/**
* Source Code first verified at https://etherscan.io on Thursday, May 9, 2019
(UTC) */
pragma solidity ^0.5.0;
/**
* @title ERC20 interface
* @dev see https://eips.ethereum.org/EIPS/eip-20
*/
interface IERC20 {
function transfer(address to, uint256 value) external returns (bool);
function approve(address spender, uint256 value) external returns (bool);
function transferFrom(address from, address to, uint256 value) external returns (bool);
function totalSupply() external view returns (uint256);
function balanceOf(address who) external view returns (uint256);
function allowance(address owner, address spender) external view returns (uint256);
event Transfer(address indexed from, address indexed to, uint256 value);
event Approval(address indexed owner, address indexed spender, uint256 value);
}
pragma solidity ^0.5.0;
/**
* @title SafeMath
* @dev Unsigned math operations with safety checks that revert on error.
*/
library SafeMath {
/**
* @dev Multiplies two unsigned integers, reverts on overflow.
*/
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
// Gas optimization: this is cheaper than requiring '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;
}
uint256 c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");
return c;
}
/**
* @dev Integer division of two unsigned integers truncating the quotient, reverts on division by zero.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) {
// Solidity only automatically asserts when dividing by 0
require(b > 0, "SafeMath: division by zero");
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 unsigned integers, reverts on overflow (i.e. if subtrahend is greater than minuend).
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
require(b <= a, "SafeMath: subtraction overflow");
uint256 c = a - b;
return c;
}
/**
* @dev Adds two unsigned integers, reverts on overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a, "SafeMath: addition overflow");
return c;
}
/**
* @dev Divides two unsigned integers and returns the remainder (unsigned integer modulo),
* reverts when dividing by zero.
*/
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
require(b != 0, "SafeMath: modulo by zero");
return a % b;
}
}
pragma solidity ^0.5.0;
/**
* Utility library of inline functions on addresses
*/
library Address {
/**
* Returns whether the target address is a contract
* @dev This function will return false if invoked during the constructor of a contract,
* as the code is not actually created until after the constructor finishes.
* @param account address of the account to check
* @return whether the target address is a contract
*/
function isContract(address account) internal view returns (bool) {
uint256 size;
// XXX Currently there is no better way to check if there is a contract in an address
// than to check the size of the code at that address.
// See https://ethereum.stackexchange.com/a/14016/36603
// for more details about how this works.
// TODO Check this again before the Serenity release, because all addresses will be
// contracts then.
// solhint-disable-next-line no-inline-assembly
assembly { size := extcodesize(account) }
return size > 0;
}
}
pragma solidity ^0.5.0;
/**
* @title SafeERC20
* @dev Wrappers around ERC20 operations that throw on failure (when the token
* contract returns false). Tokens that return no value (and instead revert or
* throw on failure) are also supported, non-reverting calls are assumed to be
* successful.
* 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 {
using SafeMath for uint256;
using Address for address;
function safeTransfer(IERC20 token, address to, uint256 value) internal {
callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
}
function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
}
function safeApprove(IERC20 token, address spender, uint256 value) internal {
// safeApprove should only be called when setting an initial allowance,
// or when resetting it to zero. To increase and decrease it, use
// 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
// solhint-disable-next-line max-line-length
require((value == 0) || (token.allowance(address(this), spender) == 0),
"SafeERC20: approve from non-zero to non-zero allowance"
);
callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
}
function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
uint256 newAllowance = token.allowance(address(this), spender).add(value);
callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
uint256 newAllowance = token.allowance(address(this), spender).sub(value);
callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
/**
* @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
* on the return value: the return value is optional (but if data is returned, it must not be false).
* @param token The token targeted by the call.
* @param data The call data (encoded using abi.encode or one of its variants).
*/
function callOptionalReturn(IERC20 token, bytes memory data) private {
// We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
// we're implementing it ourselves.
// A Solidity high level call has three parts:
// 1. The target address is checked to verify it contains contract code
// 2. The call itself is made, and success asserted
// 3. The return value is decoded, which in turn checks the size of the returned data.
// solhint-disable-next-line max-line-length
require(address(token).isContract(), "SafeERC20: call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = address(token).call(data);
require(success, "SafeERC20: low-level call failed");
if (returndata.length > 0) { // Return data is optional
// solhint-disable-next-line max-line-length
require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
}
}
}
pragma solidity ^0.5.0;
/**
* @title Helps contracts guard against reentrancy attacks.
* @author Remco Bloemen <[email protected]π.com>, Eenae <[email protected]>
* @dev If you mark a function `nonReentrant`, you should also
* mark it `external`.
*/
contract ReentrancyGuard {
/// @dev counter to allow mutex lock with only one SSTORE operation
uint256 private _guardCounter;
constructor () internal {
// The counter starts at one to prevent changing it from zero to a non-zero
// value, which is a more expensive operation.
_guardCounter = 1;
}
/**
* @dev Prevents a contract from calling itself, directly or indirectly.
* Calling a `nonReentrant` function from another `nonReentrant`
* function is not supported. It is possible to prevent this from happening
* by making the `nonReentrant` function external, and make it call a
* `private` function that does the actual work.
*/
modifier nonReentrant() {
_guardCounter += 1;
uint256 localCounter = _guardCounter;
_;
require(localCounter == _guardCounter, "ReentrancyGuard: reentrant call");
}
}
pragma solidity ^0.5.0;
/**
* @title Crowdsale
* @dev Crowdsale is a base contract for managing a token crowdsale,
* allowing investors to purchase tokens with ether. This contract implements
* such functionality in its most fundamental form and can be extended to provide additional
* functionality and/or custom behavior.
* The external interface represents the basic interface for purchasing tokens, and conforms
* the base architecture for crowdsales. It is *not* intended to be modified / overridden.
* The internal interface conforms the extensible and modifiable surface of crowdsales. Override
* the methods to add functionality. Consider using 'super' where appropriate to concatenate
* behavior.
*/
contract Crowdsale is ReentrancyGuard {
using SafeMath for uint256;
using SafeERC20 for IERC20;
// The token being sold
IERC20 private _token;
// Address where funds are collected
address payable private _wallet;
// How many token units a buyer gets per wei.
// The rate is the conversion between wei and the smallest and indivisible token unit.
// So, if you are using a rate of 1 with a ERC20Detailed token with 3 decimals called TOK
// 1 wei will give you 1 unit, or 0.001 TOK.
uint256 private _rate;
// Amount of wei raised
uint256 private _weiRaised;
/**
* Event for token purchase logging
* @param purchaser who paid for the tokens
* @param beneficiary who got the tokens
* @param value weis paid for purchase
* @param amount amount of tokens purchased
*/
event TokensPurchased(address indexed purchaser, address indexed beneficiary, uint256 value, uint256 amount);
/**
* @param rate Number of token units a buyer gets per wei
* @dev The rate is the conversion between wei and the smallest and indivisible
* token unit. So, if you are using a rate of 1 with a ERC20Detailed token
* with 3 decimals called TOK, 1 wei will give you 1 unit, or 0.001 TOK.
* @param wallet Address where collected funds will be forwarded to
* @param token Address of the token being sold
*/
constructor (uint256 rate, address payable wallet, IERC20 token) public {
require(rate > 0, "Crowdsale: rate is 0");
require(wallet != address(0), "Crowdsale: wallet is the zero address");
require(address(token) != address(0), "Crowdsale: token is the zero address");
_rate = rate;
_wallet = wallet;
_token = token;
}
/**
* @dev fallback function ***DO NOT OVERRIDE***
* Note that other contracts will transfer funds with a base gas stipend
* of 2300, which is not enough to call buyTokens. Consider calling
* buyTokens directly when purchasing tokens from a contract.
*/
function () external payable {
buyTokens(msg.sender);
}
/**
* @return the token being sold.
*/
function token() public view returns (IERC20) {
return _token;
}
/**
* @return the address where funds are collected.
*/
function wallet() public view returns (address payable) {
return _wallet;
}
/**
* @return the number of token units a buyer gets per wei.
*/
function rate() public view returns (uint256) {
return _rate;
}
/**
* @return the amount of wei raised.
*/
function weiRaised() public view returns (uint256) {
return _weiRaised;
}
/**
* @dev low level token purchase ***DO NOT OVERRIDE***
* This function has a non-reentrancy guard, so it shouldn't be called by
* another `nonReentrant` function.
* @param beneficiary Recipient of the token purchase
*/
function buyTokens(address beneficiary) public nonReentrant payable {
uint256 weiAmount = msg.value;
_preValidatePurchase(beneficiary, weiAmount);
// calculate token amount to be created
uint256 tokens = _getTokenAmount(weiAmount);
// update state
_weiRaised = _weiRaised.add(weiAmount);
_processPurchase(beneficiary, tokens);
emit TokensPurchased(msg.sender, beneficiary, weiAmount, tokens);
_updatePurchasingState(beneficiary, weiAmount);
_forwardFunds();
_postValidatePurchase(beneficiary, weiAmount);
}
/**
* @dev Validation of an incoming purchase. Use require statements to revert state when conditions are not met.
* Use `super` in contracts that inherit from Crowdsale to extend their validations.
* Example from CappedCrowdsale.sol's _preValidatePurchase method:
* super._preValidatePurchase(beneficiary, weiAmount);
* require(weiRaised().add(weiAmount) <= cap);
* @param beneficiary Address performing the token purchase
* @param weiAmount Value in wei involved in the purchase
*/
function _preValidatePurchase(address beneficiary, uint256 weiAmount) internal view {
require(beneficiary != address(0), "Crowdsale: beneficiary is the zero address");
require(weiAmount != 0, "Crowdsale: weiAmount is 0");
}
/**
* @dev Validation of an executed purchase. Observe state and use revert statements to undo rollback when valid
* conditions are not met.
* @param beneficiary Address performing the token purchase
* @param weiAmount Value in wei involved in the purchase
*/
function _postValidatePurchase(address beneficiary, uint256 weiAmount) internal view {
// solhint-disable-previous-line no-empty-blocks
}
/**
* @dev Source of tokens. Override this method to modify the way in which the crowdsale ultimately gets and sends
* its tokens.
* @param beneficiary Address performing the token purchase
* @param tokenAmount Number of tokens to be emitted
*/
function _deliverTokens(address beneficiary, uint256 tokenAmount) internal {
_token.safeTransfer(beneficiary, tokenAmount);
}
/**
* @dev Executed when a purchase has been validated and is ready to be executed. Doesn't necessarily emit/send
* tokens.
* @param beneficiary Address receiving the tokens
* @param tokenAmount Number of tokens to be purchased
*/
function _processPurchase(address beneficiary, uint256 tokenAmount) internal {
_deliverTokens(beneficiary, tokenAmount);
}
/**
* @dev Override for extensions that require an internal state to check for validity (current user contributions,
* etc.)
* @param beneficiary Address receiving the tokens
* @param weiAmount Value in wei involved in the purchase
*/
function _updatePurchasingState(address beneficiary, uint256 weiAmount) internal {
// solhint-disable-previous-line no-empty-blocks
}
/**
* @dev Override to extend the way in which ether is converted to tokens.
* @param weiAmount Value in wei to be converted into tokens
* @return Number of tokens that can be purchased with the specified _weiAmount
*/
function _getTokenAmount(uint256 weiAmount) internal view returns (uint256) {
return weiAmount.mul(_rate);
}
/**
* @dev Determines how ETH is stored/forwarded on purchases.
*/
function _forwardFunds() internal {
_wallet.transfer(msg.value);
}
}
pragma solidity ^0.5.0;
/**
* @title Roles
* @dev Library for managing addresses assigned to a Role.
*/
library Roles {
struct Role {
mapping (address => bool) bearer;
}
/**
* @dev Give an account access to this role.
*/
function add(Role storage role, address account) internal {
require(!has(role, account), "Roles: account already has role");
role.bearer[account] = true;
}
/**
* @dev Remove an account's access to this role.
*/
function remove(Role storage role, address account) internal {
require(has(role, account), "Roles: account does not have role");
role.bearer[account] = false;
}
/**
* @dev Check if an account has this role.
* @return bool
*/
function has(Role storage role, address account) internal view returns (bool) {
require(account != address(0), "Roles: account is the zero address");
return role.bearer[account];
}
}
pragma solidity ^0.5.0;
contract PauserRole {
using Roles for Roles.Role;
event PauserAdded(address indexed account);
event PauserRemoved(address indexed account);
Roles.Role private _pausers;
constructor () internal {
_addPauser(msg.sender);
}
modifier onlyPauser() {
require(isPauser(msg.sender), "PauserRole: caller does not have the Pauser role");
_;
}
function isPauser(address account) public view returns (bool) {
return _pausers.has(account);
}
function addPauser(address account) public onlyPauser {
_addPauser(account);
}
function renouncePauser() public {
_removePauser(msg.sender);
}
function _addPauser(address account) internal {
_pausers.add(account);
emit PauserAdded(account);
}
function _removePauser(address account) internal {
_pausers.remove(account);
emit PauserRemoved(account);
}
}
pragma solidity ^0.5.0;
/**
* @title Pausable
* @dev Base contract which allows children to implement an emergency stop mechanism.
*/
contract Pausable is PauserRole {
event Paused(address account);
event Unpaused(address account);
bool private _paused;
constructor () internal {
_paused = false;
}
/**
* @return True if the contract is paused, false otherwise.
*/
function paused() public view returns (bool) {
return _paused;
}
/**
* @dev Modifier to make a function callable only when the contract is not paused.
*/
modifier whenNotPaused() {
require(!_paused, "Pausable: paused");
_;
}
/**
* @dev Modifier to make a function callable only when the contract is paused.
*/
modifier whenPaused() {
require(_paused, "Pausable: not paused");
_;
}
/**
* @dev Called by a pauser to pause, triggers stopped state.
*/
function pause() public onlyPauser whenNotPaused {
_paused = true;
emit Paused(msg.sender);
}
/**
* @dev Called by a pauser to unpause, returns to normal state.
*/
function unpause() public onlyPauser whenPaused {
_paused = false;
emit Unpaused(msg.sender);
}
}
pragma solidity ^0.5.0;
/**
* @title PausableCrowdsale
* @dev Extension of Crowdsale contract where purchases can be paused and unpaused by the pauser role.
*/
contract PausableCrowdsale is Crowdsale, Pausable {
/**
* @dev Validation of an incoming purchase. Use require statements to revert state when conditions are not met.
* Use super to concatenate validations.
* Adds the validation that the crowdsale must not be paused.
* @param _beneficiary Address performing the token purchase
* @param _weiAmount Value in wei involved in the purchase
*/
function _preValidatePurchase(address _beneficiary, uint256 _weiAmount) internal view whenNotPaused {
return super._preValidatePurchase(_beneficiary, _weiAmount);
}
}
pragma solidity ^0.5.0;
/**
* @title CappedCrowdsale
* @dev Crowdsale with a limit for total contributions.
*/
contract CappedCrowdsale is Crowdsale {
using SafeMath for uint256;
uint256 private _cap;
/**
* @dev Constructor, takes maximum amount of wei accepted in the crowdsale.
* @param cap Max amount of wei to be contributed
*/
constructor (uint256 cap) public {
require(cap > 0, "CappedCrowdsale: cap is 0");
_cap = cap;
}
/**
* @return the cap of the crowdsale.
*/
function cap() public view returns (uint256) {
return _cap;
}
/**
* @dev Checks whether the cap has been reached.
* @return Whether the cap was reached
*/
function capReached() public view returns (bool) {
return weiRaised() >= _cap;
}
/**
* @dev Extend parent behavior requiring purchase to respect the funding cap.
* @param beneficiary Token purchaser
* @param weiAmount Amount of wei contributed
*/
function _preValidatePurchase(address beneficiary, uint256 weiAmount) internal view {
super._preValidatePurchase(beneficiary, weiAmount);
require(weiRaised().add(weiAmount) <= _cap, "CappedCrowdsale: cap exceeded");
}
}
pragma solidity ^0.5.0;
/**
* @title Standard ERC20 token
*
* @dev Implementation of the basic standard token.
* https://eips.ethereum.org/EIPS/eip-20
* Originally based on code by FirstBlood:
* https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
*
* This implementation emits additional Approval events, allowing applications to reconstruct the allowance status for
* all accounts just by listening to said events. Note that this isn't required by the specification, and other
* compliant implementations may not do it.
*/
contract ERC20 is IERC20 {
using SafeMath for uint256;
mapping (address => uint256) private _balances;
mapping (address => mapping (address => uint256)) private _allowed;
uint256 private _totalSupply;
/**
* @dev Total number of tokens in existence.
*/
function totalSupply() public view returns (uint256) {
return _totalSupply;
}
/**
* @dev Gets the balance of the specified address.
* @param owner The address to query the balance of.
* @return A uint256 representing the amount owned by the passed address.
*/
function balanceOf(address owner) public view returns (uint256) {
return _balances[owner];
}
/**
* @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 Transfer token to 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) {
_transfer(msg.sender, 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) {
_approve(msg.sender, spender, value);
return true;
}
/**
* @dev Transfer tokens from one address to another.
* Note that while this function emits an Approval event, this is not required as per the specification,
* and other compliant implementations may not emit the event.
* @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) {
_transfer(from, to, value);
_approve(from, msg.sender, _allowed[from][msg.sender].sub(value));
return true;
}
/**
* @dev Increase the amount of tokens that an owner allowed to a spender.
* approve should be called when _allowed[msg.sender][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
* Emits an Approval event.
* @param spender The address which will spend the funds.
* @param addedValue The amount of tokens to increase the allowance by.
*/
function increaseAllowance(address spender, uint256 addedValue) public returns (bool) {
_approve(msg.sender, spender, _allowed[msg.sender][spender].add(addedValue));
return true;
}
/**
* @dev Decrease the amount of tokens that an owner allowed to a spender.
* approve should be called when _allowed[msg.sender][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
* Emits an Approval event.
* @param spender The address which will spend the funds.
* @param subtractedValue The amount of tokens to decrease the allowance by.
*/
function decreaseAllowance(address spender, uint256 subtractedValue) public returns (bool) {
_approve(msg.sender, spender, _allowed[msg.sender][spender].sub(subtractedValue));
return true;
}
/**
* @dev Transfer token for a specified addresses.
* @param from The address to transfer from.
* @param to The address to transfer to.
* @param value The amount to be transferred.
*/
function _transfer(address from, address to, uint256 value) internal {
require(to != address(0), "ERC20: transfer to the zero address");
_balances[from] = _balances[from].sub(value);
_balances[to] = _balances[to].add(value);
emit Transfer(from, to, value);
}
/**
* @dev Internal function that mints an amount of the token and assigns it to
* an account. This encapsulates the modification of balances such that the
* proper events are emitted.
* @param account The account that will receive the created tokens.
* @param value The amount that will be created.
*/
function _mint(address account, uint256 value) internal {
require(account != address(0), "ERC20: mint to the zero address");
_totalSupply = _totalSupply.add(value);
_balances[account] = _balances[account].add(value);
emit Transfer(address(0), account, value);
}
/**
* @dev Internal function that burns an amount of the token of a given
* account.
* @param account The account whose tokens will be burnt.
* @param value The amount that will be burnt.
*/
function _burn(address account, uint256 value) internal {
require(account != address(0), "ERC20: burn from the zero address");
_totalSupply = _totalSupply.sub(value);
_balances[account] = _balances[account].sub(value);
emit Transfer(account, address(0), value);
}
/**
* @dev Approve an address to spend another addresses' tokens.
* @param owner The address that owns the tokens.
* @param spender The address that will spend the tokens.
* @param value The number of tokens that can be spent.
*/
function _approve(address owner, address spender, uint256 value) internal {
require(owner != address(0), "ERC20: approve from the zero address");
require(spender != address(0), "ERC20: approve to the zero address");
_allowed[owner][spender] = value;
emit Approval(owner, spender, value);
}
/**
* @dev Internal function that burns an amount of the token of a given
* account, deducting from the sender's allowance for said account. Uses the
* internal burn function.
* Emits an Approval event (reflecting the reduced allowance).
* @param account The account whose tokens will be burnt.
* @param value The amount that will be burnt.
*/
function _burnFrom(address account, uint256 value) internal {
_burn(account, value);
_approve(account, msg.sender, _allowed[account][msg.sender].sub(value));
}
}
pragma solidity ^0.5.0;
contract MinterRole {
using Roles for Roles.Role;
event MinterAdded(address indexed account);
event MinterRemoved(address indexed account);
Roles.Role private _minters;
constructor () internal {
_addMinter(msg.sender);
}
modifier onlyMinter() {
require(isMinter(msg.sender), "MinterRole: caller does not have the Minter role");
_;
}
function isMinter(address account) public view returns (bool) {
return _minters.has(account);
}
function addMinter(address account) public onlyMinter {
_addMinter(account);
}
function renounceMinter() public {
_removeMinter(msg.sender);
}
function _addMinter(address account) internal {
_minters.add(account);
emit MinterAdded(account);
}
function _removeMinter(address account) internal {
_minters.remove(account);
emit MinterRemoved(account);
}
}
pragma solidity ^0.5.0;
/**
* @title ERC20Mintable
* @dev ERC20 minting logic.
*/
contract ERC20Mintable is ERC20, MinterRole {
/**
* @dev Function to mint tokens
* @param to The address that will receive the minted tokens.
* @param value The amount of tokens to mint.
* @return A boolean that indicates if the operation was successful.
*/
function mint(address to, uint256 value) public onlyMinter returns (bool) {
_mint(to, value);
return true;
}
}
pragma solidity ^0.5.0;
/**
* @title MintedCrowdsale
* @dev Extension of Crowdsale contract whose tokens are minted in each purchase.
* Token ownership should be transferred to MintedCrowdsale for minting.
*/
contract MintedCrowdsale is Crowdsale {
/**
* @dev Overrides delivery by minting tokens upon purchase.
* @param beneficiary Token purchaser
* @param tokenAmount Number of tokens to be minted
*/
function _deliverTokens(address beneficiary, uint256 tokenAmount) internal {
// Potentially dangerous assumption about the type of the token.
require(
ERC20Mintable(address(token())).mint(beneficiary, tokenAmount),
"MintedCrowdsale: minting failed"
);
}
}
pragma solidity ^0.5.0;
/**
* @title TimedCrowdsale
* @dev Crowdsale accepting contributions only within a time frame.
*/
contract TimedCrowdsale is Crowdsale {
using SafeMath for uint256;
uint256 private _openingTime;
uint256 private _closingTime;
/**
* Event for crowdsale extending
* @param newClosingTime new closing time
* @param prevClosingTime old closing time
*/
event TimedCrowdsaleExtended(uint256 prevClosingTime, uint256 newClosingTime);
/**
* @dev Reverts if not in crowdsale time range.
*/
modifier onlyWhileOpen {
require(isOpen(), "TimedCrowdsale: not open");
_;
}
/**
* @dev Constructor, takes crowdsale opening and closing times.
* @param openingTime Crowdsale opening time
* @param closingTime Crowdsale closing time
*/
constructor (uint256 openingTime, uint256 closingTime) public {
// solhint-disable-next-line not-rely-on-time
require(openingTime >= block.timestamp, "TimedCrowdsale: opening time is before current time");
// solhint-disable-next-line max-line-length
require(closingTime > openingTime, "TimedCrowdsale: opening time is not before closing time");
_openingTime = openingTime;
_closingTime = closingTime;
}
/**
* @return the crowdsale opening time.
*/
function openingTime() public view returns (uint256) {
return _openingTime;
}
/**
* @return the crowdsale closing time.
*/
function closingTime() public view returns (uint256) {
return _closingTime;
}
/**
* @return true if the crowdsale is open, false otherwise.
*/
function isOpen() public view returns (bool) {
// solhint-disable-next-line not-rely-on-time
return block.timestamp >= _openingTime && block.timestamp <= _closingTime;
}
/**
* @dev Checks whether the period in which the crowdsale is open has already elapsed.
* @return Whether crowdsale period has elapsed
*/
function hasClosed() public view returns (bool) {
// solhint-disable-next-line not-rely-on-time
return block.timestamp > _closingTime;
}
/**
* @dev Extend parent behavior requiring to be within contributing period.
* @param beneficiary Token purchaser
* @param weiAmount Amount of wei contributed
*/
function _preValidatePurchase(address beneficiary, uint256 weiAmount) internal onlyWhileOpen view {
super._preValidatePurchase(beneficiary, weiAmount);
}
/**
* @dev Extend crowdsale.
* @param newClosingTime Crowdsale closing time
*/
function _extendTime(uint256 newClosingTime) internal {
require(!hasClosed(), "TimedCrowdsale: already closed");
// solhint-disable-next-line max-line-length
require(newClosingTime > _closingTime, "TimedCrowdsale: new closing time is before current closing time");
emit TimedCrowdsaleExtended(_closingTime, newClosingTime);
_closingTime = newClosingTime;
}
}
pragma solidity ^0.5.0;
/**
* @title FinalizableCrowdsale
* @dev Extension of TimedCrowdsale with a one-off finalization action, where one
* can do extra work after finishing.
*/
contract FinalizableCrowdsale is TimedCrowdsale {
using SafeMath for uint256;
bool private _finalized;
event CrowdsaleFinalized();
constructor () internal {
_finalized = false;
}
/**
* @return true if the crowdsale is finalized, false otherwise.
*/
function finalized() public view returns (bool) {
return _finalized;
}
/**
* @dev Must be called after crowdsale ends, to do some extra finalization
* work. Calls the contract's finalization function.
*/
function finalize() public {
require(!_finalized, "FinalizableCrowdsale: already finalized");
require(hasClosed(), "FinalizableCrowdsale: not closed");
_finalized = true;
_finalization();
emit CrowdsaleFinalized();
}
/**
* @dev Can be overridden to add finalization logic. The overriding function
* should call super._finalization() to ensure the chain of finalization is
* executed entirely.
*/
function _finalization() internal {
// solhint-disable-previous-line no-empty-blocks
}
}
pragma solidity ^0.5.0;
/**
* @title Capped token
* @dev Mintable token with a token cap.
*/
contract ERC20Capped is ERC20Mintable {
uint256 private _cap;
constructor (uint256 cap) public {
require(cap > 0, "ERC20Capped: cap is 0");
_cap = cap;
}
/**
* @return the cap for the token minting.
*/
function cap() public view returns (uint256) {
return _cap;
}
function _mint(address account, uint256 value) internal {
require(totalSupply().add(value) <= _cap, "ERC20Capped: cap exceeded");
super._mint(account, value);
}
}
pragma solidity ^0.5.0;
contract MTB19Crowdsale is MintedCrowdsale, PausableCrowdsale, FinalizableCrowdsale, CappedCrowdsale {
constructor(uint256 rate, address payable wallet, IERC20 token,
uint256 openingTime, uint256 closingTime,
uint256 cap
) public Crowdsale(rate, wallet, token)
TimedCrowdsale(openingTime, closingTime)
FinalizableCrowdsale()
CappedCrowdsale(cap) { }
/**
* @dev Overrides finalization of FinalizableCrowdsale. It stores the remaining tokens to the
fundwallet and renounces minter role.
*/
function _finalization() internal {
uint256 remaining = ERC20Capped(address(token())).cap() - ERC20(address(token())).totalSupply();
if (remaining > 0) ERC20Capped(address(super.token())).mint(super.wallet(), remaining);
MinterRole(address(token())).renounceMinter();
super._finalization();
}
}