Last active
September 7, 2020 09:06
-
-
Save clar/2c6cabfce2ec6b231ed57abc0f8aeb19 to your computer and use it in GitHub Desktop.
ERC20StandardToken
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
/** | |
*Submitted for verification at Etherscan.io on 2020-03-14 | |
*/ | |
pragma solidity ^0.4.24; | |
//ERC20 | |
contract ERC20Ownable { | |
address public owner; | |
constructor() public{ | |
owner = msg.sender; | |
} | |
modifier onlyOwner { | |
require(msg.sender == owner); | |
_; | |
} | |
function transferOwnership(address newOwner) onlyOwner public{ | |
if (newOwner != address(0)) { | |
owner = newOwner; | |
} | |
} | |
} | |
contract ERC20 { | |
function transfer(address to, uint256 value) public returns (bool); | |
function balanceOf(address who) public view returns (uint256); | |
event Transfer(address indexed from, address indexed to, uint256 value); | |
} | |
contract ERC20Token is ERC20,ERC20Ownable { | |
mapping (address => uint256) balances; | |
mapping (address => mapping (address => uint256)) allowed; | |
event Transfer( | |
address indexed _from, | |
address indexed _to, | |
uint256 _value | |
); | |
event Approval( | |
address indexed _owner, | |
address indexed _spender, | |
uint256 _value | |
); | |
//Fix for short address attack against ERC20 | |
modifier onlyPayloadSize(uint size) { | |
assert(msg.data.length == size + 4); | |
_; | |
} | |
function balanceOf(address _owner) constant public returns (uint256) { | |
return balances[_owner]; | |
} | |
function transfer(address _to, uint256 _value) onlyPayloadSize(2*32) public returns (bool){ | |
require(balances[msg.sender] >= _value && _value > 0); | |
balances[msg.sender] -= _value; | |
balances[_to] += _value; | |
emit Transfer(msg.sender, _to, _value); | |
return true; | |
} | |
function transferFrom(address _from, address _to, uint256 _value) public returns (bool) { | |
require(balances[_from] >= _value && allowed[_from][msg.sender] >= _value && _value > 0); | |
balances[_to] += _value; | |
balances[_from] -= _value; | |
allowed[_from][msg.sender] -= _value; | |
emit Transfer(_from, _to, _value); | |
return true; | |
} | |
function approve(address _spender, uint256 _value) public { | |
allowed[msg.sender][_spender] = _value; | |
emit Approval(msg.sender, _spender, _value); | |
} | |
/* Approves and then calls the receiving contract */ | |
function approveAndCall(address _spender, uint256 _value, bytes _extraData) public returns (bool success) { | |
allowed[msg.sender][_spender] = _value; | |
emit Approval(msg.sender, _spender, _value); | |
//call the receiveApproval function on the contract you want to be notified. This crafts the function signature manually so one doesn't have to include a contract in here just for this. | |
//receiveApproval(address _from, uint256 _value, address _tokenContract, bytes _extraData) | |
//it is assumed that when does this that the call *should* succeed, otherwise one would use vanilla approve instead. | |
//require(_spender.call(bytes4(keccak256("receiveApproval(address,uint256,address,bytes)")), abi.encode(msg.sender, _value, this, _extraData))); | |
require(_spender.call(abi.encodeWithSelector(bytes4(keccak256("receiveApproval(address,uint256,address,bytes)")),msg.sender, _value, this, _extraData))); | |
return true; | |
} | |
function allowance(address _owner, address _spender) constant public returns (uint256) { | |
return allowed[_owner][_spender]; | |
} | |
} | |
contract ERC20StandardToken is ERC20Token { | |
uint256 public totalSupply; | |
string public name; | |
uint256 public decimals; | |
string public symbol; | |
bool public mintable; | |
constructor(address _owner, string _name, string _symbol, uint256 _decimals, uint256 _totalSupply, bool _mintable) public { | |
require(_owner != address(0)); | |
owner = _owner; | |
decimals = _decimals; | |
symbol = _symbol; | |
name = _name; | |
mintable = _mintable; | |
totalSupply = _totalSupply; | |
balances[_owner] = totalSupply; | |
emit Transfer(address(0), _owner, totalSupply); | |
} | |
function mint(uint256 amount) onlyOwner public { | |
require(mintable); | |
require(amount >= 0); | |
balances[msg.sender] += amount; | |
totalSupply += amount; | |
} | |
function burn(uint256 _value) onlyOwner public returns (bool) { | |
require(balances[msg.sender] >= _value && totalSupply >=_value && _value > 0); | |
balances[msg.sender] -= _value; | |
totalSupply -= _value; | |
emit Transfer(msg.sender, 0x0, _value); | |
return true; | |
} | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment