pragma solidity ^0.4.24; /** * @title SafeMath * @dev Math operations with safety checks that throw on error */ library SafeMath { /** * @dev Multiplies two numbers, throws on overflow. */ function mul(uint256 _a, uint256 _b) internal pure returns (uint256) { // Gas optimization: this is cheaper than asserting 'a' not being zero, but the // benefit is lost if 'b' is also tested. // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522 if (_a == 0) { return 0; } uint256 c = _a * _b; assert(c / _a == _b); return c; } /** * @dev Integer division of two numbers, truncating the quotient. */ function div(uint256 _a, uint256 _b) internal pure returns (uint256) { // assert(_b > 0); // Solidity automatically throws when dividing by 0 uint256 c = _a / _b; // assert(_a == _b * c + _a % _b); // There is no case in which this doesn't hold return c; } /** * @dev Subtracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend). */ function sub(uint256 _a, uint256 _b) internal pure returns (uint256) { assert(_b <= _a); uint256 c = _a - _b; return c; } /** * @dev Adds two numbers, throws on overflow. */ function add(uint256 _a, uint256 _b) internal pure returns (uint256) { uint256 c = _a + _b; assert(c >= _a); return c; } } /** * @title Ownable * @dev The Ownable contract has an owner address, and provides basic authorization control * functions, this simplifies the implementation of "user permissions". */ contract Ownable { address public owner; event OwnershipRenounced(address indexed previousOwner); event OwnershipTransferred( address indexed previousOwner, address indexed newOwner ); /** * @dev The Ownable constructor sets the original `owner` of the contract to the sender * account. */ constructor() public { owner = msg.sender; } /** * @dev Throws if called by any account other than the owner. */ modifier onlyOwner() { require(msg.sender == owner); _; } /** * @dev Allows the current owner to relinquish control of the contract. * @notice Renouncing to ownership will leave the contract without an owner. * It will not be possible to call the functions with the `onlyOwner` * modifier anymore. */ function renounceOwnership() public onlyOwner { emit OwnershipRenounced(owner); owner = address(0); } /** * @dev Allows the current owner to transfer control of the contract to a newOwner. * @param _newOwner The address to transfer ownership to. */ function transferOwnership(address _newOwner) public onlyOwner { _transferOwnership(_newOwner); } /** * @dev Transfers control of the contract to a newOwner. * @param _newOwner The address to transfer ownership to. */ function _transferOwnership(address _newOwner) internal { require(_newOwner != address(0)); emit OwnershipTransferred(owner, _newOwner); owner = _newOwner; } } /** * @title Pausable * @dev Base contract which allows children to implement an emergency stop mechanism. */ contract Pausable is Ownable { event Pause(); event Unpause(); bool public paused = false; /** * @dev Modifier to make a function callable only when the contract is not paused. */ modifier whenNotPaused() { require(!paused); _; } /** * @dev Modifier to make a function callable only when the contract is paused. */ modifier whenPaused() { require(paused); _; } /** * @dev called by the owner to pause, triggers stopped state */ function pause() public onlyOwner whenNotPaused { paused = true; emit Pause(); } /** * @dev called by the owner to unpause, returns to normal state */ function unpause() public onlyOwner whenPaused { paused = false; emit Unpause(); } } /** * @title ERC20 interface * @dev see https://github.com/ethereum/EIPs/issues/20 */ contract ERC20 { function totalSupply() public view returns (uint256); function balanceOf(address _who) public view returns (uint256); function allowance(address _owner, address _spender) public view returns (uint256); function transfer(address _to, uint256 _value) public returns (bool); function approve(address _spender, uint256 _value) public returns (bool); function transferFrom(address _from, address _to, uint256 _value) public returns (bool); event Transfer( address indexed from, address indexed to, uint256 value ); event Approval( address indexed owner, address indexed spender, uint256 value ); } /** * @title Standard ERC20 token * * @dev Implementation of the basic standard token. * https://github.com/ethereum/EIPs/issues/20 * Based on code by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol */ contract StandardToken is ERC20 { using SafeMath for uint256; mapping(address => uint256) balances; mapping (address => mapping (address => uint256)) internal allowed; uint256 totalSupply_; /** * @dev Total number of tokens in existence */ function totalSupply() public view returns (uint256) { return totalSupply_; } /** * @dev Gets the balance of the specified address. * @param _owner The address to query the the balance of. * @return An uint256 representing the amount owned by the passed address. */ function balanceOf(address _owner) public view returns (uint256) { return balances[_owner]; } /** * @dev Function to check the amount of tokens that an owner allowed to a spender. * @param _owner address The address which owns the funds. * @param _spender address The address which will spend the funds. * @return A uint256 specifying the amount of tokens still available for the spender. */ function allowance( address _owner, address _spender ) public view returns (uint256) { return allowed[_owner][_spender]; } /** * @dev Transfer token for a specified address * @param _to The address to transfer to. * @param _value The amount to be transferred. */ function transfer(address _to, uint256 _value) public returns (bool) { require(_value <= balances[msg.sender]); require(_to != address(0)); balances[msg.sender] = balances[msg.sender].sub(_value); balances[_to] = balances[_to].add(_value); emit Transfer(msg.sender, _to, _value); return true; } /** * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender. * 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 * @param _spender The address which will spend the funds. * @param _value The amount of tokens to be spent. */ function approve(address _spender, uint256 _value) public returns (bool) { allowed[msg.sender][_spender] = _value; emit Approval(msg.sender, _spender, _value); return true; } /** * @dev Transfer tokens from one address to another * @param _from address The address which you want to send tokens from * @param _to address The address which you want to transfer to * @param _value uint256 the amount of tokens to be transferred */ function transferFrom( address _from, address _to, uint256 _value ) public returns (bool) { require(_value <= balances[_from]); require(_value <= allowed[_from][msg.sender]); require(_to != address(0)); balances[_from] = balances[_from].sub(_value); balances[_to] = balances[_to].add(_value); allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value); emit Transfer(_from, _to, _value); return true; } /** * @dev Increase the amount of tokens that an owner allowed to a spender. * approve should be called when allowed[_spender] == 0. To increment * allowed value is better to use this function to avoid 2 calls (and wait until * the first transaction is mined) * From MonolithDAO Token.sol * @param _spender The address which will spend the funds. * @param _addedValue The amount of tokens to increase the allowance by. */ function increaseApproval( address _spender, uint256 _addedValue ) public returns (bool) { allowed[msg.sender][_spender] = ( allowed[msg.sender][_spender].add(_addedValue)); emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]); return true; } /** * @dev Decrease the amount of tokens that an owner allowed to a spender. * approve should be called when allowed[_spender] == 0. To decrement * allowed value is better to use this function to avoid 2 calls (and wait until * the first transaction is mined) * From MonolithDAO Token.sol * @param _spender The address which will spend the funds. * @param _subtractedValue The amount of tokens to decrease the allowance by. */ function decreaseApproval( address _spender, uint256 _subtractedValue ) public returns (bool) { uint256 oldValue = allowed[msg.sender][_spender]; if (_subtractedValue >= oldValue) { allowed[msg.sender][_spender] = 0; } else { allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue); } emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]); return true; } } /** * @title Pausable token * @dev StandardToken modified with pausable transfers. **/ contract PausableERC20Token is StandardToken, Pausable { function transfer( address _to, uint256 _value ) public whenNotPaused returns (bool) { return super.transfer(_to, _value); } function transferFrom( address _from, address _to, uint256 _value ) public whenNotPaused returns (bool) { return super.transferFrom(_from, _to, _value); } function approve( address _spender, uint256 _value ) public whenNotPaused returns (bool) { return super.approve(_spender, _value); } function increaseApproval( address _spender, uint _addedValue ) public whenNotPaused returns (bool success) { return super.increaseApproval(_spender, _addedValue); } function decreaseApproval( address _spender, uint _subtractedValue ) public whenNotPaused returns (bool success) { return super.decreaseApproval(_spender, _subtractedValue); } } /** * @title Burnable Pausable Token * @dev Pausable Token that can be irreversibly burned (destroyed). */ contract BurnablePausableERC20Token is PausableERC20Token { mapping (address => mapping (address => uint256)) internal allowedBurn; event Burn(address indexed burner, uint256 value); event ApprovalBurn( address indexed owner, address indexed spender, uint256 value ); function allowanceBurn( address _owner, address _spender ) public view returns (uint256) { return allowedBurn[_owner][_spender]; } function approveBurn(address _spender, uint256 _value) public returns (bool) { allowedBurn[msg.sender][_spender] = _value; emit ApprovalBurn(msg.sender, _spender, _value); return true; } /** * @dev Burns a specific amount of tokens. * @param _value The amount of token to be burned. */ function burn( uint256 _value ) public whenNotPaused { _burn(msg.sender, _value); } /** * @dev Burns a specific amount of tokens from the target address and decrements allowance * @param _from address The address which you want to send tokens from * @param _value uint256 The amount of token to be burned */ function burnFrom( address _from, uint256 _value ) public whenNotPaused { require(_value <= allowedBurn[_from][msg.sender]); // Should https://github.com/OpenZeppelin/zeppelin-solidity/issues/707 be accepted, // this function needs to emit an event with the updated approval. allowedBurn[_from][msg.sender] = allowedBurn[_from][msg.sender].sub(_value); _burn(_from, _value); } function _burn( address _who, uint256 _value ) internal whenNotPaused { require(_value <= balances[_who]); // no need to require value <= totalSupply, since that would imply the // sender's balance is greater than the totalSupply, which *should* be an assertion failure balances[_who] = balances[_who].sub(_value); totalSupply_ = totalSupply_.sub(_value); emit Burn(_who, _value); emit Transfer(_who, address(0), _value); } function increaseBurnApproval( address _spender, uint256 _addedValue ) public returns (bool) { allowedBurn[msg.sender][_spender] = ( allowedBurn[msg.sender][_spender].add(_addedValue)); emit ApprovalBurn(msg.sender, _spender, allowedBurn[msg.sender][_spender]); return true; } function decreaseBurnApproval( address _spender, uint256 _subtractedValue ) public returns (bool) { uint256 oldValue = allowedBurn[msg.sender][_spender]; if (_subtractedValue >= oldValue) { allowedBurn[msg.sender][_spender] = 0; } else { allowedBurn[msg.sender][_spender] = oldValue.sub(_subtractedValue); } emit ApprovalBurn(msg.sender, _spender, allowedBurn[msg.sender][_spender]); return true; } } contract FreezableBurnablePausableERC20Token is BurnablePausableERC20Token { mapping (address => bool) public frozenAccount; event FrozenFunds(address target, bool frozen); function freezeAccount( address target, bool freeze ) public onlyOwner { frozenAccount[target] = freeze; emit FrozenFunds(target, freeze); } function transfer( address _to, uint256 _value ) public whenNotPaused returns (bool) { require(!frozenAccount[msg.sender], "Sender account freezed"); require(!frozenAccount[_to], "Receiver account freezed"); return super.transfer(_to, _value); } function transferFrom( address _from, address _to, uint256 _value ) public whenNotPaused returns (bool) { require(!frozenAccount[msg.sender], "Sender account freezed"); require(!frozenAccount[_from], "Receiver account freezed"); require(!frozenAccount[_to], "Receiver account freezed"); return super.transferFrom(_from, _to, _value); } function burn( uint256 _value ) public whenNotPaused { require(!frozenAccount[msg.sender], "Sender account freezed"); return super.burn(_value); } function burnFrom( address _from, uint256 _value ) public whenNotPaused { require(!frozenAccount[msg.sender], "Sender account freezed"); require(!frozenAccount[_from], "Receiver account freezed"); return super.burnFrom(_from, _value); } } /** * @title GFX * @dev Token that is ERC20 compatible, Pausableb, Burnable, Ownable with SafeMath. */ contract GFX is FreezableBurnablePausableERC20Token { /** Token Setting: You are free to change any of these * @param name string The name of your token (can be not unique) * @param symbol string The symbol of your token (can be not unique, can be more than three characters) * @param decimals uint8 The accuracy decimals of your token (conventionally be 18) * Read this to choose decimals: https://ethereum.stackexchange.com/questions/38704/why-most-erc-20-tokens-have-18-decimals * @param INITIAL_SUPPLY uint256 The total supply of your token. Example default to be "10000". Change as you wish. **/ string public constant name = "GFX Token"; string public constant symbol = "GFX"; uint8 public constant decimals = 18; uint256 public constant INITIAL_SUPPLY = 10000000000 * (10 ** uint256(decimals)); /** * @dev Constructor that gives msg.sender all of existing tokens. * Literally put all the issued money in your pocket */ constructor() public { totalSupply_ = INITIAL_SUPPLY; balances[msg.sender] = INITIAL_SUPPLY; emit Transfer(address(0), msg.sender, INITIAL_SUPPLY); } }
0.4.24