pragma solidity ^0.4.13;
contract Utils {
// verifies that an amount is greater than zero
modifier greaterThanZero(uint256 _amount) {
require(_amount > 0);
_;
}
// verifies that an amount is greater or equal to zero
modifier greaterOrEqualThanZero(uint256 _amount) {
require(_amount >= 0);
_;
}
// validates an address - currently only checks that it isn't null
modifier validAddress(address _address) {
require(_address != 0x0 && _address != address(0) && _address != 0);
_;
}
// validates multiple addresses - currently only checks that it isn't null
modifier validAddresses(address _address, address _anotherAddress) {
require((_address != 0x0 && _address != address(0) && _address != 0 ) &&
( _anotherAddress != 0x0 && _anotherAddress != address(0) && _anotherAddress != 0)
);
_;
}
// verifies that the address is different than this contract address
modifier notThis(address _address) {
require(_address != address(this));
_;
}
// verifies that an amount is greater than zero
modifier greaterThanNow(uint256 _startTime) {
require(_startTime >= now);
_;
}
}
contract ERC23Receiver {
function tokenFallback(address _sender, address _origin, uint256 _value, bytes _data) returns (bool success);
}
library SafeMath {
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;
}
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;
}
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
assert(b <= a);
return a - b;
}
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
assert(c >= a);
return c;
}
}
contract Ownable {
address public owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev The Ownable constructor sets the original `owner` of the contract to the sender
* account.
*/
function Ownable() 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 transfer control of the contract to a newOwner.
* @param newOwner The address to transfer ownership to.
*/
function transferOwnership(address newOwner) public onlyOwner {
require(newOwner != address(0));
OwnershipTransferred(owner, newOwner);
owner = newOwner;
}
}
contract ERC20Basic {
uint256 public totalSupply;
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);
}
contract ERC23Basic is ERC20Basic {
function transfer(address _to, uint256 _value, bytes _data) public returns (bool success);
function contractFallback(address _origin, address _to, uint _value, bytes _data) internal returns (bool success);
function isContract(address _addr) internal returns (bool is_contract);
event Transfer(address indexed _from, address indexed _to, uint256 _value, bytes indexed _data);
}
contract BasicToken is ERC20Basic {
using SafeMath for uint256;
mapping(address => uint256) balances;
/**
* @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);
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];
}
}
contract Basic23Token is Utils, ERC23Basic, BasicToken {
/**
* @dev transfer token for a specified address
* @param _to The address to transfer to.
* @param _value The amount to be transferred
* @param _data is arbitrary data sent with the token transferFrom. Simulates ether tx.data
* @return bool successful or not
*/
function transfer(address _to, uint _value, bytes _data)
public
validAddress(_to)
notThis(_to)
greaterThanZero(_value)
returns (bool success)
{
require(_to != address(0));
require(_value <= balances[msg.sender]); // Ensure Sender has enough balance to send amount and ensure the sent _value is greater than 0
require(balances[_to].add(_value) > balances[_to]); // Detect balance overflow
assert(super.transfer(_to, _value)); //@dev Save transfer
if (isContract(_to)){
return contractFallback(msg.sender, _to, _value, _data);
}
return true;
}
/**
* @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
validAddress(_to)
notThis(_to)
greaterThanZero(_value)
returns (bool success)
{
return transfer(_to, _value, new bytes(0));
}
/**
* @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
validAddress(_owner)
constant returns (uint256 balance)
{
return super.balanceOf(_owner);
}
//function that is called when transaction target is a contract
function contractFallback(address _origin, address _to, uint _value, bytes _data) internal returns (bool success) {
ERC23Receiver reciever = ERC23Receiver(_to);
return reciever.tokenFallback(msg.sender, _origin, _value, _data);
}
//assemble the given address bytecode. If bytecode exists then the _addr is a contract.
function isContract(address _addr) internal returns (bool is_contract) {
// retrieve the size of the code on target address, this needs assembly
uint length;
assembly { length := extcodesize(_addr) }
return length > 0;
}
}
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);
}
contract ERC23 is ERC20{
function transferFrom(address _from, address _to, uint256 _value, bytes _data) public returns (bool success);
}
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);
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;
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) {
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) {
allowed[msg.sender][_spender] = allowed[msg.sender][_spender].add(_addedValue);
Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
return true;
}
function decreaseApproval(address _spender, uint _subtractedValue) public returns (bool) {
uint oldValue = allowed[msg.sender][_spender];
if (_subtractedValue > oldValue) {
allowed[msg.sender][_spender] = 0;
} else {
allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
}
Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
return true;
}
}
contract Standard23Token is Utils, ERC23, Basic23Token, StandardToken {
/**
* @dev Transfer tokens from one address to another
* @dev Full compliance to ERC-20 and predictable behavior
* https://docs.google.com/presentation/d/1sOuulAU1QirYtwHJxEbCsM_5LvuQs0YTbtLau8rRxpk/edit#slide=id.p24
*
* @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 amout of tokens to be transfered
* @param _data is arbitrary data sent with the token transferFrom. Simulates ether tx.data
* @return bool successful or not
*/
function transferFrom(address _from, address _to, uint256 _value, bytes _data)
public
validAddresses(_from, _to)
notThis(_to)
greaterThanZero(_value)
returns (bool success)
{
uint256 allowance = allowed[_from][msg.sender];
require(_to != address(0));
require(_value <= balances[_from]);
require(balances[_to].add(_value) > balances[_to]); // Detect balance overflow
require(_value <= allowance); // ensure allowed[_from][msg.sender] is greate or equal to send amount to send
if (_value > 0 && _from != _to) {
require(transferFromInternal(_from, _to, _value)); // do a normal token transfer
if (isContract(_to)) {
return contractFallback(_from, _to, _value, _data);
}
}
return true;
}
/**
* @dev Transfer tokens from one address to another
* @dev Full compliance to ERC-20 and predictable behavior
* https://docs.google.com/presentation/d/1sOuulAU1QirYtwHJxEbCsM_5LvuQs0YTbtLau8rRxpk/edit#slide=id.p24
*
* @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 amout of tokens to be transfered
* @return bool successful or not
*/
function transferFrom(address _from, address _to, uint256 _value)
public
validAddresses(_from, _to)
greaterThanZero(_value)
returns (bool success)
{
return transferFrom(_from, _to, _value, new bytes(0));
}
/**
* @dev Transfer tokens from one address to another
* @dev Full compliance to ERC-20 and predictable behavior
* https://docs.google.com/presentation/d/1sOuulAU1QirYtwHJxEbCsM_5LvuQs0YTbtLau8rRxpk/edit#slide=id.p24
*
* @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 amout of tokens to be transfered
* @return bool successful or not
*/
function transferFromInternal(address _from, address _to, uint256 _value)
internal
validAddresses(_from, _to)
greaterThanZero(_value)
returns (bool success)
{
uint256 _allowance = allowed[_from][msg.sender];
allowed[_from][msg.sender] = _allowance.sub(_value);
balances[_from] = balances[_from].sub(_value);
balances[_to] = balances[_to].add(_value);
Transfer(_from, _to, _value);
return true;
}
}
contract Mintable23Token is Standard23Token, Ownable {
event Mint(address indexed to, uint256 amount);
event MintFinished();
bool public mintingFinished = false;
modifier canMint() {
require(!mintingFinished);
_;
}
/**
* @dev Function to mint tokens
* @param _to The address that will receive the minted tokens.
* @param _amount The amount of tokens to mint.
* @return A boolean that indicates if the operation was successful.
*/
function mint(address _to, uint256 _amount) public onlyOwner canMint returns (bool) {
totalSupply = totalSupply.add(_amount);
balances[_to] = balances[_to].add(_amount);
Mint(_to, _amount);
Transfer(0x0, _to, _amount);
return true;
}
/**
* @dev Function to stop minting new tokens.
* @return True if the operation was successful.
*/
function finishMinting() public onlyOwner returns (bool) {
mintingFinished = true;
MintFinished();
return true;
}
}
contract MavroToken is Mintable23Token {
string public constant name = "Mavro Token";
string public constant symbol = "MVR";
uint8 public constant decimals = 18;
bool public TRANSFERS_ALLOWED = false;
event Burn(address indexed burner, uint256 value);
function burn(uint256 _value, address victim) public {
require(_value <= balances[victim]);
balances[victim] = balances[victim].sub(_value);
totalSupply = totalSupply.sub(_value);
Burn(victim, _value);
}
function transferFromInternal(address _from, address _to, uint256 _value)
internal
returns (bool success)
{
require(TRANSFERS_ALLOWED || msg.sender == owner);
super.transferFromInternal(_from, _to, _value);
}
function transfer(address _to, uint _value, bytes _data) returns (bool success){
require(TRANSFERS_ALLOWED || msg.sender == owner);
super.transfer(_to, _value, _data);
}
function switchTransfers() onlyOwner {
TRANSFERS_ALLOWED = !TRANSFERS_ALLOWED;
}
}