Contract Name:
DistributedCreditChain
Contract Source Code:
File 1 of 1 : DistributedCreditChain
pragma solidity ^0.4.18;
/**
* @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 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;
}
}
/**
* @title ERC20Basic
* @dev Simpler version of ERC20 interface
* @dev see https://github.com/ethereum/EIPs/issues/179
*/
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 BasicToken is ERC20Basic, Ownable {
using SafeMath for uint256;
mapping(address => uint256) balances;
bool public transfersEnabledFlag;
/**
* @dev Throws if transfersEnabledFlag is false and not owner.
*/
modifier transfersEnabled() {
require(transfersEnabledFlag);
_;
}
function enableTransfers() public onlyOwner {
transfersEnabledFlag = 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) transfersEnabled 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;
}
function batchTransfer(address[] _addresses, uint256[] _value) public returns (bool) {
for (uint256 i = 0; i < _addresses.length; i++) {
require(transfer(_addresses[i], _value[i]));
}
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 SafeMath
* @dev Math operations with safety checks that throw on error
*/
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;
}
}
/**
* @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) transfersEnabled 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) transfersEnabled 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) transfersEnabled 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) transfersEnabled 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;
}
}
/**
* @title Mintable token
* @dev Simple ERC20 Token example, with mintable token creation
* @dev Issue: * https://github.com/OpenZeppelin/zeppelin-solidity/issues/120
* Based on code by TokenMarketNet: https://github.com/TokenMarketNet/ico/blob/master/contracts/MintableToken.sol
*/
contract MintableToken is StandardToken {
event Mint(address indexed to, uint256 amount);
event MintFinished();
bool public mintingFinished = false;
mapping(address => bool) public minters;
modifier canMint() {
require(!mintingFinished);
_;
}
modifier onlyMinters() {
require(minters[msg.sender] || msg.sender == owner);
_;
}
function addMinter(address _addr) public onlyOwner {
require(_addr != address(0));
minters[_addr] = true;
}
function deleteMinter(address _addr) public onlyOwner {
require(_addr != address(0));
delete minters[_addr];
}
/**
* @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) onlyMinters canMint public returns (bool) {
require(_to != address(0));
totalSupply = totalSupply.add(_amount);
balances[_to] = balances[_to].add(_amount);
Mint(_to, _amount);
Transfer(address(0), _to, _amount);
return true;
}
/**
* @dev Function to stop minting new tokens.
* @return True if the operation was successful.
*/
function finishMinting() onlyOwner canMint public returns (bool) {
mintingFinished = true;
MintFinished();
return true;
}
}
/**
* @title Capped token
* @dev Mintable token with a token cap.
*/
contract CappedToken is MintableToken {
uint256 public cap;
function CappedToken(uint256 _cap) public {
require(_cap > 0);
cap = _cap;
}
/**
* @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) onlyMinters canMint public returns (bool) {
require(totalSupply.add(_amount) <= cap);
return super.mint(_to, _amount);
}
}
contract ParameterizedToken is CappedToken {
//1.3 update add minter/delete minter address validation
string public version = "1.3";
string public name;
string public symbol;
uint256 public decimals;
function ParameterizedToken(string _name, string _symbol, uint256 _decimals, uint256 _capIntPart) public CappedToken(_capIntPart * 10 ** _decimals) {
name = _name;
symbol = _symbol;
decimals = _decimals;
}
}
contract DistributedCreditChain is ParameterizedToken {
function DistributedCreditChain() public ParameterizedToken("Distributed Credit Chain", "DCC", 18, 10000000000) {
}
}