Contract Name:
Fuzziemints
Contract Source Code:
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./Context.sol";
import "./Strings.sol";
import "./ERC165.sol";
/**
* @dev External interface of AccessControl declared to support ERC165 detection.
*/
interface IAccessControl {
function hasRole(bytes32 role, address account) external view returns (bool);
function getRoleAdmin(bytes32 role) external view returns (bytes32);
function grantRole(bytes32 role, address account) external;
function revokeRole(bytes32 role, address account) external;
function renounceRole(bytes32 role, address account) external;
}
/**
* @dev Contract module that allows children to implement role-based access
* control mechanisms. This is a lightweight version that doesn't allow enumerating role
* members except through off-chain means by accessing the contract event logs. Some
* applications may benefit from on-chain enumerability, for those cases see
* {AccessControlEnumerable}.
*
* Roles are referred to by their `bytes32` identifier. These should be exposed
* in the external API and be unique. The best way to achieve this is by
* using `public constant` hash digests:
*
* ```
* bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
* ```
*
* Roles can be used to represent a set of permissions. To restrict access to a
* function call, use {hasRole}:
*
* ```
* function foo() public {
* require(hasRole(MY_ROLE, msg.sender));
* ...
* }
* ```
*
* Roles can be granted and revoked dynamically via the {grantRole} and
* {revokeRole} functions. Each role has an associated admin role, and only
* accounts that have a role's admin role can call {grantRole} and {revokeRole}.
*
* By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
* that only accounts with this role will be able to grant or revoke other
* roles. More complex role relationships can be created by using
* {_setRoleAdmin}.
*
* WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
* grant and revoke this role. Extra precautions should be taken to secure
* accounts that have been granted it.
*/
abstract contract AccessControl is Context, IAccessControl, ERC165 {
struct RoleData {
mapping (address => bool) members;
bytes32 adminRole;
}
mapping (bytes32 => RoleData) private _roles;
bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;
/**
* @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
*
* `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
* {RoleAdminChanged} not being emitted signaling this.
*
* _Available since v3.1._
*/
event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);
/**
* @dev Emitted when `account` is granted `role`.
*
* `sender` is the account that originated the contract call, an admin role
* bearer except when using {_setupRole}.
*/
event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);
/**
* @dev Emitted when `account` is revoked `role`.
*
* `sender` is the account that originated the contract call:
* - if using `revokeRole`, it is the admin role bearer
* - if using `renounceRole`, it is the role bearer (i.e. `account`)
*/
event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);
/**
* @dev Modifier that checks that an account has a specific role. Reverts
* with a standardized message including the required role.
*
* The format of the revert reason is given by the following regular expression:
*
* /^AccessControl: account (0x[0-9a-f]{20}) is missing role (0x[0-9a-f]{32})$/
*
* _Available since v4.1._
*/
modifier onlyRole(bytes32 role) {
_checkRole(role, _msgSender());
_;
}
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
return interfaceId == type(IAccessControl).interfaceId
|| super.supportsInterface(interfaceId);
}
/**
* @dev Returns `true` if `account` has been granted `role`.
*/
function hasRole(bytes32 role, address account) public view override returns (bool) {
return _roles[role].members[account];
}
/**
* @dev Revert with a standard message if `account` is missing `role`.
*
* The format of the revert reason is given by the following regular expression:
*
* /^AccessControl: account (0x[0-9a-f]{20}) is missing role (0x[0-9a-f]{32})$/
*/
function _checkRole(bytes32 role, address account) internal view {
if(!hasRole(role, account)) {
revert(string(abi.encodePacked(
"AccessControl: account ",
Strings.toHexString(uint160(account), 20),
" is missing role ",
Strings.toHexString(uint256(role), 32)
)));
}
}
/**
* @dev Returns the admin role that controls `role`. See {grantRole} and
* {revokeRole}.
*
* To change a role's admin, use {_setRoleAdmin}.
*/
function getRoleAdmin(bytes32 role) public view override returns (bytes32) {
return _roles[role].adminRole;
}
/**
* @dev Grants `role` to `account`.
*
* If `account` had not been already granted `role`, emits a {RoleGranted}
* event.
*
* Requirements:
*
* - the caller must have ``role``'s admin role.
*/
function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
_grantRole(role, account);
}
/**
* @dev Revokes `role` from `account`.
*
* If `account` had been granted `role`, emits a {RoleRevoked} event.
*
* Requirements:
*
* - the caller must have ``role``'s admin role.
*/
function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
_revokeRole(role, account);
}
/**
* @dev Revokes `role` from the calling account.
*
* Roles are often managed via {grantRole} and {revokeRole}: this function's
* purpose is to provide a mechanism for accounts to lose their privileges
* if they are compromised (such as when a trusted device is misplaced).
*
* If the calling account had been granted `role`, emits a {RoleRevoked}
* event.
*
* Requirements:
*
* - the caller must be `account`.
*/
function renounceRole(bytes32 role, address account) public virtual override {
require(account == _msgSender(), "AccessControl: can only renounce roles for self");
_revokeRole(role, account);
}
/**
* @dev Grants `role` to `account`.
*
* If `account` had not been already granted `role`, emits a {RoleGranted}
* event. Note that unlike {grantRole}, this function doesn't perform any
* checks on the calling account.
*
* [WARNING]
* ====
* This function should only be called from the constructor when setting
* up the initial roles for the system.
*
* Using this function in any other way is effectively circumventing the admin
* system imposed by {AccessControl}.
* ====
*/
function _setupRole(bytes32 role, address account) internal virtual {
_grantRole(role, account);
}
/**
* @dev Sets `adminRole` as ``role``'s admin role.
*
* Emits a {RoleAdminChanged} event.
*/
function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
emit RoleAdminChanged(role, getRoleAdmin(role), adminRole);
_roles[role].adminRole = adminRole;
}
function _grantRole(bytes32 role, address account) private {
if (!hasRole(role, account)) {
_roles[role].members[account] = true;
emit RoleGranted(role, account, _msgSender());
}
}
function _revokeRole(bytes32 role, address account) private {
if (hasRole(role, account)) {
_roles[role].members[account] = false;
emit RoleRevoked(role, account, _msgSender());
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./AccessControl.sol";
import "./EnumerableSet.sol";
/**
* @dev External interface of AccessControlEnumerable declared to support ERC165 detection.
*/
interface IAccessControlEnumerable {
function getRoleMember(bytes32 role, uint256 index) external view returns (address);
function getRoleMemberCount(bytes32 role) external view returns (uint256);
}
/**
* @dev Extension of {AccessControl} that allows enumerating the members of each role.
*/
abstract contract AccessControlEnumerable is IAccessControlEnumerable, AccessControl {
using EnumerableSet for EnumerableSet.AddressSet;
mapping (bytes32 => EnumerableSet.AddressSet) private _roleMembers;
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
return interfaceId == type(IAccessControlEnumerable).interfaceId
|| super.supportsInterface(interfaceId);
}
/**
* @dev Returns one of the accounts that have `role`. `index` must be a
* value between 0 and {getRoleMemberCount}, non-inclusive.
*
* Role bearers are not sorted in any particular way, and their ordering may
* change at any point.
*
* WARNING: When using {getRoleMember} and {getRoleMemberCount}, make sure
* you perform all queries on the same block. See the following
* https://forum.openzeppelin.com/t/iterating-over-elements-on-enumerableset-in-openzeppelin-contracts/2296[forum post]
* for more information.
*/
function getRoleMember(bytes32 role, uint256 index) public view override returns (address) {
return _roleMembers[role].at(index);
}
/**
* @dev Returns the number of accounts that have `role`. Can be used
* together with {getRoleMember} to enumerate all bearers of a role.
*/
function getRoleMemberCount(bytes32 role) public view override returns (uint256) {
return _roleMembers[role].length();
}
/**
* @dev Overload {grantRole} to track enumerable memberships
*/
function grantRole(bytes32 role, address account) public virtual override {
super.grantRole(role, account);
_roleMembers[role].add(account);
}
/**
* @dev Overload {revokeRole} to track enumerable memberships
*/
function revokeRole(bytes32 role, address account) public virtual override {
super.revokeRole(role, account);
_roleMembers[role].remove(account);
}
/**
* @dev Overload {renounceRole} to track enumerable memberships
*/
function renounceRole(bytes32 role, address account) public virtual override {
super.renounceRole(role, account);
_roleMembers[role].remove(account);
}
/**
* @dev Overload {_setupRole} to track enumerable memberships
*/
function _setupRole(bytes32 role, address account) internal virtual override {
super._setupRole(role, account);
_roleMembers[role].add(account);
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize, which returns 0 for contracts in
// construction, since the code is only stored at the end of the
// constructor execution.
uint256 size;
// solhint-disable-next-line no-inline-assembly
assembly { size := extcodesize(account) }
return size > 0;
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient balance");
// solhint-disable-next-line avoid-low-level-calls, avoid-call-value
(bool success, ) = recipient.call{ value: amount }("");
require(success, "Address: unable to send value, recipient may have reverted");
}
/**
* @dev Performs a Solidity function call using a low level `call`. A
* plain`call` is an unsafe replacement for a function call: use this
* function instead.
*
* If `target` reverts with a revert reason, it is bubbled up by this
* function (like regular Solidity function calls).
*
* Returns the raw returned data. To convert to the expected return value,
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
*
* Requirements:
*
* - `target` must be a contract.
* - calling `target` with `data` must not revert.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return functionCall(target, data, "Address: low-level call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
* `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but also transferring `value` wei to `target`.
*
* Requirements:
*
* - the calling contract must have an ETH balance of at least `value`.
* - the called Solidity function must be `payable`.
*
* _Available since v3.1._
*/
function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
}
/**
* @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
* with `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
require(address(this).balance >= value, "Address: insufficient balance for call");
require(isContract(target), "Address: call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.call{ value: value }(data);
return _verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
return functionStaticCall(target, data, "Address: low-level static call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
require(isContract(target), "Address: static call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.staticcall(data);
return _verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
return functionDelegateCall(target, data, "Address: low-level delegate call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
require(isContract(target), "Address: delegate call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.delegatecall(data);
return _verifyCallResult(success, returndata, errorMessage);
}
function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
if (success) {
return returndata;
} else {
// Look for revert reason and bubble it up if present
if (returndata.length > 0) {
// The easiest way to bubble the revert reason is using memory via assembly
// solhint-disable-next-line no-inline-assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/*
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
return msg.data;
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @title Counters
* @author Matt Condon (@shrugs)
* @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number
* of elements in a mapping, issuing ERC721 ids, or counting request ids.
*
* Include with `using Counters for Counters.Counter;`
*/
library Counters {
struct Counter {
// This variable should never be directly accessed by users of the library: interactions must be restricted to
// the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
// this feature: see https://github.com/ethereum/solidity/issues/4637
uint256 _value; // default: 0
}
function current(Counter storage counter) internal view returns (uint256) {
return counter._value;
}
function increment(Counter storage counter) internal {
unchecked {
counter._value += 1;
}
}
function decrement(Counter storage counter) internal {
uint256 value = counter._value;
require(value > 0, "Counter: decrement overflow");
unchecked {
counter._value = value - 1;
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
*
* These functions can be used to verify that a message was signed by the holder
* of the private keys of a given address.
*/
library ECDSA {
enum RecoverError {
NoError,
InvalidSignature,
InvalidSignatureLength,
InvalidSignatureS,
InvalidSignatureV
}
function _throwError(RecoverError error) private pure {
if (error == RecoverError.NoError) {
return; // no error: do nothing
} else if (error == RecoverError.InvalidSignature) {
revert("ECDSA: invalid signature");
} else if (error == RecoverError.InvalidSignatureLength) {
revert("ECDSA: invalid signature length");
} else if (error == RecoverError.InvalidSignatureS) {
revert("ECDSA: invalid signature 's' value");
} else if (error == RecoverError.InvalidSignatureV) {
revert("ECDSA: invalid signature 'v' value");
}
}
/**
* @dev Returns the address that signed a hashed message (`hash`) with
* `signature` or error string. This address can then be used for verification purposes.
*
* The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
* this function rejects them by requiring the `s` value to be in the lower
* half order, and the `v` value to be either 27 or 28.
*
* IMPORTANT: `hash` _must_ be the result of a hash operation for the
* verification to be secure: it is possible to craft signatures that
* recover to arbitrary addresses for non-hashed data. A safe way to ensure
* this is by receiving a hash of the original message (which may otherwise
* be too long), and then calling {toEthSignedMessageHash} on it.
*
* Documentation for signature generation:
* - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
* - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
*
* _Available since v4.3._
*/
function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError) {
// Check the signature length
// - case 65: r,s,v signature (standard)
// - case 64: r,vs signature (cf https://eips.ethereum.org/EIPS/eip-2098) _Available since v4.1._
if (signature.length == 65) {
bytes32 r;
bytes32 s;
uint8 v;
// ecrecover takes the signature parameters, and the only way to get them
// currently is to use assembly.
assembly {
r := mload(add(signature, 0x20))
s := mload(add(signature, 0x40))
v := byte(0, mload(add(signature, 0x60)))
}
return tryRecover(hash, v, r, s);
} else if (signature.length == 64) {
bytes32 r;
bytes32 vs;
// ecrecover takes the signature parameters, and the only way to get them
// currently is to use assembly.
assembly {
r := mload(add(signature, 0x20))
vs := mload(add(signature, 0x40))
}
return tryRecover(hash, r, vs);
} else {
return (address(0), RecoverError.InvalidSignatureLength);
}
}
/**
* @dev Returns the address that signed a hashed message (`hash`) with
* `signature`. This address can then be used for verification purposes.
*
* The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
* this function rejects them by requiring the `s` value to be in the lower
* half order, and the `v` value to be either 27 or 28.
*
* IMPORTANT: `hash` _must_ be the result of a hash operation for the
* verification to be secure: it is possible to craft signatures that
* recover to arbitrary addresses for non-hashed data. A safe way to ensure
* this is by receiving a hash of the original message (which may otherwise
* be too long), and then calling {toEthSignedMessageHash} on it.
*/
function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
(address recovered, RecoverError error) = tryRecover(hash, signature);
_throwError(error);
return recovered;
}
/**
* @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
*
* See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
*
* _Available since v4.3._
*/
function tryRecover(
bytes32 hash,
bytes32 r,
bytes32 vs
) internal pure returns (address, RecoverError) {
bytes32 s;
uint8 v;
assembly {
s := and(vs, 0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff)
v := add(shr(255, vs), 27)
}
return tryRecover(hash, v, r, s);
}
/**
* @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
*
* _Available since v4.2._
*/
function recover(
bytes32 hash,
bytes32 r,
bytes32 vs
) internal pure returns (address) {
(address recovered, RecoverError error) = tryRecover(hash, r, vs);
_throwError(error);
return recovered;
}
/**
* @dev Overload of {ECDSA-tryRecover} that receives the `v`,
* `r` and `s` signature fields separately.
*
* _Available since v4.3._
*/
function tryRecover(
bytes32 hash,
uint8 v,
bytes32 r,
bytes32 s
) internal pure returns (address, RecoverError) {
// EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
// unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
// the valid range for s in (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): v ∈ {27, 28}. Most
// signatures from current libraries generate a unique signature with an s-value in the lower half order.
//
// If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
// with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
// vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
// these malleable signatures as well.
if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {
return (address(0), RecoverError.InvalidSignatureS);
}
if (v != 27 && v != 28) {
return (address(0), RecoverError.InvalidSignatureV);
}
// If the signature is valid (and not malleable), return the signer address
address signer = ecrecover(hash, v, r, s);
if (signer == address(0)) {
return (address(0), RecoverError.InvalidSignature);
}
return (signer, RecoverError.NoError);
}
/**
* @dev Overload of {ECDSA-recover} that receives the `v`,
* `r` and `s` signature fields separately.
*/
function recover(
bytes32 hash,
uint8 v,
bytes32 r,
bytes32 s
) internal pure returns (address) {
(address recovered, RecoverError error) = tryRecover(hash, v, r, s);
_throwError(error);
return recovered;
}
/**
* @dev Returns an Ethereum Signed Message, created from a `hash`. This
* produces hash corresponding to the one signed with the
* https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
* JSON-RPC method as part of EIP-191.
*
* See {recover}.
*/
function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) {
// 32 is the length in bytes of hash,
// enforced by the type signature above
return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n32", hash));
}
/**
* @dev Returns an Ethereum Signed Typed Data, created from a
* `domainSeparator` and a `structHash`. This produces hash corresponding
* to the one signed with the
* https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]
* JSON-RPC method as part of EIP-712.
*
* See {recover}.
*/
function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32) {
return keccak256(abi.encodePacked("\x19\x01", domainSeparator, structHash));
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @dev Library for managing
* https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
* types.
*
* Sets have the following properties:
*
* - Elements are added, removed, and checked for existence in constant time
* (O(1)).
* - Elements are enumerated in O(n). No guarantees are made on the ordering.
*
* ```
* contract Example {
* // Add the library methods
* using EnumerableSet for EnumerableSet.AddressSet;
*
* // Declare a set state variable
* EnumerableSet.AddressSet private mySet;
* }
* ```
*
* As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
* and `uint256` (`UintSet`) are supported.
*/
library EnumerableSet {
// To implement this library for multiple types with as little code
// repetition as possible, we write it in terms of a generic Set type with
// bytes32 values.
// The Set implementation uses private functions, and user-facing
// implementations (such as AddressSet) are just wrappers around the
// underlying Set.
// This means that we can only create new EnumerableSets for types that fit
// in bytes32.
struct Set {
// Storage of set values
bytes32[] _values;
// Position of the value in the `values` array, plus 1 because index 0
// means a value is not in the set.
mapping (bytes32 => uint256) _indexes;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/
function _add(Set storage set, bytes32 value) private returns (bool) {
if (!_contains(set, value)) {
set._values.push(value);
// The value is stored at length-1, but we add 1 to all indexes
// and use 0 as a sentinel value
set._indexes[value] = set._values.length;
return true;
} else {
return false;
}
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/
function _remove(Set storage set, bytes32 value) private returns (bool) {
// We read and store the value's index to prevent multiple reads from the same storage slot
uint256 valueIndex = set._indexes[value];
if (valueIndex != 0) { // Equivalent to contains(set, value)
// To delete an element from the _values array in O(1), we swap the element to delete with the last one in
// the array, and then remove the last element (sometimes called as 'swap and pop').
// This modifies the order of the array, as noted in {at}.
uint256 toDeleteIndex = valueIndex - 1;
uint256 lastIndex = set._values.length - 1;
if (lastIndex != toDeleteIndex) {
bytes32 lastvalue = set._values[lastIndex];
// Move the last value to the index where the value to delete is
set._values[toDeleteIndex] = lastvalue;
// Update the index for the moved value
set._indexes[lastvalue] = valueIndex; // Replace lastvalue's index to valueIndex
}
// Delete the slot where the moved value was stored
set._values.pop();
// Delete the index for the deleted slot
delete set._indexes[value];
return true;
} else {
return false;
}
}
/**
* @dev Returns true if the value is in the set. O(1).
*/
function _contains(Set storage set, bytes32 value) private view returns (bool) {
return set._indexes[value] != 0;
}
/**
* @dev Returns the number of values on the set. O(1).
*/
function _length(Set storage set) private view returns (uint256) {
return set._values.length;
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/
function _at(Set storage set, uint256 index) private view returns (bytes32) {
return set._values[index];
}
// Bytes32Set
struct Bytes32Set {
Set _inner;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/
function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
return _add(set._inner, value);
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/
function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
return _remove(set._inner, value);
}
/**
* @dev Returns true if the value is in the set. O(1).
*/
function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
return _contains(set._inner, value);
}
/**
* @dev Returns the number of values in the set. O(1).
*/
function length(Bytes32Set storage set) internal view returns (uint256) {
return _length(set._inner);
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/
function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
return _at(set._inner, index);
}
// AddressSet
struct AddressSet {
Set _inner;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/
function add(AddressSet storage set, address value) internal returns (bool) {
return _add(set._inner, bytes32(uint256(uint160(value))));
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/
function remove(AddressSet storage set, address value) internal returns (bool) {
return _remove(set._inner, bytes32(uint256(uint160(value))));
}
/**
* @dev Returns true if the value is in the set. O(1).
*/
function contains(AddressSet storage set, address value) internal view returns (bool) {
return _contains(set._inner, bytes32(uint256(uint160(value))));
}
/**
* @dev Returns the number of values in the set. O(1).
*/
function length(AddressSet storage set) internal view returns (uint256) {
return _length(set._inner);
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/
function at(AddressSet storage set, uint256 index) internal view returns (address) {
return address(uint160(uint256(_at(set._inner, index))));
}
// UintSet
struct UintSet {
Set _inner;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/
function add(UintSet storage set, uint256 value) internal returns (bool) {
return _add(set._inner, bytes32(value));
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/
function remove(UintSet storage set, uint256 value) internal returns (bool) {
return _remove(set._inner, bytes32(value));
}
/**
* @dev Returns true if the value is in the set. O(1).
*/
function contains(UintSet storage set, uint256 value) internal view returns (bool) {
return _contains(set._inner, bytes32(value));
}
/**
* @dev Returns the number of values on the set. O(1).
*/
function length(UintSet storage set) internal view returns (uint256) {
return _length(set._inner);
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/
function at(UintSet storage set, uint256 index) internal view returns (uint256) {
return uint256(_at(set._inner, index));
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./IERC165.sol";
/**
* @dev Implementation of the {IERC165} interface.
*
* Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
* for the additional interface id that will be supported. For example:
*
* ```solidity
* function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
* return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
* }
* ```
*
* Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
*/
abstract contract ERC165 is IERC165 {
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
return interfaceId == type(IERC165).interfaceId;
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./IERC721.sol";
import "./IERC721Receiver.sol";
import "./IERC721Metadata.sol";
import "./Address.sol";
import "./Context.sol";
import "./Strings.sol";
import "./ERC165.sol";
/**
* @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
* the Metadata extension, but not including the Enumerable extension, which is available separately as
* {ERC721Enumerable}.
*/
contract ERC721 is Context, ERC165, IERC721, IERC721Metadata {
using Address for address;
using Strings for uint256;
// Token name
string private _name;
// Token symbol
string private _symbol;
// Mapping from token ID to owner address
mapping (uint256 => address) private _owners;
// Mapping owner address to token count
mapping (address => uint256) private _balances;
// Mapping from token ID to approved address
mapping (uint256 => address) private _tokenApprovals;
// Mapping from owner to operator approvals
mapping (address => mapping (address => bool)) private _operatorApprovals;
/**
* @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
*/
constructor (string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
}
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
return interfaceId == type(IERC721).interfaceId
|| interfaceId == type(IERC721Metadata).interfaceId
|| super.supportsInterface(interfaceId);
}
/**
* @dev See {IERC721-balanceOf}.
*/
function balanceOf(address owner) public view virtual override returns (uint256) {
require(owner != address(0), "ERC721: balance query for the zero address");
return _balances[owner];
}
/**
* @dev See {IERC721-ownerOf}.
*/
function ownerOf(uint256 tokenId) public view virtual override returns (address) {
address owner = _owners[tokenId];
require(owner != address(0), "ERC721: owner query for nonexistent token");
return owner;
}
/**
* @dev See {IERC721Metadata-name}.
*/
function name() public view virtual override returns (string memory) {
return _name;
}
/**
* @dev See {IERC721Metadata-symbol}.
*/
function symbol() public view virtual override returns (string memory) {
return _symbol;
}
/**
* @dev See {IERC721Metadata-tokenURI}.
*/
function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token");
string memory baseURI = _baseURI();
return bytes(baseURI).length > 0
? string(abi.encodePacked(baseURI, tokenId.toString()))
: '';
}
/**
* @dev Base URI for computing {tokenURI}. Empty by default, can be overriden
* in child contracts.
*/
function _baseURI() internal view virtual returns (string memory) {
return "";
}
/**
* @dev See {IERC721-approve}.
*/
function approve(address to, uint256 tokenId) public virtual override {
address owner = ERC721.ownerOf(tokenId);
require(to != owner, "ERC721: approval to current owner");
require(_msgSender() == owner || isApprovedForAll(owner, _msgSender()),
"ERC721: approve caller is not owner nor approved for all"
);
_approve(to, tokenId);
}
/**
* @dev See {IERC721-getApproved}.
*/
function getApproved(uint256 tokenId) public view virtual override returns (address) {
require(_exists(tokenId), "ERC721: approved query for nonexistent token");
return _tokenApprovals[tokenId];
}
/**
* @dev See {IERC721-setApprovalForAll}.
*/
function setApprovalForAll(address operator, bool approved) public virtual override {
require(operator != _msgSender(), "ERC721: approve to caller");
_operatorApprovals[_msgSender()][operator] = approved;
emit ApprovalForAll(_msgSender(), operator, approved);
}
/**
* @dev See {IERC721-isApprovedForAll}.
*/
function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
return _operatorApprovals[owner][operator];
}
/**
* @dev See {IERC721-transferFrom}.
*/
function transferFrom(address from, address to, uint256 tokenId) public virtual override {
//solhint-disable-next-line max-line-length
require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
_transfer(from, to, tokenId);
}
/**
* @dev See {IERC721-safeTransferFrom}.
*/
function safeTransferFrom(address from, address to, uint256 tokenId) public virtual override {
safeTransferFrom(from, to, tokenId, "");
}
/**
* @dev See {IERC721-safeTransferFrom}.
*/
function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public virtual override {
require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
_safeTransfer(from, to, tokenId, _data);
}
/**
* @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
* are aware of the ERC721 protocol to prevent tokens from being forever locked.
*
* `_data` is additional data, it has no specified format and it is sent in call to `to`.
*
* This internal function is equivalent to {safeTransferFrom}, and can be used to e.g.
* implement alternative mechanisms to perform token transfer, such as signature-based.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function _safeTransfer(address from, address to, uint256 tokenId, bytes memory _data) internal virtual {
_transfer(from, to, tokenId);
require(_checkOnERC721Received(from, to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer");
}
/**
* @dev Returns whether `tokenId` exists.
*
* Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
*
* Tokens start existing when they are minted (`_mint`),
* and stop existing when they are burned (`_burn`).
*/
function _exists(uint256 tokenId) internal view virtual returns (bool) {
return _owners[tokenId] != address(0);
}
/**
* @dev Returns whether `spender` is allowed to manage `tokenId`.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) {
require(_exists(tokenId), "ERC721: operator query for nonexistent token");
address owner = ERC721.ownerOf(tokenId);
return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));
}
/**
* @dev Safely mints `tokenId` and transfers it to `to`.
*
* Requirements:
*
* - `tokenId` must not exist.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function _safeMint(address to, uint256 tokenId) internal virtual {
_safeMint(to, tokenId, "");
}
/**
* @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is
* forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
*/
function _safeMint(address to, uint256 tokenId, bytes memory _data) internal virtual {
_mint(to, tokenId);
require(_checkOnERC721Received(address(0), to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer");
}
/**
* @dev Mints `tokenId` and transfers it to `to`.
*
* WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible
*
* Requirements:
*
* - `tokenId` must not exist.
* - `to` cannot be the zero address.
*
* Emits a {Transfer} event.
*/
function _mint(address to, uint256 tokenId) internal virtual {
require(to != address(0), "ERC721: mint to the zero address");
require(!_exists(tokenId), "ERC721: token already minted");
_beforeTokenTransfer(address(0), to, tokenId);
_balances[to] += 1;
_owners[tokenId] = to;
emit Transfer(address(0), to, tokenId);
}
/**
* @dev Destroys `tokenId`.
* The approval is cleared when the token is burned.
*
* Requirements:
*
* - `tokenId` must exist.
*
* Emits a {Transfer} event.
*/
function _burn(uint256 tokenId) internal virtual {
address owner = ERC721.ownerOf(tokenId);
_beforeTokenTransfer(owner, address(0), tokenId);
// Clear approvals
_approve(address(0), tokenId);
_balances[owner] -= 1;
delete _owners[tokenId];
emit Transfer(owner, address(0), tokenId);
}
/**
* @dev Transfers `tokenId` from `from` to `to`.
* As opposed to {transferFrom}, this imposes no restrictions on msg.sender.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
*
* Emits a {Transfer} event.
*/
function _transfer(address from, address to, uint256 tokenId) internal virtual {
require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer of token that is not own");
require(to != address(0), "ERC721: transfer to the zero address");
_beforeTokenTransfer(from, to, tokenId);
// Clear approvals from the previous owner
_approve(address(0), tokenId);
_balances[from] -= 1;
_balances[to] += 1;
_owners[tokenId] = to;
emit Transfer(from, to, tokenId);
}
/**
* @dev Approve `to` to operate on `tokenId`
*
* Emits a {Approval} event.
*/
function _approve(address to, uint256 tokenId) internal virtual {
_tokenApprovals[tokenId] = to;
emit Approval(ERC721.ownerOf(tokenId), to, tokenId);
}
/**
* @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
* The call is not executed if the target address is not a contract.
*
* @param from address representing the previous owner of the given token ID
* @param to target address that will receive the tokens
* @param tokenId uint256 ID of the token to be transferred
* @param _data bytes optional data to send along with the call
* @return bool whether the call correctly returned the expected magic value
*/
function _checkOnERC721Received(address from, address to, uint256 tokenId, bytes memory _data)
private returns (bool)
{
if (to.isContract()) {
try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {
return retval == IERC721Receiver(to).onERC721Received.selector;
} catch (bytes memory reason) {
if (reason.length == 0) {
revert("ERC721: transfer to non ERC721Receiver implementer");
} else {
// solhint-disable-next-line no-inline-assembly
assembly {
revert(add(32, reason), mload(reason))
}
}
}
} else {
return true;
}
}
/**
* @dev Hook that is called before any token transfer. This includes minting
* and burning.
*
* Calling conditions:
*
* - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
* transferred to `to`.
* - When `from` is zero, `tokenId` will be minted for `to`.
* - When `to` is zero, ``from``'s `tokenId` will be burned.
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(address from, address to, uint256 tokenId) internal virtual { }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./ERC721.sol";
import "./Context.sol";
/**
* @title ERC721 Burnable Token
* @dev ERC721 Token that can be irreversibly burned (destroyed).
*/
abstract contract ERC721Burnable is Context, ERC721 {
/**
* @dev Burns `tokenId`. See {ERC721-_burn}.
*
* Requirements:
*
* - The caller must own `tokenId` or be an approved operator.
*/
function burn(uint256 tokenId) public virtual {
//solhint-disable-next-line max-line-length
require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721Burnable: caller is not owner nor approved");
_burn(tokenId);
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./ERC721.sol";
import "./IERC721Enumerable.sol";
/**
* @dev This implements an optional extension of {ERC721} defined in the EIP that adds
* enumerability of all the token ids in the contract as well as all token ids owned by each
* account.
*/
abstract contract ERC721Enumerable is ERC721, IERC721Enumerable {
// Mapping from owner to list of owned token IDs
mapping(address => mapping(uint256 => uint256)) private _ownedTokens;
// Mapping from token ID to index of the owner tokens list
mapping(uint256 => uint256) private _ownedTokensIndex;
// Array with all token ids, used for enumeration
uint256[] private _allTokens;
// Mapping from token id to position in the allTokens array
mapping(uint256 => uint256) private _allTokensIndex;
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165, ERC721) returns (bool) {
return interfaceId == type(IERC721Enumerable).interfaceId
|| super.supportsInterface(interfaceId);
}
/**
* @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
*/
function tokenOfOwnerByIndex(address owner, uint256 index) public view virtual override returns (uint256) {
require(index < ERC721.balanceOf(owner), "ERC721Enumerable: owner index out of bounds");
return _ownedTokens[owner][index];
}
/**
* @dev See {IERC721Enumerable-totalSupply}.
*/
function totalSupply() public view virtual override returns (uint256) {
return _allTokens.length;
}
/**
* @dev See {IERC721Enumerable-tokenByIndex}.
*/
function tokenByIndex(uint256 index) public view virtual override returns (uint256) {
require(index < ERC721Enumerable.totalSupply(), "ERC721Enumerable: global index out of bounds");
return _allTokens[index];
}
/**
* @dev Hook that is called before any token transfer. This includes minting
* and burning.
*
* Calling conditions:
*
* - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
* transferred to `to`.
* - When `from` is zero, `tokenId` will be minted for `to`.
* - When `to` is zero, ``from``'s `tokenId` will be burned.
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(address from, address to, uint256 tokenId) internal virtual override {
super._beforeTokenTransfer(from, to, tokenId);
if (from == address(0)) {
_addTokenToAllTokensEnumeration(tokenId);
} else if (from != to) {
_removeTokenFromOwnerEnumeration(from, tokenId);
}
if (to == address(0)) {
_removeTokenFromAllTokensEnumeration(tokenId);
} else if (to != from) {
_addTokenToOwnerEnumeration(to, tokenId);
}
}
/**
* @dev Private function to add a token to this extension's ownership-tracking data structures.
* @param to address representing the new owner of the given token ID
* @param tokenId uint256 ID of the token to be added to the tokens list of the given address
*/
function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {
uint256 length = ERC721.balanceOf(to);
_ownedTokens[to][length] = tokenId;
_ownedTokensIndex[tokenId] = length;
}
/**
* @dev Private function to add a token to this extension's token tracking data structures.
* @param tokenId uint256 ID of the token to be added to the tokens list
*/
function _addTokenToAllTokensEnumeration(uint256 tokenId) private {
_allTokensIndex[tokenId] = _allTokens.length;
_allTokens.push(tokenId);
}
/**
* @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that
* while the token is not assigned a new owner, the `_ownedTokensIndex` mapping is _not_ updated: this allows for
* gas optimizations e.g. when performing a transfer operation (avoiding double writes).
* This has O(1) time complexity, but alters the order of the _ownedTokens array.
* @param from address representing the previous owner of the given token ID
* @param tokenId uint256 ID of the token to be removed from the tokens list of the given address
*/
function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {
// To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and
// then delete the last slot (swap and pop).
uint256 lastTokenIndex = ERC721.balanceOf(from) - 1;
uint256 tokenIndex = _ownedTokensIndex[tokenId];
// When the token to delete is the last token, the swap operation is unnecessary
if (tokenIndex != lastTokenIndex) {
uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];
_ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
_ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
}
// This also deletes the contents at the last position of the array
delete _ownedTokensIndex[tokenId];
delete _ownedTokens[from][lastTokenIndex];
}
/**
* @dev Private function to remove a token from this extension's token tracking data structures.
* This has O(1) time complexity, but alters the order of the _allTokens array.
* @param tokenId uint256 ID of the token to be removed from the tokens list
*/
function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {
// To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and
// then delete the last slot (swap and pop).
uint256 lastTokenIndex = _allTokens.length - 1;
uint256 tokenIndex = _allTokensIndex[tokenId];
// When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so
// rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding
// an 'if' statement (like in _removeTokenFromOwnerEnumeration)
uint256 lastTokenId = _allTokens[lastTokenIndex];
_allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
_allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
// This also deletes the contents at the last position of the array
delete _allTokensIndex[tokenId];
_allTokens.pop();
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./ERC721.sol";
import "./Pausable.sol";
/**
* @dev ERC721 token with pausable token transfers, minting and burning.
*
* Useful for scenarios such as preventing trades until the end of an evaluation
* period, or having an emergency switch for freezing all token transfers in the
* event of a large bug.
*/
abstract contract ERC721Pausable is ERC721, Pausable {
/**
* @dev See {ERC721-_beforeTokenTransfer}.
*
* Requirements:
*
* - the contract must not be paused.
*/
function _beforeTokenTransfer(address from, address to, uint256 tokenId) internal virtual override {
super._beforeTokenTransfer(from, to, tokenId);
require(!paused(), "ERC721Pausable: token transfer while paused");
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./ERC721.sol";
import "./ERC721Enumerable.sol";
import "./ERC721Burnable.sol";
import "./ERC721Pausable.sol";
import "./AccessControlEnumerable.sol";
import "./Context.sol";
import "./Counters.sol";
/**
* @dev {ERC721} token, including:
*
* - ability for holders to burn (destroy) their tokens
* - a minter role that allows for token minting (creation)
* - a pauser role that allows to stop all token transfers
* - token ID and URI autogeneration
*
* This contract uses {AccessControl} to lock permissioned functions using the
* different roles - head to its documentation for details.
*
* The account that deploys the contract will be granted the minter and pauser
* roles, as well as the default admin role, which will let it grant both minter
* and pauser roles to other accounts.
*/
contract ERC721PresetMinterPauserAutoId is Context, AccessControlEnumerable, ERC721Enumerable, ERC721Burnable, ERC721Pausable {
using Counters for Counters.Counter;
bytes32 public constant MINTER_ROLE = keccak256("MINTER_ROLE");
bytes32 public constant PAUSER_ROLE = keccak256("PAUSER_ROLE");
Counters.Counter private _tokenIdTracker;
mapping(string => uint8) hashes;
string private _baseTokenURI;
mapping (uint256 => string) private _tokenURIs;
/**
* @dev Grants `DEFAULT_ADMIN_ROLE`, `MINTER_ROLE` and `PAUSER_ROLE` to the
* account that deploys the contract.
*
* Token URIs will be autogenerated based on `baseURI` and their token IDs.
* See {ERC721-tokenURI}.
*/
constructor(string memory name, string memory symbol, string memory baseTokenURI) ERC721(name, symbol) {
_baseTokenURI = baseTokenURI;
_setupRole(DEFAULT_ADMIN_ROLE, _msgSender());
_setupRole(MINTER_ROLE, _msgSender());
_setupRole(PAUSER_ROLE, _msgSender());
}
function _baseURI() internal view virtual override returns (string memory) {
return _baseTokenURI;
}
function _setTokenURI(uint256 tokenId, string memory _tokenURI) internal virtual {
require(_exists(tokenId), "ERC721Metadata: URI set of nonexistent token");
_tokenURIs[tokenId] = _tokenURI;
}
function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token");
string memory _tokenURI = _tokenURIs[tokenId];
string memory base = _baseURI();
// If there is no base URI, return the token URI.
if (bytes(base).length == 0) {
return _tokenURI;
}
// If both are set, concatenate the baseURI and tokenURI (via abi.encodePacked).
if (bytes(_tokenURI).length > 0) {
return string(abi.encodePacked(base, _tokenURI));
}
// If there is a baseURI but no tokenURI, concatenate the tokenID to the baseURI.
return base;
}
/**
* @dev Creates a new token for `to`. Its token ID will be automatically
* assigned (and available on the emitted {IERC721-Transfer} event), and the token
* URI autogenerated based on the base URI passed at construction.
*
* See {ERC721-_mint}.
*
* Requirements:
*
* - the caller must have the `MINTER_ROLE`.
*/
function mint(address to, string memory hash, string memory metadata) public virtual {
require(hasRole(MINTER_ROLE, _msgSender()), "ERC721PresetMinterPauserAutoId: must have minter role to mint");
require(hashes[hash] != 1, "Hash value has already been used");
hashes[hash] = 1;
// We cannot just use balanceOf to create the new tokenId because tokens
// can be burned (destroyed), so we need a separate counter.
_tokenIdTracker.increment();
uint256 newItemId = _tokenIdTracker.current();
_mint(to, newItemId);
_setTokenURI(newItemId, metadata);
// return newItemId
}
/**
* @dev Pauses all token transfers.
*
* See {ERC721Pausable} and {Pausable-_pause}.
*
* Requirements:
*
* - the caller must have the `PAUSER_ROLE`.
*/
function pause() public virtual {
require(hasRole(PAUSER_ROLE, _msgSender()), "ERC721PresetMinterPauserAutoId: must have pauser role to pause");
_pause();
}
/**
* @dev Unpauses all token transfers.
*
* See {ERC721Pausable} and {Pausable-_unpause}.
*
* Requirements:
*
* - the caller must have the `PAUSER_ROLE`.
*/
function unpause() public virtual {
require(hasRole(PAUSER_ROLE, _msgSender()), "ERC721PresetMinterPauserAutoId: must have pauser role to unpause");
_unpause();
}
function _beforeTokenTransfer(address from, address to, uint256 tokenId) internal virtual override(ERC721, ERC721Enumerable, ERC721Pausable) {
super._beforeTokenTransfer(from, to, tokenId);
}
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override(AccessControlEnumerable, ERC721, ERC721Enumerable) returns (bool) {
return super.supportsInterface(interfaceId);
}
}
pragma solidity ^0.8.4;
import "./SniftieERC721Common.sol";
import "./Counters.sol";
import "./ECDSA.sol";
contract Fuzziemints is SniftieERC721Common {
using ECDSA for bytes32;
using Counters for Counters.Counter;
Counters.Counter private _fuzzieTokenIdTracker;
// backend signer address used for checking if data was created by Sniftie's server
address private _backend;
// payable wallet addresses
address payable private _charity1;
address payable private _charity2;
address payable private _charity3;
address payable private _sniftie;
address payable private _f100royalty;
address payable private _fuzziemints;
uint256 public constant FUZZIE_PREMINT_MAX = 205;
uint256 public constant FUZZIEMAX = 5555;
uint8 public constant PURCHASE_LIMIT = 17;
uint256 private constant PAYMENT_GAS_LIMIT = 5000;
uint256 private constant PRICE_PER_TOKEN = 55000000 gwei;
uint256 private _eachCharityPercentage = 100;
uint256 private _f100RoyaltyPercentage = 1090;
uint256 private _sniftieRoyaltyPercentage = 2200;
uint256 private _fuzziemintsPercentage = 6410;
mapping(address => uint8) whitelistMintCount;
mapping(address => bool) whitelistAddresses;
bool private _isPublicSaleLocked = true;
constructor (string memory name, string memory symbol, string memory baseTokenURI, string memory contractMetadataURI, address sniftieAdmin, address backend, address payable[] memory payableAddresses) SniftieERC721Common(name, symbol, baseTokenURI, contractMetadataURI, sniftieAdmin) {
_backend = backend;
// payable addresses array must be in this order
_charity1 = payableAddresses[0];
_charity2 = payableAddresses[1];
_charity3 = payableAddresses[2];
_f100royalty = payableAddresses[3];
_sniftie = payableAddresses[4];
_fuzziemints = payableAddresses[5];
}
function getIsPublicSaleLocked() public view returns (bool) { return _isPublicSaleLocked; }
function getBackend() public view returns (address) { return _backend; }
function getSniftie() public view returns (address) { return _sniftie; }
function getFuzziemints() public view returns (address) { return _fuzziemints; }
function getF100royalty() public view returns (address) { return _f100royalty; }
function getCharity1() public view returns (address) { return _charity1; }
function getCharity2() public view returns (address) { return _charity2; }
function getCharity3() public view returns (address) { return _charity3; }
function setIsPublicSalesLocked(bool locked) public {
require(hasRole(DEFAULT_ADMIN_ROLE, _msgSender()), "Must have DEFAULT_ADMIN_ROLE");
_isPublicSaleLocked = locked;
}
function setBackend(address backend) public {
require(hasRole(DEFAULT_ADMIN_ROLE, _msgSender()), "Must have DEFAULT_ADMIN_ROLE");
_backend = backend;
}
function setSniftie(address payable sniftie) public {
require(hasRole(DEFAULT_ADMIN_ROLE, _msgSender()), "Must have DEFAULT_ADMIN_ROLE");
_sniftie = sniftie;
}
function setFuzziemints(address payable fuzziemints) public {
require(hasRole(DEFAULT_ADMIN_ROLE, _msgSender()), "Must have DEFAULT_ADMIN_ROLE");
_fuzziemints = fuzziemints;
}
function setF100royalty(address payable f100royalty) public {
require(hasRole(DEFAULT_ADMIN_ROLE, _msgSender()), "Must have DEFAULT_ADMIN_ROLE");
_f100royalty = f100royalty;
}
function setCharity1(address payable charity1) public {
require(hasRole(DEFAULT_ADMIN_ROLE, _msgSender()), "Must have DEFAULT_ADMIN_ROLE");
_charity1 = charity1;
}
function setCharity2(address payable charity2) public {
require(hasRole(DEFAULT_ADMIN_ROLE, _msgSender()), "Must have DEFAULT_ADMIN_ROLE");
_charity2 = charity2;
}
function setCharity3(address payable charity3) public {
require(hasRole(DEFAULT_ADMIN_ROLE, _msgSender()), "Must have DEFAULT_ADMIN_ROLE");
_charity3 = charity3;
}
function premint() public {
require(hasRole(DEFAULT_ADMIN_ROLE, _msgSender()), "Must have DEFAULT_ADMIN_ROLE to mint first 100 tokens");
uint totalSupply = totalSupply();
uint available = FUZZIE_PREMINT_MAX - totalSupply;
uint mintQty = available >= 25 ? 25 : available;
require(mintQty > 0, "Premint limit reached");
for (uint i = 0; i < mintQty; i++) {
mintToken(_msgSender());
}
}
function addToWhitelist(address[] memory add) public {
require(hasRole(DEFAULT_ADMIN_ROLE, _msgSender()), "Must have DEFAULT_ADMIN_ROLE to add to whitelist");
for (uint i = 0; i < add.length; i++) {
whitelistAddresses[add[i]] = true;
}
}
function removeFromWhitelist(address[] memory remove) public {
require(hasRole(DEFAULT_ADMIN_ROLE, _msgSender()), "Must have DEFAULT_ADMIN_ROLE remove from whitelist");
for (uint i = 0; i < remove.length; i++) {
whitelistAddresses[remove[i]] = false;
}
}
function mintToken(address to) internal returns (uint256) {
// We cannot just use balanceOf to create the new tokenId because tokens
// can be burned (destroyed), so we need a separate counter.
_fuzzieTokenIdTracker.increment();
uint256 newItemId = _fuzzieTokenIdTracker.current();
_mint(to, newItemId);
return newItemId;
}
function salePayment(uint256 charityAmount, uint256 f100RoyaltyAmount, uint256 sniftieAmount, uint256 fuzziemintsAmount) internal {
// transfer amounts to respective wallets
(bool charity1Success, ) = _charity1.call{ value:charityAmount, gas: PAYMENT_GAS_LIMIT }("");
require(charity1Success, "Charity 1 payment failed");
(bool charity2Success, ) = _charity2.call{ value:charityAmount, gas: PAYMENT_GAS_LIMIT }("");
require(charity2Success, "Charity 2 payment failed");
(bool charity3Success, ) = _charity3.call{ value:charityAmount, gas: PAYMENT_GAS_LIMIT }("");
require(charity3Success, "Charity 3 payment failed");
(bool f100Success, ) = _f100royalty.call{ value:f100RoyaltyAmount, gas: PAYMENT_GAS_LIMIT }("");
require(f100Success, "First 100 royalty payment failed");
(bool sniftieSuccess, ) = _sniftie.call{ value:sniftieAmount, gas: PAYMENT_GAS_LIMIT }("");
require(sniftieSuccess, "Sniftie payment failed");
(bool fuzziemintsSuccess, ) = _fuzziemints.call{ value:fuzziemintsAmount, gas: PAYMENT_GAS_LIMIT }("");
require(fuzziemintsSuccess, "Fuzziemints payment failed");
}
function purchaseAndMint(bytes32 message, bytes32 messageHash, bytes memory signature, uint8 qty) public payable {
// calculate signer address and check if it is equal to _backendSigner
require(messageHash.recover(signature) == _backend, "Content not signed by Sniftie");
// regenerate hash from parameters and check if it is equal to hash generated from sniftie's backend server
require(keccak256(abi.encodePacked(qty)) == message, "Message hash does not match");
// check if public sale is locked
require(!_isPublicSaleLocked, "Public sales is still closed");
// check if total supply does not exceed FUZZIEMAX
require(totalSupply() + qty <= FUZZIEMAX, "Qty exceeds max number of tokens");
// check for maximum token quantity to mint
require(qty <= PURCHASE_LIMIT, "Cannot purchase more than 17 tokens");
// check if amount sent is at least equal to the price of token
require(msg.value >= PRICE_PER_TOKEN * qty, "Amount less than required price");
// calculate amounts to transfer
uint256 charityAmount = (msg.value / 10000) * _eachCharityPercentage;
uint256 f100RoyaltyAmount = (msg.value / 10000) * _f100RoyaltyPercentage;
uint256 sniftieAmount = (msg.value / 10000) * _sniftieRoyaltyPercentage;
uint256 fuzziemintsAmount = msg.value - ((charityAmount * 3) + f100RoyaltyAmount + sniftieAmount);
// call payment function to make the payments
salePayment(charityAmount, f100RoyaltyAmount, sniftieAmount, fuzziemintsAmount);
// call mint function
for (uint i = 0; i < qty; i++) {
mintToken(msg.sender);
}
}
function whitelistedPurchaseAndMint(bytes32 message, bytes32 messageHash, bytes memory signature, uint8 qty) public payable {
// calculate signer address and check if it is equal to _backendSigner
require(messageHash.recover(signature) == _backend, "Content not signed by Sniftie");
// regenerate hash from parameters and check if it is equal to hash generated from sniftie's backend server
require(keccak256(abi.encodePacked(qty)) == message, "Message hash does not match");
// check if public sale is locked and sender is whitelisted
require(_isPublicSaleLocked && whitelistAddresses[msg.sender], "Public sales is still closed and you are not whitelisted");
// limit token purchase to 5 if public sale is locked (whitelist period)
require(whitelistMintCount[msg.sender] + qty <= 5, "Whitelist minting restricted to 5 tokens");
// check if total supply does not exceed FUZZIEMAX
require(totalSupply() + qty <= FUZZIEMAX, "Qty exceeds max number of tokens");
// check for maximum token quantity to mint
require(qty <= PURCHASE_LIMIT, "Cannot purchase more than 17 tokens");
// check if amount sent is at least equal to the price of token
require(msg.value >= PRICE_PER_TOKEN * qty, "Amount less than required price");
// calculate amounts to transfer
uint256 charityAmount = (msg.value / 10000) * _eachCharityPercentage;
uint256 f100RoyaltyAmount = (msg.value / 10000) * _f100RoyaltyPercentage;
uint256 sniftieAmount = (msg.value / 10000) * _sniftieRoyaltyPercentage;
uint256 fuzziemintsAmount = msg.value - ((charityAmount * 3) + f100RoyaltyAmount + sniftieAmount);
// call payment function to make the payments
salePayment(charityAmount, f100RoyaltyAmount, sniftieAmount, fuzziemintsAmount);
// implement minting here
for (uint i = 0; i < qty; i++) {
mintToken(msg.sender);
}
// update whitelist mint count tracker
whitelistMintCount[msg.sender] = whitelistMintCount[msg.sender] + qty;
}
function setTokenMediaHashAndURI(uint tokenId, string memory mediaHashOrId, string memory tokenURI) public {
require(hasRole(DEFAULT_ADMIN_ROLE, _msgSender()), "Cannot set media hash and token URI if not admin");
setTokenURI(tokenId, tokenURI);
setTokenMediaHash(tokenId, mediaHashOrId);
}
function batchSetTokenMediaHashAndURI(uint256 startAtTokenIndex, string[] memory mediaHashes, string[] memory tokenURIs) public {
require(mediaHashes.length == tokenURIs.length, "MediaHash Array and TokenURI Array lengths must match");
require(hasRole(DEFAULT_ADMIN_ROLE, _msgSender()), "Cannot batch set media hash and token URI if not admin");
for (uint i = startAtTokenIndex; i < startAtTokenIndex + mediaHashes.length; i++) {
uint256 tokenId = tokenByIndex(i);
uint256 zeroIndex = i - startAtTokenIndex;
setTokenMediaHashAndURI(tokenId, mediaHashes[zeroIndex], tokenURIs[zeroIndex]);
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC165 standard, as defined in the
* https://eips.ethereum.org/EIPS/eip-165[EIP].
*
* Implementers can declare support of contract interfaces, which can then be
* queried by others ({ERC165Checker}).
*
* For an implementation, see {ERC165}.
*/
interface IERC165 {
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
* to learn more about how these ids are created.
*
* This function call must use less than 30 000 gas.
*/
function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./IERC165.sol";
/**
* @dev Required interface of an ERC721 compliant contract.
*/
interface IERC721 is IERC165 {
/**
* @dev Emitted when `tokenId` token is transferred from `from` to `to`.
*/
event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
*/
event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
*/
event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
/**
* @dev Returns the number of tokens in ``owner``'s account.
*/
function balanceOf(address owner) external view returns (uint256 balance);
/**
* @dev Returns the owner of the `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function ownerOf(uint256 tokenId) external view returns (address owner);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
* are aware of the ERC721 protocol to prevent tokens from being forever locked.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(address from, address to, uint256 tokenId) external;
/**
* @dev Transfers `tokenId` token from `from` to `to`.
*
* WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
*
* Emits a {Transfer} event.
*/
function transferFrom(address from, address to, uint256 tokenId) external;
/**
* @dev Gives permission to `to` to transfer `tokenId` token to another account.
* The approval is cleared when the token is transferred.
*
* Only a single account can be approved at a time, so approving the zero address clears previous approvals.
*
* Requirements:
*
* - The caller must own the token or be an approved operator.
* - `tokenId` must exist.
*
* Emits an {Approval} event.
*/
function approve(address to, uint256 tokenId) external;
/**
* @dev Returns the account approved for `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function getApproved(uint256 tokenId) external view returns (address operator);
/**
* @dev Approve or remove `operator` as an operator for the caller.
* Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
*
* Requirements:
*
* - The `operator` cannot be the caller.
*
* Emits an {ApprovalForAll} event.
*/
function setApprovalForAll(address operator, bool _approved) external;
/**
* @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
*
* See {setApprovalForAll}
*/
function isApprovedForAll(address owner, address operator) external view returns (bool);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(address from, address to, uint256 tokenId, bytes calldata data) external;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./IERC721.sol";
/**
* @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
* @dev See https://eips.ethereum.org/EIPS/eip-721
*/
interface IERC721Enumerable is IERC721 {
/**
* @dev Returns the total amount of tokens stored by the contract.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns a token ID owned by `owner` at a given `index` of its token list.
* Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
*/
function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256 tokenId);
/**
* @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
* Use along with {totalSupply} to enumerate all tokens.
*/
function tokenByIndex(uint256 index) external view returns (uint256);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./IERC721.sol";
/**
* @title ERC-721 Non-Fungible Token Standard, optional metadata extension
* @dev See https://eips.ethereum.org/EIPS/eip-721
*/
interface IERC721Metadata is IERC721 {
/**
* @dev Returns the token collection name.
*/
function name() external view returns (string memory);
/**
* @dev Returns the token collection symbol.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
*/
function tokenURI(uint256 tokenId) external view returns (string memory);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @title ERC721 token receiver interface
* @dev Interface for any contract that wants to support safeTransfers
* from ERC721 asset contracts.
*/
interface IERC721Receiver {
/**
* @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
* by `operator` from `from`, this function is called.
*
* It must return its Solidity selector to confirm the token transfer.
* If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
*
* The selector can be obtained in Solidity with `IERC721.onERC721Received.selector`.
*/
function onERC721Received(address operator, address from, uint256 tokenId, bytes calldata data) external returns (bytes4);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
abstract contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor() {
_setOwner(_msgSender());
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
_;
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions anymore. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
_setOwner(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
_setOwner(newOwner);
}
function _setOwner(address newOwner) private {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./Context.sol";
/**
* @dev Contract module which allows children to implement an emergency stop
* mechanism that can be triggered by an authorized account.
*
* This module is used through inheritance. It will make available the
* modifiers `whenNotPaused` and `whenPaused`, which can be applied to
* the functions of your contract. Note that they will not be pausable by
* simply including this module, only once the modifiers are put in place.
*/
abstract contract Pausable is Context {
/**
* @dev Emitted when the pause is triggered by `account`.
*/
event Paused(address account);
/**
* @dev Emitted when the pause is lifted by `account`.
*/
event Unpaused(address account);
bool private _paused;
/**
* @dev Initializes the contract in unpaused state.
*/
constructor () {
_paused = false;
}
/**
* @dev Returns true if the contract is paused, and false otherwise.
*/
function paused() public view virtual returns (bool) {
return _paused;
}
/**
* @dev Modifier to make a function callable only when the contract is not paused.
*
* Requirements:
*
* - The contract must not be paused.
*/
modifier whenNotPaused() {
require(!paused(), "Pausable: paused");
_;
}
/**
* @dev Modifier to make a function callable only when the contract is paused.
*
* Requirements:
*
* - The contract must be paused.
*/
modifier whenPaused() {
require(paused(), "Pausable: not paused");
_;
}
/**
* @dev Triggers stopped state.
*
* Requirements:
*
* - The contract must not be paused.
*/
function _pause() internal virtual whenNotPaused {
_paused = true;
emit Paused(_msgSender());
}
/**
* @dev Returns to normal state.
*
* Requirements:
*
* - The contract must be paused.
*/
function _unpause() internal virtual whenPaused {
_paused = false;
emit Unpaused(_msgSender());
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;
import "./ERC721.sol";
import "./ERC721Enumerable.sol";
import "./ERC721Burnable.sol";
import "./ERC721Pausable.sol";
import "./AccessControlEnumerable.sol";
import "./Context.sol";
import "./Counters.sol";
import "./SniftieUtils.sol";
import "./Ownable.sol";
contract SniftieERC721Common is Context, AccessControlEnumerable, ERC721Enumerable, ERC721Burnable, ERC721Pausable, Ownable {
using Counters for Counters.Counter;
bytes32 public constant MINTER_ROLE = keccak256("MINTER_ROLE");
bytes32 public constant PAUSER_ROLE = keccak256("PAUSER_ROLE");
Counters.Counter private _tokenIdTracker;
mapping(string => uint8) hashes;
string private _baseTokenURI;
string private _contractMetadataURI;
mapping (uint256 => string) private _tokenURIs;
/**
* @dev Grants `DEFAULT_ADMIN_ROLE`, `MINTER_ROLE` and `PAUSER_ROLE` to the
* account that deploys the contract.
*
* Token URIs will be autogenerated based on `baseURI` and their token IDs.
* See {ERC721-tokenURI}.
*/
constructor(string memory name, string memory symbol, string memory baseTokenURI, string memory contractMetadataURI, address sniftieAdmin) ERC721(name, symbol) {
_baseTokenURI = baseTokenURI;
_contractMetadataURI = contractMetadataURI;
_setupRole(DEFAULT_ADMIN_ROLE, _msgSender());
_setupRole(DEFAULT_ADMIN_ROLE, sniftieAdmin);
_setupRole(MINTER_ROLE, _msgSender());
_setupRole(MINTER_ROLE, sniftieAdmin);
_setupRole(PAUSER_ROLE, _msgSender());
_setupRole(PAUSER_ROLE, sniftieAdmin);
}
function contractURI() public view returns (string memory) {
return _contractMetadataURI;
}
function setContractMetadataURI(string memory contractMetadataURI) public {
require(hasRole(DEFAULT_ADMIN_ROLE, _msgSender()), "Must have DEFAULT_ADMIN_ROLE to set contract metadata uri");
_contractMetadataURI = contractMetadataURI;
}
function _baseURI() internal view virtual override returns (string memory) {
return _baseTokenURI;
}
function setBaseURI(string memory baseURI) public {
require(hasRole(DEFAULT_ADMIN_ROLE, _msgSender()), "Must have DEFAULT_ADMIN_ROLE to set base uri");
_baseTokenURI = baseURI;
}
function _setTokenURI(uint256 tokenId, string memory _tokenURI) internal virtual {
require(_exists(tokenId), "ERC721Metadata: URI set of nonexistent token");
_tokenURIs[tokenId] = _tokenURI;
}
function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
require(_exists(tokenId), "URI query for nonexistent token");
string memory _tokenURI = _tokenURIs[tokenId];
string memory base = _baseURI();
// If there is no base URI, return the token URI.
if (bytes(base).length == 0) {
return _tokenURI;
}
if (bytes(_tokenURI).length > 0) {
if (SniftieUtils.stringContains("://", _tokenURI)) return _tokenURI; // _tokenURI is absolute (e.g. http://domain.com/metadata/1)
return string(abi.encodePacked(base, _tokenURI)); // _tokenURI is an identifier so concatenate with base uri
}
// If there is a baseURI but no tokenURI, concatenate the tokenID to the baseURI.
return string(abi.encodePacked(base, Strings.toString(tokenId)));
}
function setTokenURI(uint256 tokenId, string memory tokenUri) public {
require(_exists(tokenId), "Cannot set metadata hash for nonexistent token");
require(hasRole(DEFAULT_ADMIN_ROLE, _msgSender()), "Cannot set metadata hash if not admin");
_setTokenURI(tokenId, tokenUri);
}
// this function is needed in children contracts that do not use the standard mint function and
// also do not set the media hash upon minting (a token's media hash must be unique)
function setTokenMediaHash(uint tokenId, string memory mediaHashOrId) public {
require(_exists(tokenId), "Cannot set media hash for nonexistent token");
require(hasRole(DEFAULT_ADMIN_ROLE, _msgSender()), "Cannot set media hash if not admin");
require(hashes[mediaHashOrId] != 1, "Hash value has already been used");
hashes[mediaHashOrId] = 1;
}
/**
* @dev Pauses all token transfers.
*
* See {ERC721Pausable} and {Pausable-_pause}.
*
* Requirements:
*
* - the caller must have the `PAUSER_ROLE`.
*/
function pause() public virtual {
require(hasRole(PAUSER_ROLE, _msgSender()), "ERC721PresetMinterPauserAutoId: must have pauser role to pause");
_pause();
}
/**
* @dev Unpauses all token transfers.
*
* See {ERC721Pausable} and {Pausable-_unpause}.
*
* Requirements:
*
* - the caller must have the `PAUSER_ROLE`.
*/
function unpause() public virtual {
require(hasRole(PAUSER_ROLE, _msgSender()), "ERC721PresetMinterPauserAutoId: must have pauser role to unpause");
_unpause();
}
function _beforeTokenTransfer(address from, address to, uint256 tokenId) internal virtual override(ERC721, ERC721Enumerable, ERC721Pausable) {
super._beforeTokenTransfer(from, to, tokenId);
}
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override(AccessControlEnumerable, ERC721, ERC721Enumerable) returns (bool) {
return super.supportsInterface(interfaceId);
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./ERC721.sol";
import "./ERC721Enumerable.sol";
import "./ERC721Burnable.sol";
import "./ERC721Pausable.sol";
import "./AccessControlEnumerable.sol";
import "./Context.sol";
import "./Counters.sol";
import "./Ownable.sol";
/**
* @dev {ERC721} token, including:
*
* - ability for holders to burn (destroy) their tokens
* - a minter role that allows for token minting (creation)
* - a pauser role that allows to stop all token transfers
* - token ID and URI autogeneration
*
* This contract uses {AccessControl} to lock permissioned functions using the
* different roles - head to its documentation for details.
*
* The account that deploys the contract will be granted the minter and pauser
* roles, as well as the default admin role, which will let it grant both minter
* and pauser roles to other accounts.
*/
contract SniftieERC721IPFS is Context, AccessControlEnumerable, ERC721Enumerable, ERC721Burnable, ERC721Pausable, Ownable {
using Counters for Counters.Counter;
bytes32 public constant MINTER_ROLE = keccak256("MINTER_ROLE");
bytes32 public constant PAUSER_ROLE = keccak256("PAUSER_ROLE");
Counters.Counter private _tokenIdTracker;
mapping(string => uint8) hashes;
string private _baseTokenURI;
string private _contractMetadataURI;
mapping (uint256 => string) private _tokenURIs;
/**
* @dev Grants `DEFAULT_ADMIN_ROLE`, `MINTER_ROLE` and `PAUSER_ROLE` to the
* account that deploys the contract.
*
* Token URIs will be autogenerated based on `baseURI` and their token IDs.
* See {ERC721-tokenURI}.
*/
constructor(string memory name, string memory symbol, string memory baseTokenURI, address sniftieMinterContract, string memory contractMetadataURI) ERC721(name, symbol) {
_baseTokenURI = baseTokenURI;
_contractMetadataURI = contractMetadataURI;
_setupRole(DEFAULT_ADMIN_ROLE, _msgSender());
_setupRole(MINTER_ROLE, _msgSender());
_setupRole(PAUSER_ROLE, _msgSender());
_setupRole(MINTER_ROLE, sniftieMinterContract);
}
function contractURI() public view returns (string memory) {
return _contractMetadataURI;
}
function _baseURI() internal view virtual override returns (string memory) {
return _baseTokenURI;
}
function setBaseURI(string memory baseURI) public {
require(hasRole(DEFAULT_ADMIN_ROLE, _msgSender()), "Must have DEFAULT_ADMIN_ROLE to set base uri");
_baseTokenURI = baseURI;
}
function _setTokenURI(uint256 tokenId, string memory _tokenURI) internal virtual {
require(_exists(tokenId), "ERC721Metadata: URI set of nonexistent token");
_tokenURIs[tokenId] = _tokenURI;
}
function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token");
string memory _tokenURI = _tokenURIs[tokenId];
string memory base = _baseURI();
// If there is no base URI, return the token URI.
if (bytes(base).length == 0) {
return _tokenURI;
}
// If both are set, concatenate the baseURI and tokenURI (via abi.encodePacked).
if (bytes(_tokenURI).length > 0) {
return string(abi.encodePacked(base, _tokenURI));
}
// If there is a baseURI but no tokenURI, concatenate the tokenID to the baseURI.
return base;
}
/**
* @dev Creates a new token for `to`. Its token ID will be automatically
* assigned (and available on the emitted {IERC721-Transfer} event), and the token
* URI autogenerated based on the base URI passed at construction.
*
* See {ERC721-_mint}.
*
* Requirements:
*
* - the caller must have the `MINTER_ROLE`.
*/
function mint(address to, string memory hash, string memory metadata) public virtual {
require(hasRole(MINTER_ROLE, _msgSender()), "ERC721PresetMinterPauserAutoId: must have minter role to mint");
require(hashes[hash] != 1, "Hash value has already been used");
hashes[hash] = 1;
// We cannot just use balanceOf to create the new tokenId because tokens
// can be burned (destroyed), so we need a separate counter.
_tokenIdTracker.increment();
uint256 newItemId = _tokenIdTracker.current();
_mint(to, newItemId);
_setTokenURI(newItemId, metadata);
// return newItemId
}
/**
* @dev Pauses all token transfers.
*
* See {ERC721Pausable} and {Pausable-_pause}.
*
* Requirements:
*
* - the caller must have the `PAUSER_ROLE`.
*/
function pause() public virtual {
require(hasRole(PAUSER_ROLE, _msgSender()), "ERC721PresetMinterPauserAutoId: must have pauser role to pause");
_pause();
}
/**
* @dev Unpauses all token transfers.
*
* See {ERC721Pausable} and {Pausable-_unpause}.
*
* Requirements:
*
* - the caller must have the `PAUSER_ROLE`.
*/
function unpause() public virtual {
require(hasRole(PAUSER_ROLE, _msgSender()), "ERC721PresetMinterPauserAutoId: must have pauser role to unpause");
_unpause();
}
function _beforeTokenTransfer(address from, address to, uint256 tokenId) internal virtual override(ERC721, ERC721Enumerable, ERC721Pausable) {
super._beforeTokenTransfer(from, to, tokenId);
}
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override(AccessControlEnumerable, ERC721, ERC721Enumerable) returns (bool) {
return super.supportsInterface(interfaceId);
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./ERC721.sol";
import "./ERC721Enumerable.sol";
import "./ERC721Burnable.sol";
import "./ERC721Pausable.sol";
import "./AccessControlEnumerable.sol";
import "./Context.sol";
import "./Counters.sol";
/**
* @dev {ERC721} token, including:
*
* - ability for holders to burn (destroy) their tokens
* - a minter role that allows for token minting (creation)
* - a pauser role that allows to stop all token transfers
* - token ID and URI autogeneration
*
* This contract uses {AccessControl} to lock permissioned functions using the
* different roles - head to its documentation for details.
*
* The account that deploys the contract will be granted the minter and pauser
* roles, as well as the default admin role, which will let it grant both minter
* and pauser roles to other accounts.
*/
contract SniftieERC721IPFSMultimint is Context, AccessControlEnumerable, ERC721Enumerable, ERC721Burnable, ERC721Pausable {
using Counters for Counters.Counter;
bytes32 public constant MINTER_ROLE = keccak256("MINTER_ROLE");
bytes32 public constant PAUSER_ROLE = keccak256("PAUSER_ROLE");
Counters.Counter private _tokenIdTracker;
mapping(string => uint8) hashes;
string private _baseTokenURI;
string private _contractMetadataURI;
mapping (uint256 => string) private _tokenURIs;
/**
* @dev Grants `DEFAULT_ADMIN_ROLE`, `MINTER_ROLE` and `PAUSER_ROLE` to the
* account that deploys the contract.
*
* Token URIs will be autogenerated based on `baseURI` and their token IDs.
* See {ERC721-tokenURI}.
*/
constructor(string memory name, string memory symbol, string memory baseTokenURI, address sniftieMinterContract, string memory contractMetadataURI) ERC721(name, symbol) {
_baseTokenURI = baseTokenURI;
_contractMetadataURI = contractMetadataURI;
_setupRole(DEFAULT_ADMIN_ROLE, _msgSender());
_setupRole(MINTER_ROLE, _msgSender());
_setupRole(PAUSER_ROLE, _msgSender());
_setupRole(MINTER_ROLE, sniftieMinterContract);
}
function contractURI() public view returns (string memory) {
return _contractMetadataURI;
}
function _baseURI() internal view virtual override returns (string memory) {
return _baseTokenURI;
}
function setBaseURI(string memory baseURI) public {
require(hasRole(DEFAULT_ADMIN_ROLE, _msgSender()), "Must have DEFAULT_ADMIN_ROLE to set base uri");
_baseTokenURI = baseURI;
}
function _setTokenURI(uint256 tokenId, string memory _tokenURI) internal virtual {
require(_exists(tokenId), "ERC721Metadata: URI set of nonexistent token");
_tokenURIs[tokenId] = _tokenURI;
}
function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
require(_exists(tokenId), "URI query for nonexistent token");
string memory _tokenURI = _tokenURIs[tokenId];
string memory base = _baseURI();
// If there is no base URI, return the token URI.
if (bytes(base).length == 0) {
return _tokenURI;
}
// If both are set, concatenate the baseURI and tokenURI (via abi.encodePacked).
if (bytes(_tokenURI).length > 0) {
return string(abi.encodePacked(base, _tokenURI));
}
// If there is a baseURI but no tokenURI, concatenate the tokenID to the baseURI.
return base;
}
function setMetadataHash(uint256 tokenId, string memory metadataHash) public {
require(_exists(tokenId), "Cannot set metadata hash for nonexistent token");
require(_isApprovedOrOwner(_msgSender(), tokenId) || hasRole(DEFAULT_ADMIN_ROLE, _msgSender()), "Cannot set metadata hash if not owner or admin");
_setTokenURI(tokenId, metadataHash);
}
/**
* @dev Creates a new token for `to`. Its token ID will be automatically
* assigned (and available on the emitted {IERC721-Transfer} event), and the token
* URI autogenerated based on the base URI passed at construction.
*
* See {ERC721-_mint}.
*
* Requirements:
*
* - the caller must have the `MINTER_ROLE`.
*/
function mint(address to, string memory hash, string memory metadata) public virtual {
require(hasRole(MINTER_ROLE, _msgSender()), "ERC721PresetMinterPauserAutoId: must have minter role to mint");
require(hashes[hash] != 1, "Hash value has already been used");
hashes[hash] = 1;
// We cannot just use balanceOf to create the new tokenId because tokens
// can be burned (destroyed), so we need a separate counter.
_tokenIdTracker.increment();
uint256 newItemId = _tokenIdTracker.current();
_mint(to, newItemId);
_setTokenURI(newItemId, metadata);
// return newItemId
}
function mint(address to, string[] memory mediaHashArray, string[] memory metadataHashArray) public virtual {
require(hasRole(MINTER_ROLE, _msgSender()), "ERC721PresetMinterPauserAutoId: must have minter role to mint");
require(mediaHashArray.length == metadataHashArray.length, "Media Hash Array and Metadata Hash Array lengths must match");
for (uint i = 0; i < mediaHashArray.length; i++) {
string memory mediaHash = mediaHashArray[i];
require(hashes[mediaHash] != 1, "Hash value has already been used");
}
for (uint i = 0; i < mediaHashArray.length; i++) {
string memory mediaHash = mediaHashArray[i];
string memory metadataHash = metadataHashArray[i];
hashes[mediaHash] = 1;
// We cannot just use balanceOf to create the new tokenId because tokens
// can be burned (destroyed), so we need a separate counter.
_tokenIdTracker.increment();
uint256 newItemId = _tokenIdTracker.current();
_mint(to, newItemId);
_setTokenURI(newItemId, metadataHash);
// return newItemId
}
}
/**
* @dev Pauses all token transfers.
*
* See {ERC721Pausable} and {Pausable-_pause}.
*
* Requirements:
*
* - the caller must have the `PAUSER_ROLE`.
*/
function pause() public virtual {
require(hasRole(PAUSER_ROLE, _msgSender()), "ERC721PresetMinterPauserAutoId: must have pauser role to pause");
_pause();
}
/**
* @dev Unpauses all token transfers.
*
* See {ERC721Pausable} and {Pausable-_unpause}.
*
* Requirements:
*
* - the caller must have the `PAUSER_ROLE`.
*/
function unpause() public virtual {
require(hasRole(PAUSER_ROLE, _msgSender()), "ERC721PresetMinterPauserAutoId: must have pauser role to unpause");
_unpause();
}
function _beforeTokenTransfer(address from, address to, uint256 tokenId) internal virtual override(ERC721, ERC721Enumerable, ERC721Pausable) {
super._beforeTokenTransfer(from, to, tokenId);
}
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override(AccessControlEnumerable, ERC721, ERC721Enumerable) returns (bool) {
return super.supportsInterface(interfaceId);
}
}
// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.0;
/**
* @dev reusable utility functions
*/
library SniftieUtils {
/**
* @dev checks if string where contains string what
*/
function stringContains(string memory what, string memory where) internal pure returns (bool) {
bytes memory whatBytes = bytes(what);
bytes memory whereBytes = bytes(where);
bool found = false;
for (uint i = 0; i < whereBytes.length - whatBytes.length; i++) {
bool flag = true;
for (uint j = 0; j < whatBytes.length; j++)
if (whereBytes [i + j] != whatBytes [j]) {
flag = false;
break;
}
if (flag) {
found = true;
break;
}
}
return found;
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @dev String operations.
*/
library Strings {
bytes16 private constant alphabet = "0123456789abcdef";
/**
* @dev Converts a `uint256` to its ASCII `string` decimal representation.
*/
function toString(uint256 value) internal pure returns (string memory) {
// Inspired by OraclizeAPI's implementation - MIT licence
// https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
if (value == 0) {
return "0";
}
uint256 temp = value;
uint256 digits;
while (temp != 0) {
digits++;
temp /= 10;
}
bytes memory buffer = new bytes(digits);
while (value != 0) {
digits -= 1;
buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
value /= 10;
}
return string(buffer);
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
*/
function toHexString(uint256 value) internal pure returns (string memory) {
if (value == 0) {
return "0x00";
}
uint256 temp = value;
uint256 length = 0;
while (temp != 0) {
length++;
temp >>= 8;
}
return toHexString(value, length);
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
*/
function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
bytes memory buffer = new bytes(2 * length + 2);
buffer[0] = "0";
buffer[1] = "x";
for (uint256 i = 2 * length + 1; i > 1; --i) {
buffer[i] = alphabet[value & 0xf];
value >>= 4;
}
require(value == 0, "Strings: hex length insufficient");
return string(buffer);
}
}
