{"sources":{"contracts/ERC20Token.sol":{"content":"// SPDX-License-Identifier: MIT\npragma solidity ^0.8.9;\n\n// Import OpenZeppelin contacts locally\nimport \"@openzeppelin/contracts/utils/math/SafeMath.sol\";\nimport \"@openzeppelin/contracts/security/Pausable.sol\";\nimport \"@openzeppelin/contracts/token/ERC20/ERC20.sol\";\nimport \"@openzeppelin/contracts/token/ERC20/extensions/draft-ERC20Permit.sol\";\nimport \"@openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol\";\nimport \"./roleAccess.sol\";\n\ncontract XToken is Pausable, RoleAccess, ERC20Burnable, ERC20Permit {\n using SafeMath for uint256;\n\n // variables\n uint256 internal _cap;\n mapping(address => bool) private frozen;\n\n constructor(\n string memory name,\n string memory symbol,\n uint256 cap_\n ) ERC20Permit(name) ERC20(name, symbol) {\n require(cap_ > 0, \"ERC20: cap is 0\");\n _cap = cap_;\n\n // owner has all roles\n _setupRole(DEFAULT_ADMIN_ROLE, _msgSender());\n _setupRole(ADMIN_ROLE, _msgSender());\n _setupRole(MINTER_ROLE, _msgSender());\n _setupRole(BURNER_ROLE, _msgSender());\n _setupRole(BLACKLISTER_ROLE, _msgSender());\n }\n\n function cap() public view returns (uint256) {\n return _cap;\n }\n\n function setCap(uint256 cap_) external onlyAdmin returns (uint256) {\n require(cap_ > 0, \"ERC20: cap is 0\");\n require(\n cap_ > totalSupply(),\n \"ERC20: new cap should be larger than total supply\"\n );\n _cap = cap_;\n return _cap;\n }\n\n // only account with minter role can mint\n function mint(address account, uint256 amount)\n public\n onlyMinter\n whenNotPaused\n {\n require(ERC20.totalSupply() + amount <= cap(), \"ERC20Capped: cap exceeded\");\n _mint(account, amount);\n }\n\n function burn(uint256 amount) public override onlyBurner whenNotPaused {\n super.burn(amount);\n }\n\n function burnFrom(address account, uint256 amount)\n public\n override\n onlyBurner\n whenNotPaused\n {\n super.burnFrom(account, amount);\n }\n\n // when paused, both mint(), burn() and transfer() will revert\n function pause() external onlyAdmin {\n _pause();\n }\n\n function unpause() external onlyAdmin {\n _unpause();\n }\n\n // follow finCEN AML guidance\n function freeze(address account) external onlyBlacklister {\n frozen[account] = true;\n }\n\n function defrost(address account) external onlyBlacklister {\n frozen[account] = false;\n }\n\n // this hook runs before any mint or transfer function\n // it checks for pause and token cap\n function _beforeTokenTransfer(\n address from,\n address to,\n uint256 amount\n ) internal override {\n super._beforeTokenTransfer(from, to, amount);\n require(!paused(), \"ERC20 Pausable: token transfer while paused\");\n require(!frozen[from], \"Source account frozen\");\n require(!frozen[to], \"Destination account frozen\");\n }\n}\n"},"contracts/roleAccess.sol":{"content":"// SPDX-License-Identifier: Unlicense\npragma solidity ^0.8.9;\n\nimport \"@openzeppelin/contracts/access/AccessControlEnumerable.sol\";\n\ncontract RoleAccess is AccessControlEnumerable {\n // role definition\n bytes32 public constant ADMIN_ROLE = keccak256(\"ADMIN_ROLE\");\n bytes32 public constant MINTER_ROLE = keccak256(\"MINTER_ROLE\");\n bytes32 public constant BURNER_ROLE = keccak256(\"BURNER_ROLE\");\n bytes32 public constant BLACKLISTER_ROLE = keccak256(\"BLACKLISTER_ROLE\");\n\n // struct\n struct Role {\n bytes32 role;\n string describe;\n }\n\n // modifier\n modifier onlyAdmin() {\n require(hasRole(ADMIN_ROLE, _msgSender()), \"Caller is not a admin\");\n _;\n }\n\n modifier onlyMinter() {\n require(hasRole(MINTER_ROLE, _msgSender()), \"Caller is not a minter\");\n _;\n }\n\n modifier onlyBurner() {\n require(hasRole(BURNER_ROLE, _msgSender()), \"Caller is not a burner\");\n _;\n }\n\n modifier onlyBlacklister() {\n require(\n hasRole(BLACKLISTER_ROLE, _msgSender()),\n \"Caller is not a blacklister\"\n );\n _;\n }\n\n function getRoles() public pure returns (Role[] memory) {\n Role[] memory result = new Role[](4);\n result[1] = Role(ADMIN_ROLE, \"admin for the contract\");\n result[2] = Role(MINTER_ROLE, \"minter can mint new coins\");\n result[3] = Role(BURNER_ROLE, \"burner can burn coins\");\n result[4] = Role(BLACKLISTER_ROLE, \"blacklister can update blacklist\");\n return result;\n }\n\n function addRoleMember(bytes32 role, address member)\n external\n onlyAdmin\n returns (bool)\n {\n grantRole(role, member);\n return true;\n }\n\n function removeRoleMember(bytes32 role, address member)\n external\n onlyAdmin\n returns (bool)\n {\n if (hasRole(role, member)) {\n revokeRole(role, member);\n }\n return true;\n }\n\n function getRoleMembers(bytes32 role)\n external\n view\n returns (address[] memory)\n {\n uint256 count = getRoleMemberCount(role);\n address[] memory members_ = new address[](count);\n for (uint256 index = 0; index < count; index++) {\n members_[index] = getRoleMember(role, index);\n }\n return members_;\n }\n\n // A few helper functions:\n\n // assign minter role to another EOA or smart contract\n function grantMinter(address minter) external onlyAdmin returns (bool) {\n grantRole(MINTER_ROLE, minter);\n return true;\n }\n\n // revoke minter role to another EOA or smart contract\n function revokeMinter(address minter) external onlyAdmin returns (bool) {\n revokeRole(MINTER_ROLE, minter);\n return true;\n }\n\n // assign burner role to another EOA or smart contract\n function grantBurner(address burner) external onlyAdmin returns (bool) {\n grantRole(BURNER_ROLE, burner);\n return true;\n }\n\n // revoke burner role to another EOA or smart contract\n function revokeBurner(address burner) external onlyAdmin returns (bool) {\n revokeRole(BURNER_ROLE, burner);\n return true;\n }\n\n // assign blacklister role to another EOA or smart contract\n function grantBlacklister(address blacklister)\n external\n onlyAdmin\n returns (bool)\n {\n grantRole(BLACKLISTER_ROLE, blacklister);\n return true;\n }\n\n // revoke blacklister role to another EOA or smart contract\n function revokeBlacklister(address blacklister)\n external\n onlyAdmin\n returns (bool)\n {\n revokeRole(BLACKLISTER_ROLE, blacklister);\n return true;\n }\n}\n"},"@openzeppelin/contracts/utils/Context.sol":{"content":"// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Provides information about the current execution context, including the\n * sender of the transaction and its data. While these are generally available\n * via msg.sender and msg.data, they should not be accessed in such a direct\n * manner, since when dealing with meta-transactions the account sending and\n * paying for execution may not be the actual sender (as far as an application\n * is concerned).\n *\n * This contract is only required for intermediate, library-like contracts.\n */\nabstract contract Context {\n function _msgSender() internal view virtual returns (address) {\n return msg.sender;\n }\n\n function _msgData() internal view virtual returns (bytes calldata) {\n return msg.data;\n }\n}\n"},"@openzeppelin/contracts/utils/Strings.sol":{"content":"// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @dev String operations.\n */\nlibrary Strings {\n bytes16 private constant _HEX_SYMBOLS = \"0123456789abcdef\";\n\n /**\n * @dev Converts a `uint256` to its ASCII `string` decimal representation.\n */\n function toString(uint256 value) internal pure returns (string memory) {\n // Inspired by OraclizeAPI's implementation - MIT licence\n // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol\n\n if (value == 0) {\n return \"0\";\n }\n uint256 temp = value;\n uint256 digits;\n while (temp != 0) {\n digits++;\n temp /= 10;\n }\n bytes memory buffer = new bytes(digits);\n while (value != 0) {\n digits -= 1;\n buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));\n value /= 10;\n }\n return string(buffer);\n }\n\n /**\n * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.\n */\n function toHexString(uint256 value) internal pure returns (string memory) {\n if (value == 0) {\n return \"0x00\";\n }\n uint256 temp = value;\n uint256 length = 0;\n while (temp != 0) {\n length++;\n temp >>= 8;\n }\n return toHexString(value, length);\n }\n\n /**\n * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.\n */\n function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {\n bytes memory buffer = new bytes(2 * length + 2);\n buffer[0] = \"0\";\n buffer[1] = \"x\";\n for (uint256 i = 2 * length + 1; i > 1; --i) {\n buffer[i] = _HEX_SYMBOLS[value & 0xf];\n value >>= 4;\n }\n require(value == 0, \"Strings: hex length insufficient\");\n return string(buffer);\n }\n}\n"},"@openzeppelin/contracts/utils/Counters.sol":{"content":"// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (utils/Counters.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @title Counters\n * @author Matt Condon (@shrugs)\n * @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number\n * of elements in a mapping, issuing ERC721 ids, or counting request ids.\n *\n * Include with `using Counters for Counters.Counter;`\n */\nlibrary Counters {\n struct Counter {\n // This variable should never be directly accessed by users of the library: interactions must be restricted to\n // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add\n // this feature: see https://github.com/ethereum/solidity/issues/4637\n uint256 _value; // default: 0\n }\n\n function current(Counter storage counter) internal view returns (uint256) {\n return counter._value;\n }\n\n function increment(Counter storage counter) internal {\n unchecked {\n counter._value += 1;\n }\n }\n\n function decrement(Counter storage counter) internal {\n uint256 value = counter._value;\n require(value > 0, \"Counter: decrement overflow\");\n unchecked {\n counter._value = value - 1;\n }\n }\n\n function reset(Counter storage counter) internal {\n counter._value = 0;\n }\n}\n"},"@openzeppelin/contracts/security/Pausable.sol":{"content":"// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (security/Pausable.sol)\n\npragma solidity ^0.8.0;\n\nimport \"../utils/Context.sol\";\n\n/**\n * @dev Contract module which allows children to implement an emergency stop\n * mechanism that can be triggered by an authorized account.\n *\n * This module is used through inheritance. It will make available the\n * modifiers `whenNotPaused` and `whenPaused`, which can be applied to\n * the functions of your contract. Note that they will not be pausable by\n * simply including this module, only once the modifiers are put in place.\n */\nabstract contract Pausable is Context {\n /**\n * @dev Emitted when the pause is triggered by `account`.\n */\n event Paused(address account);\n\n /**\n * @dev Emitted when the pause is lifted by `account`.\n */\n event Unpaused(address account);\n\n bool private _paused;\n\n /**\n * @dev Initializes the contract in unpaused state.\n */\n constructor() {\n _paused = false;\n }\n\n /**\n * @dev Returns true if the contract is paused, and false otherwise.\n */\n function paused() public view virtual returns (bool) {\n return _paused;\n }\n\n /**\n * @dev Modifier to make a function callable only when the contract is not paused.\n *\n * Requirements:\n *\n * - The contract must not be paused.\n */\n modifier whenNotPaused() {\n require(!paused(), \"Pausable: paused\");\n _;\n }\n\n /**\n * @dev Modifier to make a function callable only when the contract is paused.\n *\n * Requirements:\n *\n * - The contract must be paused.\n */\n modifier whenPaused() {\n require(paused(), \"Pausable: not paused\");\n _;\n }\n\n /**\n * @dev Triggers stopped state.\n *\n * Requirements:\n *\n * - The contract must not be paused.\n */\n function _pause() internal virtual whenNotPaused {\n _paused = true;\n emit Paused(_msgSender());\n }\n\n /**\n * @dev Returns to normal state.\n *\n * Requirements:\n *\n * - The contract must be paused.\n */\n function _unpause() internal virtual whenPaused {\n _paused = false;\n emit Unpaused(_msgSender());\n }\n}\n"},"@openzeppelin/contracts/token/ERC20/ERC20.sol":{"content":"// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/ERC20.sol)\n\npragma solidity ^0.8.0;\n\nimport \"./IERC20.sol\";\nimport \"./extensions/IERC20Metadata.sol\";\nimport \"../../utils/Context.sol\";\n\n/**\n * @dev Implementation of the {IERC20} interface.\n *\n * This implementation is agnostic to the way tokens are created. This means\n * that a supply mechanism has to be added in a derived contract using {_mint}.\n * For a generic mechanism see {ERC20PresetMinterPauser}.\n *\n * TIP: For a detailed writeup see our guide\n * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How\n * to implement supply mechanisms].\n *\n * We have followed general OpenZeppelin Contracts guidelines: functions revert\n * instead returning `false` on failure. This behavior is nonetheless\n * conventional and does not conflict with the expectations of ERC20\n * applications.\n *\n * Additionally, an {Approval} event is emitted on calls to {transferFrom}.\n * This allows applications to reconstruct the allowance for all accounts just\n * by listening to said events. Other implementations of the EIP may not emit\n * these events, as it isn't required by the specification.\n *\n * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}\n * functions have been added to mitigate the well-known issues around setting\n * allowances. See {IERC20-approve}.\n */\ncontract ERC20 is Context, IERC20, IERC20Metadata {\n mapping(address => uint256) private _balances;\n\n mapping(address => mapping(address => uint256)) private _allowances;\n\n uint256 private _totalSupply;\n\n string private _name;\n string private _symbol;\n\n /**\n * @dev Sets the values for {name} and {symbol}.\n *\n * The default value of {decimals} is 18. To select a different value for\n * {decimals} you should overload it.\n *\n * All two of these values are immutable: they can only be set once during\n * construction.\n */\n constructor(string memory name_, string memory symbol_) {\n _name = name_;\n _symbol = symbol_;\n }\n\n /**\n * @dev Returns the name of the token.\n */\n function name() public view virtual override returns (string memory) {\n return _name;\n }\n\n /**\n * @dev Returns the symbol of the token, usually a shorter version of the\n * name.\n */\n function symbol() public view virtual override returns (string memory) {\n return _symbol;\n }\n\n /**\n * @dev Returns the number of decimals used to get its user representation.\n * For example, if `decimals` equals `2`, a balance of `505` tokens should\n * be displayed to a user as `5.05` (`505 / 10 ** 2`).\n *\n * Tokens usually opt for a value of 18, imitating the relationship between\n * Ether and Wei. This is the value {ERC20} uses, unless this function is\n * overridden;\n *\n * NOTE: This information is only used for _display_ purposes: it in\n * no way affects any of the arithmetic of the contract, including\n * {IERC20-balanceOf} and {IERC20-transfer}.\n */\n function decimals() public view virtual override returns (uint8) {\n return 18;\n }\n\n /**\n * @dev See {IERC20-totalSupply}.\n */\n function totalSupply() public view virtual override returns (uint256) {\n return _totalSupply;\n }\n\n /**\n * @dev See {IERC20-balanceOf}.\n */\n function balanceOf(address account) public view virtual override returns (uint256) {\n return _balances[account];\n }\n\n /**\n * @dev See {IERC20-transfer}.\n *\n * Requirements:\n *\n * - `to` cannot be the zero address.\n * - the caller must have a balance of at least `amount`.\n */\n function transfer(address to, uint256 amount) public virtual override returns (bool) {\n address owner = _msgSender();\n _transfer(owner, to, amount);\n return true;\n }\n\n /**\n * @dev See {IERC20-allowance}.\n */\n function allowance(address owner, address spender) public view virtual override returns (uint256) {\n return _allowances[owner][spender];\n }\n\n /**\n * @dev See {IERC20-approve}.\n *\n * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on\n * `transferFrom`. This is semantically equivalent to an infinite approval.\n *\n * Requirements:\n *\n * - `spender` cannot be the zero address.\n */\n function approve(address spender, uint256 amount) public virtual override returns (bool) {\n address owner = _msgSender();\n _approve(owner, spender, amount);\n return true;\n }\n\n /**\n * @dev See {IERC20-transferFrom}.\n *\n * Emits an {Approval} event indicating the updated allowance. This is not\n * required by the EIP. See the note at the beginning of {ERC20}.\n *\n * NOTE: Does not update the allowance if the current allowance\n * is the maximum `uint256`.\n *\n * Requirements:\n *\n * - `from` and `to` cannot be the zero address.\n * - `from` must have a balance of at least `amount`.\n * - the caller must have allowance for ``from``'s tokens of at least\n * `amount`.\n */\n function transferFrom(\n address from,\n address to,\n uint256 amount\n ) public virtual override returns (bool) {\n address spender = _msgSender();\n _spendAllowance(from, spender, amount);\n _transfer(from, to, amount);\n return true;\n }\n\n /**\n * @dev Atomically increases the allowance granted to `spender` by the caller.\n *\n * This is an alternative to {approve} that can be used as a mitigation for\n * problems described in {IERC20-approve}.\n *\n * Emits an {Approval} event indicating the updated allowance.\n *\n * Requirements:\n *\n * - `spender` cannot be the zero address.\n */\n function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {\n address owner = _msgSender();\n _approve(owner, spender, _allowances[owner][spender] + addedValue);\n return true;\n }\n\n /**\n * @dev Atomically decreases the allowance granted to `spender` by the caller.\n *\n * This is an alternative to {approve} that can be used as a mitigation for\n * problems described in {IERC20-approve}.\n *\n * Emits an {Approval} event indicating the updated allowance.\n *\n * Requirements:\n *\n * - `spender` cannot be the zero address.\n * - `spender` must have allowance for the caller of at least\n * `subtractedValue`.\n */\n function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {\n address owner = _msgSender();\n uint256 currentAllowance = _allowances[owner][spender];\n require(currentAllowance >= subtractedValue, \"ERC20: decreased allowance below zero\");\n unchecked {\n _approve(owner, spender, currentAllowance - subtractedValue);\n }\n\n return true;\n }\n\n /**\n * @dev Moves `amount` of tokens from `sender` to `recipient`.\n *\n * This internal function is equivalent to {transfer}, and can be used to\n * e.g. implement automatic token fees, slashing mechanisms, etc.\n *\n * Emits a {Transfer} event.\n *\n * Requirements:\n *\n * - `from` cannot be the zero address.\n * - `to` cannot be the zero address.\n * - `from` must have a balance of at least `amount`.\n */\n function _transfer(\n address from,\n address to,\n uint256 amount\n ) internal virtual {\n require(from != address(0), \"ERC20: transfer from the zero address\");\n require(to != address(0), \"ERC20: transfer to the zero address\");\n\n _beforeTokenTransfer(from, to, amount);\n\n uint256 fromBalance = _balances[from];\n require(fromBalance >= amount, \"ERC20: transfer amount exceeds balance\");\n unchecked {\n _balances[from] = fromBalance - amount;\n }\n _balances[to] += amount;\n\n emit Transfer(from, to, amount);\n\n _afterTokenTransfer(from, to, amount);\n }\n\n /** @dev Creates `amount` tokens and assigns them to `account`, increasing\n * the total supply.\n *\n * Emits a {Transfer} event with `from` set to the zero address.\n *\n * Requirements:\n *\n * - `account` cannot be the zero address.\n */\n function _mint(address account, uint256 amount) internal virtual {\n require(account != address(0), \"ERC20: mint to the zero address\");\n\n _beforeTokenTransfer(address(0), account, amount);\n\n _totalSupply += amount;\n _balances[account] += amount;\n emit Transfer(address(0), account, amount);\n\n _afterTokenTransfer(address(0), account, amount);\n }\n\n /**\n * @dev Destroys `amount` tokens from `account`, reducing the\n * total supply.\n *\n * Emits a {Transfer} event with `to` set to the zero address.\n *\n * Requirements:\n *\n * - `account` cannot be the zero address.\n * - `account` must have at least `amount` tokens.\n */\n function _burn(address account, uint256 amount) internal virtual {\n require(account != address(0), \"ERC20: burn from the zero address\");\n\n _beforeTokenTransfer(account, address(0), amount);\n\n uint256 accountBalance = _balances[account];\n require(accountBalance >= amount, \"ERC20: burn amount exceeds balance\");\n unchecked {\n _balances[account] = accountBalance - amount;\n }\n _totalSupply -= amount;\n\n emit Transfer(account, address(0), amount);\n\n _afterTokenTransfer(account, address(0), amount);\n }\n\n /**\n * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.\n *\n * This internal function is equivalent to `approve`, and can be used to\n * e.g. set automatic allowances for certain subsystems, etc.\n *\n * Emits an {Approval} event.\n *\n * Requirements:\n *\n * - `owner` cannot be the zero address.\n * - `spender` cannot be the zero address.\n */\n function _approve(\n address owner,\n address spender,\n uint256 amount\n ) internal virtual {\n require(owner != address(0), \"ERC20: approve from the zero address\");\n require(spender != address(0), \"ERC20: approve to the zero address\");\n\n _allowances[owner][spender] = amount;\n emit Approval(owner, spender, amount);\n }\n\n /**\n * @dev Spend `amount` form the allowance of `owner` toward `spender`.\n *\n * Does not update the allowance amount in case of infinite allowance.\n * Revert if not enough allowance is available.\n *\n * Might emit an {Approval} event.\n */\n function _spendAllowance(\n address owner,\n address spender,\n uint256 amount\n ) internal virtual {\n uint256 currentAllowance = allowance(owner, spender);\n if (currentAllowance != type(uint256).max) {\n require(currentAllowance >= amount, \"ERC20: insufficient allowance\");\n unchecked {\n _approve(owner, spender, currentAllowance - amount);\n }\n }\n }\n\n /**\n * @dev Hook that is called before any transfer of tokens. This includes\n * minting and burning.\n *\n * Calling conditions:\n *\n * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens\n * will be transferred to `to`.\n * - when `from` is zero, `amount` tokens will be minted for `to`.\n * - when `to` is zero, `amount` of ``from``'s tokens will be burned.\n * - `from` and `to` are never both zero.\n *\n * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].\n */\n function _beforeTokenTransfer(\n address from,\n address to,\n uint256 amount\n ) internal virtual {}\n\n /**\n * @dev Hook that is called after any transfer of tokens. This includes\n * minting and burning.\n *\n * Calling conditions:\n *\n * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens\n * has been transferred to `to`.\n * - when `from` is zero, `amount` tokens have been minted for `to`.\n * - when `to` is zero, `amount` of ``from``'s tokens have been burned.\n * - `from` and `to` are never both zero.\n *\n * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].\n */\n function _afterTokenTransfer(\n address from,\n address to,\n uint256 amount\n ) internal virtual {}\n}\n"},"@openzeppelin/contracts/token/ERC20/IERC20.sol":{"content":"// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/IERC20.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Interface of the ERC20 standard as defined in the EIP.\n */\ninterface IERC20 {\n /**\n * @dev Returns the amount of tokens in existence.\n */\n function totalSupply() external view returns (uint256);\n\n /**\n * @dev Returns the amount of tokens owned by `account`.\n */\n function balanceOf(address account) external view returns (uint256);\n\n /**\n * @dev Moves `amount` tokens from the caller's account to `to`.\n *\n * Returns a boolean value indicating whether the operation succeeded.\n *\n * Emits a {Transfer} event.\n */\n function transfer(address to, uint256 amount) external returns (bool);\n\n /**\n * @dev Returns the remaining number of tokens that `spender` will be\n * allowed to spend on behalf of `owner` through {transferFrom}. This is\n * zero by default.\n *\n * This value changes when {approve} or {transferFrom} are called.\n */\n function allowance(address owner, address spender) external view returns (uint256);\n\n /**\n * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.\n *\n * Returns a boolean value indicating whether the operation succeeded.\n *\n * IMPORTANT: Beware that changing an allowance with this method brings the risk\n * that someone may use both the old and the new allowance by unfortunate\n * transaction ordering. One possible solution to mitigate this race\n * condition is to first reduce the spender's allowance to 0 and set the\n * desired value afterwards:\n * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729\n *\n * Emits an {Approval} event.\n */\n function approve(address spender, uint256 amount) external returns (bool);\n\n /**\n * @dev Moves `amount` tokens from `from` to `to` using the\n * allowance mechanism. `amount` is then deducted from the caller's\n * allowance.\n *\n * Returns a boolean value indicating whether the operation succeeded.\n *\n * Emits a {Transfer} event.\n */\n function transferFrom(\n address from,\n address to,\n uint256 amount\n ) external returns (bool);\n\n /**\n * @dev Emitted when `value` tokens are moved from one account (`from`) to\n * another (`to`).\n *\n * Note that `value` may be zero.\n */\n event Transfer(address indexed from, address indexed to, uint256 value);\n\n /**\n * @dev Emitted when the allowance of a `spender` for an `owner` is set by\n * a call to {approve}. `value` is the new allowance.\n */\n event Approval(address indexed owner, address indexed spender, uint256 value);\n}\n"},"@openzeppelin/contracts/utils/math/SafeMath.sol":{"content":"// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (utils/math/SafeMath.sol)\n\npragma solidity ^0.8.0;\n\n// CAUTION\n// This version of SafeMath should only be used with Solidity 0.8 or later,\n// because it relies on the compiler's built in overflow checks.\n\n/**\n * @dev Wrappers over Solidity's arithmetic operations.\n *\n * NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler\n * now has built in overflow checking.\n */\nlibrary SafeMath {\n /**\n * @dev Returns the addition of two unsigned integers, with an overflow flag.\n *\n * _Available since v3.4._\n */\n function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n unchecked {\n uint256 c = a + b;\n if (c < a) return (false, 0);\n return (true, c);\n }\n }\n\n /**\n * @dev Returns the substraction of two unsigned integers, with an overflow flag.\n *\n * _Available since v3.4._\n */\n function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n unchecked {\n if (b > a) return (false, 0);\n return (true, a - b);\n }\n }\n\n /**\n * @dev Returns the multiplication of two unsigned integers, with an overflow flag.\n *\n * _Available since v3.4._\n */\n function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n unchecked {\n // Gas optimization: this is cheaper than requiring 'a' not being zero, but the\n // benefit is lost if 'b' is also tested.\n // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\n if (a == 0) return (true, 0);\n uint256 c = a * b;\n if (c / a != b) return (false, 0);\n return (true, c);\n }\n }\n\n /**\n * @dev Returns the division of two unsigned integers, with a division by zero flag.\n *\n * _Available since v3.4._\n */\n function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n unchecked {\n if (b == 0) return (false, 0);\n return (true, a / b);\n }\n }\n\n /**\n * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.\n *\n * _Available since v3.4._\n */\n function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n unchecked {\n if (b == 0) return (false, 0);\n return (true, a % b);\n }\n }\n\n /**\n * @dev Returns the addition of two unsigned integers, reverting on\n * overflow.\n *\n * Counterpart to Solidity's `+` operator.\n *\n * Requirements:\n *\n * - Addition cannot overflow.\n */\n function add(uint256 a, uint256 b) internal pure returns (uint256) {\n return a + b;\n }\n\n /**\n * @dev Returns the subtraction of two unsigned integers, reverting on\n * overflow (when the result is negative).\n *\n * Counterpart to Solidity's `-` operator.\n *\n * Requirements:\n *\n * - Subtraction cannot overflow.\n */\n function sub(uint256 a, uint256 b) internal pure returns (uint256) {\n return a - b;\n }\n\n /**\n * @dev Returns the multiplication of two unsigned integers, reverting on\n * overflow.\n *\n * Counterpart to Solidity's `*` operator.\n *\n * Requirements:\n *\n * - Multiplication cannot overflow.\n */\n function mul(uint256 a, uint256 b) internal pure returns (uint256) {\n return a * b;\n }\n\n /**\n * @dev Returns the integer division of two unsigned integers, reverting on\n * division by zero. The result is rounded towards zero.\n *\n * Counterpart to Solidity's `/` operator.\n *\n * Requirements:\n *\n * - The divisor cannot be zero.\n */\n function div(uint256 a, uint256 b) internal pure returns (uint256) {\n return a / b;\n }\n\n /**\n * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n * reverting when dividing by zero.\n *\n * Counterpart to Solidity's `%` operator. This function uses a `revert`\n * opcode (which leaves remaining gas untouched) while Solidity uses an\n * invalid opcode to revert (consuming all remaining gas).\n *\n * Requirements:\n *\n * - The divisor cannot be zero.\n */\n function mod(uint256 a, uint256 b) internal pure returns (uint256) {\n return a % b;\n }\n\n /**\n * @dev Returns the subtraction of two unsigned integers, reverting with custom message on\n * overflow (when the result is negative).\n *\n * CAUTION: This function is deprecated because it requires allocating memory for the error\n * message unnecessarily. For custom revert reasons use {trySub}.\n *\n * Counterpart to Solidity's `-` operator.\n *\n * Requirements:\n *\n * - Subtraction cannot overflow.\n */\n function sub(\n uint256 a,\n uint256 b,\n string memory errorMessage\n ) internal pure returns (uint256) {\n unchecked {\n require(b <= a, errorMessage);\n return a - b;\n }\n }\n\n /**\n * @dev Returns the integer division of two unsigned integers, reverting with custom message on\n * division by zero. The result is rounded towards zero.\n *\n * Counterpart to Solidity's `/` operator. Note: this function uses a\n * `revert` opcode (which leaves remaining gas untouched) while Solidity\n * uses an invalid opcode to revert (consuming all remaining gas).\n *\n * Requirements:\n *\n * - The divisor cannot be zero.\n */\n function div(\n uint256 a,\n uint256 b,\n string memory errorMessage\n ) internal pure returns (uint256) {\n unchecked {\n require(b > 0, errorMessage);\n return a / b;\n }\n }\n\n /**\n * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n * reverting with custom message when dividing by zero.\n *\n * CAUTION: This function is deprecated because it requires allocating memory for the error\n * message unnecessarily. For custom revert reasons use {tryMod}.\n *\n * Counterpart to Solidity's `%` operator. This function uses a `revert`\n * opcode (which leaves remaining gas untouched) while Solidity uses an\n * invalid opcode to revert (consuming all remaining gas).\n *\n * Requirements:\n *\n * - The divisor cannot be zero.\n */\n function mod(\n uint256 a,\n uint256 b,\n string memory errorMessage\n ) internal pure returns (uint256) {\n unchecked {\n require(b > 0, errorMessage);\n return a % b;\n }\n }\n}\n"},"@openzeppelin/contracts/access/AccessControl.sol":{"content":"// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.5.0) (access/AccessControl.sol)\n\npragma solidity ^0.8.0;\n\nimport \"./IAccessControl.sol\";\nimport \"../utils/Context.sol\";\nimport \"../utils/Strings.sol\";\nimport \"../utils/introspection/ERC165.sol\";\n\n/**\n * @dev Contract module that allows children to implement role-based access\n * control mechanisms. This is a lightweight version that doesn't allow enumerating role\n * members except through off-chain means by accessing the contract event logs. Some\n * applications may benefit from on-chain enumerability, for those cases see\n * {AccessControlEnumerable}.\n *\n * Roles are referred to by their `bytes32` identifier. These should be exposed\n * in the external API and be unique. The best way to achieve this is by\n * using `public constant` hash digests:\n *\n * ```\n * bytes32 public constant MY_ROLE = keccak256(\"MY_ROLE\");\n * ```\n *\n * Roles can be used to represent a set of permissions. To restrict access to a\n * function call, use {hasRole}:\n *\n * ```\n * function foo() public {\n * require(hasRole(MY_ROLE, msg.sender));\n * ...\n * }\n * ```\n *\n * Roles can be granted and revoked dynamically via the {grantRole} and\n * {revokeRole} functions. Each role has an associated admin role, and only\n * accounts that have a role's admin role can call {grantRole} and {revokeRole}.\n *\n * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means\n * that only accounts with this role will be able to grant or revoke other\n * roles. More complex role relationships can be created by using\n * {_setRoleAdmin}.\n *\n * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to\n * grant and revoke this role. Extra precautions should be taken to secure\n * accounts that have been granted it.\n */\nabstract contract AccessControl is Context, IAccessControl, ERC165 {\n struct RoleData {\n mapping(address => bool) members;\n bytes32 adminRole;\n }\n\n mapping(bytes32 => RoleData) private _roles;\n\n bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;\n\n /**\n * @dev Modifier that checks that an account has a specific role. Reverts\n * with a standardized message including the required role.\n *\n * The format of the revert reason is given by the following regular expression:\n *\n * /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/\n *\n * _Available since v4.1._\n */\n modifier onlyRole(bytes32 role) {\n _checkRole(role, _msgSender());\n _;\n }\n\n /**\n * @dev See {IERC165-supportsInterface}.\n */\n function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {\n return interfaceId == type(IAccessControl).interfaceId || super.supportsInterface(interfaceId);\n }\n\n /**\n * @dev Returns `true` if `account` has been granted `role`.\n */\n function hasRole(bytes32 role, address account) public view virtual override returns (bool) {\n return _roles[role].members[account];\n }\n\n /**\n * @dev Revert with a standard message if `account` is missing `role`.\n *\n * The format of the revert reason is given by the following regular expression:\n *\n * /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/\n */\n function _checkRole(bytes32 role, address account) internal view virtual {\n if (!hasRole(role, account)) {\n revert(\n string(\n abi.encodePacked(\n \"AccessControl: account \",\n Strings.toHexString(uint160(account), 20),\n \" is missing role \",\n Strings.toHexString(uint256(role), 32)\n )\n )\n );\n }\n }\n\n /**\n * @dev Returns the admin role that controls `role`. See {grantRole} and\n * {revokeRole}.\n *\n * To change a role's admin, use {_setRoleAdmin}.\n */\n function getRoleAdmin(bytes32 role) public view virtual override returns (bytes32) {\n return _roles[role].adminRole;\n }\n\n /**\n * @dev Grants `role` to `account`.\n *\n * If `account` had not been already granted `role`, emits a {RoleGranted}\n * event.\n *\n * Requirements:\n *\n * - the caller must have ``role``'s admin role.\n */\n function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {\n _grantRole(role, account);\n }\n\n /**\n * @dev Revokes `role` from `account`.\n *\n * If `account` had been granted `role`, emits a {RoleRevoked} event.\n *\n * Requirements:\n *\n * - the caller must have ``role``'s admin role.\n */\n function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {\n _revokeRole(role, account);\n }\n\n /**\n * @dev Revokes `role` from the calling account.\n *\n * Roles are often managed via {grantRole} and {revokeRole}: this function's\n * purpose is to provide a mechanism for accounts to lose their privileges\n * if they are compromised (such as when a trusted device is misplaced).\n *\n * If the calling account had been revoked `role`, emits a {RoleRevoked}\n * event.\n *\n * Requirements:\n *\n * - the caller must be `account`.\n */\n function renounceRole(bytes32 role, address account) public virtual override {\n require(account == _msgSender(), \"AccessControl: can only renounce roles for self\");\n\n _revokeRole(role, account);\n }\n\n /**\n * @dev Grants `role` to `account`.\n *\n * If `account` had not been already granted `role`, emits a {RoleGranted}\n * event. Note that unlike {grantRole}, this function doesn't perform any\n * checks on the calling account.\n *\n * [WARNING]\n * ====\n * This function should only be called from the constructor when setting\n * up the initial roles for the system.\n *\n * Using this function in any other way is effectively circumventing the admin\n * system imposed by {AccessControl}.\n * ====\n *\n * NOTE: This function is deprecated in favor of {_grantRole}.\n */\n function _setupRole(bytes32 role, address account) internal virtual {\n _grantRole(role, account);\n }\n\n /**\n * @dev Sets `adminRole` as ``role``'s admin role.\n *\n * Emits a {RoleAdminChanged} event.\n */\n function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {\n bytes32 previousAdminRole = getRoleAdmin(role);\n _roles[role].adminRole = adminRole;\n emit RoleAdminChanged(role, previousAdminRole, adminRole);\n }\n\n /**\n * @dev Grants `role` to `account`.\n *\n * Internal function without access restriction.\n */\n function _grantRole(bytes32 role, address account) internal virtual {\n if (!hasRole(role, account)) {\n _roles[role].members[account] = true;\n emit RoleGranted(role, account, _msgSender());\n }\n }\n\n /**\n * @dev Revokes `role` from `account`.\n *\n * Internal function without access restriction.\n */\n function _revokeRole(bytes32 role, address account) internal virtual {\n if (hasRole(role, account)) {\n _roles[role].members[account] = false;\n emit RoleRevoked(role, account, _msgSender());\n }\n }\n}\n"},"@openzeppelin/contracts/access/IAccessControl.sol":{"content":"// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (access/IAccessControl.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @dev External interface of AccessControl declared to support ERC165 detection.\n */\ninterface IAccessControl {\n /**\n * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`\n *\n * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite\n * {RoleAdminChanged} not being emitted signaling this.\n *\n * _Available since v3.1._\n */\n event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);\n\n /**\n * @dev Emitted when `account` is granted `role`.\n *\n * `sender` is the account that originated the contract call, an admin role\n * bearer except when using {AccessControl-_setupRole}.\n */\n event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);\n\n /**\n * @dev Emitted when `account` is revoked `role`.\n *\n * `sender` is the account that originated the contract call:\n * - if using `revokeRole`, it is the admin role bearer\n * - if using `renounceRole`, it is the role bearer (i.e. `account`)\n */\n event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);\n\n /**\n * @dev Returns `true` if `account` has been granted `role`.\n */\n function hasRole(bytes32 role, address account) external view returns (bool);\n\n /**\n * @dev Returns the admin role that controls `role`. See {grantRole} and\n * {revokeRole}.\n *\n * To change a role's admin, use {AccessControl-_setRoleAdmin}.\n */\n function getRoleAdmin(bytes32 role) external view returns (bytes32);\n\n /**\n * @dev Grants `role` to `account`.\n *\n * If `account` had not been already granted `role`, emits a {RoleGranted}\n * event.\n *\n * Requirements:\n *\n * - the caller must have ``role``'s admin role.\n */\n function grantRole(bytes32 role, address account) external;\n\n /**\n * @dev Revokes `role` from `account`.\n *\n * If `account` had been granted `role`, emits a {RoleRevoked} event.\n *\n * Requirements:\n *\n * - the caller must have ``role``'s admin role.\n */\n function revokeRole(bytes32 role, address account) external;\n\n /**\n * @dev Revokes `role` from the calling account.\n *\n * Roles are often managed via {grantRole} and {revokeRole}: this function's\n * purpose is to provide a mechanism for accounts to lose their privileges\n * if they are compromised (such as when a trusted device is misplaced).\n *\n * If the calling account had been granted `role`, emits a {RoleRevoked}\n * event.\n *\n * Requirements:\n *\n * - the caller must be `account`.\n */\n function renounceRole(bytes32 role, address account) external;\n}\n"},"@openzeppelin/contracts/utils/cryptography/ECDSA.sol":{"content":"// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.5.0) (utils/cryptography/ECDSA.sol)\n\npragma solidity ^0.8.0;\n\nimport \"../Strings.sol\";\n\n/**\n * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.\n *\n * These functions can be used to verify that a message was signed by the holder\n * of the private keys of a given address.\n */\nlibrary ECDSA {\n enum RecoverError {\n NoError,\n InvalidSignature,\n InvalidSignatureLength,\n InvalidSignatureS,\n InvalidSignatureV\n }\n\n function _throwError(RecoverError error) private pure {\n if (error == RecoverError.NoError) {\n return; // no error: do nothing\n } else if (error == RecoverError.InvalidSignature) {\n revert(\"ECDSA: invalid signature\");\n } else if (error == RecoverError.InvalidSignatureLength) {\n revert(\"ECDSA: invalid signature length\");\n } else if (error == RecoverError.InvalidSignatureS) {\n revert(\"ECDSA: invalid signature 's' value\");\n } else if (error == RecoverError.InvalidSignatureV) {\n revert(\"ECDSA: invalid signature 'v' value\");\n }\n }\n\n /**\n * @dev Returns the address that signed a hashed message (`hash`) with\n * `signature` or error string. This address can then be used for verification purposes.\n *\n * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:\n * this function rejects them by requiring the `s` value to be in the lower\n * half order, and the `v` value to be either 27 or 28.\n *\n * IMPORTANT: `hash` _must_ be the result of a hash operation for the\n * verification to be secure: it is possible to craft signatures that\n * recover to arbitrary addresses for non-hashed data. A safe way to ensure\n * this is by receiving a hash of the original message (which may otherwise\n * be too long), and then calling {toEthSignedMessageHash} on it.\n *\n * Documentation for signature generation:\n * - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]\n * - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]\n *\n * _Available since v4.3._\n */\n function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError) {\n // Check the signature length\n // - case 65: r,s,v signature (standard)\n // - case 64: r,vs signature (cf https://eips.ethereum.org/EIPS/eip-2098) _Available since v4.1._\n if (signature.length == 65) {\n bytes32 r;\n bytes32 s;\n uint8 v;\n // ecrecover takes the signature parameters, and the only way to get them\n // currently is to use assembly.\n assembly {\n r := mload(add(signature, 0x20))\n s := mload(add(signature, 0x40))\n v := byte(0, mload(add(signature, 0x60)))\n }\n return tryRecover(hash, v, r, s);\n } else if (signature.length == 64) {\n bytes32 r;\n bytes32 vs;\n // ecrecover takes the signature parameters, and the only way to get them\n // currently is to use assembly.\n assembly {\n r := mload(add(signature, 0x20))\n vs := mload(add(signature, 0x40))\n }\n return tryRecover(hash, r, vs);\n } else {\n return (address(0), RecoverError.InvalidSignatureLength);\n }\n }\n\n /**\n * @dev Returns the address that signed a hashed message (`hash`) with\n * `signature`. This address can then be used for verification purposes.\n *\n * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:\n * this function rejects them by requiring the `s` value to be in the lower\n * half order, and the `v` value to be either 27 or 28.\n *\n * IMPORTANT: `hash` _must_ be the result of a hash operation for the\n * verification to be secure: it is possible to craft signatures that\n * recover to arbitrary addresses for non-hashed data. A safe way to ensure\n * this is by receiving a hash of the original message (which may otherwise\n * be too long), and then calling {toEthSignedMessageHash} on it.\n */\n function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {\n (address recovered, RecoverError error) = tryRecover(hash, signature);\n _throwError(error);\n return recovered;\n }\n\n /**\n * @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.\n *\n * See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]\n *\n * _Available since v4.3._\n */\n function tryRecover(\n bytes32 hash,\n bytes32 r,\n bytes32 vs\n ) internal pure returns (address, RecoverError) {\n bytes32 s = vs & bytes32(0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);\n uint8 v = uint8((uint256(vs) >> 255) + 27);\n return tryRecover(hash, v, r, s);\n }\n\n /**\n * @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.\n *\n * _Available since v4.2._\n */\n function recover(\n bytes32 hash,\n bytes32 r,\n bytes32 vs\n ) internal pure returns (address) {\n (address recovered, RecoverError error) = tryRecover(hash, r, vs);\n _throwError(error);\n return recovered;\n }\n\n /**\n * @dev Overload of {ECDSA-tryRecover} that receives the `v`,\n * `r` and `s` signature fields separately.\n *\n * _Available since v4.3._\n */\n function tryRecover(\n bytes32 hash,\n uint8 v,\n bytes32 r,\n bytes32 s\n ) internal pure returns (address, RecoverError) {\n // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature\n // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines\n // the valid range for s in (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): v ∈ {27, 28}. Most\n // signatures from current libraries generate a unique signature with an s-value in the lower half order.\n //\n // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value\n // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or\n // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept\n // these malleable signatures as well.\n if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {\n return (address(0), RecoverError.InvalidSignatureS);\n }\n if (v != 27 && v != 28) {\n return (address(0), RecoverError.InvalidSignatureV);\n }\n\n // If the signature is valid (and not malleable), return the signer address\n address signer = ecrecover(hash, v, r, s);\n if (signer == address(0)) {\n return (address(0), RecoverError.InvalidSignature);\n }\n\n return (signer, RecoverError.NoError);\n }\n\n /**\n * @dev Overload of {ECDSA-recover} that receives the `v`,\n * `r` and `s` signature fields separately.\n */\n function recover(\n bytes32 hash,\n uint8 v,\n bytes32 r,\n bytes32 s\n ) internal pure returns (address) {\n (address recovered, RecoverError error) = tryRecover(hash, v, r, s);\n _throwError(error);\n return recovered;\n }\n\n /**\n * @dev Returns an Ethereum Signed Message, created from a `hash`. This\n * produces hash corresponding to the one signed with the\n * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]\n * JSON-RPC method as part of EIP-191.\n *\n * See {recover}.\n */\n function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) {\n // 32 is the length in bytes of hash,\n // enforced by the type signature above\n return keccak256(abi.encodePacked(\"\\x19Ethereum Signed Message:\\n32\", hash));\n }\n\n /**\n * @dev Returns an Ethereum Signed Message, created from `s`. This\n * produces hash corresponding to the one signed with the\n * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]\n * JSON-RPC method as part of EIP-191.\n *\n * See {recover}.\n */\n function toEthSignedMessageHash(bytes memory s) internal pure returns (bytes32) {\n return keccak256(abi.encodePacked(\"\\x19Ethereum Signed Message:\\n\", Strings.toString(s.length), s));\n }\n\n /**\n * @dev Returns an Ethereum Signed Typed Data, created from a\n * `domainSeparator` and a `structHash`. This produces hash corresponding\n * to the one signed with the\n * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]\n * JSON-RPC method as part of EIP-712.\n *\n * See {recover}.\n */\n function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32) {\n return keccak256(abi.encodePacked(\"\\x19\\x01\", domainSeparator, structHash));\n }\n}\n"},"@openzeppelin/contracts/utils/introspection/ERC165.sol":{"content":"// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)\n\npragma solidity ^0.8.0;\n\nimport \"./IERC165.sol\";\n\n/**\n * @dev Implementation of the {IERC165} interface.\n *\n * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check\n * for the additional interface id that will be supported. For example:\n *\n * ```solidity\n * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {\n * return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);\n * }\n * ```\n *\n * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.\n */\nabstract contract ERC165 is IERC165 {\n /**\n * @dev See {IERC165-supportsInterface}.\n */\n function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {\n return interfaceId == type(IERC165).interfaceId;\n }\n}\n"},"@openzeppelin/contracts/utils/introspection/IERC165.sol":{"content":"// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Interface of the ERC165 standard, as defined in the\n * https://eips.ethereum.org/EIPS/eip-165[EIP].\n *\n * Implementers can declare support of contract interfaces, which can then be\n * queried by others ({ERC165Checker}).\n *\n * For an implementation, see {ERC165}.\n */\ninterface IERC165 {\n /**\n * @dev Returns true if this contract implements the interface defined by\n * `interfaceId`. See the corresponding\n * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]\n * to learn more about how these ids are created.\n *\n * This function call must use less than 30 000 gas.\n */\n function supportsInterface(bytes4 interfaceId) external view returns (bool);\n}\n"},"@openzeppelin/contracts/utils/structs/EnumerableSet.sol":{"content":"// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (utils/structs/EnumerableSet.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Library for managing\n * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive\n * types.\n *\n * Sets have the following properties:\n *\n * - Elements are added, removed, and checked for existence in constant time\n * (O(1)).\n * - Elements are enumerated in O(n). No guarantees are made on the ordering.\n *\n * ```\n * contract Example {\n * // Add the library methods\n * using EnumerableSet for EnumerableSet.AddressSet;\n *\n * // Declare a set state variable\n * EnumerableSet.AddressSet private mySet;\n * }\n * ```\n *\n * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)\n * and `uint256` (`UintSet`) are supported.\n */\nlibrary EnumerableSet {\n // To implement this library for multiple types with as little code\n // repetition as possible, we write it in terms of a generic Set type with\n // bytes32 values.\n // The Set implementation uses private functions, and user-facing\n // implementations (such as AddressSet) are just wrappers around the\n // underlying Set.\n // This means that we can only create new EnumerableSets for types that fit\n // in bytes32.\n\n struct Set {\n // Storage of set values\n bytes32[] _values;\n // Position of the value in the `values` array, plus 1 because index 0\n // means a value is not in the set.\n mapping(bytes32 => uint256) _indexes;\n }\n\n /**\n * @dev Add a value to a set. O(1).\n *\n * Returns true if the value was added to the set, that is if it was not\n * already present.\n */\n function _add(Set storage set, bytes32 value) private returns (bool) {\n if (!_contains(set, value)) {\n set._values.push(value);\n // The value is stored at length-1, but we add 1 to all indexes\n // and use 0 as a sentinel value\n set._indexes[value] = set._values.length;\n return true;\n } else {\n return false;\n }\n }\n\n /**\n * @dev Removes a value from a set. O(1).\n *\n * Returns true if the value was removed from the set, that is if it was\n * present.\n */\n function _remove(Set storage set, bytes32 value) private returns (bool) {\n // We read and store the value's index to prevent multiple reads from the same storage slot\n uint256 valueIndex = set._indexes[value];\n\n if (valueIndex != 0) {\n // Equivalent to contains(set, value)\n // To delete an element from the _values array in O(1), we swap the element to delete with the last one in\n // the array, and then remove the last element (sometimes called as 'swap and pop').\n // This modifies the order of the array, as noted in {at}.\n\n uint256 toDeleteIndex = valueIndex - 1;\n uint256 lastIndex = set._values.length - 1;\n\n if (lastIndex != toDeleteIndex) {\n bytes32 lastvalue = set._values[lastIndex];\n\n // Move the last value to the index where the value to delete is\n set._values[toDeleteIndex] = lastvalue;\n // Update the index for the moved value\n set._indexes[lastvalue] = valueIndex; // Replace lastvalue's index to valueIndex\n }\n\n // Delete the slot where the moved value was stored\n set._values.pop();\n\n // Delete the index for the deleted slot\n delete set._indexes[value];\n\n return true;\n } else {\n return false;\n }\n }\n\n /**\n * @dev Returns true if the value is in the set. O(1).\n */\n function _contains(Set storage set, bytes32 value) private view returns (bool) {\n return set._indexes[value] != 0;\n }\n\n /**\n * @dev Returns the number of values on the set. O(1).\n */\n function _length(Set storage set) private view returns (uint256) {\n return set._values.length;\n }\n\n /**\n * @dev Returns the value stored at position `index` in the set. O(1).\n *\n * Note that there are no guarantees on the ordering of values inside the\n * array, and it may change when more values are added or removed.\n *\n * Requirements:\n *\n * - `index` must be strictly less than {length}.\n */\n function _at(Set storage set, uint256 index) private view returns (bytes32) {\n return set._values[index];\n }\n\n /**\n * @dev Return the entire set in an array\n *\n * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed\n * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that\n * this function has an unbounded cost, and using it as part of a state-changing function may render the function\n * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.\n */\n function _values(Set storage set) private view returns (bytes32[] memory) {\n return set._values;\n }\n\n // Bytes32Set\n\n struct Bytes32Set {\n Set _inner;\n }\n\n /**\n * @dev Add a value to a set. O(1).\n *\n * Returns true if the value was added to the set, that is if it was not\n * already present.\n */\n function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {\n return _add(set._inner, value);\n }\n\n /**\n * @dev Removes a value from a set. O(1).\n *\n * Returns true if the value was removed from the set, that is if it was\n * present.\n */\n function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {\n return _remove(set._inner, value);\n }\n\n /**\n * @dev Returns true if the value is in the set. O(1).\n */\n function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {\n return _contains(set._inner, value);\n }\n\n /**\n * @dev Returns the number of values in the set. O(1).\n */\n function length(Bytes32Set storage set) internal view returns (uint256) {\n return _length(set._inner);\n }\n\n /**\n * @dev Returns the value stored at position `index` in the set. O(1).\n *\n * Note that there are no guarantees on the ordering of values inside the\n * array, and it may change when more values are added or removed.\n *\n * Requirements:\n *\n * - `index` must be strictly less than {length}.\n */\n function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {\n return _at(set._inner, index);\n }\n\n /**\n * @dev Return the entire set in an array\n *\n * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed\n * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that\n * this function has an unbounded cost, and using it as part of a state-changing function may render the function\n * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.\n */\n function values(Bytes32Set storage set) internal view returns (bytes32[] memory) {\n return _values(set._inner);\n }\n\n // AddressSet\n\n struct AddressSet {\n Set _inner;\n }\n\n /**\n * @dev Add a value to a set. O(1).\n *\n * Returns true if the value was added to the set, that is if it was not\n * already present.\n */\n function add(AddressSet storage set, address value) internal returns (bool) {\n return _add(set._inner, bytes32(uint256(uint160(value))));\n }\n\n /**\n * @dev Removes a value from a set. O(1).\n *\n * Returns true if the value was removed from the set, that is if it was\n * present.\n */\n function remove(AddressSet storage set, address value) internal returns (bool) {\n return _remove(set._inner, bytes32(uint256(uint160(value))));\n }\n\n /**\n * @dev Returns true if the value is in the set. O(1).\n */\n function contains(AddressSet storage set, address value) internal view returns (bool) {\n return _contains(set._inner, bytes32(uint256(uint160(value))));\n }\n\n /**\n * @dev Returns the number of values in the set. O(1).\n */\n function length(AddressSet storage set) internal view returns (uint256) {\n return _length(set._inner);\n }\n\n /**\n * @dev Returns the value stored at position `index` in the set. O(1).\n *\n * Note that there are no guarantees on the ordering of values inside the\n * array, and it may change when more values are added or removed.\n *\n * Requirements:\n *\n * - `index` must be strictly less than {length}.\n */\n function at(AddressSet storage set, uint256 index) internal view returns (address) {\n return address(uint160(uint256(_at(set._inner, index))));\n }\n\n /**\n * @dev Return the entire set in an array\n *\n * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed\n * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that\n * this function has an unbounded cost, and using it as part of a state-changing function may render the function\n * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.\n */\n function values(AddressSet storage set) internal view returns (address[] memory) {\n bytes32[] memory store = _values(set._inner);\n address[] memory result;\n\n assembly {\n result := store\n }\n\n return result;\n }\n\n // UintSet\n\n struct UintSet {\n Set _inner;\n }\n\n /**\n * @dev Add a value to a set. O(1).\n *\n * Returns true if the value was added to the set, that is if it was not\n * already present.\n */\n function add(UintSet storage set, uint256 value) internal returns (bool) {\n return _add(set._inner, bytes32(value));\n }\n\n /**\n * @dev Removes a value from a set. O(1).\n *\n * Returns true if the value was removed from the set, that is if it was\n * present.\n */\n function remove(UintSet storage set, uint256 value) internal returns (bool) {\n return _remove(set._inner, bytes32(value));\n }\n\n /**\n * @dev Returns true if the value is in the set. O(1).\n */\n function contains(UintSet storage set, uint256 value) internal view returns (bool) {\n return _contains(set._inner, bytes32(value));\n }\n\n /**\n * @dev Returns the number of values on the set. O(1).\n */\n function length(UintSet storage set) internal view returns (uint256) {\n return _length(set._inner);\n }\n\n /**\n * @dev Returns the value stored at position `index` in the set. O(1).\n *\n * Note that there are no guarantees on the ordering of values inside the\n * array, and it may change when more values are added or removed.\n *\n * Requirements:\n *\n * - `index` must be strictly less than {length}.\n */\n function at(UintSet storage set, uint256 index) internal view returns (uint256) {\n return uint256(_at(set._inner, index));\n }\n\n /**\n * @dev Return the entire set in an array\n *\n * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed\n * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that\n * this function has an unbounded cost, and using it as part of a state-changing function may render the function\n * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.\n */\n function values(UintSet storage set) internal view returns (uint256[] memory) {\n bytes32[] memory store = _values(set._inner);\n uint256[] memory result;\n\n assembly {\n result := store\n }\n\n return result;\n }\n}\n"},"@openzeppelin/contracts/access/AccessControlEnumerable.sol":{"content":"// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.5.0) (access/AccessControlEnumerable.sol)\n\npragma solidity ^0.8.0;\n\nimport \"./IAccessControlEnumerable.sol\";\nimport \"./AccessControl.sol\";\nimport \"../utils/structs/EnumerableSet.sol\";\n\n/**\n * @dev Extension of {AccessControl} that allows enumerating the members of each role.\n */\nabstract contract AccessControlEnumerable is IAccessControlEnumerable, AccessControl {\n using EnumerableSet for EnumerableSet.AddressSet;\n\n mapping(bytes32 => EnumerableSet.AddressSet) private _roleMembers;\n\n /**\n * @dev See {IERC165-supportsInterface}.\n */\n function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {\n return interfaceId == type(IAccessControlEnumerable).interfaceId || super.supportsInterface(interfaceId);\n }\n\n /**\n * @dev Returns one of the accounts that have `role`. `index` must be a\n * value between 0 and {getRoleMemberCount}, non-inclusive.\n *\n * Role bearers are not sorted in any particular way, and their ordering may\n * change at any point.\n *\n * WARNING: When using {getRoleMember} and {getRoleMemberCount}, make sure\n * you perform all queries on the same block. See the following\n * https://forum.openzeppelin.com/t/iterating-over-elements-on-enumerableset-in-openzeppelin-contracts/2296[forum post]\n * for more information.\n */\n function getRoleMember(bytes32 role, uint256 index) public view virtual override returns (address) {\n return _roleMembers[role].at(index);\n }\n\n /**\n * @dev Returns the number of accounts that have `role`. Can be used\n * together with {getRoleMember} to enumerate all bearers of a role.\n */\n function getRoleMemberCount(bytes32 role) public view virtual override returns (uint256) {\n return _roleMembers[role].length();\n }\n\n /**\n * @dev Overload {_grantRole} to track enumerable memberships\n */\n function _grantRole(bytes32 role, address account) internal virtual override {\n super._grantRole(role, account);\n _roleMembers[role].add(account);\n }\n\n /**\n * @dev Overload {_revokeRole} to track enumerable memberships\n */\n function _revokeRole(bytes32 role, address account) internal virtual override {\n super._revokeRole(role, account);\n _roleMembers[role].remove(account);\n }\n}\n"},"@openzeppelin/contracts/access/IAccessControlEnumerable.sol":{"content":"// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (access/IAccessControlEnumerable.sol)\n\npragma solidity ^0.8.0;\n\nimport \"./IAccessControl.sol\";\n\n/**\n * @dev External interface of AccessControlEnumerable declared to support ERC165 detection.\n */\ninterface IAccessControlEnumerable is IAccessControl {\n /**\n * @dev Returns one of the accounts that have `role`. `index` must be a\n * value between 0 and {getRoleMemberCount}, non-inclusive.\n *\n * Role bearers are not sorted in any particular way, and their ordering may\n * change at any point.\n *\n * WARNING: When using {getRoleMember} and {getRoleMemberCount}, make sure\n * you perform all queries on the same block. See the following\n * https://forum.openzeppelin.com/t/iterating-over-elements-on-enumerableset-in-openzeppelin-contracts/2296[forum post]\n * for more information.\n */\n function getRoleMember(bytes32 role, uint256 index) external view returns (address);\n\n /**\n * @dev Returns the number of accounts that have `role`. Can be used\n * together with {getRoleMember} to enumerate all bearers of a role.\n */\n function getRoleMemberCount(bytes32 role) external view returns (uint256);\n}\n"},"@openzeppelin/contracts/utils/cryptography/draft-EIP712.sol":{"content":"// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (utils/cryptography/draft-EIP712.sol)\n\npragma solidity ^0.8.0;\n\nimport \"./ECDSA.sol\";\n\n/**\n * @dev https://eips.ethereum.org/EIPS/eip-712[EIP 712] is a standard for hashing and signing of typed structured data.\n *\n * The encoding specified in the EIP is very generic, and such a generic implementation in Solidity is not feasible,\n * thus this contract does not implement the encoding itself. Protocols need to implement the type-specific encoding\n * they need in their contracts using a combination of `abi.encode` and `keccak256`.\n *\n * This contract implements the EIP 712 domain separator ({_domainSeparatorV4}) that is used as part of the encoding\n * scheme, and the final step of the encoding to obtain the message digest that is then signed via ECDSA\n * ({_hashTypedDataV4}).\n *\n * The implementation of the domain separator was designed to be as efficient as possible while still properly updating\n * the chain id to protect against replay attacks on an eventual fork of the chain.\n *\n * NOTE: This contract implements the version of the encoding known as \"v4\", as implemented by the JSON RPC method\n * https://docs.metamask.io/guide/signing-data.html[`eth_signTypedDataV4` in MetaMask].\n *\n * _Available since v3.4._\n */\nabstract contract EIP712 {\n /* solhint-disable var-name-mixedcase */\n // Cache the domain separator as an immutable value, but also store the chain id that it corresponds to, in order to\n // invalidate the cached domain separator if the chain id changes.\n bytes32 private immutable _CACHED_DOMAIN_SEPARATOR;\n uint256 private immutable _CACHED_CHAIN_ID;\n address private immutable _CACHED_THIS;\n\n bytes32 private immutable _HASHED_NAME;\n bytes32 private immutable _HASHED_VERSION;\n bytes32 private immutable _TYPE_HASH;\n\n /* solhint-enable var-name-mixedcase */\n\n /**\n * @dev Initializes the domain separator and parameter caches.\n *\n * The meaning of `name` and `version` is specified in\n * https://eips.ethereum.org/EIPS/eip-712#definition-of-domainseparator[EIP 712]:\n *\n * - `name`: the user readable name of the signing domain, i.e. the name of the DApp or the protocol.\n * - `version`: the current major version of the signing domain.\n *\n * NOTE: These parameters cannot be changed except through a xref:learn::upgrading-smart-contracts.adoc[smart\n * contract upgrade].\n */\n constructor(string memory name, string memory version) {\n bytes32 hashedName = keccak256(bytes(name));\n bytes32 hashedVersion = keccak256(bytes(version));\n bytes32 typeHash = keccak256(\n \"EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)\"\n );\n _HASHED_NAME = hashedName;\n _HASHED_VERSION = hashedVersion;\n _CACHED_CHAIN_ID = block.chainid;\n _CACHED_DOMAIN_SEPARATOR = _buildDomainSeparator(typeHash, hashedName, hashedVersion);\n _CACHED_THIS = address(this);\n _TYPE_HASH = typeHash;\n }\n\n /**\n * @dev Returns the domain separator for the current chain.\n */\n function _domainSeparatorV4() internal view returns (bytes32) {\n if (address(this) == _CACHED_THIS && block.chainid == _CACHED_CHAIN_ID) {\n return _CACHED_DOMAIN_SEPARATOR;\n } else {\n return _buildDomainSeparator(_TYPE_HASH, _HASHED_NAME, _HASHED_VERSION);\n }\n }\n\n function _buildDomainSeparator(\n bytes32 typeHash,\n bytes32 nameHash,\n bytes32 versionHash\n ) private view returns (bytes32) {\n return keccak256(abi.encode(typeHash, nameHash, versionHash, block.chainid, address(this)));\n }\n\n /**\n * @dev Given an already https://eips.ethereum.org/EIPS/eip-712#definition-of-hashstruct[hashed struct], this\n * function returns the hash of the fully encoded EIP712 message for this domain.\n *\n * This hash can be used together with {ECDSA-recover} to obtain the signer of a message. For example:\n *\n * ```solidity\n * bytes32 digest = _hashTypedDataV4(keccak256(abi.encode(\n * keccak256(\"Mail(address to,string contents)\"),\n * mailTo,\n * keccak256(bytes(mailContents))\n * )));\n * address signer = ECDSA.recover(digest, signature);\n * ```\n */\n function _hashTypedDataV4(bytes32 structHash) internal view virtual returns (bytes32) {\n return ECDSA.toTypedDataHash(_domainSeparatorV4(), structHash);\n }\n}\n"},"@openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol":{"content":"// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/extensions/ERC20Burnable.sol)\n\npragma solidity ^0.8.0;\n\nimport \"../ERC20.sol\";\nimport \"../../../utils/Context.sol\";\n\n/**\n * @dev Extension of {ERC20} that allows token holders to destroy both their own\n * tokens and those that they have an allowance for, in a way that can be\n * recognized off-chain (via event analysis).\n */\nabstract contract ERC20Burnable is Context, ERC20 {\n /**\n * @dev Destroys `amount` tokens from the caller.\n *\n * See {ERC20-_burn}.\n */\n function burn(uint256 amount) public virtual {\n _burn(_msgSender(), amount);\n }\n\n /**\n * @dev Destroys `amount` tokens from `account`, deducting from the caller's\n * allowance.\n *\n * See {ERC20-_burn} and {ERC20-allowance}.\n *\n * Requirements:\n *\n * - the caller must have allowance for ``accounts``'s tokens of at least\n * `amount`.\n */\n function burnFrom(address account, uint256 amount) public virtual {\n _spendAllowance(account, _msgSender(), amount);\n _burn(account, amount);\n }\n}\n"},"@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol":{"content":"// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)\n\npragma solidity ^0.8.0;\n\nimport \"../IERC20.sol\";\n\n/**\n * @dev Interface for the optional metadata functions from the ERC20 standard.\n *\n * _Available since v4.1._\n */\ninterface IERC20Metadata is IERC20 {\n /**\n * @dev Returns the name of the token.\n */\n function name() external view returns (string memory);\n\n /**\n * @dev Returns the symbol of the token.\n */\n function symbol() external view returns (string memory);\n\n /**\n * @dev Returns the decimals places of the token.\n */\n function decimals() external view returns (uint8);\n}\n"},"@openzeppelin/contracts/token/ERC20/extensions/draft-ERC20Permit.sol":{"content":"// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-ERC20Permit.sol)\n\npragma solidity ^0.8.0;\n\nimport \"./draft-IERC20Permit.sol\";\nimport \"../ERC20.sol\";\nimport \"../../../utils/cryptography/draft-EIP712.sol\";\nimport \"../../../utils/cryptography/ECDSA.sol\";\nimport \"../../../utils/Counters.sol\";\n\n/**\n * @dev Implementation of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in\n * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].\n *\n * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by\n * presenting a message signed by the account. By not relying on `{IERC20-approve}`, the token holder account doesn't\n * need to send a transaction, and thus is not required to hold Ether at all.\n *\n * _Available since v3.4._\n */\nabstract contract ERC20Permit is ERC20, IERC20Permit, EIP712 {\n using Counters for Counters.Counter;\n\n mapping(address => Counters.Counter) private _nonces;\n\n // solhint-disable-next-line var-name-mixedcase\n bytes32 private immutable _PERMIT_TYPEHASH =\n keccak256(\"Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)\");\n\n /**\n * @dev Initializes the {EIP712} domain separator using the `name` parameter, and setting `version` to `\"1\"`.\n *\n * It's a good idea to use the same `name` that is defined as the ERC20 token name.\n */\n constructor(string memory name) EIP712(name, \"1\") {}\n\n /**\n * @dev See {IERC20Permit-permit}.\n */\n function permit(\n address owner,\n address spender,\n uint256 value,\n uint256 deadline,\n uint8 v,\n bytes32 r,\n bytes32 s\n ) public virtual override {\n require(block.timestamp <= deadline, \"ERC20Permit: expired deadline\");\n\n bytes32 structHash = keccak256(abi.encode(_PERMIT_TYPEHASH, owner, spender, value, _useNonce(owner), deadline));\n\n bytes32 hash = _hashTypedDataV4(structHash);\n\n address signer = ECDSA.recover(hash, v, r, s);\n require(signer == owner, \"ERC20Permit: invalid signature\");\n\n _approve(owner, spender, value);\n }\n\n /**\n * @dev See {IERC20Permit-nonces}.\n */\n function nonces(address owner) public view virtual override returns (uint256) {\n return _nonces[owner].current();\n }\n\n /**\n * @dev See {IERC20Permit-DOMAIN_SEPARATOR}.\n */\n // solhint-disable-next-line func-name-mixedcase\n function DOMAIN_SEPARATOR() external view override returns (bytes32) {\n return _domainSeparatorV4();\n }\n\n /**\n * @dev \"Consume a nonce\": return the current value and increment.\n *\n * _Available since v4.1._\n */\n function _useNonce(address owner) internal virtual returns (uint256 current) {\n Counters.Counter storage nonce = _nonces[owner];\n current = nonce.current();\n nonce.increment();\n }\n}\n"},"@openzeppelin/contracts/token/ERC20/extensions/draft-IERC20Permit.sol":{"content":"// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-IERC20Permit.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in\n * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].\n *\n * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by\n * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't\n * need to send a transaction, and thus is not required to hold Ether at all.\n */\ninterface IERC20Permit {\n /**\n * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,\n * given ``owner``'s signed approval.\n *\n * IMPORTANT: The same issues {IERC20-approve} has related to transaction\n * ordering also apply here.\n *\n * Emits an {Approval} event.\n *\n * Requirements:\n *\n * - `spender` cannot be the zero address.\n * - `deadline` must be a timestamp in the future.\n * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`\n * over the EIP712-formatted function arguments.\n * - the signature must use ``owner``'s current nonce (see {nonces}).\n *\n * For more information on the signature format, see the\n * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP\n * section].\n */\n function permit(\n address owner,\n address spender,\n uint256 value,\n uint256 deadline,\n uint8 v,\n bytes32 r,\n bytes32 s\n ) external;\n\n /**\n * @dev Returns the current nonce for `owner`. This value must be\n * included whenever a signature is generated for {permit}.\n *\n * Every successful call to {permit} increases ``owner``'s nonce by one. This\n * prevents a signature from being used multiple times.\n */\n function nonces(address owner) external view returns (uint256);\n\n /**\n * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.\n */\n // solhint-disable-next-line func-name-mixedcase\n function DOMAIN_SEPARATOR() external view returns (bytes32);\n}\n"}},"compilation":{"language":"Solidity","compiler":"solc","compilerVersion":"0.8.9+commit.e5eed63a","compilerSettings":{"metadata":{"bytecodeHash":"ipfs","useLiteralContent":true},"libraries":{},"optimizer":{"runs":200,"enabled":true},"evmVersion":"london","remappings":[]},"name":"XToken","fullyQualifiedName":"contracts/ERC20Token.sol:XToken"},"matchId":"5268114","creationMatch":"match","runtimeMatch":"match","verifiedAt":"2024-09-04T04:24:07Z","match":"match","chainId":"137","address":"0xAC0F66379A6d7801D7726d5a943356A172549Adb"}