Contract Source Code:
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)
pragma solidity ^0.8.0;
import "../utils/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.
*
* 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.
*/
abstract 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() {
_transferOwnership(_msgSender());
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
_checkOwner();
_;
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if the sender is not the owner.
*/
function _checkOwner() internal view virtual {
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 {
_transferOwnership(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");
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Internal function without access restriction.
*/
function _transferOwnership(address newOwner) internal virtual {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
/**
* @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 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) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/cryptography/MerkleProof.sol)
pragma solidity ^0.8.0;
/**
* @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 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}
*
* _Available since v4.7._
*/
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.
*
* _Available since v4.4._
*/
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}
*
* _Available since v4.7._
*/
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.
*
* _Available since v4.7._
*/
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.
*
* _Available since v4.7._
*/
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).
*
* _Available since v4.7._
*/
function processMultiProof(
bytes32[] memory proof,
bool[] memory proofFlags,
bytes32[] memory leaves
) internal pure returns (bytes32 merkleRoot) {
// This function rebuild 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 totalHashes = proofFlags.length;
// Check proof validity.
require(leavesLen + proof.length - 1 == totalHashes, "MerkleProof: invalid multiproof");
// 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 for 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) {
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.
*
* _Available since v4.7._
*/
function processMultiProofCalldata(
bytes32[] calldata proof,
bool[] calldata proofFlags,
bytes32[] memory leaves
) internal pure returns (bytes32 merkleRoot) {
// This function rebuild 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 totalHashes = proofFlags.length;
// Check proof validity.
require(leavesLen + proof.length - 1 == totalHashes, "MerkleProof: invalid multiproof");
// 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 for 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) {
return hashes[totalHashes - 1];
} else if (leavesLen > 0) {
return leaves[0];
} else {
return proof[0];
}
}
function _hashPair(bytes32 a, bytes32 b) private pure returns (bytes32) {
return a < b ? _efficientHash(a, b) : _efficientHash(b, a);
}
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
pragma solidity >=0.8.0;
interface IAirdropClaim {
event Claimed(address indexed who, address indexed to, uint256 amount, uint256 veShareAmount, uint256 vestingShareAmount);
function claim(address who, uint amount, address to) external;
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.8.0;
import {MerkleProof} from "@openzeppelin/contracts/utils/cryptography/MerkleProof.sol";
import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";
import "../interfaces/IAirdropClaim.sol";
contract MerkleTree is Ownable {
/// ============ Mutable storage ============
/// @notice ERC20-claimee inclusion root
bytes32 public merkleRoot;
/// @notice airdrop managment
address public airdropClaim;
/// @notice Mapping of addresses who have claimed tokens
mapping(address => bool) public hasClaimed;
/// ============ Errors ============
/// @notice Thrown if address has already claimed
error AlreadyClaimed(address _who);
/// @notice Thrown if address/amount are not part of Merkle tree
error NotInMerkle(address _who, uint _amnt);
/// ============ Constructor ============
/// @notice Creates a new MerkleClaimERC20 contract
/// @param _airdropClaim claim manager
constructor(address _airdropClaim) {
airdropClaim = _airdropClaim;
}
/// ============ Events ============
/// @notice Emitted after a successful token claim
/// @param who has right to claim
/// @param to recipient of claim
/// @param amount of tokens claimed
event ClaimSet(address indexed who, address indexed to, uint256 amount);
/// ============ Functions ============
/// @notice Allows claiming tokens if address is part of merkle tree
/// @param to address of claimee
/// @param amount of tokens owed to claimee
/// @param proof merkle proof to prove address and amount are in tree
function claim(
address to,
uint256 amount,
bytes32[] calldata proof
) external {
// Throw if address has already claimed tokens
if (hasClaimed[msg.sender]) revert AlreadyClaimed(msg.sender);
// Verify merkle proof, or revert if not in tree
bytes32 leaf = keccak256(
abi.encodePacked(keccak256(abi.encodePacked(msg.sender, amount)))
);
bool isValidLeaf = MerkleProof.verify(proof, merkleRoot, leaf);
if (!isValidLeaf) revert NotInMerkle(msg.sender, amount);
// Set address to claimed
hasClaimed[msg.sender] = true;
// Mint tokens to msg.sender
IAirdropClaim(airdropClaim).claim(msg.sender, amount, to);
// Emit claim event
emit ClaimSet(msg.sender, to, amount);
}
/// @notice Set Merkle Root (before starting the claim!)
/// @param _merkleRoot merkle root
function setMerkleRoot(bytes32 _merkleRoot) external onlyOwner {
require(_merkleRoot != bytes32(0), "root 0");
require(merkleRoot == bytes32(0), "Already initialized");
merkleRoot = _merkleRoot;
}
function setUserClaimed(address[] memory users) external onlyOwner {
uint i = 0;
for (i = 0; i < users.length; i++) {
hasClaimed[users[i]] = true;
}
}
}