pragma solidity ^0.4.23;


/**
 * @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);
}

pragma solidity ^0.4.23;


/**
 * @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
  );
}

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 c) {
    // 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;
    }

    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 a / b;
  }

  /**
  * @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 c) {
    c = a + b;
    assert(c >= a);
    return c;
  }
}


pragma solidity ^0.4.23;


/**
 * @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.
   */
  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;
  }
}

pragma solidity ^0.4.23;


/**
 * @title Roles
 * @author Francisco Giordano (@frangio)
 * @dev Library for managing addresses assigned to a Role.
 *      See RBAC.sol for example usage.
 */
library Roles {
  struct Role {
    mapping (address => bool) bearer;
  }

  /**
   * @dev give an address access to this role
   */
  function add(Role storage role, address addr)
    internal
  {
    role.bearer[addr] = true;
  }

  /**
   * @dev remove an address' access to this role
   */
  function remove(Role storage role, address addr)
    internal
  {
    role.bearer[addr] = false;
  }

  /**
   * @dev check if an address has this role
   * // reverts
   */
  function check(Role storage role, address addr)
    view
    internal
  {
    require(has(role, addr));
  }

  /**
   * @dev check if an address has this role
   * @return bool
   */
  function has(Role storage role, address addr)
    view
    internal
    returns (bool)
  {
    return role.bearer[addr];
  }
}

pragma solidity ^0.4.23;

/**
 * @title RBAC (Role-Based Access Control)
 * @author Matt Condon (@Shrugs)
 * @dev Stores and provides setters and getters for roles and addresses.
 * @dev Supports unlimited numbers of roles and addresses.
 * @dev See //contracts/mocks/RBACMock.sol for an example of usage.
 * This RBAC method uses strings to key roles. It may be beneficial
 *  for you to write your own implementation of this interface using Enums or similar.
 * It's also recommended that you define constants in the contract, like ROLE_ADMIN below,
 *  to avoid typos.
 */
contract RBAC {
  using Roles for Roles.Role;

  mapping (string => Roles.Role) private roles;

  event RoleAdded(address addr, string roleName);
  event RoleRemoved(address addr, string roleName);

  /**
   * @dev reverts if addr does not have role
   * @param addr address
   * @param roleName the name of the role
   * // reverts
   */
  function checkRole(address addr, string roleName)
    view
    public
  {
    roles[roleName].check(addr);
  }

  /**
   * @dev determine if addr has role
   * @param addr address
   * @param roleName the name of the role
   * @return bool
   */
  function hasRole(address addr, string roleName)
    view
    public
    returns (bool)
  {
    return roles[roleName].has(addr);
  }

  /**
   * @dev add a role to an address
   * @param addr address
   * @param roleName the name of the role
   */
  function addRole(address addr, string roleName)
    internal
  {
    roles[roleName].add(addr);
    emit RoleAdded(addr, roleName);
  }

  /**
   * @dev remove a role from an address
   * @param addr address
   * @param roleName the name of the role
   */
  function removeRole(address addr, string roleName)
    internal
  {
    roles[roleName].remove(addr);
    emit RoleRemoved(addr, roleName);
  }

  /**
   * @dev modifier to scope access to a single role (uses msg.sender as addr)
   * @param roleName the name of the role
   * // reverts
   */
  modifier onlyRole(string roleName)
  {
    checkRole(msg.sender, roleName);
    _;
  }

  /**
   * @dev modifier to scope access to a set of roles (uses msg.sender as addr)
   * @param roleNames the names of the roles to scope access to
   * // reverts
   *
   * @TODO - when solidity supports dynamic arrays as arguments to modifiers, provide this
   *  see: https://github.com/ethereum/solidity/issues/2467
   */
  // modifier onlyRoles(string[] roleNames) {
  //     bool hasAnyRole = false;
  //     for (uint8 i = 0; i < roleNames.length; i++) {
  //         if (hasRole(msg.sender, roleNames[i])) {
  //             hasAnyRole = true;
  //             break;
  //         }
  //     }

  //     require(hasAnyRole);

  //     _;
  // }
}

pragma solidity ^0.4.23;

/**
 * @title Basic token
 * @dev Basic version of StandardToken, with no allowances.
 */
contract BasicToken is ERC20Basic {
  using SafeMath for uint256;

  mapping(address => uint256) balances;

  uint256 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]);

    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) {
    return balances[_owner];
  }

}

pragma solidity ^0.4.23;


/**
 * @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);
  }
}

pragma solidity ^0.4.23;

/**
 * @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)
  {
    return allowed[_owner][_spender];
  }

  /**
   * @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,
    uint _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,
    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);
    }
    emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
    return true;
  }

}

pragma solidity ^0.4.23;

/**
 * @title Mintable token
 * @dev Simple ERC20 Token example, with mintable token creation
 * @dev Issue: * https://github.com/OpenZeppelin/openzeppelin-solidity/issues/120
 * Based on code by TokenMarketNet: https://github.com/TokenMarketNet/ico/blob/master/contracts/MintableToken.sol
 */
contract MintableToken is StandardToken, Ownable {
  event Mint(address indexed to, uint256 amount);
  event MintFinished();

  bool public mintingFinished = false;


  modifier canMint() {
    require(!mintingFinished);
    _;
  }

  modifier hasMintPermission() {
    require(msg.sender == owner);
    _;
  }

  /**
   * @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
  )
    hasMintPermission
    canMint
    public
    returns (bool)
  {
    totalSupply_ = totalSupply_.add(_amount);
    balances[_to] = balances[_to].add(_amount);
    emit Mint(_to, _amount);
    emit 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;
    emit MintFinished();
    return true;
  }
}

pragma solidity ^0.4.23;

/**
 * @title Whitelist
 * @dev The Whitelist contract has a whitelist of addresses, and provides basic authorization control functions.
 * @dev This simplifies the implementation of "user permissions".
 */
contract Whitelist is Ownable, RBAC {
  event WhitelistedAddressAdded(address addr);
  event WhitelistedAddressRemoved(address addr);

  string public constant ROLE_WHITELISTED = "whitelist";

  /**
   * @dev Throws if called by any account that's not whitelisted.
   */
  modifier onlyWhitelisted() {
    checkRole(msg.sender, ROLE_WHITELISTED);
    _;
  }

  /**
   * @dev add an address to the whitelist
   * @param addr address
   * @return true if the address was added to the whitelist, false if the address was already in the whitelist
   */
  function addAddressToWhitelist(address addr)
    onlyOwner
    public
  {
    addRole(addr, ROLE_WHITELISTED);
    emit WhitelistedAddressAdded(addr);
  }

  /**
   * @dev getter to determine if address is in whitelist
   */
  function whitelist(address addr)
    public
    view
    returns (bool)
  {
    return hasRole(addr, ROLE_WHITELISTED);
  }

  /**
   * @dev add addresses to the whitelist
   * @param addrs addresses
   * @return true if at least one address was added to the whitelist,
   * false if all addresses were already in the whitelist
   */
  function addAddressesToWhitelist(address[] addrs)
    onlyOwner
    public
  {
    for (uint256 i = 0; i < addrs.length; i++) {
      addAddressToWhitelist(addrs[i]);
    }
  }

  /**
   * @dev remove an address from the whitelist
   * @param addr address
   * @return true if the address was removed from the whitelist,
   * false if the address wasn't in the whitelist in the first place
   */
  function removeAddressFromWhitelist(address addr)
    onlyOwner
    public
  {
    removeRole(addr, ROLE_WHITELISTED);
    emit WhitelistedAddressRemoved(addr);
  }

  /**
   * @dev remove addresses from the whitelist
   * @param addrs addresses
   * @return true if at least one address was removed from the whitelist,
   * false if all addresses weren't in the whitelist in the first place
   */
  function removeAddressesFromWhitelist(address[] addrs)
    onlyOwner
    public
  {
    for (uint256 i = 0; i < addrs.length; i++) {
      removeAddressFromWhitelist(addrs[i]);
    }
  }

}

pragma solidity 0.4.24;

contract DXCASH is StandardToken, MintableToken, BurnableToken, Whitelist {
  string public symbol;
  string public name;
  uint8 public decimals;
  address[] public WhiteListAddresses;

  constructor (
    string symbol_,
    string name_,
    uint8 decimals_,
    uint256 totalSupply,
    address owner,
    address supplyOwnerAddress
  ) public {
    symbol = symbol_;
    name = name_;
    decimals = decimals_;
    totalSupply_ = totalSupply;
    balances[supplyOwnerAddress] = totalSupply;
    
    WhiteListAddresses.push(owner); 
    WhiteListAddresses.push(supplyOwnerAddress);

    addAddressesToWhitelist(WhiteListAddresses);
    transferOwnership(owner);
    emit Transfer(0x0, supplyOwnerAddress, totalSupply);
  }
  
  modifier onlyRecipientWhitelisted(address _to) {
    checkRole(_to, ROLE_WHITELISTED);
    _;
  }

  function transfer(
    address _to,
    uint256 _value
  ) 
    public
    onlyRecipientWhitelisted(_to)
    returns (bool) 
  {
    BasicToken.transfer(_to, _value);
  }

  function transferFrom(
    address _from,
    address _to,
    uint256 _value
  )
    public
    onlyRecipientWhitelisted(_to)
    returns (bool)
  {
    StandardToken.transferFrom(_from, _to, _value);
  }

  function approve(
    address _spender,
    uint256 _value
  ) public
    onlyRecipientWhitelisted(_spender)
    returns (bool)
  {
    StandardToken.approve(_spender, _value);
  }

  function mint(
    address _to,
    uint256 _amount
  )
    hasMintPermission
    canMint
    onlyRecipientWhitelisted(_to)
    public
    returns (bool)
  {
    MintableToken.mint(_to, _amount);
  }

}