Contract Source Code:
File 1 of 1 : MintDrop
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// SPDX-License-Identifier: MIT
pragma solidity 0.6.11;
/**
* @dev Standard math utilities missing in the Solidity language.
*/
library Math {
/**
* @dev Returns the largest of two numbers.
*/
function max(uint256 a, uint256 b) internal pure returns (uint256) {
return a >= b ? a : b;
}
/**
* @dev Returns the smallest of two numbers.
*/
function min(uint256 a, uint256 b) internal pure returns (uint256) {
return a < b ? a : b;
}
/**
* @dev Returns the average of two numbers. The result is rounded towards
* zero.
*/
function average(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b) / 2 can overflow, so we distribute
return (a / 2) + (b / 2) + ((a % 2 + b % 2) / 2);
}
}
pragma solidity 0.6.11;
/**
* @dev Wrappers over Solidity's arithmetic operations with added overflow
* checks.
*
* Arithmetic operations in Solidity wrap on overflow. This can easily result
* in bugs, because programmers usually assume that an overflow raises an
* error, which is the standard behavior in high level programming languages.
* `SafeMath` restores this intuition by reverting the transaction when an
* operation overflows.
*
* Using this library instead of the unchecked operations eliminates an entire
* class of bugs, so it's recommended to use it always.
*/
library SafeMath {
/**
* @dev Returns the addition of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `+` operator.
*
* Requirements:
*
* - Addition cannot overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a, "SafeMath: addition overflow");
return c;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
return sub(a, b, "SafeMath: subtraction overflow");
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b <= a, errorMessage);
uint256 c = a - b;
return c;
}
/**
* @dev Returns the multiplication of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `*` operator.
*
* Requirements:
*
* - Multiplication cannot 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-contracts/pull/522
if (a == 0) {
return 0;
}
uint256 c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");
return c;
}
/**
* @dev Returns the integer division of two unsigned integers. Reverts on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) {
return div(a, b, "SafeMath: division by zero");
}
/**
* @dev Returns the integer division of two unsigned integers. Reverts with custom message on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b > 0, errorMessage);
uint256 c = a / b;
// assert(a == b * c + a % b); // There is no case in which this doesn't hold
return c;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
return mod(a, b, "SafeMath: modulo by zero");
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts with custom message when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b != 0, errorMessage);
return a % b;
}
}
pragma solidity 0.6.11;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `recipient`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address recipient, uint256 amount) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: 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
*
* Emits an {Approval} event.
*/
function approve(address spender, uint256 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `sender` to `recipient` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
}
pragma solidity 0.6.11;
/*
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with GSN meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address payable) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes memory) {
this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
return msg.data;
}
}
pragma solidity 0.6.11;
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor () internal {
address msgSender = _msgSender();
_owner = msgSender;
emit OwnershipTransferred(address(0), msgSender);
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view returns (address) {
return _owner;
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require(_owner == _msgSender(), "Ownable: caller is not the owner");
_;
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions anymore. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
emit OwnershipTransferred(_owner, address(0));
_owner = address(0);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
emit OwnershipTransferred(_owner, newOwner);
_owner = newOwner;
}
}
pragma solidity 0.6.11;
// This interface is designed to be compatible with the Vyper version.
/// @notice This is the Ethereum 2.0 deposit contract interface.
/// For more information see the Phase 0 specification under https://github.com/ethereum/eth2.0-specs
interface IDepositContract {
/// @notice A processed deposit event.
event DepositEvent(
bytes pubkey,
bytes withdrawal_credentials,
bytes amount,
bytes signature,
bytes index
);
/// @notice Submit a Phase 0 DepositData object.
/// @param pubkey A BLS12-381 public key.
/// @param withdrawal_credentials Commitment to a public key for withdrawals.
/// @param signature A BLS12-381 signature.
/// @param deposit_data_root The SHA-256 hash of the SSZ-encoded DepositData object.
/// Used as a protection against malformed input.
function deposit(
bytes calldata pubkey,
bytes calldata withdrawal_credentials,
bytes calldata signature,
bytes32 deposit_data_root
) external payable;
/// @notice Query the current deposit root hash.
/// @return The deposit root hash.
function get_deposit_root() external view returns (bytes32);
/// @notice Query the current deposit count.
/// @return The deposit count encoded as a little endian 64-bit number.
function get_deposit_count() external view returns (bytes memory);
}
pragma solidity 0.6.11;
interface IVETH {
function mint(address account, uint amount) external;
function burn(address account, uint amount) external;
function unpause() external;
function paused() external view returns (bool);
}
pragma solidity 0.6.11;
contract MintDrop is Ownable {
using SafeMath for uint;
/* ========== CONSTANTS ========== */
uint constant public BONUS_DURATION = 32 days;
uint constant public MAX_CLAIM_DURATION = 8 days;
uint constant public TOTAL_BNC_REWARDS = 100000 ether;
/* ========== STATE VARIABLES ========== */
// address of vETH
address public immutable vETHAddress;
// address of Ethereum 2.0 Deposit Contract
address public immutable depositAddress;
// a timestamp when the bonus activity initialized
uint public immutable bonusStartAt;
// a flag to control whether the withdraw function is locked
bool public withdrawLocked;
// total amount of ETH deposited to Ethereum 2.0 Deposit Contract
uint public totalLocked;
// total amount of ETH deposited in this contract
uint public totalDeposit;
// total claimed amount of BNC rewards
uint public claimedRewards;
// user address => amount of ETH deposited by this user in this contract
mapping(address => uint) public myDeposit;
// user address => amount of BNC rewards that will rewarded to this user
mapping(address => uint) public myRewards;
// user address => a timestamp that this user claimed rewards
mapping(address => uint) public myLastClaimedAt;
// user address => the address of this user which in ss58 format on Bifrost Network
mapping(address => string) public bifrostAddress;
/* ========== EVENTS ========== */
event Deposit(address indexed sender, uint amount);
event Withdrawal(address indexed sender, uint amount);
event Claimed(address indexed sender, uint amount, uint claimed);
event NewValidator(bytes little_endian_deposit_count);
event BindAddress(address indexed sender, string bifrostAddress);
/* ========== CONSTRUCTOR ========== */
constructor(address vETHAddress_, address depositAddress_, uint bonusStartAt_) public Ownable() {
vETHAddress = vETHAddress_;
depositAddress = depositAddress_;
bonusStartAt = bonusStartAt_;
}
/* ========== MUTATIVE FUNCTIONS ========== */
function deposit() external payable {
claimRewards();
myDeposit[msg.sender] = myDeposit[msg.sender].add(msg.value);
totalDeposit = totalDeposit.add(msg.value);
// mint vETH, MintDrop should have ownership of vETH contract
IVETH(vETHAddress).mint(msg.sender, msg.value);
emit Deposit(msg.sender, msg.value);
}
function withdraw(uint amount) external isWithdrawNotLocked {
claimRewards();
myDeposit[msg.sender] = myDeposit[msg.sender].sub(amount);
totalDeposit = totalDeposit.sub(amount);
// burn vETH, MintDrop should have ownership of vETH contract
IVETH(vETHAddress).burn(msg.sender, amount);
msg.sender.transfer(amount);
emit Withdrawal(msg.sender, amount);
}
function claimRewards() public {
// claim must start from bonusStartAt
if (now < bonusStartAt) {
if (myLastClaimedAt[msg.sender] < bonusStartAt) {
myLastClaimedAt[msg.sender] = bonusStartAt;
}
return;
}
if (myLastClaimedAt[msg.sender] >= bonusStartAt) {
uint rewards = getIncrementalRewards(msg.sender);
myRewards[msg.sender] = myRewards[msg.sender].add(rewards);
claimedRewards = claimedRewards.add(rewards);
emit Claimed(msg.sender, myRewards[msg.sender], claimedRewards);
}
myLastClaimedAt[msg.sender] = now > bonusStartAt.add(BONUS_DURATION)
? bonusStartAt.add(BONUS_DURATION)
: now;
}
function lockForValidator(
bytes calldata pubkey,
bytes calldata withdrawal_credentials,
bytes calldata signature,
bytes32 deposit_data_root
) external onlyOwner isWithdrawLocked {
uint amount = 32 ether;
require(address(this).balance >= amount, "insufficient balance");
totalLocked = totalLocked.add(amount);
IDepositContract(depositAddress).deposit{value: amount}(
pubkey,
withdrawal_credentials,
signature,
deposit_data_root
);
emit NewValidator(IDepositContract(depositAddress).get_deposit_count());
}
function bindBifrostAddress(string memory bifrostAddress_) external {
bifrostAddress[msg.sender] = bifrostAddress_;
emit BindAddress(msg.sender, bifrostAddress_);
}
function lockWithdraw() external onlyOwner isWithdrawNotLocked {
withdrawLocked = true;
// enable vETH transfer, MintDrop should have ownership of vETH contract
if (IVETH(vETHAddress).paused()) {
IVETH(vETHAddress).unpause();
}
}
function unlockWithdraw() external onlyOwner isWithdrawLocked {
withdrawLocked = false;
}
/* ========== VIEWS ========== */
function getTotalRewards() public view returns (uint) {
if (now < bonusStartAt) {
return 0;
}
uint duration = now.sub(bonusStartAt);
if (duration > BONUS_DURATION) {
return TOTAL_BNC_REWARDS;
}
return TOTAL_BNC_REWARDS.mul(duration).div(BONUS_DURATION);
}
function getIncrementalRewards(address target) public view returns (uint) {
uint totalRewards = getTotalRewards();
if (
myLastClaimedAt[target] < bonusStartAt ||
totalDeposit == 0 ||
totalRewards == 0
) {
return 0;
}
uint remainingRewards = totalRewards.sub(claimedRewards);
uint myDuration = now > bonusStartAt.add(BONUS_DURATION)
? bonusStartAt.add(BONUS_DURATION).sub(myLastClaimedAt[target])
: now.sub(myLastClaimedAt[target]);
if (myDuration > MAX_CLAIM_DURATION) {
myDuration = MAX_CLAIM_DURATION;
}
uint rewards = remainingRewards
.mul(myDeposit[target])
.div(totalDeposit)
.mul(myDuration)
.div(MAX_CLAIM_DURATION);
return rewards;
}
function getRewards(address target) external view returns (uint) {
return myRewards[target].add(getIncrementalRewards(target));
}
modifier isWithdrawLocked() {
require(withdrawLocked, "withdrawal not locked");
_;
}
modifier isWithdrawNotLocked() {
require(!withdrawLocked, "withdrawal locked");
_;
}
}