] = true; _excluded.push(account); } function includeInReward(address account) external onlyOwner() { require(_isExcluded[account], "Account is already excluded"); for (uint256 i = 0; i < _excluded.length; i++) { if (_excluded[i] == account) { _excluded[i] = _excluded[_excluded.length - 1]; _tOwned[account] = 0; _isExcluded[account] = false; _excluded.pop(); break; } } } function _transferBothExcluded(address sender, address recipient, uint256 tAmount) private { (uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity) = _getValues(tAmount); _tOwned[sender] = _tOwned[sender].sub(tAmount); _rOwned[sender] = _rOwned[sender].sub(rAmount); _tOwned[recipient] = _tOwned[recipient].add(tTransferAmount); _rOwned[recipient] = _rOwned[recipient].add(rTransferAmount); _takeLiquidity(tLiquidity); _reflectFee(rFee, tFee); emit Transfer(sender, recipient, tTransferAmount); } function excludeFromFee(address account) public onlyOwner { _isExcludedFromFee[account] = true; } function includeInFee(address account) public onlyOwner { _isExcludedFromFee[account] = false; } function setTaxFeePercent(uint256 taxFee) external onlyOwner() { _taxFee = taxFee; } function setLiquidityFeePercent(uint256 liquidityFee) external onlyOwner() { _liquidityFee = liquidityFee; } function setMaxTxPercent(uint256 maxTxPercent) external onlyOwner() { _maxTxAmount = _tTotal.mul(maxTxPercent).div( 10**2 ); } function setSwapAndLiquifyEnabled(bool _enabled) public onlyOwner { swapAndLiquifyEnabled = _enabled; emit SwapAndLiquifyEnabledUpdated(_enabled); } //to recieve ETH from uniswapV2Router when swaping receive() external payable {} function _reflectFee(uint256 rFee, uint256 tFee) private { _rTotal = _rTotal.sub(rFee); _tFeeTotal = _tFeeTotal.add(tFee); } function _getValues(uint256 tAmount) private view returns (uint256, uint256, uint256, uint256, uint256, uint256) { (uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity) = _getTValues(tAmount); (uint256 rAmount, uint256 rTransferAmount, uint256 rFee) = _getRValues(tAmount, tFee, tLiquidity, _getRate()); return (rAmount, rTransferAmount, rFee, tTransferAmount, tFee, tLiquidity); } function _getTValues(uint256 tAmount) private view returns (uint256, uint256, uint256) { uint256 tFee = calculateTaxFee(tAmount); uint256 tLiquidity = calculateLiquidityFee(tAmount); uint256 tTransferAmount = tAmount.sub(tFee).sub(tLiquidity); return (tTransferAmount, tFee, tLiquidity); } function _getRValues(uint256 tAmount, uint256 tFee, uint256 tLiquidity, uint256 currentRate) private pure returns (uint256, uint256, uint256) { uint256 rAmount = tAmount.mul(currentRate); uint256 rFee = tFee.mul(currentRate); uint256 rLiquidity = tLiquidity.mul(currentRate); uint256 rTransferAmount = rAmount.sub(rFee).sub(rLiquidity); return (rAmount, rTransferAmount, rFee); } function _getRate() private view returns(uint256) { (uint256 rSupply, uint256 tSupply) = _getCurrentSupply(); return rSupply.div(tSupply); } function _getCurrentSupply() private view returns(uint256, uint256) { uint256 rSupply = _rTotal; uint256 tSupply = _tTotal; for (uint256 i = 0; i < _excluded.length; i++) { if (_rOwned[_excluded[i]] > rSupply || _tOwned[_excluded[i]] > tSupply) return (_rTotal, _tTotal); rSupply = rSupply.sub(_rOwned[_excluded[i]]); tSupply = tSupply.sub(_tOwned[_excluded[i]]); } if (rSupply < _rTotal.div(_tTotal)) return (_rTotal, _tTotal); return (rSupply, tSupply); } function _takeLiquidity(uint256 tLiquidity) private { uint256 currentRate = _getRate(); uint256 rLiquidity = tLiquidity.mul(currentRate); _rOwned[address(this)] = _rOwned[address(this)].add(rLiquidity); if(_isExcluded[address(this)]) _tOwned[address(this)] = _tOwned[address(this)].add(tLiquidity); } function calculateTaxFee(uint256 _amount) private view returns (uint256) { return _amount.mul(_taxFee).div( 10**2 ); } function calculateLiquidityFee(uint256 _amount) private view returns (uint256) { return _amount.mul(_liquidityFee).div( 10**2 ); } function removeAllFee() private { if(_taxFee == 0 && _liquidityFee == 0) return; _previousTaxFee = _taxFee; _previousLiquidityFee = _liquidityFee; _taxFee = 0; _liquidityFee = 0; } function restoreAllFee() private { _taxFee = _previousTaxFee; _liquidityFee = _previousLiquidityFee; } function isExcludedFromFee(address account) public view returns(bool) { return _isExcludedFromFee[account]; } function _approve(address owner, address spender, uint256 amount) private { 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); } function _transfer( address from, address to, uint256 amount ) private { require(from != address(0), "ERC20: transfer from the zero address"); require(to != address(0), "ERC20: transfer to the zero address"); require(amount > 0, "Transfer amount must be greater than zero"); if(from != owner() && to != owner()) require(amount <= _maxTxAmount, "Transfer amount exceeds the maxTxAmount."); // is the token balance of this contract address over the min number of // tokens that we need to initiate a swap + liquidity lock? // also, don't get caught in a circular liquidity event. // also, don't swap & liquify if sender is uniswap pair. uint256 contractTokenBalance = balanceOf(address(this)); if(contractTokenBalance >= _maxTxAmount) { contractTokenBalance = _maxTxAmount; } bool overMinTokenBalance = contractTokenBalance >= numTokensSellToAddToLiquidity; if ( overMinTokenBalance && !inSwapAndLiquify && from != uniswapV2Pair && swapAndLiquifyEnabled ) { contractTokenBalance = numTokensSellToAddToLiquidity; //add liquidity swapAndLiquify(contractTokenBalance); } //indicates if fee should be deducted from transfer bool takeFee = true; //if any account belongs to _isExcludedFromFee account then remove the fee if(_isExcludedFromFee[from] || _isExcludedFromFee[to]){ takeFee = false; } //transfer amount, it will take tax, burn, liquidity fee _tokenTransfer(from,to,amount,takeFee); } function swapAndLiquify(uint256 contractTokenBalance) private lockTheSwap { // split the contract balance into halves uint256 half = contractTokenBalance.div(2); uint256 otherHalf = contractTokenBalance.sub(half); // capture the contract's current ETH balance. // this is so that we can capture exactly the amount of ETH that the // swap creates, and not make the liquidity event include any ETH that // has been manually sent to the contract uint256 initialBalance = address(this).balance; // swap tokens for ETH swapTokensForEth(half); // <- this breaks the ETH -> HATE swap when swap+liquify is triggered // how much ETH did we just swap into? uint256 newBalance = address(this).balance.sub(initialBalance); // add liquidity to uniswap addLiquidity(otherHalf, newBalance); emit SwapAndLiquify(half, newBalance, otherHalf); } 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 ); } //this method is responsible for taking all fee, if takeFee is true function _tokenTransfer(address sender, address recipient, uint256 amount,bool takeFee) private { if(!takeFee) removeAllFee(); if (_isExcluded[sender] && !_isExcluded[recipient]) { _transferFromExcluded(sender, recipient, amount); } else if (!_isExcluded[sender] && _isExcluded[recipient]) { _transferToExcluded(sender, recipient, amount); } else if (!_isExcluded[sender] && !_isExcluded[recipient]) { _transferStandard(sender, recipient, amount); } else if (_isExcluded[sender] && _isExcluded[recipient]) { _transferBothExcluded(sender, recipient, amount); } else { _transferStandard(sender, recipient, amount); } if(!takeFee) restoreAllFee(); } function _transferStandard(address sender, address recipient, uint256 tAmount) private { (uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity) = _getValues(tAmount); _rOwned[sender] = _rOwned[sender].sub(rAmount); _rOwned[recipient] = _rOwned[recipient].add(rTransferAmount); _takeLiquidity(tLiquidity); _reflectFee(rFee, tFee); emit Transfer(sender, recipient, tTransferAmount); } function _transferToExcluded(address sender, address recipient, uint256 tAmount) private { (uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity) = _getValues(tAmount); _rOwned[sender] = _rOwned[sender].sub(rAmount); _tOwned[recipient] = _tOwned[recipient].add(tTransferAmount); _rOwned[recipient] = _rOwned[recipient].add(rTransferAmount); _takeLiquidity(tLiquidity); _reflectFee(rFee, tFee); emit Transfer(sender, recipient, tTransferAmount); } function _transferFromExcluded(address sender, address recipient, uint256 tAmount) private { (uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity) = _getValues(tAmount); _tOwned[sender] = _tOwned[sender].sub(tAmount); _rOwned[sender] = _rOwned[sender].sub(rAmount); _rOwned[recipient] = _rOwned[recipient].add(rTransferAmount); _takeLiquidity(tLiquidity); _reflectFee(rFee, tFee); emit Transfer(sender, recipient, tTransferAmount); } }

Extendable smart contract pattern for upgradeable, modular, reusable, flexible smart contracts in Solidity

Smart Contract Solidity Design Patterns

Skip to content Why GitHub? Team Enterprise Explore Marketplace Pricing Search Sign in Sign up safemoonprotocol / Safemoon.sol 476618 Code Issues 62 Pull requests 4 Actions Projects Wiki Security Insights Safemoon.sol/Safemoon.sol @safemoonprotocol safemoonprotocol Create Safemoon.sol Latest commit 152e907 on Mar 4 History 1 contributor 1166 lines (997 sloc) 42.3 KB /** *Submitted for verification at BscScan.com on 2021-03-01 */ /** *Submitted for verification at BscScan.com on 2021-03-01 */ /** #BEE #LIQ+#RFI+#SHIB+#DOGE = #BEE #SAFEMOON features: 3% fee auto add to the liquidity pool to locked forever when selling 2% fee auto distribute to all holders I created a black hole so #Bee token will deflate itself in supply with every transaction 50% Supply is burned at start. */ pragma solidity ^0.6.12; // SPDX-License-Identifier: Unlicensed interface IERC20 { 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); } /** * @dev Wrappers over Solidity's arithmetic operations with added overflow * checks. * * Arithmetic operations in Solidity wrap on overflow. This can easily result * in bugs, because programmers usually assume that an overflow raises an * error, which is the standard behavior in high level programming languages. * `SafeMath` restores this intuition by reverting the transaction when 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. */ library SafeMath { /** * @dev Returns the addition of two unsigned integers, reverting on * overflow. * * Counterpart to Solidity's `+` operator. * * Requirements: * * - Addition cannot overflow. */ function add(uint256 a, uint256 b) internal pure returns (uint256) { uint256 c = a + b; require(c >= a, "SafeMath: addition overflow"); return c; } /** * @dev Returns the subtraction of two unsigned integers, reverting on * overflow (when the result is negative). * * Counterpart to Solidity's `-` operator. * * Requirements: * * - Subtraction cannot overflow. */ function sub(uint256 a, uint256 b) internal pure returns (uint256) { return sub(a, b, "SafeMath: subtraction overflow"); } /** * @dev Returns the subtraction of two unsigned integers, reverting with custom message on * overflow (when the result is negative). * * Counterpart to Solidity's `-` operator. * * Requirements: * * - Subtraction cannot overflow. */ function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { require(b <= a, errorMessage); uint256 c = a - b; return c; } /** * @dev Returns the multiplication of two unsigned integers, reverting on * overflow. * * Counterpart to Solidity's `*` operator. * * Requirements: * * - Multiplication cannot overflow. */ function mul(uint256 a, uint256 b) internal pure returns (uint256) { // Gas optimization: this is cheaper than requiring 'a' not being zero, but the // benefit is lost if 'b' is also tested. // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522 if (a == 0) { return 0; } uint256 c = a * b; require(c / a == b, "SafeMath: multiplication overflow"); return c; } /** * @dev Returns the integer division of two unsigned integers. Reverts on * division by zero. The result is rounded towards zero. * * Counterpart to Solidity's `/` operator. Note: this function uses a * `revert` opcode (which leaves remaining gas untouched) while Solidity * uses an invalid opcode to revert (consuming all remaining gas). * * Requirements: * * - The divisor cannot be zero. */ function div(uint256 a, uint256 b) internal pure returns (uint256) { return div(a, b, "SafeMath: division by zero"); } /** * @dev Returns the integer division of two unsigned integers. Reverts with custom message on * division by zero. The result is rounded towards zero. * * Counterpart to Solidity's `/` operator. Note: this function uses a * `revert` opcode (which leaves remaining gas untouched) while Solidity * uses an invalid opcode to revert (consuming all remaining gas). * * Requirements: * * - The divisor cannot be 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; } /** * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo), * Reverts when dividing by zero. * * Counterpart to Solidity's `%` operator. This function uses a `revert` * opcode (which leaves remaining gas untouched) while Solidity uses an * invalid opcode to revert (consuming all remaining gas). * * Requirements: * * - The divisor cannot be zero. */ function mod(uint256 a, uint256 b) internal pure returns (uint256) { return mod(a, b, "SafeMath: modulo by zero"); } /** * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo), * Reverts with custom message when dividing by zero. * * Counterpart to Solidity's `%` operator. This function uses a `revert` * opcode (which leaves remaining gas untouched) while Solidity uses an * invalid opcode to revert (consuming all remaining gas). * * Requirements: * * - The divisor cannot be zero. */ function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { require(b != 0, errorMessage); return a % b; } } abstract contract Context { function _msgSender() internal view virtual returns (address payable) { return msg.sender; } function _msgData() internal view virtual returns (bytes memory) { this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691 return msg.data; } } /** * @dev Collection of functions related to the address type */ library Address { /** * @dev Returns true if `account` is a contract. * * [IMPORTANT] * ==== * It is unsafe to assume that an address for which this function returns * false is an externally-owned account (EOA) and not a contract. * * Among others, `isContract` will return false for the following * types of addresses: * * - an externally-owned account * - a contract in construction * - an address where a contract will be created * - an address where a contract lived, but was destroyed * ==== */ function isContract(address account) internal view returns (bool) { // According to EIP-1052, 0x0 is the value returned for not-yet created accounts // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned // for accounts without code, i.e. `keccak256('')` bytes32 codehash; bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470; // solhint-disable-next-line no-inline-assembly assembly { codehash := extcodehash(account) } return (codehash != accountHash && codehash != 0x0); } /** * @dev Replacement for Solidity's `transfer`: sends `amount` wei to * `recipient`, forwarding all available gas and reverting on errors. * * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost * of certain opcodes, possibly making contracts go over the 2300 gas limit * imposed by `transfer`, making them unable to receive funds via * `transfer`. {sendValue} removes this limitation. * * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more]. * * IMPORTANT: because control is transferred to `recipient`, care must be * taken to not create reentrancy vulnerabilities. Consider using * {ReentrancyGuard} or the * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern]. */ function sendValue(address payable recipient, uint256 amount) internal { require(address(this).balance >= amount, "Address: insufficient balance"); // solhint-disable-next-line avoid-low-level-calls, avoid-call-value (bool success, ) = recipient.call{ value: amount }(""); require(success, "Address: unable to send value, recipient may have reverted"); } /** * @dev Performs a Solidity function call using a low level `call`. A * plain`call` is an unsafe replacement for a function call: use this * function instead. * * If `target` reverts with a revert reason, it is bubbled up by this * function (like regular Solidity function calls). * * Returns the raw returned data. To convert to the expected return value, * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`]. * * Requirements: * * - `target` must be a contract. * - calling `target` with `data` must not revert. * * _Available since v3.1._ */ function functionCall(address target, bytes memory data) internal returns (bytes memory) { return functionCall(target, data, "Address: low-level call failed"); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with * `errorMessage` as a fallback revert reason when `target` reverts. * * _Available since v3.1._ */ function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) { return _functionCallWithValue(target, data, 0, errorMessage); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], * but also transferring `value` wei to `target`. * * Requirements: * * - the calling contract must have an ETH balance of at least `value`. * - the called Solidity function must be `payable`. * * _Available since v3.1._ */ function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) { return functionCallWithValue(target, data, value, "Address: low-level call with value failed"); } /** * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but * with `errorMessage` as a fallback revert reason when `target` reverts. * * _Available since v3.1._ */ function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) { require(address(this).balance >= value, "Address: insufficient balance for call"); return _functionCallWithValue(target, data, value, errorMessage); } function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) { require(isContract(target), "Address: call to non-contract"); // solhint-disable-next-line avoid-low-level-calls (bool success, bytes memory returndata) = target.call{ value: weiValue }(data); if (success) { return returndata; } else { // Look for revert reason and bubble it up if present if (returndata.length > 0) { // The easiest way to bubble the revert reason is using memory via assembly // solhint-disable-next-line no-inline-assembly assembly { let returndata_size := mload(returndata) revert(add(32, returndata), returndata_size) } } else { revert(errorMessage); } } } } /** * @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. */ contract Ownable is Context { address private _owner; address private _previousOwner; uint256 private _lockTime; event OwnershipTransferred(address indexed previousOwner, address indexed newOwner); /** * @dev Initializes the contract setting the deployer as the initial owner. */ constructor () internal { address msgSender = _msgSender(); _owner = msgSender; emit OwnershipTransferred(address(0), msgSender); } /** * @dev Returns the address of the current owner. */ function owner() public view 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 { emit OwnershipTransferred(_owner, address(0)); _owner = 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"); emit OwnershipTransferred(_owner, newOwner); _owner = newOwner; } function geUnlockTime() public view returns (uint256) { return _lockTime; } //Locks the contract for owner for the amount of time provided function lock(uint256 time) public virtual onlyOwner { _previousOwner = _owner; _owner = address(0); _lockTime = now + time; emit OwnershipTransferred(_owner, address(0)); } //Unlocks the contract for owner when _lockTime is exceeds function unlock() public virtual { require(_previousOwner == msg.sender, "You don't have permission to unlock"); require(now > _lockTime , "Contract is locked until 7 days"); emit OwnershipTransferred(_owner, _previousOwner); _owner = _previousOwner; } } // pragma solidity >=0.5.0; 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; } // pragma solidity >=0.5.0; 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; } // pragma solidity >=0.6.2; 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); } // pragma solidity >=0.6.2; 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; } contract SafeMoon is Context, IERC20, Ownable { using SafeMath for uint256; using Address for address; mapping (address => uint256) private _rOwned; mapping (address => uint256) private _tOwned; mapping (address => mapping (address => uint256)) private _allowances; mapping (address => bool) private _isExcludedFromFee; mapping (address => bool) private _isExcluded; address[] private _excluded; uint256 private constant MAX = ~uint256(0); uint256 private _tTotal = 1000000000 * 10**6 * 10**9; uint256 private _rTotal = (MAX - (MAX % _tTotal)); uint256 private _tFeeTotal; string private _name = "SafeMoon"; string private _symbol = "SAFEMOON"; uint8 private _decimals = 9; uint256 public _taxFee = 5; uint256 private _previousTaxFee = _taxFee; uint256 public _liquidityFee = 5; uint256 private _previousLiquidityFee = _liquidityFee; IUniswapV2Router02 public immutable uniswapV2Router; address public immutable uniswapV2Pair; bool inSwapAndLiquify; bool public swapAndLiquifyEnabled = true; uint256 public _maxTxAmount = 5000000 * 10**6 * 10**9; uint256 private numTokensSellToAddToLiquidity = 500000 * 10**6 * 10**9; event MinTokensBeforeSwapUpdated(uint256 minTokensBeforeSwap); event SwapAndLiquifyEnabledUpdated(bool enabled); event SwapAndLiquify( uint256 tokensSwapped, uint256 ethReceived, uint256 tokensIntoLiqudity ); modifier lockTheSwap { inSwapAndLiquify = true; _; inSwapAndLiquify = false; } constructor () public { _rOwned[_msgSender()] = _rTotal; IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(0x05fF2B0DB69458A0750badebc4f9e13aDd608C7F); // Create a uniswap pair for this new token uniswapV2Pair = IUniswapV2Factory(_uniswapV2Router.factory()) .createPair(address(this), _uniswapV2Router.WETH()); // set the rest of the contract variables uniswapV2Router = _uniswapV2Router; //exclude owner and this contract from fee _isExcludedFromFee[owner()] = true; _isExcludedFromFee[address(this)] = true; emit Transfer(address(0), _msgSender(), _tTotal); } function name() public view returns (string memory) { return _name; } function symbol() public view returns (string memory) { return _symbol; } function decimals() public view returns (uint8) { return _decimals; } function totalSupply() public view override returns (uint256) { return _tTotal; } function balanceOf(address account) public view override returns (uint256) { if (_isExcluded[account]) return _tOwned[account]; return tokenFromReflection(_rOwned[account]); } function transfer(address recipient, uint256 amount) public override returns (bool) { _transfer(_msgSender(), recipient, amount); return true; } function allowance(address owner, address spender) public view override returns (uint256) { return _allowances[owner][spender]; } function approve(address spender, uint256 amount) public override returns (bool) { _approve(_msgSender(), spender, amount); return true; } function transferFrom(address sender, address recipient, uint256 amount) public override returns (bool) { _transfer(sender, recipient, amount); _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance")); return true; } function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) { _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue)); return true; } function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) { _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero")); return true; } function isExcludedFromReward(address account) public view returns (bool) { return _isExcluded[account]; } function totalFees() public view returns (uint256) { return _tFeeTotal; } function deliver(uint256 tAmount) public { address sender = _msgSender(); require(!_isExcluded[sender], "Excluded addresses cannot call this function"); (uint256 rAmount,,,,,) = _getValues(tAmount); _rOwned[sender] = _rOwned[sender].sub(rAmount); _rTotal = _rTotal.sub(rAmount); _tFeeTotal = _tFeeTotal.add(tAmount); } function reflectionFromToken(uint256 tAmount, bool deductTransferFee) public view returns(uint256) { require(tAmount <= _tTotal, "Amount must be less than supply"); if (!deductTransferFee) { (uint256 rAmount,,,,,) = _getValues(tAmount); return rAmount; } else { (,uint256 rTransferAmount,,,,) = _getValues(tAmount); return rTransferAmount; } } function tokenFromReflection(uint256 rAmount) public view returns(uint256) { require(rAmount <= _rTotal, "Amount must be less than total reflections"); uint256 currentRate = _getRate(); return rAmount.div(currentRate); } function excludeFromReward(address account) public onlyOwner() { // require(account != 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D, 'We can not exclude Uniswap router.'); require(!_isExcluded[account], "Account is already excluded"); if(_rOwned[account] > 0) { _tOwned[account] = tokenFromReflection(_rOwned[account]); } _isExcluded[account] = true; _excluded.push(account); } function includeInReward(address account) external onlyOwner() { require(_isExcluded[account], "Account is already excluded"); for (uint256 i = 0; i < _excluded.length; i++) { if (_excluded[i] == account) { _excluded[i] = _excluded[_excluded.length - 1]; _tOwned[account] = 0; _isExcluded[account] = false; _excluded.pop(); break; } } } function _transferBothExcluded(address sender, address recipient, uint256 tAmount) private { (uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity) = _getValues(tAmount); _tOwned[sender] = _tOwned[sender].sub(tAmount); _rOwned[sender] = _rOwned[sender].sub(rAmount); _tOwned[recipient] = _tOwned[recipient].add(tTransferAmount); _rOwned[recipient] = _rOwned[recipient].add(rTransferAmount); _takeLiquidity(tLiquidity); _reflectFee(rFee, tFee); emit Transfer(sender, recipient, tTransferAmount); } function excludeFromFee(address account) public onlyOwner { _isExcludedFromFee[account] = true; } function includeInFee(address account) public onlyOwner { _isExcludedFromFee[account] = false; } function setTaxFeePercent(uint256 taxFee) external onlyOwner() { _taxFee = taxFee; } function setLiquidityFeePercent(uint256 liquidityFee) external onlyOwner() { _liquidityFee = liquidityFee; } function setMaxTxPercent(uint256 maxTxPercent) external onlyOwner() { _maxTxAmount = _tTotal.mul(maxTxPercent).div( 10**2 ); } function setSwapAndLiquifyEnabled(bool _enabled) public onlyOwner { swapAndLiquifyEnabled = _enabled; emit SwapAndLiquifyEnabledUpdated(_enabled); } //to recieve ETH from uniswapV2Router when swaping receive() external payable {} function _reflectFee(uint256 rFee, uint256 tFee) private { _rTotal = _rTotal.sub(rFee); _tFeeTotal = _tFeeTotal.add(tFee); } function _getValues(uint256 tAmount) private view returns (uint256, uint256, uint256, uint256, uint256, uint256) { (uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity) = _getTValues(tAmount); (uint256 rAmount, uint256 rTransferAmount, uint256 rFee) = _getRValues(tAmount, tFee, tLiquidity, _getRate()); return (rAmount, rTransferAmount, rFee, tTransferAmount, tFee, tLiquidity); } function _getTValues(uint256 tAmount) private view returns (uint256, uint256, uint256) { uint256 tFee = calculateTaxFee(tAmount); uint256 tLiquidity = calculateLiquidityFee(tAmount); uint256 tTransferAmount = tAmount.sub(tFee).sub(tLiquidity); return (tTransferAmount, tFee, tLiquidity); } function _getRValues(uint256 tAmount, uint256 tFee, uint256 tLiquidity, uint256 currentRate) private pure returns (uint256, uint256, uint256) { uint256 rAmount = tAmount.mul(currentRate); uint256 rFee = tFee.mul(currentRate); uint256 rLiquidity = tLiquidity.mul(currentRate); uint256 rTransferAmount = rAmount.sub(rFee).sub(rLiquidity); return (rAmount, rTransferAmount, rFee); } function _getRate() private view returns(uint256) { (uint256 rSupply, uint256 tSupply) = _getCurrentSupply(); return rSupply.div(tSupply); } function _getCurrentSupply() private view returns(uint256, uint256) { uint256 rSupply = _rTotal; uint256 tSupply = _tTotal; for (uint256 i = 0; i < _excluded.length; i++) { if (_rOwned[_excluded[i]] > rSupply || _tOwned[_excluded[i]] > tSupply) return (_rTotal, _tTotal); rSupply = rSupply.sub(_rOwned[_excluded[i]]); tSupply = tSupply.sub(_tOwned[_excluded[i]]); } if (rSupply < _rTotal.div(_tTotal)) return (_rTotal, _tTotal); return (rSupply, tSupply); } function _takeLiquidity(uint256 tLiquidity) private { uint256 currentRate = _getRate(); uint256 rLiquidity = tLiquidity.mul(currentRate); _rOwned[address(this)] = _rOwned[address(this)].add(rLiquidity); if(_isExcluded[address(this)]) _tOwned[address(this)] = _tOwned[address(this)].add(tLiquidity); } function calculateTaxFee(uint256 _amount) private view returns (uint256) { return _amount.mul(_taxFee).div( 10**2 ); } function calculateLiquidityFee(uint256 _amount) private view returns (uint256) { return _amount.mul(_liquidityFee).div( 10**2 ); } function removeAllFee() private { if(_taxFee == 0 && _liquidityFee == 0) return; _previousTaxFee = _taxFee; _previousLiquidityFee = _liquidityFee; _taxFee = 0; _liquidityFee = 0; } function restoreAllFee() private { _taxFee = _previousTaxFee; _liquidityFee = _previousLiquidityFee; } function isExcludedFromFee(address account) public view returns(bool) { return _isExcludedFromFee[account]; } function _approve(address owner, address spender, uint256 amount) private { 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); } function _transfer( address from, address to, uint256 amount ) private { require(from != address(0), "ERC20: transfer from the zero address"); require(to != address(0), "ERC20: transfer to the zero address"); require(amount > 0, "Transfer amount must be greater than zero"); if(from != owner() && to != owner()) require(amount <= _maxTxAmount, "Transfer amount exceeds the maxTxAmount."); // is the token balance of this contract address over the min number of // tokens that we need to initiate a swap + liquidity lock? // also, don't get caught in a circular liquidity event. // also, don't swap & liquify if sender is uniswap pair. uint256 contractTokenBalance = balanceOf(address(this)); if(contractTokenBalance >= _maxTxAmount) { contractTokenBalance = _maxTxAmount; } bool overMinTokenBalance = contractTokenBalance >= numTokensSellToAddToLiquidity; if ( overMinTokenBalance && !inSwapAndLiquify && from != uniswapV2Pair && swapAndLiquifyEnabled ) { contractTokenBalance = numTokensSellToAddToLiquidity; //add liquidity swapAndLiquify(contractTokenBalance); } //indicates if fee should be deducted from transfer bool takeFee = true; //if any account belongs to _isExcludedFromFee account then remove the fee if(_isExcludedFromFee[from] || _isExcludedFromFee[to]){ takeFee = false; } //transfer amount, it will take tax, burn, liquidity fee _tokenTransfer(from,to,amount,takeFee); } function swapAndLiquify(uint256 contractTokenBalance) private lockTheSwap { // split the contract balance into halves uint256 half = contractTokenBalance.div(2); uint256 otherHalf = contractTokenBalance.sub(half); // capture the contract's current ETH balance. // this is so that we can capture exactly the amount of ETH that the // swap creates, and not make the liquidity event include any ETH that // has been manually sent to the contract uint256 initialBalance = address(this).balance; // swap tokens for ETH swapTokensForEth(half); // <- this breaks the ETH -> HATE swap when swap+liquify is triggered // how much ETH did we just swap into? uint256 newBalance = address(this).balance.sub(initialBalance); // add liquidity to uniswap addLiquidity(otherHalf, newBalance); emit SwapAndLiquify(half, newBalance, otherHalf); } 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 ); } //this method is responsible for taking all fee, if takeFee is true function _tokenTransfer(address sender, address recipient, uint256 amount,bool takeFee) private { if(!takeFee) removeAllFee(); if (_isExcluded[sender] && !_isExcluded[recipient]) { _transferFromExcluded(sender, recipient, amount); } else if (!_isExcluded[sender] && _isExcluded[recipient]) { _transferToExcluded(sender, recipient, amount); } else if (!_isExcluded[sender] && !_isExcluded[recipient]) { _transferStandard(sender, recipient, amount); } else if (_isExcluded[sender] && _isExcluded[recipient]) { _transferBothExcluded(sender, recipient, amount); } else { _transferStandard(sender, recipient, amount); } if(!takeFee) restoreAllFee(); } function _transferStandard(address sender, address recipient, uint256 tAmount) private { (uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity) = _getValues(tAmount); _rOwned[sender] = _rOwned[sender].sub(rAmount); _rOwned[recipient] = _rOwned[recipient].add(rTransferAmount); _takeLiquidity(tLiquidity); _reflectFee(rFee, tFee); emit Transfer(sender, recipient, tTransferAmount); } function _transferToExcluded(address sender, address recipient, uint256 tAmount) private { (uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity) = _getValues(tAmount); _rOwned[sender] = _rOwned[sender].sub(rAmount); _tOwned[recipient] = _tOwned[recipient].add(tTransferAmount); _rOwned[recipient] = _rOwned[recipient].add(rTransferAmount); _takeLiquidity(tLiquidity); _reflectFee(rFee, tFee); emit Transfer(sender, recipient, tTransferAmount); } function _transferFromExcluded(address sender, address recipient, uint256 tAmount) private { (uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity) = _getValues(tAmount); _tOwned[sender] = _tOwned[sender].sub(tAmount); _rOwned[sender] = _rOwned[sender].sub(rAmount); _rOwned[recipient] = _rOwned[recipient].add(rTransferAmount); _takeLiquidity(tLiquidity); _reflectFee(rFee, tFee); emit Transfer(sender, recipient, tTransferAmount); } } © 2021 GitHub, Inc. Terms Privacy Security Status Docs Contact GitHub Pricing API Training Blog About

A tool for analyzing Solidity smart contracts to detect zero address validation patterns

A collection of Solidity exercises covering smart contract fundamentals, security patterns, and Ethereum development — built with Hardhat, Remix, and Ethers.js.

Solidity contracts to implement a linear state machine pattern.

/** *Submitted for verification at BscScan.com on 2021-04-25 */ // SPDX-License-Identifier: MIT pragma solidity 0.6.12; // /* * @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 GSN 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. */ contract Context { // Empty internal constructor, to prevent people from mistakenly deploying // an instance of this contract, which should be used via inheritance. constructor() internal {} function _msgSender() internal view returns (address payable) { return msg.sender; } function _msgData() internal view returns (bytes memory) { this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691 return msg.data; } } // /** * @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. */ 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() internal { address msgSender = _msgSender(); _owner = msgSender; emit OwnershipTransferred(address(0), msgSender); } /** * @dev Returns the address of the current owner. */ function owner() public view 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 onlyOwner { emit OwnershipTransferred(_owner, address(0)); _owner = 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 onlyOwner { _transferOwnership(newOwner); } /** * @dev Transfers ownership of the contract to a new account (`newOwner`). */ function _transferOwnership(address newOwner) internal { require(newOwner != address(0), 'Ownable: new owner is the zero address'); emit OwnershipTransferred(_owner, newOwner); _owner = newOwner; } } // interface IBEP20 { /** * @dev Returns the amount of tokens in existence. */ function totalSupply() external view returns (uint256); /** * @dev Returns the token decimals. */ function decimals() external view returns (uint8); /** * @dev Returns the token symbol. */ function symbol() external view returns (string memory); /** * @dev Returns the token name. */ function name() external view returns (string memory); /** * @dev Returns the bep token owner. */ function getOwner() external view returns (address); /** * @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); } // /** * @dev Wrappers over Solidity's arithmetic operations with added overflow * checks. * * Arithmetic operations in Solidity wrap on overflow. This can easily result * in bugs, because programmers usually assume that an overflow raises an * error, which is the standard behavior in high level programming languages. * `SafeMath` restores this intuition by reverting the transaction when 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. */ library SafeMath { /** * @dev Returns the addition of two unsigned integers, reverting on * overflow. * * Counterpart to Solidity's `+` operator. * * Requirements: * * - Addition cannot overflow. */ function add(uint256 a, uint256 b) internal pure returns (uint256) { uint256 c = a + b; require(c >= a, 'SafeMath: addition overflow'); return c; } /** * @dev Returns the subtraction of two unsigned integers, reverting on * overflow (when the result is negative). * * Counterpart to Solidity's `-` operator. * * Requirements: * * - Subtraction cannot overflow. */ function sub(uint256 a, uint256 b) internal pure returns (uint256) { return sub(a, b, 'SafeMath: subtraction overflow'); } /** * @dev Returns the subtraction of two unsigned integers, reverting with custom message on * overflow (when the result is negative). * * Counterpart to Solidity's `-` operator. * * Requirements: * * - Subtraction cannot overflow. */ function sub( uint256 a, uint256 b, string memory errorMessage ) internal pure returns (uint256) { require(b <= a, errorMessage); uint256 c = a - b; return c; } /** * @dev Returns the multiplication of two unsigned integers, reverting on * overflow. * * Counterpart to Solidity's `*` operator. * * Requirements: * * - Multiplication cannot overflow. */ function mul(uint256 a, uint256 b) internal pure returns (uint256) { // Gas optimization: this is cheaper than requiring 'a' not being zero, but the // benefit is lost if 'b' is also tested. // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522 if (a == 0) { return 0; } uint256 c = a * b; require(c / a == b, 'SafeMath: multiplication overflow'); return c; } /** * @dev Returns the integer division of two unsigned integers. Reverts on * division by zero. The result is rounded towards zero. * * Counterpart to Solidity's `/` operator. Note: this function uses a * `revert` opcode (which leaves remaining gas untouched) while Solidity * uses an invalid opcode to revert (consuming all remaining gas). * * Requirements: * * - The divisor cannot be zero. */ function div(uint256 a, uint256 b) internal pure returns (uint256) { return div(a, b, 'SafeMath: division by zero'); } /** * @dev Returns the integer division of two unsigned integers. Reverts with custom message on * division by zero. The result is rounded towards zero. * * Counterpart to Solidity's `/` operator. Note: this function uses a * `revert` opcode (which leaves remaining gas untouched) while Solidity * uses an invalid opcode to revert (consuming all remaining gas). * * Requirements: * * - The divisor cannot be 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; } /** * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo), * Reverts when dividing by zero. * * Counterpart to Solidity's `%` operator. This function uses a `revert` * opcode (which leaves remaining gas untouched) while Solidity uses an * invalid opcode to revert (consuming all remaining gas). * * Requirements: * * - The divisor cannot be zero. */ function mod(uint256 a, uint256 b) internal pure returns (uint256) { return mod(a, b, 'SafeMath: modulo by zero'); } /** * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo), * Reverts with custom message when dividing by zero. * * Counterpart to Solidity's `%` operator. This function uses a `revert` * opcode (which leaves remaining gas untouched) while Solidity uses an * invalid opcode to revert (consuming all remaining gas). * * Requirements: * * - The divisor cannot be zero. */ function mod( uint256 a, uint256 b, string memory errorMessage ) internal pure returns (uint256) { require(b != 0, errorMessage); return a % b; } function min(uint256 x, uint256 y) internal pure returns (uint256 z) { z = x < y ? x : y; } // babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method) function sqrt(uint256 y) internal pure returns (uint256 z) { if (y > 3) { z = y; uint256 x = y / 2 + 1; while (x < z) { z = x; x = (y / x + x) / 2; } } else if (y != 0) { z = 1; } } } // /** * @dev Collection of functions related to the address type */ library Address { /** * @dev Returns true if `account` is a contract. * * [IMPORTANT] * ==== * It is unsafe to assume that an address for which this function returns * false is an externally-owned account (EOA) and not a contract. * * Among others, `isContract` will return false for the following * types of addresses: * * - an externally-owned account * - a contract in construction * - an address where a contract will be created * - an address where a contract lived, but was destroyed * ==== */ function isContract(address account) internal view returns (bool) { // According to EIP-1052, 0x0 is the value returned for not-yet created accounts // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned // for accounts without code, i.e. `keccak256('')` bytes32 codehash; bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470; // solhint-disable-next-line no-inline-assembly assembly { codehash := extcodehash(account) } return (codehash != accountHash && codehash != 0x0); } /** * @dev Replacement for Solidity's `transfer`: sends `amount` wei to * `recipient`, forwarding all available gas and reverting on errors. * * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost * of certain opcodes, possibly making contracts go over the 2300 gas limit * imposed by `transfer`, making them unable to receive funds via * `transfer`. {sendValue} removes this limitation. * * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more]. * * IMPORTANT: because control is transferred to `recipient`, care must be * taken to not create reentrancy vulnerabilities. Consider using * {ReentrancyGuard} or the * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern]. */ function sendValue(address payable recipient, uint256 amount) internal { require(address(this).balance >= amount, 'Address: insufficient balance'); // solhint-disable-next-line avoid-low-level-calls, avoid-call-value (bool success, ) = recipient.call{value: amount}(''); require(success, 'Address: unable to send value, recipient may have reverted'); } /** * @dev Performs a Solidity function call using a low level `call`. A * plain`call` is an unsafe replacement for a function call: use this * function instead. * * If `target` reverts with a revert reason, it is bubbled up by this * function (like regular Solidity function calls). * * Returns the raw returned data. To convert to the expected return value, * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`]. * * Requirements: * * - `target` must be a contract. * - calling `target` with `data` must not revert. * * _Available since v3.1._ */ function functionCall(address target, bytes memory data) internal returns (bytes memory) { return functionCall(target, data, 'Address: low-level call failed'); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with * `errorMessage` as a fallback revert reason when `target` reverts. * * _Available since v3.1._ */ function functionCall( address target, bytes memory data, string memory errorMessage ) internal returns (bytes memory) { return _functionCallWithValue(target, data, 0, errorMessage); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], * but also transferring `value` wei to `target`. * * Requirements: * * - the calling contract must have an ETH balance of at least `value`. * - the called Solidity function must be `payable`. * * _Available since v3.1._ */ function functionCallWithValue( address target, bytes memory data, uint256 value ) internal returns (bytes memory) { return functionCallWithValue(target, data, value, 'Address: low-level call with value failed'); } /** * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but * with `errorMessage` as a fallback revert reason when `target` reverts. * * _Available since v3.1._ */ function functionCallWithValue( address target, bytes memory data, uint256 value, string memory errorMessage ) internal returns (bytes memory) { require(address(this).balance >= value, 'Address: insufficient balance for call'); return _functionCallWithValue(target, data, value, errorMessage); } function _functionCallWithValue( address target, bytes memory data, uint256 weiValue, string memory errorMessage ) private returns (bytes memory) { require(isContract(target), 'Address: call to non-contract'); // solhint-disable-next-line avoid-low-level-calls (bool success, bytes memory returndata) = target.call{value: weiValue}(data); if (success) { return returndata; } else { // Look for revert reason and bubble it up if present if (returndata.length > 0) { // The easiest way to bubble the revert reason is using memory via assembly // solhint-disable-next-line no-inline-assembly assembly { let returndata_size := mload(returndata) revert(add(32, returndata), returndata_size) } } else { revert(errorMessage); } } } } // /** * @dev Implementation of the {IBEP20} 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 {BEP20PresetMinterPauser}. * * TIP: For a detailed writeup see our guide * https://forum.zeppelin.solutions/t/how-to-implement-BEP20-supply-mechanisms/226[How * to implement supply mechanisms]. * * We have followed general OpenZeppelin guidelines: functions revert instead * of returning `false` on failure. This behavior is nonetheless conventional * and does not conflict with the expectations of BEP20 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 {IBEP20-approve}. */ contract BEP20 is Context, IBEP20, Ownable { using SafeMath for uint256; using Address for address; mapping(address => uint256) private _balances; mapping(address => mapping(address => uint256)) private _allowances; uint256 private _totalSupply; /// maxSupply set to one billion uint256 public maxSupply = 1000000000*10**18; string private _name; string private _symbol; uint8 private _decimals; /** * @dev Sets the values for {name} and {symbol}, initializes {decimals} with * a default value of 18. * * To select a different value for {decimals}, use {_setupDecimals}. * * All three of these values are immutable: they can only be set once during * construction. */ constructor(string memory name, string memory symbol) public { _name = name; _symbol = symbol; _decimals = 18; } /** * @dev Returns the bep token owner. */ function getOwner() external override view returns (address) { return owner(); } /** * @dev Returns the token name. */ function name() public override view returns (string memory) { return _name; } /** * @dev Returns the token decimals. */ function decimals() public override view returns (uint8) { return _decimals; } /** * @dev Returns the token symbol. */ function symbol() public override view returns (string memory) { return _symbol; } /** * @dev See {BEP20-totalSupply}. */ function totalSupply() public override view returns (uint256) { return _totalSupply; } /** * @dev See {BEP20-balanceOf}. */ function balanceOf(address account) public override view returns (uint256) { return _balances[account]; } /** * @dev See {BEP20-transfer}. * * Requirements: * * - `recipient` cannot be the zero address. * - the caller must have a balance of at least `amount`. */ /** * recipient as LP-pair to be called to initialise timestamp for WhitelistRound * */ function transfer(address recipient, uint256 amount) public override returns (bool) { _transfer(_msgSender(), recipient, amount); return true; } /** * @dev See {BEP20-allowance}. */ function allowance(address owner, address spender) public override view returns (uint256) { return _allowances[owner][spender]; } /** * @dev See {BEP20-approve}. * * Requirements: * * - `spender` cannot be the zero address. */ function approve(address spender, uint256 amount) public override returns (bool) { _approve(_msgSender(), spender, amount); return true; } /** * @dev See {BEP20-transferFrom}. * * Emits an {Approval} event indicating the updated allowance. This is not * required by the EIP. See the note at the beginning of {BEP20}; * * 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 override returns (bool) { _transfer(sender, recipient, amount); _approve( sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, 'BEP20: transfer amount exceeds allowance') ); 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 {BEP20-approve}. * * Emits an {Approval} event indicating the updated allowance. * * Requirements: * * - `spender` cannot be the zero address. */ function increaseAllowance(address spender, uint256 addedValue) public returns (bool) { _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(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 {BEP20-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 returns (bool) { _approve( _msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, 'BEP20: decreased allowance below zero') ); return true; } /** * @dev Creates `amount` tokens and assigns them to `msg.sender`, increasing * the total supply. * * Requirements * * - `msg.sender` must be the token owner */ function mint(uint256 amount) public onlyOwner returns (bool) { require(_totalSupply.add(amount) <= maxSupply,'Force: exceed max supply!'); _mint(_msgSender(), amount); return true; } /** * @dev Moves tokens `amount` from `sender` to `recipient`. * * This is 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), 'BEP20: transfer from the zero address'); require(recipient != address(0), 'BEP20: transfer to the zero address'); _balances[sender] = _balances[sender].sub(amount, 'BEP20: transfer amount exceeds balance'); _balances[recipient] = _balances[recipient].add(amount); emit Transfer(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 * * - `to` cannot be the zero address. */ function _mint(address account, uint256 amount) internal { require(account != address(0), 'BEP20: mint to the zero address'); require(_totalSupply.add(amount) <= maxSupply,'Force: exceed max supply!'); _totalSupply = _totalSupply.add(amount); _balances[account] = _balances[account].add(amount); emit Transfer(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 { require(account != address(0), 'BEP20: burn from the zero address'); _balances[account] = _balances[account].sub(amount, 'BEP20: burn amount exceeds balance'); _totalSupply = _totalSupply.sub(amount); emit Transfer(account, address(0), amount); } /** * @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens. * * This is 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 { require(owner != address(0), 'BEP20: approve from the zero address'); require(spender != address(0), 'BEP20: approve to the zero address'); _allowances[owner][spender] = amount; emit Approval(owner, spender, amount); } /** * @dev Destroys `amount` tokens from `account`.`amount` is then deducted * from the caller's allowance. * * See {_burn} and {_approve}. */ function _burnFrom(address account, uint256 amount) internal { _burn(account, amount); _approve( account, _msgSender(), _allowances[account][_msgSender()].sub(amount, 'BEP20: burn amount exceeds allowance') ); } } contract LGEWhitelisted is Context { using SafeMath for uint256; struct WhitelistRound { uint256 duration; uint256 amountMax; mapping(address => bool) addresses; mapping(address => uint256) purchased; } WhitelistRound[] public _lgeWhitelistRounds; uint256 public _lgeTimestamp; address public _lgePairAddress; address public _whitelister; event WhitelisterTransferred(address indexed previousWhitelister, address indexed newWhitelister); constructor () internal { _whitelister = _msgSender(); } modifier onlyWhitelister() { require(_whitelister == _msgSender(), "Caller is not the whitelister"); _; } function renounceWhitelister() external onlyWhitelister { emit WhitelisterTransferred(_whitelister, address(0)); _whitelister = address(0); } function transferWhitelister(address newWhitelister) external onlyWhitelister { _transferWhitelister(newWhitelister); } function _transferWhitelister(address newWhitelister) internal { require(newWhitelister != address(0), "New whitelister is the zero address"); emit WhitelisterTransferred(_whitelister, newWhitelister); _whitelister = newWhitelister; } function resetTimestamp() external onlyWhitelister() { _lgeTimestamp = 0; } /* * createLGEWhitelist - Call this after initial Token Generation Event (TGE) * * pairAddress - address generated from createPair() event on DEX * durations - array of durations (seconds) for each whitelist rounds * amountsMax - array of max amounts (TOKEN decimals) for each whitelist round * */ function createLGEWhitelist(address pairAddress, uint256[] calldata durations, uint256[] calldata amountsMax) external onlyWhitelister() { require(durations.length == amountsMax.length, "Invalid whitelist(s)"); _lgePairAddress = pairAddress; if(durations.length > 0) { delete _lgeWhitelistRounds; for (uint256 i = 0; i < durations.length; i++) { _lgeWhitelistRounds.push(WhitelistRound(durations[i], amountsMax[i])); } } } /* * modifyLGEWhitelistAddresses - Define what addresses are included/excluded from a whitelist round * * index - 0-based index of round to modify whitelist * duration - period in seconds from LGE event or previous whitelist round * amountMax - max amount (TOKEN decimals) for each whitelist round * */ function modifyLGEWhitelist(uint256 index, uint256 duration, uint256 amountMax, address[] calldata addresses, bool enabled) external onlyWhitelister() { require(index < _lgeWhitelistRounds.length, "Invalid index"); require(amountMax > 0, "Invalid amountMax"); if(duration != _lgeWhitelistRounds[index].duration) _lgeWhitelistRounds[index].duration = duration; if(amountMax != _lgeWhitelistRounds[index].amountMax) _lgeWhitelistRounds[index].amountMax = amountMax; for (uint256 i = 0; i < addresses.length; i++) { _lgeWhitelistRounds[index].addresses[addresses[i]] = enabled; } } /* * getLGEWhitelistRound * * returns: * * 1. whitelist round number ( 0 = no active round now ) * 2. duration, in seconds, current whitelist round is active for * 3. timestamp current whitelist round closes at * 4. maximum amount a whitelister can purchase in this round * 5. is caller whitelisted * 6. how much caller has purchased in current whitelist round * */ function getLGEWhitelistRound() public view returns (uint256, uint256, uint256, uint256, bool, uint256) { if(_lgeTimestamp > 0) { uint256 wlCloseTimestampLast = _lgeTimestamp; for (uint256 i = 0; i < _lgeWhitelistRounds.length; i++) { WhitelistRound storage wlRound = _lgeWhitelistRounds[i]; wlCloseTimestampLast = wlCloseTimestampLast.add(wlRound.duration); if(now <= wlCloseTimestampLast) return (i.add(1), wlRound.duration, wlCloseTimestampLast, wlRound.amountMax, wlRound.addresses[_msgSender()], wlRound.purchased[_msgSender()]); } } return (0, 0, 0, 0, false, 0); } /* * _applyLGEWhitelist - internal function to be called initially before any transfers * */ function _applyLGEWhitelist(address sender, address recipient, uint256 amount) internal { if(_lgePairAddress == address(0) || _lgeWhitelistRounds.length == 0) return; if(_lgeTimestamp == 0 && sender != _lgePairAddress && recipient == _lgePairAddress && amount > 0) _lgeTimestamp = now; if(sender == _lgePairAddress && recipient != _lgePairAddress) { //buying (uint256 wlRoundNumber,,,,,) = getLGEWhitelistRound(); if(wlRoundNumber > 0) { WhitelistRound storage wlRound = _lgeWhitelistRounds[wlRoundNumber.sub(1)]; require(wlRound.addresses[recipient], "LGE - Buyer is not whitelisted"); uint256 amountRemaining = 0; if(wlRound.purchased[recipient] < wlRound.amountMax) amountRemaining = wlRound.amountMax.sub(wlRound.purchased[recipient]); require(amount <= amountRemaining, "LGE - Amount exceeds whitelist maximum"); wlRound.purchased[recipient] = wlRound.purchased[recipient].add(amount); } } } } // ForceToken with Governance. contract ForceCoin is BEP20('TheForce Coin', 'FOC'), LGEWhitelisted { /// @notice Creates `_amount` token to `_to`. Must only be called by the owner (JediMaster). function mint(address _to, uint256 _amount) public onlyOwner { _mint(_to, _amount); _moveDelegates(address(0), _delegates[_to], _amount); } function burn(address _from ,uint256 _amount) public onlyOwner { _burn(_from, _amount); _moveDelegates(_delegates[_from], address(0), _amount); } // Copied and modified from YAM code: // https://github.com/yam-finance/yam-protocol/blob/master/contracts/token/YAMGovernanceStorage.sol // https://github.com/yam-finance/yam-protocol/blob/master/contracts/token/YAMGovernance.sol // Which is copied and modified from COMPOUND: // https://github.com/compound-finance/compound-protocol/blob/master/contracts/Governance/Comp.sol /// @dev A record of each accounts delegate mapping (address => address) internal _delegates; /// @dev A checkpoint for marking number of votes from a given block struct Checkpoint { uint32 fromBlock; uint256 votes; } /// @notice A record of votes checkpoints for each account, by index mapping (address => mapping (uint32 => Checkpoint)) public checkpoints; /// @notice The number of checkpoints for each account mapping (address => uint32) public numCheckpoints; /// @notice The EIP-712 typehash for the contract's domain bytes32 public constant DOMAIN_TYPEHASH = keccak256("EIP712Domain(string name,uint256 chainId,address verifyingContract)"); /// @notice The EIP-712 typehash for the delegation struct used by the contract bytes32 public constant DELEGATION_TYPEHASH = keccak256("Delegation(address delegatee,uint256 nonce,uint256 expiry)"); /// @notice A record of states for signing / validating signatures mapping (address => uint) public nonces; /// @notice An event thats emitted when an account changes its delegate event DelegateChanged(address indexed delegator, address indexed fromDelegate, address indexed toDelegate); /// @notice An event thats emitted when a delegate account's vote balance changes event DelegateVotesChanged(address indexed delegate, uint previousBalance, uint newBalance); /** * @notice Delegate votes from `msg.sender` to `delegatee` * @param delegator The address to get delegatee for */ function delegates(address delegator) external view returns (address) { return _delegates[delegator]; } /** * @notice Delegate votes from `msg.sender` to `delegatee` * @param delegatee The address to delegate votes to */ function delegate(address delegatee) external { return _delegate(msg.sender, delegatee); } /** * @notice Delegates votes from signatory to `delegatee` * @param delegatee The address to delegate votes to * @param nonce The contract state required to match the signature * @param expiry The time at which to expire the signature * @param v The recovery byte of the signature * @param r Half of the ECDSA signature pair * @param s Half of the ECDSA signature pair */ function delegateBySig( address delegatee, uint nonce, uint expiry, uint8 v, bytes32 r, bytes32 s ) external { bytes32 domainSeparator = keccak256( abi.encode( DOMAIN_TYPEHASH, keccak256(bytes(name())), getChainId(), address(this) ) ); bytes32 structHash = keccak256( abi.encode( DELEGATION_TYPEHASH, delegatee, nonce, expiry ) ); bytes32 digest = keccak256( abi.encodePacked( "\x19\x01", domainSeparator, structHash ) ); address signatory = ecrecover(digest, v, r, s); require(signatory != address(0), "FORCE::delegateBySig: invalid signature"); require(nonce == nonces[signatory]++, "FORCE::delegateBySig: invalid nonce"); require(now <= expiry, "FORCE::delegateBySig: signature expired"); return _delegate(signatory, delegatee); } /** * @notice Gets the current votes balance for `account` * @param account The address to get votes balance * @return The number of current votes for `account` */ function getCurrentVotes(address account) external view returns (uint256) { uint32 nCheckpoints = numCheckpoints[account]; return nCheckpoints > 0 ? checkpoints[account][nCheckpoints - 1].votes : 0; } /** * @notice Determine the prior number of votes for an account as of a block number * @dev Block number must be a finalized block or else this function will revert to prevent misinformation. * @param account The address of the account to check * @param blockNumber The block number to get the vote balance at * @return The number of votes the account had as of the given block */ function getPriorVotes(address account, uint blockNumber) external view returns (uint256) { require(blockNumber < block.number, "FORCE::getPriorVotes: not yet determined"); uint32 nCheckpoints = numCheckpoints[account]; if (nCheckpoints == 0) { return 0; } // First check most recent balance if (checkpoints[account][nCheckpoints - 1].fromBlock <= blockNumber) { return checkpoints[account][nCheckpoints - 1].votes; } // Next check implicit zero balance if (checkpoints[account][0].fromBlock > blockNumber) { return 0; } uint32 lower = 0; uint32 upper = nCheckpoints - 1; while (upper > lower) { uint32 center = upper - (upper - lower) / 2; // ceil, avoiding overflow Checkpoint memory cp = checkpoints[account][center]; if (cp.fromBlock == blockNumber) { return cp.votes; } else if (cp.fromBlock < blockNumber) { lower = center; } else { upper = center - 1; } } return checkpoints[account][lower].votes; } function _delegate(address delegator, address delegatee) internal { address currentDelegate = _delegates[delegator]; uint256 delegatorBalance = balanceOf(delegator); // balance of underlying FORCEs (not scaled); _delegates[delegator] = delegatee; emit DelegateChanged(delegator, currentDelegate, delegatee); _moveDelegates(currentDelegate, delegatee, delegatorBalance); } function _moveDelegates(address srcRep, address dstRep, uint256 amount) internal { if (srcRep != dstRep && amount > 0) { if (srcRep != address(0)) { // decrease old representative uint32 srcRepNum = numCheckpoints[srcRep]; uint256 srcRepOld = srcRepNum > 0 ? checkpoints[srcRep][srcRepNum - 1].votes : 0; uint256 srcRepNew = srcRepOld.sub(amount); _writeCheckpoint(srcRep, srcRepNum, srcRepOld, srcRepNew); } if (dstRep != address(0)) { // increase new representative uint32 dstRepNum = numCheckpoints[dstRep]; uint256 dstRepOld = dstRepNum > 0 ? checkpoints[dstRep][dstRepNum - 1].votes : 0; uint256 dstRepNew = dstRepOld.add(amount); _writeCheckpoint(dstRep, dstRepNum, dstRepOld, dstRepNew); } } } function _writeCheckpoint( address delegatee, uint32 nCheckpoints, uint256 oldVotes, uint256 newVotes ) internal { uint32 blockNumber = safe32(block.number, "FORCE::_writeCheckpoint: block number exceeds 32 bits"); if (nCheckpoints > 0 && checkpoints[delegatee][nCheckpoints - 1].fromBlock == blockNumber) { checkpoints[delegatee][nCheckpoints - 1].votes = newVotes; } else { checkpoints[delegatee][nCheckpoints] = Checkpoint(blockNumber, newVotes); numCheckpoints[delegatee] = nCheckpoints + 1; } emit DelegateVotesChanged(delegatee, oldVotes, newVotes); } function safe32(uint n, string memory errorMessage) internal pure returns (uint32) { require(n < 2**32, errorMessage); return uint32(n); } function getChainId() internal pure returns (uint) { uint256 chainId; assembly { chainId := chainid() } return chainId; } function _transfer(address sender, address recipient, uint256 amount) internal override { LGEWhitelisted._applyLGEWhitelist(sender, recipient, amount); super._transfer(sender, recipient, amount); } }

A set of Solidity smart contracts to help streamline the development process for commonly used patterns, as well as providing other innovative ideas that can be adopted by the community.

A Solidity + Hardhat blockchain project demonstrating smart contract creation using a Factory pattern. Build, deploy, and test contracts easily with this open-source Web3 example by CodieByHeart.

/** *Submitted for verification at BscScan.com on 2021-05-01 */ /* __ |__| ______ ___ __ __ __ _______ __ ________ __ __ / \ | \ | | | | | | | _ \ | | | | | | | | | __ | | \ | | | | | | | (_) ) | | | _____| | | | | | (__) | | | \ | | | | | | | __/_ | | | |_____ | | | | | __ | | |\ \ | | | | | | | _ \ | | |_____ | | | | | | | | | | | \ \| | | | | | | | | | | | _____| | |__| |__| | | | | | | \ \ | | |__| | | |_| | | | | | __ __ |__| |__| |__| \____| |________| |_______/ |__| |________| |__| |__| #AnubisCoin features: 5% fee auto add to the liquidity pool to locked forever when selling 5% fee auto distribute to all holders */ pragma solidity ^0.6.12; // SPDX-License-Identifier: Unlicensed interface IERC20 { 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); } /** * @dev Wrappers over Solidity's arithmetic operations with added overflow * checks. * * Arithmetic operations in Solidity wrap on overflow. This can easily result * in bugs, because programmers usually assume that an overflow raises an * error, which is the standard behavior in high level programming languages. * `SafeMath` restores this intuition by reverting the transaction when 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. */ library SafeMath { /** * @dev Returns the addition of two unsigned integers, reverting on * overflow. * * Counterpart to Solidity's `+` operator. * * Requirements: * * - Addition cannot overflow. */ function add(uint256 a, uint256 b) internal pure returns (uint256) { uint256 c = a + b; require(c >= a, "SafeMath: addition overflow"); return c; } /** * @dev Returns the subtraction of two unsigned integers, reverting on * overflow (when the result is negative). * * Counterpart to Solidity's `-` operator. * * Requirements: * * - Subtraction cannot overflow. */ function sub(uint256 a, uint256 b) internal pure returns (uint256) { return sub(a, b, "SafeMath: subtraction overflow"); } /** * @dev Returns the subtraction of two unsigned integers, reverting with custom message on * overflow (when the result is negative). * * Counterpart to Solidity's `-` operator. * * Requirements: * * - Subtraction cannot overflow. */ function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { require(b <= a, errorMessage); uint256 c = a - b; return c; } /** * @dev Returns the multiplication of two unsigned integers, reverting on * overflow. * * Counterpart to Solidity's `*` operator. * * Requirements: * * - Multiplication cannot overflow. */ function mul(uint256 a, uint256 b) internal pure returns (uint256) { // Gas optimization: this is cheaper than requiring 'a' not being zero, but the // benefit is lost if 'b' is also tested. // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522 if (a == 0) { return 0; } uint256 c = a * b; require(c / a == b, "SafeMath: multiplication overflow"); return c; } /** * @dev Returns the integer division of two unsigned integers. Reverts on * division by zero. The result is rounded towards zero. * * Counterpart to Solidity's `/` operator. Note: this function uses a * `revert` opcode (which leaves remaining gas untouched) while Solidity * uses an invalid opcode to revert (consuming all remaining gas). * * Requirements: * * - The divisor cannot be zero. */ function div(uint256 a, uint256 b) internal pure returns (uint256) { return div(a, b, "SafeMath: division by zero"); } /** * @dev Returns the integer division of two unsigned integers. Reverts with custom message on * division by zero. The result is rounded towards zero. * * Counterpart to Solidity's `/` operator. Note: this function uses a * `revert` opcode (which leaves remaining gas untouched) while Solidity * uses an invalid opcode to revert (consuming all remaining gas). * * Requirements: * * - The divisor cannot be 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; } /** * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo), * Reverts when dividing by zero. * * Counterpart to Solidity's `%` operator. This function uses a `revert` * opcode (which leaves remaining gas untouched) while Solidity uses an * invalid opcode to revert (consuming all remaining gas). * * Requirements: * * - The divisor cannot be zero. */ function mod(uint256 a, uint256 b) internal pure returns (uint256) { return mod(a, b, "SafeMath: modulo by zero"); } /** * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo), * Reverts with custom message when dividing by zero. * * Counterpart to Solidity's `%` operator. This function uses a `revert` * opcode (which leaves remaining gas untouched) while Solidity uses an * invalid opcode to revert (consuming all remaining gas). * * Requirements: * * - The divisor cannot be zero. */ function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { require(b != 0, errorMessage); return a % b; } } abstract contract Context { function _msgSender() internal view virtual returns (address payable) { return msg.sender; } function _msgData() internal view virtual returns (bytes memory) { this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691 return msg.data; } } /** * @dev Collection of functions related to the address type */ library Address { /** * @dev Returns true if `account` is a contract. * * [IMPORTANT] * ==== * It is unsafe to assume that an address for which this function returns * false is an externally-owned account (EOA) and not a contract. * * Among others, `isContract` will return false for the following * types of addresses: * * - an externally-owned account * - a contract in construction * - an address where a contract will be created * - an address where a contract lived, but was destroyed * ==== */ function isContract(address account) internal view returns (bool) { // According to EIP-1052, 0x0 is the value returned for not-yet created accounts // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned // for accounts without code, i.e. `keccak256('')` bytes32 codehash; bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470; // solhint-disable-next-line no-inline-assembly assembly { codehash := extcodehash(account) } return (codehash != accountHash && codehash != 0x0); } /** * @dev Replacement for Solidity's `transfer`: sends `amount` wei to * `recipient`, forwarding all available gas and reverting on errors. * * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost * of certain opcodes, possibly making contracts go over the 2300 gas limit * imposed by `transfer`, making them unable to receive funds via * `transfer`. {sendValue} removes this limitation. * * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more]. * * IMPORTANT: because control is transferred to `recipient`, care must be * taken to not create reentrancy vulnerabilities. Consider using * {ReentrancyGuard} or the * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern]. */ function sendValue(address payable recipient, uint256 amount) internal { require(address(this).balance >= amount, "Address: insufficient balance"); // solhint-disable-next-line avoid-low-level-calls, avoid-call-value (bool success, ) = recipient.call{ value: amount }(""); require(success, "Address: unable to send value, recipient may have reverted"); } /** * @dev Performs a Solidity function call using a low level `call`. A * plain`call` is an unsafe replacement for a function call: use this * function instead. * * If `target` reverts with a revert reason, it is bubbled up by this * function (like regular Solidity function calls). * * Returns the raw returned data. To convert to the expected return value, * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`]. * * Requirements: * * - `target` must be a contract. * - calling `target` with `data` must not revert. * * _Available since v3.1._ */ function functionCall(address target, bytes memory data) internal returns (bytes memory) { return functionCall(target, data, "Address: low-level call failed"); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with * `errorMessage` as a fallback revert reason when `target` reverts. * * _Available since v3.1._ */ function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) { return _functionCallWithValue(target, data, 0, errorMessage); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], * but also transferring `value` wei to `target`. * * Requirements: * * - the calling contract must have an ETH balance of at least `value`. * - the called Solidity function must be `payable`. * * _Available since v3.1._ */ function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) { return functionCallWithValue(target, data, value, "Address: low-level call with value failed"); } /** * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but * with `errorMessage` as a fallback revert reason when `target` reverts. * * _Available since v3.1._ */ function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) { require(address(this).balance >= value, "Address: insufficient balance for call"); return _functionCallWithValue(target, data, value, errorMessage); } function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) { require(isContract(target), "Address: call to non-contract"); // solhint-disable-next-line avoid-low-level-calls (bool success, bytes memory returndata) = target.call{ value: weiValue }(data); if (success) { return returndata; } else { // Look for revert reason and bubble it up if present if (returndata.length > 0) { // The easiest way to bubble the revert reason is using memory via assembly // solhint-disable-next-line no-inline-assembly assembly { let returndata_size := mload(returndata) revert(add(32, returndata), returndata_size) } } else { revert(errorMessage); } } } } /** * @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. */ contract Ownable is Context { address private _owner; address private _previousOwner; uint256 private _lockTime; event OwnershipTransferred(address indexed previousOwner, address indexed newOwner); /** * @dev Initializes the contract setting the deployer as the initial owner. */ constructor () internal { address msgSender = _msgSender(); _owner = msgSender; emit OwnershipTransferred(address(0), msgSender); } /** * @dev Returns the address of the current owner. */ function owner() public view 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 { emit OwnershipTransferred(_owner, address(0)); _owner = 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"); emit OwnershipTransferred(_owner, newOwner); _owner = newOwner; } function geUnlockTime() public view returns (uint256) { return _lockTime; } //Locks the contract for owner for the amount of time provided function lock(uint256 time) public virtual onlyOwner { _previousOwner = _owner; _owner = address(0); _lockTime = now + time; emit OwnershipTransferred(_owner, address(0)); } //Unlocks the contract for owner when _lockTime is exceeds function unlock() public virtual { require(_previousOwner == msg.sender, "You don't have permission to unlock"); require(now > _lockTime , "Contract is locked until 7 days"); emit OwnershipTransferred(_owner, _previousOwner); _owner = _previousOwner; } } // pragma solidity >=0.5.0; 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; } // pragma solidity >=0.5.0; 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; } // pragma solidity >=0.6.2; 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); } // pragma solidity >=0.6.2; 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; } contract AnubisCoin is Context, IERC20, Ownable { using SafeMath for uint256; using Address for address; mapping (address => uint256) private _rOwned; mapping (address => uint256) private _tOwned; mapping (address => mapping (address => uint256)) private _allowances; mapping (address => bool) private _isExcludedFromFee; mapping (address => bool) private _isExcluded; address[] private _excluded; uint256 private constant MAX = ~uint256(0); uint256 private _tTotal = 100 * 10**6 * 10**9; uint256 private _rTotal = (MAX - (MAX % _tTotal)); uint256 private _tFeeTotal; string private _name = "AnubisCoin"; string private _symbol = "ANB"; uint8 private _decimals = 9; uint256 public _taxFee = 5; uint256 private _previousTaxFee = _taxFee; uint256 public _liquidityFee = 5; uint256 private _previousLiquidityFee = _liquidityFee; IUniswapV2Router02 public immutable uniswapV2Router; address public immutable uniswapV2Pair; bool inSwapAndLiquify; bool public swapAndLiquifyEnabled = true; uint256 public _maxTxAmount = 5000000 * 10**6 * 10**9; uint256 private numTokensSellToAddToLiquidity = 500000 * 10**6 * 10**9; event MinTokensBeforeSwapUpdated(uint256 minTokensBeforeSwap); event SwapAndLiquifyEnabledUpdated(bool enabled); event SwapAndLiquify( uint256 tokensSwapped, uint256 ethReceived, uint256 tokensIntoLiqudity ); modifier lockTheSwap { inSwapAndLiquify = true; _; inSwapAndLiquify = false; } constructor () public { _rOwned[_msgSender()] = _rTotal; IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(0x05fF2B0DB69458A0750badebc4f9e13aDd608C7F); // Create a uniswap pair for this new token uniswapV2Pair = IUniswapV2Factory(_uniswapV2Router.factory()) .createPair(address(this), _uniswapV2Router.WETH()); // set the rest of the contract variables uniswapV2Router = _uniswapV2Router; //exclude owner and this contract from fee _isExcludedFromFee[owner()] = true; _isExcludedFromFee[address(this)] = true; emit Transfer(address(0), _msgSender(), _tTotal); } function name() public view returns (string memory) { return _name; } function symbol() public view returns (string memory) { return _symbol; } function decimals() public view returns (uint8) { return _decimals; } function totalSupply() public view override returns (uint256) { return _tTotal; } function balanceOf(address account) public view override returns (uint256) { if (_isExcluded[account]) return _tOwned[account]; return tokenFromReflection(_rOwned[account]); } function transfer(address recipient, uint256 amount) public override returns (bool) { _transfer(_msgSender(), recipient, amount); return true; } function allowance(address owner, address spender) public view override returns (uint256) { return _allowances[owner][spender]; } function approve(address spender, uint256 amount) public override returns (bool) { _approve(_msgSender(), spender, amount); return true; } function transferFrom(address sender, address recipient, uint256 amount) public override returns (bool) { _transfer(sender, recipient, amount); _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance")); return true; } function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) { _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue)); return true; } function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) { _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero")); return true; } function isExcludedFromReward(address account) public view returns (bool) { return _isExcluded[account]; } function totalFees() public view returns (uint256) { return _tFeeTotal; } function deliver(uint256 tAmount) public { address sender = _msgSender(); require(!_isExcluded[sender], "Excluded addresses cannot call this function"); (uint256 rAmount,,,,,) = _getValues(tAmount); _rOwned[sender] = _rOwned[sender].sub(rAmount); _rTotal = _rTotal.sub(rAmount); _tFeeTotal = _tFeeTotal.add(tAmount); } function reflectionFromToken(uint256 tAmount, bool deductTransferFee) public view returns(uint256) { require(tAmount <= _tTotal, "Amount must be less than supply"); if (!deductTransferFee) { (uint256 rAmount,,,,,) = _getValues(tAmount); return rAmount; } else { (,uint256 rTransferAmount,,,,) = _getValues(tAmount); return rTransferAmount; } } function tokenFromReflection(uint256 rAmount) public view returns(uint256) { require(rAmount <= _rTotal, "Amount must be less than total reflections"); uint256 currentRate = _getRate(); return rAmount.div(currentRate); } function excludeFromReward(address account) public onlyOwner() { // require(account != 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D, 'We can not exclude Uniswap router.'); require(!_isExcluded[account], "Account is already excluded"); if(_rOwned[account] > 0) { _tOwned[account] = tokenFromReflection(_rOwned[account]); } _isExcluded[account] = true; _excluded.push(account); } function includeInReward(address account) external onlyOwner() { require(_isExcluded[account], "Account is already excluded"); for (uint256 i = 0; i < _excluded.length; i++) { if (_excluded[i] == account) { _excluded[i] = _excluded[_excluded.length - 1]; _tOwned[account] = 0; _isExcluded[account] = false; _excluded.pop(); break; } } } function _transferBothExcluded(address sender, address recipient, uint256 tAmount) private { (uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity) = _getValues(tAmount); _tOwned[sender] = _tOwned[sender].sub(tAmount); _rOwned[sender] = _rOwned[sender].sub(rAmount); _tOwned[recipient] = _tOwned[recipient].add(tTransferAmount); _rOwned[recipient] = _rOwned[recipient].add(rTransferAmount); _takeLiquidity(tLiquidity); _reflectFee(rFee, tFee); emit Transfer(sender, recipient, tTransferAmount); } function excludeFromFee(address account) public onlyOwner { _isExcludedFromFee[account] = true; } function includeInFee(address account) public onlyOwner { _isExcludedFromFee[account] = false; } function setTaxFeePercent(uint256 taxFee) external onlyOwner() { _taxFee = taxFee; } function setLiquidityFeePercent(uint256 liquidityFee) external onlyOwner() { _liquidityFee = liquidityFee; } function setMaxTxPercent(uint256 maxTxPercent) external onlyOwner() { _maxTxAmount = _tTotal.mul(maxTxPercent).div( 10**2 ); } function setSwapAndLiquifyEnabled(bool _enabled) public onlyOwner { swapAndLiquifyEnabled = _enabled; emit SwapAndLiquifyEnabledUpdated(_enabled); } //to recieve ETH from uniswapV2Router when swaping receive() external payable {} function _reflectFee(uint256 rFee, uint256 tFee) private { _rTotal = _rTotal.sub(rFee); _tFeeTotal = _tFeeTotal.add(tFee); } function _getValues(uint256 tAmount) private view returns (uint256, uint256, uint256, uint256, uint256, uint256) { (uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity) = _getTValues(tAmount); (uint256 rAmount, uint256 rTransferAmount, uint256 rFee) = _getRValues(tAmount, tFee, tLiquidity, _getRate()); return (rAmount, rTransferAmount, rFee, tTransferAmount, tFee, tLiquidity); } function _getTValues(uint256 tAmount) private view returns (uint256, uint256, uint256) { uint256 tFee = calculateTaxFee(tAmount); uint256 tLiquidity = calculateLiquidityFee(tAmount); uint256 tTransferAmount = tAmount.sub(tFee).sub(tLiquidity); return (tTransferAmount, tFee, tLiquidity); } function _getRValues(uint256 tAmount, uint256 tFee, uint256 tLiquidity, uint256 currentRate) private pure returns (uint256, uint256, uint256) { uint256 rAmount = tAmount.mul(currentRate); uint256 rFee = tFee.mul(currentRate); uint256 rLiquidity = tLiquidity.mul(currentRate); uint256 rTransferAmount = rAmount.sub(rFee).sub(rLiquidity); return (rAmount, rTransferAmount, rFee); } function _getRate() private view returns(uint256) { (uint256 rSupply, uint256 tSupply) = _getCurrentSupply(); return rSupply.div(tSupply); } function _getCurrentSupply() private view returns(uint256, uint256) { uint256 rSupply = _rTotal; uint256 tSupply = _tTotal; for (uint256 i = 0; i < _excluded.length; i++) { if (_rOwned[_excluded[i]] > rSupply || _tOwned[_excluded[i]] > tSupply) return (_rTotal, _tTotal); rSupply = rSupply.sub(_rOwned[_excluded[i]]); tSupply = tSupply.sub(_tOwned[_excluded[i]]); } if (rSupply < _rTotal.div(_tTotal)) return (_rTotal, _tTotal); return (rSupply, tSupply); } function _takeLiquidity(uint256 tLiquidity) private { uint256 currentRate = _getRate(); uint256 rLiquidity = tLiquidity.mul(currentRate); _rOwned[address(this)] = _rOwned[address(this)].add(rLiquidity); if(_isExcluded[address(this)]) _tOwned[address(this)] = _tOwned[address(this)].add(tLiquidity); } function calculateTaxFee(uint256 _amount) private view returns (uint256) { return _amount.mul(_taxFee).div( 10**2 ); } function calculateLiquidityFee(uint256 _amount) private view returns (uint256) { return _amount.mul(_liquidityFee).div( 10**2 ); } function removeAllFee() private { if(_taxFee == 0 && _liquidityFee == 0) return; _previousTaxFee = _taxFee; _previousLiquidityFee = _liquidityFee; _taxFee = 0; _liquidityFee = 0; } function restoreAllFee() private { _taxFee = _previousTaxFee; _liquidityFee = _previousLiquidityFee; } function isExcludedFromFee(address account) public view returns(bool) { return _isExcludedFromFee[account]; } function _approve(address owner, address spender, uint256 amount) private { 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); } function _transfer( address from, address to, uint256 amount ) private { require(from != address(0), "ERC20: transfer from the zero address"); require(to != address(0), "ERC20: transfer to the zero address"); require(amount > 0, "Transfer amount must be greater than zero"); if(from != owner() && to != owner()) require(amount <= _maxTxAmount, "Transfer amount exceeds the maxTxAmount."); // is the token balance of this contract address over the min number of // tokens that we need to initiate a swap + liquidity lock? // also, don't get caught in a circular liquidity event. // also, don't swap & liquify if sender is uniswap pair. uint256 contractTokenBalance = balanceOf(address(this)); if(contractTokenBalance >= _maxTxAmount) { contractTokenBalance = _maxTxAmount; } bool overMinTokenBalance = contractTokenBalance >= numTokensSellToAddToLiquidity; if ( overMinTokenBalance && !inSwapAndLiquify && from != uniswapV2Pair && swapAndLiquifyEnabled ) { contractTokenBalance = numTokensSellToAddToLiquidity; //add liquidity swapAndLiquify(contractTokenBalance); } //indicates if fee should be deducted from transfer bool takeFee = true; //if any account belongs to _isExcludedFromFee account then remove the fee if(_isExcludedFromFee[from] || _isExcludedFromFee[to]){ takeFee = false; } //transfer amount, it will take tax, burn, liquidity fee _tokenTransfer(from,to,amount,takeFee); } function swapAndLiquify(uint256 contractTokenBalance) private lockTheSwap { // split the contract balance into halves uint256 half = contractTokenBalance.div(2); uint256 otherHalf = contractTokenBalance.sub(half); // capture the contract's current ETH balance. // this is so that we can capture exactly the amount of ETH that the // swap creates, and not make the liquidity event include any ETH that // has been manually sent to the contract uint256 initialBalance = address(this).balance; // swap tokens for ETH swapTokensForEth(half); // <- this breaks the ETH -> HATE swap when swap+liquify is triggered // how much ETH did we just swap into? uint256 newBalance = address(this).balance.sub(initialBalance); // add liquidity to uniswap addLiquidity(otherHalf, newBalance); emit SwapAndLiquify(half, newBalance, otherHalf); } 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 ); } //this method is responsible for taking all fee, if takeFee is true function _tokenTransfer(address sender, address recipient, uint256 amount,bool takeFee) private { if(!takeFee) removeAllFee(); if (_isExcluded[sender] && !_isExcluded[recipient]) { _transferFromExcluded(sender, recipient, amount); } else if (!_isExcluded[sender] && _isExcluded[recipient]) { _transferToExcluded(sender, recipient, amount); } else if (!_isExcluded[sender] && !_isExcluded[recipient]) { _transferStandard(sender, recipient, amount); } else if (_isExcluded[sender] && _isExcluded[recipient]) { _transferBothExcluded(sender, recipient, amount); } else { _transferStandard(sender, recipient, amount); } if(!takeFee) restoreAllFee(); } function _transferStandard(address sender, address recipient, uint256 tAmount) private { (uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity) = _getValues(tAmount); _rOwned[sender] = _rOwned[sender].sub(rAmount); _rOwned[recipient] = _rOwned[recipient].add(rTransferAmount); _takeLiquidity(tLiquidity); _reflectFee(rFee, tFee); emit Transfer(sender, recipient, tTransferAmount); } function _transferToExcluded(address sender, address recipient, uint256 tAmount) private { (uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity) = _getValues(tAmount); _rOwned[sender] = _rOwned[sender].sub(rAmount); _tOwned[recipient] = _tOwned[recipient].add(tTransferAmount); _rOwned[recipient] = _rOwned[recipient].add(rTransferAmount); _takeLiquidity(tLiquidity); _reflectFee(rFee, tFee); emit Transfer(sender, recipient, tTransferAmount); } function _transferFromExcluded(address sender, address recipient, uint256 tAmount) private { (uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity) = _getValues(tAmount); _tOwned[sender] = _tOwned[sender].sub(tAmount); _rOwned[sender] = _rOwned[sender].sub(rAmount); _rOwned[recipient] = _rOwned[recipient].add(rTransferAmount); _takeLiquidity(tLiquidity); _reflectFee(rFee, tFee); emit Transfer(sender, recipient, tTransferAmount); } }

This repository contains reusable, security-focused smart contract modules, inspired by OpenZeppelin’s security patterns, but written from scratch with modern Solidity features.

Solidity Vulnerability Patterns repository, the ultimate arena for detecting and understanding the most cunning vulnerabilities that lurk in the shadows of smart contract development.

From O(n) to O(1): Understanding tree and graph data structures in production DeFi protocols. Case studies, Solidity implementations, and gas optimization patterns for smart contract engineers.