Contract Name:
RenERC20Proxy
Contract Source Code:
pragma solidity ^0.5.16;
import "@openzeppelin/contracts-ethereum-package/contracts/ownership/Ownable.sol";
import "@openzeppelin/upgrades/contracts/upgradeability/InitializableAdminUpgradeabilityProxy.sol";
import "@openzeppelin/upgrades/contracts/Initializable.sol";
import "@openzeppelin/contracts-ethereum-package/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts-ethereum-package/contracts/token/ERC20/ERC20Detailed.sol";
import "../Governance/Claimable.sol";
import "../libraries/CanReclaimTokens.sol";
import "./ERC20WithRate.sol";
import "./ERC20WithPermit.sol";
/// @notice RenERC20 represents a digital asset that has been bridged on to
/// the Ethereum ledger. It exposes mint and burn functions that can only be
/// called by it's associated Gateway contract.
contract RenERC20LogicV1 is
Initializable,
ERC20,
ERC20Detailed,
ERC20WithRate,
ERC20WithPermit,
Claimable,
CanReclaimTokens
{
/* solium-disable-next-line no-empty-blocks */
function initialize(
uint256 _chainId,
address _nextOwner,
uint256 _initialRate,
string memory _version,
string memory _name,
string memory _symbol,
uint8 _decimals
) public initializer {
ERC20Detailed.initialize(_name, _symbol, _decimals);
ERC20WithRate.initialize(_nextOwner, _initialRate);
ERC20WithPermit.initialize(
_chainId,
_version,
_name,
_symbol,
_decimals
);
Claimable.initialize(_nextOwner);
CanReclaimTokens.initialize(_nextOwner);
}
function updateSymbol(string memory symbol) public onlyOwner {
ERC20Detailed._symbol = symbol;
}
/// @notice mint can only be called by the tokens' associated Gateway
/// contract. See Gateway's mint function instead.
function mint(address _to, uint256 _amount) public onlyOwner {
_mint(_to, _amount);
}
/// @notice burn can only be called by the tokens' associated Gateway
/// contract. See Gateway's burn functions instead.
function burn(address _from, uint256 _amount) public onlyOwner {
_burn(_from, _amount);
}
function transfer(address recipient, uint256 amount) public returns (bool) {
// Disallow sending tokens to the ERC20 contract address - a common
// mistake caused by the Ethereum transaction's `to` needing to be
// the token's address.
require(
recipient != address(this),
"RenERC20: can't transfer to token address"
);
return super.transfer(recipient, amount);
}
function transferFrom(
address sender,
address recipient,
uint256 amount
) public returns (bool) {
// Disallow sending tokens to the ERC20 contract address (see comment
// in `transfer`).
require(
recipient != address(this),
"RenERC20: can't transfer to token address"
);
return super.transferFrom(sender, recipient, amount);
}
}
/* solium-disable-next-line no-empty-blocks */
contract RenERC20Proxy is InitializableAdminUpgradeabilityProxy {
}
pragma solidity ^0.5.0;
import "@openzeppelin/upgrades/contracts/Initializable.sol";
import "../GSN/Context.sol";
/**
* @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.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be aplied to your functions to restrict their use to
* the owner.
*/
contract Ownable is Initializable, Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
function initialize(address sender) public initializer {
_owner = sender;
emit OwnershipTransferred(address(0), _owner);
}
/**
* @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(isOwner(), "Ownable: caller is not the owner");
_;
}
/**
* @dev Returns true if the caller is the current owner.
*/
function isOwner() public view returns (bool) {
return _msgSender() == _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 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 onlyOwner {
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
*/
function _transferOwnership(address newOwner) internal {
require(newOwner != address(0), "Ownable: new owner is the zero address");
emit OwnershipTransferred(_owner, newOwner);
_owner = newOwner;
}
uint256[50] private ______gap;
}
pragma solidity ^0.5.0;
import './BaseAdminUpgradeabilityProxy.sol';
import './InitializableUpgradeabilityProxy.sol';
/**
* @title InitializableAdminUpgradeabilityProxy
* @dev Extends from BaseAdminUpgradeabilityProxy with an initializer for
* initializing the implementation, admin, and init data.
*/
contract InitializableAdminUpgradeabilityProxy is BaseAdminUpgradeabilityProxy, InitializableUpgradeabilityProxy {
/**
* Contract initializer.
* @param _logic address of the initial implementation.
* @param _admin Address of the proxy administrator.
* @param _data Data to send as msg.data to the implementation to initialize the proxied contract.
* It should include the signature and the parameters of the function to be called, as described in
* https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
* This parameter is optional, if no data is given the initialization call to proxied contract will be skipped.
*/
function initialize(address _logic, address _admin, bytes memory _data) public payable {
require(_implementation() == address(0));
InitializableUpgradeabilityProxy.initialize(_logic, _data);
assert(ADMIN_SLOT == bytes32(uint256(keccak256('eip1967.proxy.admin')) - 1));
_setAdmin(_admin);
}
}
pragma solidity >=0.4.24 <0.7.0;
/**
* @title Initializable
*
* @dev Helper contract to support initializer functions. To use it, replace
* the constructor with a function that has the `initializer` modifier.
* WARNING: Unlike constructors, initializer functions must be manually
* invoked. This applies both to deploying an Initializable contract, as well
* as extending an Initializable contract via inheritance.
* WARNING: When used with inheritance, manual care must be taken to not invoke
* a parent initializer twice, or ensure that all initializers are idempotent,
* because this is not dealt with automatically as with constructors.
*/
contract Initializable {
/**
* @dev Indicates that the contract has been initialized.
*/
bool private initialized;
/**
* @dev Indicates that the contract is in the process of being initialized.
*/
bool private initializing;
/**
* @dev Modifier to use in the initializer function of a contract.
*/
modifier initializer() {
require(initializing || isConstructor() || !initialized, "Contract instance has already been initialized");
bool isTopLevelCall = !initializing;
if (isTopLevelCall) {
initializing = true;
initialized = true;
}
_;
if (isTopLevelCall) {
initializing = false;
}
}
/// @dev Returns true if and only if the function is running in the constructor
function isConstructor() private view returns (bool) {
// extcodesize checks the size of the code stored in an address, and
// address returns the current address. Since the code is still not
// deployed when running a constructor, any checks on its code size will
// yield zero, making it an effective way to detect if a contract is
// under construction or not.
address self = address(this);
uint256 cs;
assembly { cs := extcodesize(self) }
return cs == 0;
}
// Reserved storage space to allow for layout changes in the future.
uint256[50] private ______gap;
}
pragma solidity ^0.5.0;
import "@openzeppelin/upgrades/contracts/Initializable.sol";
import "../../GSN/Context.sol";
import "./IERC20.sol";
import "../../math/SafeMath.sol";
/**
* @dev Implementation of the {IERC20} interface.
*
* This implementation is agnostic to the way tokens are created. This means
* that a supply mechanism has to be added in a derived contract using {_mint}.
* For a generic mechanism see {ERC20Mintable}.
*
* TIP: For a detailed writeup see our guide
* https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* We have followed general OpenZeppelin guidelines: functions revert instead
* of returning `false` on failure. This behavior is nonetheless conventional
* and does not conflict with the expectations of ERC20 applications.
*
* Additionally, an {Approval} event is emitted on calls to {transferFrom}.
* This allows applications to reconstruct the allowance for all accounts just
* by listening to said events. Other implementations of the EIP may not emit
* these events, as it isn't required by the specification.
*
* Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
* functions have been added to mitigate the well-known issues around setting
* allowances. See {IERC20-approve}.
*/
contract ERC20 is Initializable, Context, IERC20 {
using SafeMath for uint256;
mapping (address => uint256) private _balances;
mapping (address => mapping (address => uint256)) private _allowances;
uint256 private _totalSupply;
/**
* @dev See {IERC20-totalSupply}.
*/
function totalSupply() public view returns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/
function balanceOf(address account) public view returns (uint256) {
return _balances[account];
}
/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `recipient` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/
function transfer(address recipient, uint256 amount) public returns (bool) {
_transfer(_msgSender(), recipient, amount);
return true;
}
/**
* @dev See {IERC20-allowance}.
*/
function allowance(address owner, address spender) public view returns (uint256) {
return _allowances[owner][spender];
}
/**
* @dev See {IERC20-approve}.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 amount) public returns (bool) {
_approve(_msgSender(), spender, amount);
return true;
}
/**
* @dev See {IERC20-transferFrom}.
*
* Emits an {Approval} event indicating the updated allowance. This is not
* required by the EIP. See the note at the beginning of {ERC20};
*
* Requirements:
* - `sender` and `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
* - the caller must have allowance for `sender`'s tokens of at least
* `amount`.
*/
function transferFrom(address sender, address recipient, uint256 amount) public returns (bool) {
_transfer(sender, recipient, amount);
_approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
return true;
}
/**
* @dev Atomically increases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function increaseAllowance(address spender, uint256 addedValue) public returns (bool) {
_approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
return true;
}
/**
* @dev Atomically decreases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `spender` must have allowance for the caller of at least
* `subtractedValue`.
*/
function decreaseAllowance(address spender, uint256 subtractedValue) public returns (bool) {
_approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
return true;
}
/**
* @dev Moves tokens `amount` from `sender` to `recipient`.
*
* This is internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a {Transfer} event.
*
* Requirements:
*
* - `sender` cannot be the zero address.
* - `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
*/
function _transfer(address sender, address recipient, uint256 amount) internal {
require(sender != address(0), "ERC20: transfer from the zero address");
require(recipient != address(0), "ERC20: transfer to the zero address");
_balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
_balances[recipient] = _balances[recipient].add(amount);
emit Transfer(sender, recipient, amount);
}
/** @dev Creates `amount` tokens and assigns them to `account`, increasing
* the total supply.
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* Requirements
*
* - `to` cannot be the zero address.
*/
function _mint(address account, uint256 amount) internal {
require(account != address(0), "ERC20: mint to the zero address");
_totalSupply = _totalSupply.add(amount);
_balances[account] = _balances[account].add(amount);
emit Transfer(address(0), account, amount);
}
/**
* @dev Destroys `amount` tokens from `account`, reducing the
* total supply.
*
* Emits a {Transfer} event with `to` set to the zero address.
*
* Requirements
*
* - `account` cannot be the zero address.
* - `account` must have at least `amount` tokens.
*/
function _burn(address account, uint256 amount) internal {
require(account != address(0), "ERC20: burn from the zero address");
_balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
_totalSupply = _totalSupply.sub(amount);
emit Transfer(account, address(0), amount);
}
/**
* @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.
*
* This is internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*/
function _approve(address owner, address spender, uint256 amount) internal {
require(owner != address(0), "ERC20: approve from the zero address");
require(spender != address(0), "ERC20: approve to the zero address");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
/**
* @dev Destroys `amount` tokens from `account`.`amount` is then deducted
* from the caller's allowance.
*
* See {_burn} and {_approve}.
*/
function _burnFrom(address account, uint256 amount) internal {
_burn(account, amount);
_approve(account, _msgSender(), _allowances[account][_msgSender()].sub(amount, "ERC20: burn amount exceeds allowance"));
}
uint256[50] private ______gap;
}
pragma solidity ^0.5.0;
import "@openzeppelin/upgrades/contracts/Initializable.sol";
import "./IERC20.sol";
/**
* @dev Optional functions from the ERC20 standard.
*/
contract ERC20Detailed is Initializable, IERC20 {
string private _name;
string internal _symbol;
uint8 private _decimals;
/**
* @dev Sets the values for `name`, `symbol`, and `decimals`. All three of
* these values are immutable: they can only be set once during
* construction.
*/
function initialize(string memory name, string memory symbol, uint8 decimals) public initializer {
_name = name;
_symbol = symbol;
_decimals = decimals;
}
/**
* @dev Returns the name of the token.
*/
function name() public view returns (string memory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view returns (string memory) {
return _symbol;
}
/**
* @dev Returns the number of decimals used to get its user representation.
* For example, if `decimals` equals `2`, a balance of `505` tokens should
* be displayed to a user as `5,05` (`505 / 10 ** 2`).
*
* Tokens usually opt for a value of 18, imitating the relationship between
* Ether and Wei.
*
* NOTE: This information is only used for _display_ purposes: it in
* no way affects any of the arithmetic of the contract, including
* {IERC20-balanceOf} and {IERC20-transfer}.
*/
function decimals() public view returns (uint8) {
return _decimals;
}
uint256[50] private ______gap;
}
pragma solidity ^0.5.17;
import "@openzeppelin/contracts-ethereum-package/contracts/ownership/Ownable.sol";
import "@openzeppelin/upgrades/contracts/Initializable.sol";
/**
* @title Claimable
* @dev Extension for the Ownable contract, where the ownership needs to be claimed.
* This allows the new owner to accept the transfer.
*/
contract Claimable is Initializable, Ownable {
address public pendingOwner;
function initialize(address _nextOwner) public initializer {
Ownable.initialize(_nextOwner);
}
modifier onlyPendingOwner() {
require(
_msgSender() == pendingOwner,
"Claimable: caller is not the pending owner"
);
_;
}
function transferOwnership(address newOwner) public onlyOwner {
require(
newOwner != owner() && newOwner != pendingOwner,
"Claimable: invalid new owner"
);
pendingOwner = newOwner;
}
// Allow skipping two-step transfer if the recipient is known to be a valid
// owner, for use in smart-contracts only.
function _directTransferOwnership(address newOwner) public onlyOwner {
_transferOwnership(newOwner);
}
function claimOwnership() public onlyPendingOwner {
_transferOwnership(pendingOwner);
delete pendingOwner;
}
}
pragma solidity ^0.5.17;
import "@openzeppelin/contracts-ethereum-package/contracts/ownership/Ownable.sol";
import "@openzeppelin/contracts-ethereum-package/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts-ethereum-package/contracts/token/ERC20/SafeERC20.sol";
import "@openzeppelin/upgrades/contracts/Initializable.sol";
import "../Governance/Claimable.sol";
contract CanReclaimTokens is Claimable {
using SafeERC20 for ERC20;
mapping(address => bool) private recoverableTokensBlacklist;
function initialize(address _nextOwner) public initializer {
Claimable.initialize(_nextOwner);
}
function blacklistRecoverableToken(address _token) public onlyOwner {
recoverableTokensBlacklist[_token] = true;
}
/// @notice Allow the owner of the contract to recover funds accidentally
/// sent to the contract. To withdraw ETH, the token should be set to `0x0`.
function recoverTokens(address _token) external onlyOwner {
require(
!recoverableTokensBlacklist[_token],
"CanReclaimTokens: token is not recoverable"
);
if (_token == address(0x0)) {
msg.sender.transfer(address(this).balance);
} else {
ERC20(_token).safeTransfer(
msg.sender,
ERC20(_token).balanceOf(address(this))
);
}
}
}
pragma solidity ^0.5.17;
import "@openzeppelin/upgrades/contracts/Initializable.sol";
import "@openzeppelin/contracts-ethereum-package/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts-ethereum-package/contracts/math/SafeMath.sol";
import "../Governance/Claimable.sol";
/// @notice ERC20WithRate allows for a more dynamic fee model by storing a rate
/// that tracks the number of the underlying asset's unit represented by a
/// single ERC20 token.
contract ERC20WithRate is Initializable, Ownable, ERC20 {
using SafeMath for uint256;
uint256 public constant _rateScale = 1e18;
uint256 internal _rate;
event LogRateChanged(uint256 indexed _rate);
/* solium-disable-next-line no-empty-blocks */
function initialize(address _nextOwner, uint256 _initialRate)
public
initializer
{
Ownable.initialize(_nextOwner);
_setRate(_initialRate);
}
function setExchangeRate(uint256 _nextRate) public onlyOwner {
_setRate(_nextRate);
}
function exchangeRateCurrent() public view returns (uint256) {
require(_rate != 0, "ERC20WithRate: rate has not been initialized");
return _rate;
}
function _setRate(uint256 _nextRate) internal {
require(_nextRate > 0, "ERC20WithRate: rate must be greater than zero");
_rate = _nextRate;
}
function balanceOfUnderlying(address _account)
public
view
returns (uint256)
{
return toUnderlying(balanceOf(_account));
}
function toUnderlying(uint256 _amount) public view returns (uint256) {
return _amount.mul(_rate).div(_rateScale);
}
function fromUnderlying(uint256 _amountUnderlying)
public
view
returns (uint256)
{
return _amountUnderlying.mul(_rateScale).div(_rate);
}
}
pragma solidity ^0.5.17;
import "@openzeppelin/upgrades/contracts/Initializable.sol";
import "@openzeppelin/contracts-ethereum-package/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts-ethereum-package/contracts/math/SafeMath.sol";
import "@openzeppelin/contracts-ethereum-package/contracts/token/ERC20/ERC20Detailed.sol";
/// @notice Taken from the DAI token.
contract ERC20WithPermit is Initializable, ERC20, ERC20Detailed {
using SafeMath for uint256;
mapping(address => uint256) public nonces;
// If the token is redeployed, the version is increased to prevent a permit
// signature being used on both token instances.
string public version;
// --- EIP712 niceties ---
bytes32 public DOMAIN_SEPARATOR;
// PERMIT_TYPEHASH is the value returned from
// keccak256("Permit(address holder,address spender,uint256 nonce,uint256 expiry,bool allowed)")
bytes32 public constant PERMIT_TYPEHASH =
0xea2aa0a1be11a07ed86d755c93467f4f82362b452371d1ba94d1715123511acb;
function initialize(
uint256 _chainId,
string memory _version,
string memory _name,
string memory _symbol,
uint8 _decimals
) public initializer {
ERC20Detailed.initialize(_name, _symbol, _decimals);
version = _version;
DOMAIN_SEPARATOR = keccak256(
abi.encode(
keccak256(
"EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"
),
keccak256(bytes(name())),
keccak256(bytes(version)),
_chainId,
address(this)
)
);
}
// --- Approve by signature ---
function permit(
address holder,
address spender,
uint256 nonce,
uint256 expiry,
bool allowed,
uint8 v,
bytes32 r,
bytes32 s
) external {
bytes32 digest =
keccak256(
abi.encodePacked(
"\x19\x01",
DOMAIN_SEPARATOR,
keccak256(
abi.encode(
PERMIT_TYPEHASH,
holder,
spender,
nonce,
expiry,
allowed
)
)
)
);
require(holder != address(0), "ERC20WithRate: address must not be 0x0");
require(
holder == ecrecover(digest, v, r, s),
"ERC20WithRate: invalid signature"
);
require(
expiry == 0 || now <= expiry,
"ERC20WithRate: permit has expired"
);
require(nonce == nonces[holder]++, "ERC20WithRate: invalid nonce");
uint256 amount = allowed ? uint256(-1) : 0;
_approve(holder, spender, amount);
}
}
pragma solidity ^0.5.0;
import "@openzeppelin/upgrades/contracts/Initializable.sol";
/*
* @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.
*/
contract Context is Initializable {
// Empty internal constructor, to prevent people from mistakenly deploying
// an instance of this contract, which should be used via inheritance.
constructor () internal { }
// solhint-disable-previous-line no-empty-blocks
function _msgSender() internal view returns (address payable) {
return msg.sender;
}
function _msgData() internal view returns (bytes memory) {
this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
return msg.data;
}
}
pragma solidity ^0.5.0;
import './UpgradeabilityProxy.sol';
/**
* @title BaseAdminUpgradeabilityProxy
* @dev This contract combines an upgradeability proxy with an authorization
* mechanism for administrative tasks.
* All external functions in this contract must be guarded by the
* `ifAdmin` modifier. See ethereum/solidity#3864 for a Solidity
* feature proposal that would enable this to be done automatically.
*/
contract BaseAdminUpgradeabilityProxy is BaseUpgradeabilityProxy {
/**
* @dev Emitted when the administration has been transferred.
* @param previousAdmin Address of the previous admin.
* @param newAdmin Address of the new admin.
*/
event AdminChanged(address previousAdmin, address newAdmin);
/**
* @dev Storage slot with the admin of the contract.
* This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
* validated in the constructor.
*/
bytes32 internal constant ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
/**
* @dev Modifier to check whether the `msg.sender` is the admin.
* If it is, it will run the function. Otherwise, it will delegate the call
* to the implementation.
*/
modifier ifAdmin() {
if (msg.sender == _admin()) {
_;
} else {
_fallback();
}
}
/**
* @return The address of the proxy admin.
*/
function admin() external ifAdmin returns (address) {
return _admin();
}
/**
* @return The address of the implementation.
*/
function implementation() external ifAdmin returns (address) {
return _implementation();
}
/**
* @dev Changes the admin of the proxy.
* Only the current admin can call this function.
* @param newAdmin Address to transfer proxy administration to.
*/
function changeAdmin(address newAdmin) external ifAdmin {
require(newAdmin != address(0), "Cannot change the admin of a proxy to the zero address");
emit AdminChanged(_admin(), newAdmin);
_setAdmin(newAdmin);
}
/**
* @dev Upgrade the backing implementation of the proxy.
* Only the admin can call this function.
* @param newImplementation Address of the new implementation.
*/
function upgradeTo(address newImplementation) external ifAdmin {
_upgradeTo(newImplementation);
}
/**
* @dev Upgrade the backing implementation of the proxy and call a function
* on the new implementation.
* This is useful to initialize the proxied contract.
* @param newImplementation Address of the new implementation.
* @param data Data to send as msg.data in the low level call.
* It should include the signature and the parameters of the function to be called, as described in
* https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
*/
function upgradeToAndCall(address newImplementation, bytes calldata data) payable external ifAdmin {
_upgradeTo(newImplementation);
(bool success,) = newImplementation.delegatecall(data);
require(success);
}
/**
* @return The admin slot.
*/
function _admin() internal view returns (address adm) {
bytes32 slot = ADMIN_SLOT;
assembly {
adm := sload(slot)
}
}
/**
* @dev Sets the address of the proxy admin.
* @param newAdmin Address of the new proxy admin.
*/
function _setAdmin(address newAdmin) internal {
bytes32 slot = ADMIN_SLOT;
assembly {
sstore(slot, newAdmin)
}
}
/**
* @dev Only fall back when the sender is not the admin.
*/
function _willFallback() internal {
require(msg.sender != _admin(), "Cannot call fallback function from the proxy admin");
super._willFallback();
}
}
pragma solidity ^0.5.0;
import './BaseUpgradeabilityProxy.sol';
/**
* @title InitializableUpgradeabilityProxy
* @dev Extends BaseUpgradeabilityProxy with an initializer for initializing
* implementation and init data.
*/
contract InitializableUpgradeabilityProxy is BaseUpgradeabilityProxy {
/**
* @dev Contract initializer.
* @param _logic Address of the initial implementation.
* @param _data Data to send as msg.data to the implementation to initialize the proxied contract.
* It should include the signature and the parameters of the function to be called, as described in
* https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
* This parameter is optional, if no data is given the initialization call to proxied contract will be skipped.
*/
function initialize(address _logic, bytes memory _data) public payable {
require(_implementation() == address(0));
assert(IMPLEMENTATION_SLOT == bytes32(uint256(keccak256('eip1967.proxy.implementation')) - 1));
_setImplementation(_logic);
if(_data.length > 0) {
(bool success,) = _logic.delegatecall(_data);
require(success);
}
}
}
pragma solidity ^0.5.0;
import './BaseUpgradeabilityProxy.sol';
/**
* @title UpgradeabilityProxy
* @dev Extends BaseUpgradeabilityProxy with a constructor for initializing
* implementation and init data.
*/
contract UpgradeabilityProxy is BaseUpgradeabilityProxy {
/**
* @dev Contract constructor.
* @param _logic Address of the initial implementation.
* @param _data Data to send as msg.data to the implementation to initialize the proxied contract.
* It should include the signature and the parameters of the function to be called, as described in
* https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
* This parameter is optional, if no data is given the initialization call to proxied contract will be skipped.
*/
constructor(address _logic, bytes memory _data) public payable {
assert(IMPLEMENTATION_SLOT == bytes32(uint256(keccak256('eip1967.proxy.implementation')) - 1));
_setImplementation(_logic);
if(_data.length > 0) {
(bool success,) = _logic.delegatecall(_data);
require(success);
}
}
}
pragma solidity ^0.5.0;
import './Proxy.sol';
import '../utils/Address.sol';
/**
* @title BaseUpgradeabilityProxy
* @dev This contract implements a proxy that allows to change the
* implementation address to which it will delegate.
* Such a change is called an implementation upgrade.
*/
contract BaseUpgradeabilityProxy is Proxy {
/**
* @dev Emitted when the implementation is upgraded.
* @param implementation Address of the new implementation.
*/
event Upgraded(address indexed implementation);
/**
* @dev Storage slot with the address of the current implementation.
* This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
* validated in the constructor.
*/
bytes32 internal constant IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
/**
* @dev Returns the current implementation.
* @return Address of the current implementation
*/
function _implementation() internal view returns (address impl) {
bytes32 slot = IMPLEMENTATION_SLOT;
assembly {
impl := sload(slot)
}
}
/**
* @dev Upgrades the proxy to a new implementation.
* @param newImplementation Address of the new implementation.
*/
function _upgradeTo(address newImplementation) internal {
_setImplementation(newImplementation);
emit Upgraded(newImplementation);
}
/**
* @dev Sets the implementation address of the proxy.
* @param newImplementation Address of the new implementation.
*/
function _setImplementation(address newImplementation) internal {
require(OpenZeppelinUpgradesAddress.isContract(newImplementation), "Cannot set a proxy implementation to a non-contract address");
bytes32 slot = IMPLEMENTATION_SLOT;
assembly {
sstore(slot, newImplementation)
}
}
}
pragma solidity ^0.5.0;
/**
* @title Proxy
* @dev Implements delegation of calls to other contracts, with proper
* forwarding of return values and bubbling of failures.
* It defines a fallback function that delegates all calls to the address
* returned by the abstract _implementation() internal function.
*/
contract Proxy {
/**
* @dev Fallback function.
* Implemented entirely in `_fallback`.
*/
function () payable external {
_fallback();
}
/**
* @return The Address of the implementation.
*/
function _implementation() internal view returns (address);
/**
* @dev Delegates execution to an implementation contract.
* This is a low level function that doesn't return to its internal call site.
* It will return to the external caller whatever the implementation returns.
* @param implementation Address to delegate.
*/
function _delegate(address implementation) internal {
assembly {
// Copy msg.data. We take full control of memory in this inline assembly
// block because it will not return to Solidity code. We overwrite the
// Solidity scratch pad at memory position 0.
calldatacopy(0, 0, calldatasize)
// Call the implementation.
// out and outsize are 0 because we don't know the size yet.
let result := delegatecall(gas, implementation, 0, calldatasize, 0, 0)
// Copy the returned data.
returndatacopy(0, 0, returndatasize)
switch result
// delegatecall returns 0 on error.
case 0 { revert(0, returndatasize) }
default { return(0, returndatasize) }
}
}
/**
* @dev Function that is run as the first thing in the fallback function.
* Can be redefined in derived contracts to add functionality.
* Redefinitions must call super._willFallback().
*/
function _willFallback() internal {
}
/**
* @dev fallback implementation.
* Extracted to enable manual triggering.
*/
function _fallback() internal {
_willFallback();
_delegate(_implementation());
}
}
pragma solidity ^0.5.0;
/**
* Utility library of inline functions on addresses
*
* Source https://raw.githubusercontent.com/OpenZeppelin/openzeppelin-solidity/v2.1.3/contracts/utils/Address.sol
* This contract is copied here and renamed from the original to avoid clashes in the compiled artifacts
* when the user imports a zos-lib contract (that transitively causes this contract to be compiled and added to the
* build/artifacts folder) as well as the vanilla Address implementation from an openzeppelin version.
*/
library OpenZeppelinUpgradesAddress {
/**
* 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;
/**
* @dev Interface of the ERC20 standard as defined in the EIP. Does not include
* the optional functions; to access them see {ERC20Detailed}.
*/
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 ^0.5.0;
/**
* @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.
*
* _Available since v2.4.0._
*/
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.
*
* _Available since v2.4.0._
*/
function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
// Solidity only automatically asserts when dividing by 0
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.
*
* _Available since v2.4.0._
*/
function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b != 0, errorMessage);
return a % b;
}
}
pragma solidity ^0.5.0;
import "./IERC20.sol";
import "../../math/SafeMath.sol";
import "../../utils/Address.sol";
/**
* @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, "SafeERC20: decreased allowance below zero");
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 ^0.5.5;
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
* ====
*/
function isContract(address account) internal view returns (bool) {
// According to EIP-1052, 0x0 is the value returned for not-yet created accounts
// and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
// for accounts without code, i.e. `keccak256('')`
bytes32 codehash;
bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
// solhint-disable-next-line no-inline-assembly
assembly { codehash := extcodehash(account) }
return (codehash != accountHash && codehash != 0x0);
}
/**
* @dev Converts an `address` into `address payable`. Note that this is
* simply a type cast: the actual underlying value is not changed.
*
* _Available since v2.4.0._
*/
function toPayable(address account) internal pure returns (address payable) {
return address(uint160(account));
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*
* _Available since v2.4.0._
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient balance");
// solhint-disable-next-line avoid-call-value
(bool success, ) = recipient.call.value(amount)("");
require(success, "Address: unable to send value, recipient may have reverted");
}
}