zellic-audit
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{
"language": "Solidity",
"sources": {
"contracts/ERC721Storage.sol": {
"content": "// SPDX-License-Identifier: Unlicense\n// Creator: 0xVeryBased\n\npragma solidity ^0.8.9;\n\nimport \"@openzeppelin/contracts/access/Ownable.sol\";\nimport \"@openzeppelin/contracts/utils/Address.sol\";\nimport \"@openzeppelin/contracts/utils/Strings.sol\";\nimport \"@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol\";\n\ncontract ERC721Storage is Ownable {\n using Address for address;\n using Strings for uint256;\n\n // Tracker for calculating number minted/total supply and assigning token indices\n uint256 private currentIndex = 0;\n\n // Token name\n string private _name;\n\n // Token symbol\n string private _symbol;\n\n // Token owners and token balances\n mapping(uint256 => address) private _ownerships;\n mapping(address => uint256) private _balances;\n\n // Burn address and counter\n address public immutable burnAddress = 0x000000000000000000000000000000000000dEaD;\n uint256 private numTokensBurned;\n\n // Mapping from token ID to approved address\n mapping(uint256 => address) private _tokenApprovals;\n\n // Mapping from owner to operator approvals\n mapping(address => mapping(address => bool)) private _operatorApprovals;\n\n // Mapping from operators to whether or not they are restricted\n mapping(address => bool) private _operatorRestrictions;\n // Bool indicating whether one can still restrict an operator or not\n bool private _canRestrict;\n\n ERC721TopLevelProto public topLevelContract;\n\n constructor(\n string memory name_,\n string memory symbol_\n ) {\n _name = name_;\n _symbol = symbol_;\n// topLevelContract = ERC721TopLevelProto(msg.sender);\n }\n\n function setTopLevelContract(address _topLevelContract) public onlyOwner {\n topLevelContract = ERC721TopLevelProto(_topLevelContract);\n transferOwnership(_topLevelContract);\n }\n\n /**\n * @dev See {IERC721Enumerable-totalSupply}.\n **/\n function storage_totalSupply() public view returns (uint256) {\n return (currentIndex - numTokensBurned);\n }\n\n /**\n * @dev See {IERC721Enumerable-tokenByIndex}.\n **/\n function storage_tokenByIndex(uint256 index) public view returns (uint256) {\n require(index < storage_totalSupply(), \"g\");\n require(storage_ownerOf(index) != burnAddress, \"b\");\n return index;\n }\n\n /**\n * @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.\n * This read function is O(totalSupply). If calling from a separate contract, be sure to test gas first.\n * It may also degrade with extremely large collection sizes (e.g >> 10000), test for your use case.\n **/\n function storage_tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256) {\n require(index < storage_balanceOf(owner), \"b\");\n uint256 numMintedSoFar = storage_totalSupply();\n uint256 tokenIdsIdx = 0;\n address currOwnershipAddr = address(0);\n for (uint256 i = 0; i < numMintedSoFar; i++) {\n address ownership = _ownerships[i];\n if (ownership != address(0)) {\n currOwnershipAddr = ownership;\n }\n if (currOwnershipAddr == owner) {\n if (tokenIdsIdx == index) {\n return i;\n }\n tokenIdsIdx++;\n }\n }\n revert(\"u\");\n }\n\n function storage_tokenOfOwnerByIndexStepped(address owner, uint256 index, uint256 lastToken, uint256 lastIndex) public view returns (uint256) {\n require(index < storage_balanceOf(owner), \"b\");\n uint256 numTokenIds = currentIndex;\n uint256 tokenIdsIdx = ((lastIndex == 0) ? 0 : (lastIndex + 1));\n address currOwnershipAddr = address(0);\n for (uint256 i = ((lastToken == 0) ? 0 : (lastToken + 1)); i < numTokenIds; i++) {\n address ownership = _ownerships[i];\n if (ownership != address(0)) {\n currOwnershipAddr = ownership;\n }\n if (currOwnershipAddr == owner) {\n if (tokenIdsIdx == index) {\n return i;\n }\n tokenIdsIdx++;\n }\n }\n revert(\"u\");\n }\n\n// /**\n// * @dev See {IERC165-supportsInterface}.\n// **/\n// function supportsInterface(bytes4 interfaceId) public view virtual returns (bool) {\n// return (interfaceId == type(IERC721).interfaceId ||\n// interfaceId == type(IERC721Metadata).interfaceId ||\n// interfaceId == type(IERC721Enumerable).interfaceId ||\n// super.supportsInterface(interfaceId));\n// }\n\n /**\n * @dev See {IERC721-balanceOf}.\n **/\n function storage_balanceOf(address owner) public view returns (uint256) {\n require(owner != address(0), \"0\");\n return uint256(_balances[owner]);\n }\n\n /**\n * @dev See {IERC721-ownerOf}.\n **/\n function storage_ownerOf(uint256 tokenId) public view returns (address) {\n require(tokenId < currentIndex, \"t\");\n\n for (uint256 curr = tokenId; curr >= 0; curr--) {\n address ownership = _ownerships[curr];\n if (ownership != address(0)) {\n return ownership;\n }\n }\n\n revert(\"o\");\n }\n\n /**\n * @dev See {IERC721Metadata-name}.\n **/\n function storage_name() public view virtual returns (string memory) {\n return _name;\n }\n\n /**\n * @dev See {IERC721Metadata-symbol}.\n **/\n function storage_symbol() public view virtual returns (string memory) {\n return _symbol;\n }\n\n /**\n * @dev See {IERC721-approve}.\n **/\n function storage_approve(address to, uint256 tokenId, address msgSender) public onlyOwner {\n address owner = ERC721Storage.storage_ownerOf(tokenId);\n require(to != owner, \"o\");\n\n require(\n msgSender == owner || storage_isApprovedForAll(owner, msgSender),\n \"a\"\n );\n\n _approve(to, tokenId, owner);\n }\n\n /**\n * @dev See {IERC721-getApproved}.\n **/\n function storage_getApproved(uint256 tokenId) public view returns (address) {\n require(_exists(tokenId), \"a\");\n\n return _tokenApprovals[tokenId];\n }\n\n /**\n * @dev See {IERC721-setApprovalForAll}.\n **/\n function storage_setApprovalForAll(address operator, bool approved, address msgSender) public {\n // require(operator != msgSender && !(operatorRestrict[operator]), \"a;r\");\n require(operator != msgSender, \"a\");\n\n _operatorApprovals[msgSender][operator] = approved;\n topLevelContract.emitApprovalForAll(msgSender, operator, approved);\n }\n\n /**\n * @dev See {IERC721-isApprovedForAll}.\n **/\n function storage_isApprovedForAll(address owner, address operator) public view virtual returns (bool) {\n return _operatorApprovals[owner][operator];\n }\n\n /**\n * @dev See {IERC721-transferFrom}.\n **/\n function storage_transferFrom(\n address from,\n address to,\n uint256 tokenId,\n address msgSender\n ) public onlyOwner {\n _transfer(from, to, tokenId, msgSender);\n }\n\n /**\n * @dev See {IERC721-safeTransferFrom}.\n **/\n function storage_safeTransferFrom(\n address from,\n address to,\n uint256 tokenId,\n address msgSender\n ) public onlyOwner {\n storage_safeTransferFrom(from, to, tokenId, \"\", msgSender);\n }\n\n /**\n * @dev See {IERC721-safeTransferFrom}.\n **/\n function storage_safeTransferFrom(\n address from,\n address to,\n uint256 tokenId,\n bytes memory _data,\n address msgSender\n ) public onlyOwner {\n _transfer(from, to, tokenId, msgSender);\n require(\n _checkOnERC721Received(from, to, tokenId, _data, msgSender),\n \"z\"\n );\n }\n\n /**\n * @dev Burns a token to the designated burn address\n **/\n function storage_burnToken(uint256 tokenId, address msgSender) public onlyOwner {\n _transfer(storage_ownerOf(tokenId), burnAddress, tokenId, msgSender);\n numTokensBurned++;\n }\n\n /**\n * @dev Returns whether `tokenId` exists.\n *\n * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.\n *\n * Tokens start existing when they are minted (`_mint`),\n **/\n function _exists(uint256 tokenId) internal view returns (bool) {\n return (tokenId < currentIndex && storage_ownerOf(tokenId) != burnAddress);\n }\n\n function storage_exists(uint256 tokenId) public view returns (bool) {\n return _exists(tokenId);\n }\n\n function storage_safeMint(address to, uint256 quantity, address msgSender) public onlyOwner {\n storage_safeMint(to, quantity, \"\", msgSender);\n }\n\n function storage_safeMint(\n address to,\n uint256 quantity,\n bytes memory _data,\n address msgSender\n ) public onlyOwner {\n storage_mint(to, quantity);\n require(_checkOnERC721Received(address(0), to, currentIndex - 1, _data, msgSender), \"z\");\n }\n\n function storage_mint(address to, uint256 quantity) public onlyOwner {\n uint256 startTokenId = currentIndex;\n require(to != address(0), \"0\");\n // We know if the first token in the batch doesn't exist, the other ones don't as well, because of serial ordering.\n require(!_exists(startTokenId), \"a\");\n\n _balances[to] = _balances[to] + quantity;\n _ownerships[startTokenId] = to;\n\n uint256 updatedIndex = startTokenId;\n\n for (uint256 i = 0; i < quantity; i++) {\n topLevelContract.emitTransfer(address(0), to, updatedIndex);\n updatedIndex++;\n }\n\n currentIndex = updatedIndex;\n }\n\n function storage_contractURI(string memory _description, string memory _img, string memory _self) public view returns (string memory) {\n return string(\n abi.encodePacked(\n \"data:application/json;utf8,{\\\"name\\\":\\\"\", storage_name(),\"\\\",\",\n \"\\\"description\\\":\\\"\", _description, \"\\\",\",\n \"\\\"image\\\":\\\"\", _img, \"\\\",\",\n \"\\\"external_link\\\":\\\"https://crudeborne.wtf\\\",\",\n \"\\\"seller_fee_basis_points\\\":420,\\\"fee_recipient\\\":\\\"\",\n _self, \"\\\"}\"\n )\n );\n }\n\n function _transfer(\n address from,\n address to,\n uint256 tokenId,\n address msgSender\n ) private {\n address prevOwnership = storage_ownerOf(tokenId);\n\n bool isApprovedOrOwner = (msgSender == prevOwnership ||\n storage_getApproved(tokenId) == msgSender ||\n storage_isApprovedForAll(prevOwnership, msgSender));\n\n require(isApprovedOrOwner && prevOwnership == from, \"a\");\n require(prevOwnership == from, \"o\");\n require(to != address(0), \"0\");\n\n // Clear approvals from the previous owner\n _approve(address(0), tokenId, prevOwnership);\n\n _balances[from] -= 1;\n _balances[to] += 1;\n _ownerships[tokenId] = to;\n\n // If the ownership slot of tokenId+1 is not explicitly set, that means the transfer initiator owns it.\n // Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.\n uint256 nextTokenId = tokenId + 1;\n if (_ownerships[nextTokenId] == address(0)) {\n if (_exists(nextTokenId)) {\n _ownerships[nextTokenId] = prevOwnership;\n }\n }\n\n topLevelContract.emitTransfer(from, to, tokenId);\n }\n\n function _approve(\n address to,\n uint256 tokenId,\n address owner\n ) private {\n _tokenApprovals[tokenId] = to;\n topLevelContract.emitApproval(owner, to, tokenId);\n }\n\n function _checkOnERC721Received(\n address from,\n address to,\n uint256 tokenId,\n bytes memory _data,\n address msgSender\n ) private returns (bool) {\n if (to.isContract()) {\n try IERC721Receiver(to).onERC721Received(msgSender, from, tokenId, _data) returns (bytes4 retVal) {\n return retVal == IERC721Receiver(to).onERC721Received.selector;\n } catch (bytes memory reason) {\n if (reason.length == 0) {\n revert(\"z\");\n } else {\n assembly {\n revert(add(32, reason), mload(reason))\n }\n }\n }\n } else {\n return true;\n }\n }\n}\n\n////////////////////\n\nabstract contract ERC721TopLevelProto {\n function emitTransfer(address from, address to, uint256 tokenId) public virtual;\n function emitApproval(address owner, address approved, uint256 tokenId) public virtual;\n function emitApprovalForAll(address owner, address operator, bool approved) public virtual;\n}\n\n////////////////////////////////////////\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n"
},
"@openzeppelin/contracts/access/Ownable.sol": {
"content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)\n\npragma solidity ^0.8.0;\n\nimport \"../utils/Context.sol\";\n\n/**\n * @dev Contract module which provides a basic access control mechanism, where\n * there is an account (an owner) that can be granted exclusive access to\n * specific functions.\n *\n * By default, the owner account will be the one that deploys the contract. This\n * can later be changed with {transferOwnership}.\n *\n * This module is used through inheritance. It will make available the modifier\n * `onlyOwner`, which can be applied to your functions to restrict their use to\n * the owner.\n */\nabstract contract Ownable is Context {\n address private _owner;\n\n event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);\n\n /**\n * @dev Initializes the contract setting the deployer as the initial owner.\n */\n constructor() {\n _transferOwnership(_msgSender());\n }\n\n /**\n * @dev Throws if called by any account other than the owner.\n */\n modifier onlyOwner() {\n _checkOwner();\n _;\n }\n\n /**\n * @dev Returns the address of the current owner.\n */\n function owner() public view virtual returns (address) {\n return _owner;\n }\n\n /**\n * @dev Throws if the sender is not the owner.\n */\n function _checkOwner() internal view virtual {\n require(owner() == _msgSender(), \"Ownable: caller is not the owner\");\n }\n\n /**\n * @dev Leaves the contract without owner. It will not be possible to call\n * `onlyOwner` functions anymore. Can only be called by the current owner.\n *\n * NOTE: Renouncing ownership will leave the contract without an owner,\n * thereby removing any functionality that is only available to the owner.\n */\n function renounceOwnership() public virtual onlyOwner {\n _transferOwnership(address(0));\n }\n\n /**\n * @dev Transfers ownership of the contract to a new account (`newOwner`).\n * Can only be called by the current owner.\n */\n function transferOwnership(address newOwner) public virtual onlyOwner {\n require(newOwner != address(0), \"Ownable: new owner is the zero address\");\n _transferOwnership(newOwner);\n }\n\n /**\n * @dev Transfers ownership of the contract to a new account (`newOwner`).\n * Internal function without access restriction.\n */\n function _transferOwnership(address newOwner) internal virtual {\n address oldOwner = _owner;\n _owner = newOwner;\n emit OwnershipTransferred(oldOwner, newOwner);\n }\n}\n"
},
"@openzeppelin/contracts/utils/Address.sol": {
"content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.7.0) (utils/Address.sol)\n\npragma solidity ^0.8.1;\n\n/**\n * @dev Collection of functions related to the address type\n */\nlibrary Address {\n /**\n * @dev Returns true if `account` is a contract.\n *\n * [IMPORTANT]\n * ====\n * It is unsafe to assume that an address for which this function returns\n * false is an externally-owned account (EOA) and not a contract.\n *\n * Among others, `isContract` will return false for the following\n * types of addresses:\n *\n * - an externally-owned account\n * - a contract in construction\n * - an address where a contract will be created\n * - an address where a contract lived, but was destroyed\n * ====\n *\n * [IMPORTANT]\n * ====\n * You shouldn't rely on `isContract` to protect against flash loan attacks!\n *\n * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets\n * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract\n * constructor.\n * ====\n */\n function isContract(address account) internal view returns (bool) {\n // This method relies on extcodesize/address.code.length, which returns 0\n // for contracts in construction, since the code is only stored at the end\n // of the constructor execution.\n\n return account.code.length > 0;\n }\n\n /**\n * @dev Replacement for Solidity's `transfer`: sends `amount` wei to\n * `recipient`, forwarding all available gas and reverting on errors.\n *\n * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost\n * of certain opcodes, possibly making contracts go over the 2300 gas limit\n * imposed by `transfer`, making them unable to receive funds via\n * `transfer`. {sendValue} removes this limitation.\n *\n * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].\n *\n * IMPORTANT: because control is transferred to `recipient`, care must be\n * taken to not create reentrancy vulnerabilities. Consider using\n * {ReentrancyGuard} or the\n * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].\n */\n function sendValue(address payable recipient, uint256 amount) internal {\n require(address(this).balance >= amount, \"Address: insufficient balance\");\n\n (bool success, ) = recipient.call{value: amount}(\"\");\n require(success, \"Address: unable to send value, recipient may have reverted\");\n }\n\n /**\n * @dev Performs a Solidity function call using a low level `call`. A\n * plain `call` is an unsafe replacement for a function call: use this\n * function instead.\n *\n * If `target` reverts with a revert reason, it is bubbled up by this\n * function (like regular Solidity function calls).\n *\n * Returns the raw returned data. To convert to the expected return value,\n * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].\n *\n * Requirements:\n *\n * - `target` must be a contract.\n * - calling `target` with `data` must not revert.\n *\n * _Available since v3.1._\n */\n function functionCall(address target, bytes memory data) internal returns (bytes memory) {\n return functionCall(target, data, \"Address: low-level call failed\");\n }\n\n /**\n * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with\n * `errorMessage` as a fallback revert reason when `target` reverts.\n *\n * _Available since v3.1._\n */\n function functionCall(\n address target,\n bytes memory data,\n string memory errorMessage\n ) internal returns (bytes memory) {\n return functionCallWithValue(target, data, 0, errorMessage);\n }\n\n /**\n * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\n * but also transferring `value` wei to `target`.\n *\n * Requirements:\n *\n * - the calling contract must have an ETH balance of at least `value`.\n * - the called Solidity function must be `payable`.\n *\n * _Available since v3.1._\n */\n function functionCallWithValue(\n address target,\n bytes memory data,\n uint256 value\n ) internal returns (bytes memory) {\n return functionCallWithValue(target, data, value, \"Address: low-level call with value failed\");\n }\n\n /**\n * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but\n * with `errorMessage` as a fallback revert reason when `target` reverts.\n *\n * _Available since v3.1._\n */\n function functionCallWithValue(\n address target,\n bytes memory data,\n uint256 value,\n string memory errorMessage\n ) internal returns (bytes memory) {\n require(address(this).balance >= value, \"Address: insufficient balance for call\");\n require(isContract(target), \"Address: call to non-contract\");\n\n (bool success, bytes memory returndata) = target.call{value: value}(data);\n return verifyCallResult(success, returndata, errorMessage);\n }\n\n /**\n * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\n * but performing a static call.\n *\n * _Available since v3.3._\n */\n function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {\n return functionStaticCall(target, data, \"Address: low-level static call failed\");\n }\n\n /**\n * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],\n * but performing a static call.\n *\n * _Available since v3.3._\n */\n function functionStaticCall(\n address target,\n bytes memory data,\n string memory errorMessage\n ) internal view returns (bytes memory) {\n require(isContract(target), \"Address: static call to non-contract\");\n\n (bool success, bytes memory returndata) = target.staticcall(data);\n return verifyCallResult(success, returndata, errorMessage);\n }\n\n /**\n * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\n * but performing a delegate call.\n *\n * _Available since v3.4._\n */\n function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {\n return functionDelegateCall(target, data, \"Address: low-level delegate call failed\");\n }\n\n /**\n * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],\n * but performing a delegate call.\n *\n * _Available since v3.4._\n */\n function functionDelegateCall(\n address target,\n bytes memory data,\n string memory errorMessage\n ) internal returns (bytes memory) {\n require(isContract(target), \"Address: delegate call to non-contract\");\n\n (bool success, bytes memory returndata) = target.delegatecall(data);\n return verifyCallResult(success, returndata, errorMessage);\n }\n\n /**\n * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the\n * revert reason using the provided one.\n *\n * _Available since v4.3._\n */\n function verifyCallResult(\n bool success,\n bytes memory returndata,\n string memory errorMessage\n ) internal pure returns (bytes memory) {\n if (success) {\n return returndata;\n } else {\n // Look for revert reason and bubble it up if present\n if (returndata.length > 0) {\n // The easiest way to bubble the revert reason is using memory via assembly\n /// @solidity memory-safe-assembly\n assembly {\n let returndata_size := mload(returndata)\n revert(add(32, returndata), returndata_size)\n }\n } else {\n revert(errorMessage);\n }\n }\n }\n}\n"
},
"@openzeppelin/contracts/utils/Strings.sol": {
"content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.7.0) (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 uint8 private constant _ADDRESS_LENGTH = 20;\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 /**\n * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.\n */\n function toHexString(address addr) internal pure returns (string memory) {\n return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);\n }\n}\n"
},
"@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol": {
"content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/IERC721Receiver.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @title ERC721 token receiver interface\n * @dev Interface for any contract that wants to support safeTransfers\n * from ERC721 asset contracts.\n */\ninterface IERC721Receiver {\n /**\n * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}\n * by `operator` from `from`, this function is called.\n *\n * It must return its Solidity selector to confirm the token transfer.\n * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.\n *\n * The selector can be obtained in Solidity with `IERC721Receiver.onERC721Received.selector`.\n */\n function onERC721Received(\n address operator,\n address from,\n uint256 tokenId,\n bytes calldata data\n ) external returns (bytes4);\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"
}
},
"settings": {
"optimizer": {
"enabled": false,
"runs": 200
},
"outputSelection": {
"*": {
"*": [
"evm.bytecode",
"evm.deployedBytecode",
"devdoc",
"userdoc",
"metadata",
"abi"
]
}
},
"libraries": {}
}
}