Contract Name:
HashcardToken
Contract Source Code:
File 1 of 1 : HashcardToken
pragma solidity 0.4.23;
/**
* @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) {
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);
return a - b;
}
/**
* @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 ERC20Basic
* @dev Simpler version of ERC20 interface
* @dev see https://github.com/ethereum/EIPs/issues/179
*/
contract ERC20Basic {
function totalSupply() public view returns (uint256);
function balanceOf(address who) public view returns (uint256);
function transfer(address to, uint256 value) public returns (bool);
event Transfer(address indexed from, address indexed to, uint256 value);
}
/**
* @title Basic token
* @dev Basic version of StandardToken, with no allowances.
*/
contract BasicToken is ERC20Basic {
using SafeMath for uint256;
mapping(address => uint256) internal balances;
uint256 internal totalSupply_;
/**
* @dev total number of tokens in existence
*/
function totalSupply() public view returns (uint256) {
return totalSupply_;
}
/**
* @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(_to != address(0));
require(_value <= balances[msg.sender]);
// SafeMath.sub will throw if there is not enough balance.
balances[msg.sender] = balances[msg.sender].sub(_value);
balances[_to] = balances[_to].add(_value);
emit Transfer(msg.sender, _to, _value);
return true;
}
/**
* @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 balance) {
return balances[_owner];
}
}
/**
* @title ERC20 interface
* @dev see https://github.com/ethereum/EIPs/issues/20
*/
contract ERC20 is ERC20Basic {
function allowance(address owner, address spender) public view returns (uint256);
function transferFrom(address from, address to, uint256 value) public returns (bool);
function approve(address spender, uint256 value) public returns (bool);
event Approval(address indexed owner, address indexed spender, uint256 value);
}
/**
* @title Standard ERC20 token
*
* @dev Implementation of the basic standard token.
* @dev https://github.com/ethereum/EIPs/issues/20
* @dev Based on code by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
*/
contract StandardToken is ERC20, BasicToken {
mapping (address => mapping (address => uint256)) internal allowed;
/**
* @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(_to != address(0));
require(_value <= balances[_from]);
require(_value <= allowed[_from][msg.sender]);
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 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 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 remaining) {
return allowed[_owner][_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
*/
function increaseApproval (address _spender, uint _addedValue) public returns (bool success) {
allowed[msg.sender][_spender] = allowed[msg.sender][_spender].add(_addedValue);
emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
return true;
}
function decreaseApproval (address _spender, uint _subtractedValue) public returns (bool success) {
uint 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 SafeERC20
* @dev Wrappers around ERC20 operations that throw on failure.
* To use this library you can add a `using SafeERC20 for ERC20;` statement to your contract,
* which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
*/
library SafeERC20 {
function safeTransfer(ERC20Basic token, address to, uint256 value) internal {
assert(token.transfer(to, value));
}
function safeTransferFrom(ERC20 token, address from, address to, uint256 value) internal {
assert(token.transferFrom(from, to, value));
}
function safeApprove(ERC20 token, address spender, uint256 value) internal {
assert(token.approve(spender, value));
}
}
/**
* @title TokenTimelock
* @dev TokenTimelock is a token holder contract that will allow a
* beneficiary to extract the tokens after a given release time
*/
contract TokenTimelock {
using SafeERC20 for ERC20Basic;
// ERC20 basic token contract being held
ERC20Basic public token;
// beneficiary of tokens after they are released
address public beneficiary;
// timestamp when token release is enabled
uint64 public releaseTime;
constructor(ERC20Basic _token, address _beneficiary, uint64 _releaseTime) public {
require(_releaseTime > uint64(block.timestamp));
token = _token;
beneficiary = _beneficiary;
releaseTime = _releaseTime;
}
/**
* @notice Transfers tokens held by timelock to beneficiary.
*/
function release() public {
require(uint64(block.timestamp) >= releaseTime);
uint256 amount = token.balanceOf(this);
require(amount > 0);
token.safeTransfer(beneficiary, amount);
}
}
/**
* @title Burnable Token
* @dev Token that can be irreversibly burned (destroyed).
*/
contract BurnableToken is BasicToken {
event Burn(address indexed burner, uint256 value);
/**
* @dev Burns a specific amount of tokens.
* @param _value The amount of token to be burned.
*/
function burn(uint256 _value) public {
_burn(msg.sender, _value);
}
function _burn(address _who, uint256 _value) internal {
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);
}
}
contract Owned {
address public owner;
constructor() public {
owner = msg.sender;
}
modifier onlyOwner {
require(msg.sender == owner);
_;
}
}
contract HashcardToken is StandardToken, BurnableToken, Owned {
string public constant name = "Hash Card";
string public constant symbol = "HSHC";
uint8 public constant decimals = 18;
/// Maximum tokens to be allocated (150 million)
uint256 public constant HARD_CAP = 150000000 * 10**uint256(decimals);
/// This address is used to keep the tokens for sale
address public saleTokensAddress;
/// This address is used to keep the bounty tokens
address public bountyTokensAddress;
/// This address is used to keep the reserve tokens
address public reserveTokensAddress;
/// This address will receive the team tokens once they are unlocked
address public teamTokensAddress;
/// This address will receive the advisors tokens once they are unlocked
address public advisorsTokensAddress;
/// This address will hold the locked Team tokens
TokenTimelock public teamTokensLock;
/// This address will hold the locked Advisors tokens
TokenTimelock public advisorsTokensLock;
/// Team and Advisors unlock date (01 Nov 2019)
uint64 private constant date01Nov2019 = 1572566400;
/// the trading will open when this is set to true
bool public saleClosed = false;
/// Only the team is allowed to execute
modifier onlySaleTeam {
require(msg.sender == saleTokensAddress || msg.sender == bountyTokensAddress);
_;
}
/// Only allowed to execute before the token sale is closed
modifier beforeEnd {
require(!saleClosed);
_;
}
constructor(address _teamTokensAddress, address _advisorsTokensAddress, address _reserveTokensAddress,
address _saleTokensAddress, address _bountyTokensAddress) public {
require(_teamTokensAddress != address(0));
require(_advisorsTokensAddress != address(0));
require(_reserveTokensAddress != address(0));
require(_saleTokensAddress != address(0));
require(_bountyTokensAddress != address(0));
teamTokensAddress = _teamTokensAddress;
advisorsTokensAddress = _advisorsTokensAddress;
reserveTokensAddress = _reserveTokensAddress;
saleTokensAddress = _saleTokensAddress;
bountyTokensAddress = _bountyTokensAddress;
/// Maximum tokens to be allocated on the sale
/// 90 million HSHC
uint256 saleTokens = 90000000 * 10**uint256(decimals);
totalSupply_ = saleTokens;
balances[saleTokensAddress] = saleTokens;
emit Transfer(address(0), saleTokensAddress, saleTokens);
/// Bounty tokens - 6 million HSHC
uint256 bountyTokens = 6000000 * 10**uint256(decimals);
totalSupply_ = totalSupply_.add(bountyTokens);
balances[bountyTokensAddress] = bountyTokens;
emit Transfer(address(0), bountyTokensAddress, bountyTokens);
/// Reserve tokens - 24 million HSHC
uint256 reserveTokens = 24000000 * 10**uint256(decimals);
totalSupply_ = totalSupply_.add(reserveTokens);
balances[reserveTokensAddress] = reserveTokens;
emit Transfer(address(0), reserveTokensAddress, reserveTokens);
/// Team tokens - 22.5M HSHC
uint256 teamTokens = 22500000 * 10**uint256(decimals);
totalSupply_ = totalSupply_.add(teamTokens);
teamTokensLock = new TokenTimelock(this, teamTokensAddress, date01Nov2019);
balances[address(teamTokensLock)] = teamTokens;
emit Transfer(address(0), address(teamTokensLock), teamTokens);
/// Advisors tokens - 7.5M HSHC
uint256 advisorsTokens = 7500000 * 10**uint256(decimals);
totalSupply_ = totalSupply_.add(advisorsTokens);
advisorsTokensLock = new TokenTimelock(this, advisorsTokensAddress, date01Nov2019);
balances[address(advisorsTokensLock)] = advisorsTokens;
emit Transfer(address(0), address(advisorsTokensLock), advisorsTokens);
}
function close() public onlyOwner beforeEnd {
/// The unsold and unallocated bounty tokens are burnt
_burn(saleTokensAddress, balances[saleTokensAddress]);
_burn(bountyTokensAddress, balances[bountyTokensAddress]);
saleClosed = true;
}
/// @dev Trading limited - requires the token sale to have closed
function transferFrom(address _from, address _to, uint256 _value) public returns (bool) {
if(!saleClosed) return false;
return super.transferFrom(_from, _to, _value);
}
/// @dev Trading limited - requires the token sale to have closed
function transfer(address _to, uint256 _value) public returns (bool) {
if(!saleClosed && msg.sender != saleTokensAddress && msg.sender != bountyTokensAddress) return false;
return super.transfer(_to, _value);
}
}