Contract Name:
TokenStaking
Contract Source Code:
// SPDX-License-Identifier: MIT
pragma solidity >=0.8.20;
import {ReentrancyGuardUpgradeable} from "@openzeppelin5/contracts-upgradeable/utils/ReentrancyGuardUpgradeable.sol";
import {SafeERC20, IERC20} from "@openzeppelin5/contracts/token/ERC20/utils/SafeERC20.sol";
import {MerkleProof} from "@openzeppelin5/contracts/utils/cryptography/MerkleProof.sol";
import {IERC20Metadata} from "@openzeppelin5/contracts/token/ERC20/extensions/IERC20Metadata.sol";
import {ITokenStaking} from "./interfaces/ITokenStaking.sol";
contract TokenStaking is
ReentrancyGuardUpgradeable,
ITokenStaking
{
using SafeERC20 for IERC20;
uint256 private constant _MINIMUM_AMOUNT = 1e18;
IERC20 public stakeToken;
bool public stakingActive;
uint256 public totalStaked;
mapping(address => uint256) public balanceOf;
address public owner;
event StakeTokenSet(address indexed previousToken, address indexed newToken);
event OwnerSet(address indexed previousOwner, address indexed newOwner);
/// @custom:oz-upgrades-unsafe-allow constructor
constructor(address _stakeToken) {
owner = msg.sender;
stakingActive = true;
stakeToken = IERC20(_stakeToken);
}
function name() external view returns (string memory) {
return IERC20Metadata(address(stakeToken)).name();
}
function symbol() external view returns (string memory) {
return IERC20Metadata(address(stakeToken)).symbol();
}
function decimals() external view returns (uint8) {
return IERC20Metadata(address(stakeToken)).decimals();
}
// ==================
// External Functions
// ==================
/// @inheritdoc ITokenStaking
function stake(uint256 amount)
external
nonReentrant
onlyValidStakingSetup
{
_stake(msg.sender, amount);
}
/// @inheritdoc ITokenStaking
function unstake(uint256 amount)
external
nonReentrant
onlyValidStakingSetup
{
_unstake(msg.sender, amount);
}
// ============================
// Internal & Private Functions
// ============================
function _stake(address user, uint256 amount) private {
unchecked {
balanceOf[user] += amount;
}
totalStaked += amount;
stakeToken.safeTransferFrom(user, address(this), amount);
emit Transfer(address(0), user, amount);
emit Staked(user, amount, block.timestamp);
}
function _unstake(address user, uint256 amount) private {
uint256 userBalance = balanceOf[user];
if (userBalance < amount) revert InsufficientStakedBalance();
balanceOf[user] = userBalance - amount;
totalStaked -= amount;
stakeToken.safeTransfer(user, amount);
emit Transfer(user, address(0), amount);
emit Unstaked(user, amount, block.timestamp);
}
// ====================
// Validation Modifiers
// ====================
modifier onlyOwner() {
require(msg.sender == owner, "Only the owner can call this function");
_; // Continue execution of the function if the condition is met
}
modifier onlyValidStakingSetup() {
if (!stakingActive) revert StakingNotAvailable();
_;
}
modifier onlyValidAmount(uint256 amount) {
if (amount == 0 || amount < _MINIMUM_AMOUNT) revert InvalidAmount();
_;
}
// ==============
// Admin Functions
// ==============
/// @inheritdoc ITokenStaking
function setStakingActive(bool isActive) external onlyOwner {
stakingActive = isActive;
emit StakingStatusUpdated(isActive);
}
/// set owner
function setOwner(address _owner) external onlyOwner {
address previousOwner = owner;
owner = _owner;
emit OwnerSet(previousOwner, _owner);
}
// ==============
// Getters
// ==============
/**
* @notice Get the total staked amount
*/
function totalSupply() external view returns (uint256) {
return totalStaked;
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.8.20;
import {IERC20TokenTracker} from "./IERC20TokenTracker.sol";
interface ITokenStaking is IERC20TokenTracker {
struct Reward {
uint256 rewardId;
uint256 amount;
bytes32[] proof;
}
error InvalidAddress();
error InvalidAmount();
error InvalidProof();
error InvalidStakingSetup();
error InsufficientStakedBalance();
error StakingNotAvailable();
error Unauthorized();
error UpgraderRenounced();
event Staked(address indexed user, uint256 amount, uint256 stakedAt);
event Unstaked(address indexed user, uint256 amount, uint256 unstakedAt);
event RewardRedeemed(address user, uint256 rewardId, uint256 amount, uint256 redeemedAt);
event RewardStaked(uint256 rewardId, uint256 amount, uint256 stakedAt);
event StakingStatusUpdated(bool isActive);
event UpgraderUpdated(address _upgrader);
/**
* @notice Stake tokens into staking contract
* @param amount The amount of tokens to stake from user's wallet
*/
function stake(uint256 amount) external;
/**
* @notice Unstake tokens from staking contract
* @param amount The total amount of tokens to unstake from staked balance and any unredeemed rewards
*/
function unstake(uint256 amount) external;
/**
* @notice Stake rewards with specified address of depositor. Can only be called by the owner.
* @param depositor The address to stake tokens as rewards
* @param rewardId The ID of reward
* @param amount The amount of rewards to stake
* @param root The Merkle root to verify users' reward
*/
// function stakeRewards(address depositor, uint256 rewardId, uint256 amount, bytes32 root) external;
/**
* @notice Pause/unpause staking. Can only be called by the owner.
* @param isActive New boolean to indicate active or not
*/
function setStakingActive(bool isActive) external;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/extensions/IERC20Metadata.sol)
pragma solidity ^0.8.20;
import {IERC20} from "../IERC20.sol";
/**
* @dev Interface for the optional metadata functions from the ERC-20 standard.
*/
interface IERC20Metadata is IERC20 {
/**
* @dev Returns the name of the token.
*/
function name() external view returns (string memory);
/**
* @dev Returns the symbol of the token.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the decimals places of the token.
*/
function decimals() external view returns (uint8);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/cryptography/MerkleProof.sol)
pragma solidity ^0.8.20;
/**
* @dev These functions deal with verification of Merkle Tree proofs.
*
* The tree and the proofs can be generated using our
* https://github.com/OpenZeppelin/merkle-tree[JavaScript library].
* You will find a quickstart guide in the readme.
*
* WARNING: You should avoid using leaf values that are 64 bytes long prior to
* hashing, or use a hash function other than keccak256 for hashing leaves.
* This is because the concatenation of a sorted pair of internal nodes in
* the Merkle tree could be reinterpreted as a leaf value.
* OpenZeppelin's JavaScript library generates Merkle trees that are safe
* against this attack out of the box.
*/
library MerkleProof {
/**
*@dev The multiproof provided is not valid.
*/
error MerkleProofInvalidMultiproof();
/**
* @dev Returns true if a `leaf` can be proved to be a part of a Merkle tree
* defined by `root`. For this, a `proof` must be provided, containing
* sibling hashes on the branch from the leaf to the root of the tree. Each
* pair of leaves and each pair of pre-images are assumed to be sorted.
*/
function verify(bytes32[] memory proof, bytes32 root, bytes32 leaf) internal pure returns (bool) {
return processProof(proof, leaf) == root;
}
/**
* @dev Calldata version of {verify}
*/
function verifyCalldata(bytes32[] calldata proof, bytes32 root, bytes32 leaf) internal pure returns (bool) {
return processProofCalldata(proof, leaf) == root;
}
/**
* @dev Returns the rebuilt hash obtained by traversing a Merkle tree up
* from `leaf` using `proof`. A `proof` is valid if and only if the rebuilt
* hash matches the root of the tree. When processing the proof, the pairs
* of leafs & pre-images are assumed to be sorted.
*/
function processProof(bytes32[] memory proof, bytes32 leaf) internal pure returns (bytes32) {
bytes32 computedHash = leaf;
for (uint256 i = 0; i < proof.length; i++) {
computedHash = _hashPair(computedHash, proof[i]);
}
return computedHash;
}
/**
* @dev Calldata version of {processProof}
*/
function processProofCalldata(bytes32[] calldata proof, bytes32 leaf) internal pure returns (bytes32) {
bytes32 computedHash = leaf;
for (uint256 i = 0; i < proof.length; i++) {
computedHash = _hashPair(computedHash, proof[i]);
}
return computedHash;
}
/**
* @dev Returns true if the `leaves` can be simultaneously proven to be a part of a Merkle tree defined by
* `root`, according to `proof` and `proofFlags` as described in {processMultiProof}.
*
* CAUTION: Not all Merkle trees admit multiproofs. See {processMultiProof} for details.
*/
function multiProofVerify(
bytes32[] memory proof,
bool[] memory proofFlags,
bytes32 root,
bytes32[] memory leaves
) internal pure returns (bool) {
return processMultiProof(proof, proofFlags, leaves) == root;
}
/**
* @dev Calldata version of {multiProofVerify}
*
* CAUTION: Not all Merkle trees admit multiproofs. See {processMultiProof} for details.
*/
function multiProofVerifyCalldata(
bytes32[] calldata proof,
bool[] calldata proofFlags,
bytes32 root,
bytes32[] memory leaves
) internal pure returns (bool) {
return processMultiProofCalldata(proof, proofFlags, leaves) == root;
}
/**
* @dev Returns the root of a tree reconstructed from `leaves` and sibling nodes in `proof`. The reconstruction
* proceeds by incrementally reconstructing all inner nodes by combining a leaf/inner node with either another
* leaf/inner node or a proof sibling node, depending on whether each `proofFlags` item is true or false
* respectively.
*
* CAUTION: Not all Merkle trees admit multiproofs. To use multiproofs, it is sufficient to ensure that: 1) the tree
* is complete (but not necessarily perfect), 2) the leaves to be proven are in the opposite order they are in the
* tree (i.e., as seen from right to left starting at the deepest layer and continuing at the next layer).
*/
function processMultiProof(
bytes32[] memory proof,
bool[] memory proofFlags,
bytes32[] memory leaves
) internal pure returns (bytes32 merkleRoot) {
// This function rebuilds the root hash by traversing the tree up from the leaves. The root is rebuilt by
// consuming and producing values on a queue. The queue starts with the `leaves` array, then goes onto the
// `hashes` array. At the end of the process, the last hash in the `hashes` array should contain the root of
// the Merkle tree.
uint256 leavesLen = leaves.length;
uint256 proofLen = proof.length;
uint256 totalHashes = proofFlags.length;
// Check proof validity.
if (leavesLen + proofLen != totalHashes + 1) {
revert MerkleProofInvalidMultiproof();
}
// The xxxPos values are "pointers" to the next value to consume in each array. All accesses are done using
// `xxx[xxxPos++]`, which return the current value and increment the pointer, thus mimicking a queue's "pop".
bytes32[] memory hashes = new bytes32[](totalHashes);
uint256 leafPos = 0;
uint256 hashPos = 0;
uint256 proofPos = 0;
// At each step, we compute the next hash using two values:
// - a value from the "main queue". If not all leaves have been consumed, we get the next leaf, otherwise we
// get the next hash.
// - depending on the flag, either another value from the "main queue" (merging branches) or an element from the
// `proof` array.
for (uint256 i = 0; i < totalHashes; i++) {
bytes32 a = leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++];
bytes32 b = proofFlags[i]
? (leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++])
: proof[proofPos++];
hashes[i] = _hashPair(a, b);
}
if (totalHashes > 0) {
if (proofPos != proofLen) {
revert MerkleProofInvalidMultiproof();
}
unchecked {
return hashes[totalHashes - 1];
}
} else if (leavesLen > 0) {
return leaves[0];
} else {
return proof[0];
}
}
/**
* @dev Calldata version of {processMultiProof}.
*
* CAUTION: Not all Merkle trees admit multiproofs. See {processMultiProof} for details.
*/
function processMultiProofCalldata(
bytes32[] calldata proof,
bool[] calldata proofFlags,
bytes32[] memory leaves
) internal pure returns (bytes32 merkleRoot) {
// This function rebuilds the root hash by traversing the tree up from the leaves. The root is rebuilt by
// consuming and producing values on a queue. The queue starts with the `leaves` array, then goes onto the
// `hashes` array. At the end of the process, the last hash in the `hashes` array should contain the root of
// the Merkle tree.
uint256 leavesLen = leaves.length;
uint256 proofLen = proof.length;
uint256 totalHashes = proofFlags.length;
// Check proof validity.
if (leavesLen + proofLen != totalHashes + 1) {
revert MerkleProofInvalidMultiproof();
}
// The xxxPos values are "pointers" to the next value to consume in each array. All accesses are done using
// `xxx[xxxPos++]`, which return the current value and increment the pointer, thus mimicking a queue's "pop".
bytes32[] memory hashes = new bytes32[](totalHashes);
uint256 leafPos = 0;
uint256 hashPos = 0;
uint256 proofPos = 0;
// At each step, we compute the next hash using two values:
// - a value from the "main queue". If not all leaves have been consumed, we get the next leaf, otherwise we
// get the next hash.
// - depending on the flag, either another value from the "main queue" (merging branches) or an element from the
// `proof` array.
for (uint256 i = 0; i < totalHashes; i++) {
bytes32 a = leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++];
bytes32 b = proofFlags[i]
? (leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++])
: proof[proofPos++];
hashes[i] = _hashPair(a, b);
}
if (totalHashes > 0) {
if (proofPos != proofLen) {
revert MerkleProofInvalidMultiproof();
}
unchecked {
return hashes[totalHashes - 1];
}
} else if (leavesLen > 0) {
return leaves[0];
} else {
return proof[0];
}
}
/**
* @dev Sorts the pair (a, b) and hashes the result.
*/
function _hashPair(bytes32 a, bytes32 b) private pure returns (bytes32) {
return a < b ? _efficientHash(a, b) : _efficientHash(b, a);
}
/**
* @dev Implementation of keccak256(abi.encode(a, b)) that doesn't allocate or expand memory.
*/
function _efficientHash(bytes32 a, bytes32 b) private pure returns (bytes32 value) {
/// @solidity memory-safe-assembly
assembly {
mstore(0x00, a)
mstore(0x20, b)
value := keccak256(0x00, 0x40)
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/utils/SafeERC20.sol)
pragma solidity ^0.8.20;
import {IERC20} from "../IERC20.sol";
import {IERC20Permit} from "../extensions/IERC20Permit.sol";
import {Address} from "../../../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 IERC20;` statement to your contract,
* which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
*/
library SafeERC20 {
using Address for address;
/**
* @dev An operation with an ERC20 token failed.
*/
error SafeERC20FailedOperation(address token);
/**
* @dev Indicates a failed `decreaseAllowance` request.
*/
error SafeERC20FailedDecreaseAllowance(address spender, uint256 currentAllowance, uint256 requestedDecrease);
/**
* @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
* non-reverting calls are assumed to be successful.
*/
function safeTransfer(IERC20 token, address to, uint256 value) internal {
_callOptionalReturn(token, abi.encodeCall(token.transfer, (to, value)));
}
/**
* @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
* calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
*/
function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
_callOptionalReturn(token, abi.encodeCall(token.transferFrom, (from, to, value)));
}
/**
* @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
* non-reverting calls are assumed to be successful.
*/
function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
uint256 oldAllowance = token.allowance(address(this), spender);
forceApprove(token, spender, oldAllowance + value);
}
/**
* @dev Decrease the calling contract's allowance toward `spender` by `requestedDecrease`. If `token` returns no
* value, non-reverting calls are assumed to be successful.
*/
function safeDecreaseAllowance(IERC20 token, address spender, uint256 requestedDecrease) internal {
unchecked {
uint256 currentAllowance = token.allowance(address(this), spender);
if (currentAllowance < requestedDecrease) {
revert SafeERC20FailedDecreaseAllowance(spender, currentAllowance, requestedDecrease);
}
forceApprove(token, spender, currentAllowance - requestedDecrease);
}
}
/**
* @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
* non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
* to be set to zero before setting it to a non-zero value, such as USDT.
*/
function forceApprove(IERC20 token, address spender, uint256 value) internal {
bytes memory approvalCall = abi.encodeCall(token.approve, (spender, value));
if (!_callOptionalReturnBool(token, approvalCall)) {
_callOptionalReturn(token, abi.encodeCall(token.approve, (spender, 0)));
_callOptionalReturn(token, approvalCall);
}
}
/**
* @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. We use {Address-functionCall} to perform this call, which verifies that
// the target address contains contract code and also asserts for success in the low-level call.
bytes memory returndata = address(token).functionCall(data);
if (returndata.length != 0 && !abi.decode(returndata, (bool))) {
revert SafeERC20FailedOperation(address(token));
}
}
/**
* @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).
*
* This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
*/
function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
// We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
// we're implementing it ourselves. We cannot use {Address-functionCall} here since this should return false
// and not revert is the subcall reverts.
(bool success, bytes memory returndata) = address(token).call(data);
return success && (returndata.length == 0 || abi.decode(returndata, (bool))) && address(token).code.length > 0;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/ReentrancyGuard.sol)
pragma solidity ^0.8.20;
import {Initializable} from "../proxy/utils/Initializable.sol";
/**
* @dev Contract module that helps prevent reentrant calls to a function.
*
* Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
* available, which can be applied to functions to make sure there are no nested
* (reentrant) calls to them.
*
* Note that because there is a single `nonReentrant` guard, functions marked as
* `nonReentrant` may not call one another. This can be worked around by making
* those functions `private`, and then adding `external` `nonReentrant` entry
* points to them.
*
* TIP: If you would like to learn more about reentrancy and alternative ways
* to protect against it, check out our blog post
* https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
*/
abstract contract ReentrancyGuardUpgradeable is Initializable {
// Booleans are more expensive than uint256 or any type that takes up a full
// word because each write operation emits an extra SLOAD to first read the
// slot's contents, replace the bits taken up by the boolean, and then write
// back. This is the compiler's defense against contract upgrades and
// pointer aliasing, and it cannot be disabled.
// The values being non-zero value makes deployment a bit more expensive,
// but in exchange the refund on every call to nonReentrant will be lower in
// amount. Since refunds are capped to a percentage of the total
// transaction's gas, it is best to keep them low in cases like this one, to
// increase the likelihood of the full refund coming into effect.
uint256 private constant NOT_ENTERED = 1;
uint256 private constant ENTERED = 2;
/// @custom:storage-location erc7201:openzeppelin.storage.ReentrancyGuard
struct ReentrancyGuardStorage {
uint256 _status;
}
// keccak256(abi.encode(uint256(keccak256("openzeppelin.storage.ReentrancyGuard")) - 1)) & ~bytes32(uint256(0xff))
bytes32 private constant ReentrancyGuardStorageLocation = 0x9b779b17422d0df92223018b32b4d1fa46e071723d6817e2486d003becc55f00;
function _getReentrancyGuardStorage() private pure returns (ReentrancyGuardStorage storage $) {
assembly {
$.slot := ReentrancyGuardStorageLocation
}
}
/**
* @dev Unauthorized reentrant call.
*/
error ReentrancyGuardReentrantCall();
function __ReentrancyGuard_init() internal onlyInitializing {
__ReentrancyGuard_init_unchained();
}
function __ReentrancyGuard_init_unchained() internal onlyInitializing {
ReentrancyGuardStorage storage $ = _getReentrancyGuardStorage();
$._status = NOT_ENTERED;
}
/**
* @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 making it call a
* `private` function that does the actual work.
*/
modifier nonReentrant() {
_nonReentrantBefore();
_;
_nonReentrantAfter();
}
function _nonReentrantBefore() private {
ReentrancyGuardStorage storage $ = _getReentrancyGuardStorage();
// On the first call to nonReentrant, _status will be NOT_ENTERED
if ($._status == ENTERED) {
revert ReentrancyGuardReentrantCall();
}
// Any calls to nonReentrant after this point will fail
$._status = ENTERED;
}
function _nonReentrantAfter() private {
ReentrancyGuardStorage storage $ = _getReentrancyGuardStorage();
// By storing the original value once again, a refund is triggered (see
// https://eips.ethereum.org/EIPS/eip-2200)
$._status = NOT_ENTERED;
}
/**
* @dev Returns true if the reentrancy guard is currently set to "entered", which indicates there is a
* `nonReentrant` function in the call stack.
*/
function _reentrancyGuardEntered() internal view returns (bool) {
ReentrancyGuardStorage storage $ = _getReentrancyGuardStorage();
return $._status == ENTERED;
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.8.20;
/**
* @dev Interface for offchain token trackers (ex. Etherscan) via partial IERC20Metadata
*/
interface IERC20TokenTracker {
event Transfer(address indexed from, address indexed to, uint256 amount);
function name() external view returns (string memory);
function symbol() external view returns (string memory);
function decimals() external view returns (uint8);
function balanceOf(address user) external view returns (uint256);
function totalSupply() external view returns (uint256);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/Address.sol)
pragma solidity ^0.8.20;
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev The ETH balance of the account is not enough to perform the operation.
*/
error AddressInsufficientBalance(address account);
/**
* @dev There's no code at `target` (it is not a contract).
*/
error AddressEmptyCode(address target);
/**
* @dev A call to an address target failed. The target may have reverted.
*/
error FailedInnerCall();
/**
* @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://consensys.net/diligence/blog/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/v0.8.20/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/
function sendValue(address payable recipient, uint256 amount) internal {
if (address(this).balance < amount) {
revert AddressInsufficientBalance(address(this));
}
(bool success, ) = recipient.call{value: amount}("");
if (!success) {
revert FailedInnerCall();
}
}
/**
* @dev Performs a Solidity function call using a low level `call`. A
* plain `call` is an unsafe replacement for a function call: use this
* function instead.
*
* If `target` reverts with a revert reason or custom error, it is bubbled
* up by this function (like regular Solidity function calls). However, if
* the call reverted with no returned reason, this function reverts with a
* {FailedInnerCall} error.
*
* Returns the raw returned data. To convert to the expected return value,
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
*
* Requirements:
*
* - `target` must be a contract.
* - calling `target` with `data` must not revert.
*/
function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but also transferring `value` wei to `target`.
*
* Requirements:
*
* - the calling contract must have an ETH balance of at least `value`.
* - the called Solidity function must be `payable`.
*/
function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
if (address(this).balance < value) {
revert AddressInsufficientBalance(address(this));
}
(bool success, bytes memory returndata) = target.call{value: value}(data);
return verifyCallResultFromTarget(target, success, returndata);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*/
function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
(bool success, bytes memory returndata) = target.staticcall(data);
return verifyCallResultFromTarget(target, success, returndata);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*/
function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
(bool success, bytes memory returndata) = target.delegatecall(data);
return verifyCallResultFromTarget(target, success, returndata);
}
/**
* @dev Tool to verify that a low level call to smart-contract was successful, and reverts if the target
* was not a contract or bubbling up the revert reason (falling back to {FailedInnerCall}) in case of an
* unsuccessful call.
*/
function verifyCallResultFromTarget(
address target,
bool success,
bytes memory returndata
) internal view returns (bytes memory) {
if (!success) {
_revert(returndata);
} else {
// only check if target is a contract if the call was successful and the return data is empty
// otherwise we already know that it was a contract
if (returndata.length == 0 && target.code.length == 0) {
revert AddressEmptyCode(target);
}
return returndata;
}
}
/**
* @dev Tool to verify that a low level call was successful, and reverts if it wasn't, either by bubbling the
* revert reason or with a default {FailedInnerCall} error.
*/
function verifyCallResult(bool success, bytes memory returndata) internal pure returns (bytes memory) {
if (!success) {
_revert(returndata);
} else {
return returndata;
}
}
/**
* @dev Reverts with returndata if present. Otherwise reverts with {FailedInnerCall}.
*/
function _revert(bytes memory returndata) private pure {
// Look for revert reason and bubble it up if present
if (returndata.length > 0) {
// The easiest way to bubble the revert reason is using memory via assembly
/// @solidity memory-safe-assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert FailedInnerCall();
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/extensions/IERC20Permit.sol)
pragma solidity ^0.8.20;
/**
* @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
* https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
*
* Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
* presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
* need to send a transaction, and thus is not required to hold Ether at all.
*
* ==== Security Considerations
*
* There are two important considerations concerning the use of `permit`. The first is that a valid permit signature
* expresses an allowance, and it should not be assumed to convey additional meaning. In particular, it should not be
* considered as an intention to spend the allowance in any specific way. The second is that because permits have
* built-in replay protection and can be submitted by anyone, they can be frontrun. A protocol that uses permits should
* take this into consideration and allow a `permit` call to fail. Combining these two aspects, a pattern that may be
* generally recommended is:
*
* ```solidity
* function doThingWithPermit(..., uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) public {
* try token.permit(msg.sender, address(this), value, deadline, v, r, s) {} catch {}
* doThing(..., value);
* }
*
* function doThing(..., uint256 value) public {
* token.safeTransferFrom(msg.sender, address(this), value);
* ...
* }
* ```
*
* Observe that: 1) `msg.sender` is used as the owner, leaving no ambiguity as to the signer intent, and 2) the use of
* `try/catch` allows the permit to fail and makes the code tolerant to frontrunning. (See also
* {SafeERC20-safeTransferFrom}).
*
* Additionally, note that smart contract wallets (such as Argent or Safe) are not able to produce permit signatures, so
* contracts should have entry points that don't rely on permit.
*/
interface IERC20Permit {
/**
* @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
* given ``owner``'s signed approval.
*
* IMPORTANT: The same issues {IERC20-approve} has related to transaction
* ordering also apply here.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `deadline` must be a timestamp in the future.
* - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
* over the EIP712-formatted function arguments.
* - the signature must use ``owner``'s current nonce (see {nonces}).
*
* For more information on the signature format, see the
* https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
* section].
*
* CAUTION: See Security Considerations above.
*/
function permit(
address owner,
address spender,
uint256 value,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) external;
/**
* @dev Returns the current nonce for `owner`. This value must be
* included whenever a signature is generated for {permit}.
*
* Every successful call to {permit} increases ``owner``'s nonce by one. This
* prevents a signature from being used multiple times.
*/
function nonces(address owner) external view returns (uint256);
/**
* @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
*/
// solhint-disable-next-line func-name-mixedcase
function DOMAIN_SEPARATOR() external view returns (bytes32);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/IERC20.sol)
pragma solidity ^0.8.20;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @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);
/**
* @dev Returns the value of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the value of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves a `value` amount of tokens from the caller's account to `to`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address to, uint256 value) 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 a `value` amount of tokens 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 value) external returns (bool);
/**
* @dev Moves a `value` amount of tokens from `from` to `to` using the
* allowance mechanism. `value` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(address from, address to, uint256 value) external returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (proxy/utils/Initializable.sol)
pragma solidity ^0.8.20;
/**
* @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
* behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an
* external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
* function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
*
* The initialization functions use a version number. Once a version number is used, it is consumed and cannot be
* reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in
* case an upgrade adds a module that needs to be initialized.
*
* For example:
*
* [.hljs-theme-light.nopadding]
* ```solidity
* contract MyToken is ERC20Upgradeable {
* function initialize() initializer public {
* __ERC20_init("MyToken", "MTK");
* }
* }
*
* contract MyTokenV2 is MyToken, ERC20PermitUpgradeable {
* function initializeV2() reinitializer(2) public {
* __ERC20Permit_init("MyToken");
* }
* }
* ```
*
* TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
* possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
*
* CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
* that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
*
* [CAUTION]
* ====
* Avoid leaving a contract uninitialized.
*
* An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
* contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke
* the {_disableInitializers} function in the constructor to automatically lock it when it is deployed:
*
* [.hljs-theme-light.nopadding]
* ```
* /// @custom:oz-upgrades-unsafe-allow constructor
* constructor() {
* _disableInitializers();
* }
* ```
* ====
*/
abstract contract Initializable {
/**
* @dev Storage of the initializable contract.
*
* It's implemented on a custom ERC-7201 namespace to reduce the risk of storage collisions
* when using with upgradeable contracts.
*
* @custom:storage-location erc7201:openzeppelin.storage.Initializable
*/
struct InitializableStorage {
/**
* @dev Indicates that the contract has been initialized.
*/
uint64 _initialized;
/**
* @dev Indicates that the contract is in the process of being initialized.
*/
bool _initializing;
}
// keccak256(abi.encode(uint256(keccak256("openzeppelin.storage.Initializable")) - 1)) & ~bytes32(uint256(0xff))
bytes32 private constant INITIALIZABLE_STORAGE = 0xf0c57e16840df040f15088dc2f81fe391c3923bec73e23a9662efc9c229c6a00;
/**
* @dev The contract is already initialized.
*/
error InvalidInitialization();
/**
* @dev The contract is not initializing.
*/
error NotInitializing();
/**
* @dev Triggered when the contract has been initialized or reinitialized.
*/
event Initialized(uint64 version);
/**
* @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,
* `onlyInitializing` functions can be used to initialize parent contracts.
*
* Similar to `reinitializer(1)`, except that in the context of a constructor an `initializer` may be invoked any
* number of times. This behavior in the constructor can be useful during testing and is not expected to be used in
* production.
*
* Emits an {Initialized} event.
*/
modifier initializer() {
// solhint-disable-next-line var-name-mixedcase
InitializableStorage storage $ = _getInitializableStorage();
// Cache values to avoid duplicated sloads
bool isTopLevelCall = !$._initializing;
uint64 initialized = $._initialized;
// Allowed calls:
// - initialSetup: the contract is not in the initializing state and no previous version was
// initialized
// - construction: the contract is initialized at version 1 (no reininitialization) and the
// current contract is just being deployed
bool initialSetup = initialized == 0 && isTopLevelCall;
bool construction = initialized == 1 && address(this).code.length == 0;
if (!initialSetup && !construction) {
revert InvalidInitialization();
}
$._initialized = 1;
if (isTopLevelCall) {
$._initializing = true;
}
_;
if (isTopLevelCall) {
$._initializing = false;
emit Initialized(1);
}
}
/**
* @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
* contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
* used to initialize parent contracts.
*
* A reinitializer may be used after the original initialization step. This is essential to configure modules that
* are added through upgrades and that require initialization.
*
* When `version` is 1, this modifier is similar to `initializer`, except that functions marked with `reinitializer`
* cannot be nested. If one is invoked in the context of another, execution will revert.
*
* Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in
* a contract, executing them in the right order is up to the developer or operator.
*
* WARNING: Setting the version to 2**64 - 1 will prevent any future reinitialization.
*
* Emits an {Initialized} event.
*/
modifier reinitializer(uint64 version) {
// solhint-disable-next-line var-name-mixedcase
InitializableStorage storage $ = _getInitializableStorage();
if ($._initializing || $._initialized >= version) {
revert InvalidInitialization();
}
$._initialized = version;
$._initializing = true;
_;
$._initializing = false;
emit Initialized(version);
}
/**
* @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
* {initializer} and {reinitializer} modifiers, directly or indirectly.
*/
modifier onlyInitializing() {
_checkInitializing();
_;
}
/**
* @dev Reverts if the contract is not in an initializing state. See {onlyInitializing}.
*/
function _checkInitializing() internal view virtual {
if (!_isInitializing()) {
revert NotInitializing();
}
}
/**
* @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call.
* Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized
* to any version. It is recommended to use this to lock implementation contracts that are designed to be called
* through proxies.
*
* Emits an {Initialized} event the first time it is successfully executed.
*/
function _disableInitializers() internal virtual {
// solhint-disable-next-line var-name-mixedcase
InitializableStorage storage $ = _getInitializableStorage();
if ($._initializing) {
revert InvalidInitialization();
}
if ($._initialized != type(uint64).max) {
$._initialized = type(uint64).max;
emit Initialized(type(uint64).max);
}
}
/**
* @dev Returns the highest version that has been initialized. See {reinitializer}.
*/
function _getInitializedVersion() internal view returns (uint64) {
return _getInitializableStorage()._initialized;
}
/**
* @dev Returns `true` if the contract is currently initializing. See {onlyInitializing}.
*/
function _isInitializing() internal view returns (bool) {
return _getInitializableStorage()._initializing;
}
/**
* @dev Returns a pointer to the storage namespace.
*/
// solhint-disable-next-line var-name-mixedcase
function _getInitializableStorage() private pure returns (InitializableStorage storage $) {
assembly {
$.slot := INITIALIZABLE_STORAGE
}
}
}