Contract Source Code (Solidity Standard Json-Input format)

IDE

• Blockscan IDE
• 🤖 Code ReaderBeta

More Options

• Similar
• Submit Audit
• Compare

// SPDX-License-Identifier: UNLICENSED
pragma solidity =0.8.12;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/utils/cryptography/MerkleProof.sol";
import "./interfaces/IMerkleDistributor.sol";

contract MerkleDistributor is IMerkleDistributor {
    address public immutable override token;
    bytes32 public immutable override merkleRoot;

    uint256 public constant ONE_YEAR_IN_SECONDS = 31_536_000;
    uint256 public immutable activationTimestamp;
    address public immutable airdropTreasury;
    bool public isActive;

    // This is a packed array of booleans.
    mapping(uint256 => uint256) private claimedBitMap;

    event Finalised(
        address indexed calledBy,
        uint256 timestamp,
        uint256 unclaimedAmount
    );

    constructor(
        address token_,
        bytes32 merkleRoot_,
        address _treasury
    ) {
        token = token_;
        merkleRoot = merkleRoot_;

        activationTimestamp = block.timestamp;
        isActive = true;
        airdropTreasury = _treasury;
    }

    function isClaimed(uint256 index) public view override returns (bool) {
        uint256 claimedWordIndex = index / 256;
        uint256 claimedBitIndex = index % 256;
        uint256 claimedWord = claimedBitMap[claimedWordIndex];
        uint256 mask = (1 << claimedBitIndex);
        return claimedWord & mask == mask;
    }

    function _setClaimed(uint256 index) private {
        uint256 claimedWordIndex = index / 256;
        uint256 claimedBitIndex = index % 256;
        claimedBitMap[claimedWordIndex] =
            claimedBitMap[claimedWordIndex] |
            (1 << claimedBitIndex);
    }

    function claim(
        uint256 index,
        address account,
        uint256 amount,
        bytes32[] calldata merkleProof
    ) external override {
        require(!isClaimed(index), "MerkleDistributor: Drop already claimed.");

        // Verify the merkle proof.
        bytes32 node = keccak256(abi.encodePacked(index, account, amount));
        require(
            MerkleProof.verify(merkleProof, merkleRoot, node),
            "MerkleDistributor: Invalid proof."
        );

        // Mark it claimed and send the token.
        _setClaimed(index);
        require(
            IERC20(token).transfer(account, amount),
            "MerkleDistributor: Transfer failed."
        );

        emit Claimed(index, account, amount);
    }

    /**
     * @dev Finalises the airdrop and sweeps unclaimed tokens into the Optimism multisig
     */
    function clawBack() external {
        // Airdrop can only be finalised once
        require(isActive, "Airdrop: Already finalised");
        // Airdrop will remain open for one year
        require(
            block.timestamp >= activationTimestamp + ONE_YEAR_IN_SECONDS,
            "Airdrop: Drop should remain open for one year"
        );
        // Deactivate airdrop
        isActive = false;

        // Sweep unclaimed tokens
        uint256 amount = IERC20(token).balanceOf(address(this));
        require(
            IERC20(token).transfer(airdropTreasury, amount),
            "Airdrop: Finalise transfer failed"
        );

        emit Finalised(msg.sender, block.timestamp, amount);
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, 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 `from` to `to` 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 from,
        address to,
        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);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/cryptography/MerkleProof.sol)

pragma solidity ^0.8.0;

/**
 * @dev These functions deal with verification of Merkle Trees proofs.
 *
 * The proofs can be generated using the JavaScript library
 * https://github.com/miguelmota/merkletreejs[merkletreejs].
 * Note: the hashing algorithm should be keccak256 and pair sorting should be enabled.
 *
 * See `test/utils/cryptography/MerkleProof.test.js` for some examples.
 */
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 Returns the rebuilt hash obtained by traversing a Merklee 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++) {
            bytes32 proofElement = proof[i];
            if (computedHash <= proofElement) {
                // Hash(current computed hash + current element of the proof)
                computedHash = _efficientHash(computedHash, proofElement);
            } else {
                // Hash(current element of the proof + current computed hash)
                computedHash = _efficientHash(proofElement, computedHash);
            }
        }
        return computedHash;
    }

    function _efficientHash(bytes32 a, bytes32 b) private pure returns (bytes32 value) {
        assembly {
            mstore(0x00, a)
            mstore(0x20, b)
            value := keccak256(0x00, 0x40)
        }
    }
}

// SPDX-License-Identifier: UNLICENSED
pragma solidity >=0.8.12;

// Allows anyone to claim a token if they exist in a merkle root.
interface IMerkleDistributor {
    // Returns the address of the token distributed by this contract.
    function token() external view returns (address);

    // Returns the merkle root of the merkle tree containing account balances available to claim.
    function merkleRoot() external view returns (bytes32);

    // Returns true if the index has been marked claimed.
    function isClaimed(uint256 index) external view returns (bool);

    // Claim the given amount of the token to the given address. Reverts if the inputs are invalid.
    function claim(
        uint256 index,
        address account,
        uint256 amount,
        bytes32[] calldata merkleProof
    ) external;

    // This event is triggered whenever a call to #claim succeeds.
    event Claimed(uint256 index, address account, uint256 amount);
}

{
  "optimizer": {
    "enabled": false,
    "runs": 200
  },
  "outputSelection": {
    "*": {
      "*": [
        "evm.bytecode",
        "evm.deployedBytecode",
        "devdoc",
        "userdoc",
        "metadata",
        "abi"
      ]
    }
  },
  "libraries": {}
}

• No Contract Security Audit Submitted- Submit Audit Here

[{"inputs":[{"internalType":"address","name":"token_","type":"address"},{"internalType":"bytes32","name":"merkleRoot_","type":"bytes32"},{"internalType":"address","name":"_treasury","type":"address"}],"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":false,"internalType":"uint256","name":"index","type":"uint256"},{"indexed":false,"internalType":"address","name":"account","type":"address"},{"indexed":false,"internalType":"uint256","name":"amount","type":"uint256"}],"name":"Claimed","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"calledBy","type":"address"},{"indexed":false,"internalType":"uint256","name":"timestamp","type":"uint256"},{"indexed":false,"internalType":"uint256","name":"unclaimedAmount","type":"uint256"}],"name":"Finalised","type":"event"},{"inputs":[],"name":"ONE_YEAR_IN_SECONDS","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"activationTimestamp","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"airdropTreasury","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256","name":"index","type":"uint256"},{"internalType":"address","name":"account","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"},{"internalType":"bytes32[]","name":"merkleProof","type":"bytes32[]"}],"name":"claim","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"clawBack","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"isActive","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256","name":"index","type":"uint256"}],"name":"isClaimed","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"merkleRoot","outputs":[{"internalType":"bytes32","name":"","type":"bytes32"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"token","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"}]

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