​

Whitelist.sol

​

Overview

This smart contract is a simple whitelist implementation that allows an owner to add and remove addresses to/from a whitelist. The contract is designed in its current iteration to interact with EtherspotPaymaster contract to allow for a single Paymaster contract that can handle payments from sponsors to fund transaction gas for approved wallets.

​

Version

Solidity pragma version ^0.8.12.

​

Mappings

mapping(address => mapping(address => bool)) public whitelist: A mapping of sponsor addresses to another mapping of account addresses to a boolean value that indicates whether the account address is whitelisted for the sponsor address.

​

Events

• event WhitelistInitialized(address owner): Triggered when the contract is initialized.
• event AddedToWhitelist(address indexed paymaster, address indexed account): Triggered when an account is added to the whitelist for a specific paymaster.
• event AddedBatchToWhitelist(address indexed paymaster, address[] indexed accounts): Triggered when multiple accounts are added to the whitelist for a specific paymaster.
• event RemovedFromWhitelist(address indexed paymaster, address indexed account): Triggered when an account is removed from the whitelist for a specific paymaster.
• event RemovedBatchFromWhitelist(address indexed paymaster, address[] indexed accounts): Triggered when multiple accounts are removed from the whitelist for a specific paymaster.

​

External Functions

• function check(address _sponsor, address _account) external view returns (bool): Checks if an account is whitelisted for a specific sponsor.
• function add(address _account) external: Adds an account to the whitelist for the caller.
  • Emits AddedToWhitelist(msg.sender, _account).
• function addBatch(address[] calldata _accounts) external: Adds multiple accounts to the whitelist for the caller.
  • EmitsAddedBatchToWhitelist(msg.sender, _accounts).
• function remove(address _account) external: Removes an account from the whitelist for the caller.
  • Emits RemovedFromWhitelist(msg.sender, _account).
• function removeBatch(address[] calldata _accounts) external: Removes multiple accounts from the whitelist for the caller.
  • Emits RemovedBatchFromWhitelist(msg.sender, _accounts).

​

Internal Functions

• function _check(address _sponsor, address _account) internal view returns (bool): Checks if an account is whitelisted for a specific sponsor.
• function _add(address _account) internal: Adds an account to the whitelist for the caller.
  • Error Whitelist:: Zero address: Zero address cannot be added to whitelist.
  • Error Whitelist:: Account is already whitelisted: Existing whitelisted address cannot be re-added to the whitelist.
• function _addBatch(address[] calldata _accounts) internal: Adds multiple accounts to the whitelist for the caller.
• function _remove(address _account) internal: Removes an account from the whitelist for the caller.
  • Error Whitelist:: Zero address: Cannot try to remove zero address from whitelist.
  • Error Whitelist:: Account is not whitelisted: Must be a valid whitelisted account to be removed from whitelist.
• function _removeBatch(address[] calldata _accounts) internal: Removes multiple accounts from the whitelist for the caller.

​

Contact Source Code

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.12;

import "../interfaces/IWhitelist.sol";

contract Whitelist is IWhitelist {
    // Mappings
    mapping(address => mapping(address => bool)) private whitelist;

    // External
    function check(
        address _sponsor,
        address _account
    ) external view returns (bool) {
        return _check(_sponsor, _account);
    }

    function addToWhitelist(address _account) external {
        _add(_account);
        emit AddedToWhitelist(msg.sender, _account);
    }

    function addBatchToWhitelist(address[] calldata _accounts) external {
        _addBatch(_accounts);
        emit AddedBatchToWhitelist(msg.sender, _accounts);
    }

    function removeFromWhitelist(address _account) external {
        _remove(_account);
        emit RemovedFromWhitelist(msg.sender, _account);
    }

    function removeBatchFromWhitelist(address[] calldata _accounts) external {
        _removeBatch(_accounts);
        emit RemovedBatchFromWhitelist(msg.sender, _accounts);
    }

    // Internal
    function _check(
        address _sponsor,
        address _account
    ) internal view returns (bool) {
        return whitelist[_sponsor][_account];
    }

    function _add(address _account) internal {
        require(_account != address(0), "Whitelist:: Zero address");
        require(
            !_check(msg.sender, _account),
            "Whitelist:: Account is already whitelisted"
        );
        whitelist[msg.sender][_account] = true;
    }

    function _addBatch(address[] calldata _accounts) internal {
        for (uint256 ii; ii < _accounts.length; ++ii) {
            _add(_accounts[ii]);
        }
    }

    function _remove(address _account) internal {
        require(_account != address(0), "Whitelist:: Zero address");
        require(
            _check(msg.sender, _account),
            "Whitelist:: Account is not whitelisted"
        );
        whitelist[msg.sender][_account] = false;
    }

    function _removeBatch(address[] calldata _accounts) internal {
        for (uint256 ii; ii < _accounts.length; ++ii) {
            _remove(_accounts[ii]);
        }
    }
}

​

License

This contract is licensed under the MIT license.