Description:
Multi-signature wallet contract requiring multiple confirmations for transaction execution.
Blockchain: Ethereum
Source Code: View Code On The Blockchain
Solidity Source Code:
{{
"language": "Solidity",
"sources": {
"@openzeppelin/contracts/access/Ownable.sol": {
"content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable.sol)
pragma solidity ^0.8.0;
import "../utils/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() {
_transferOwnership(_msgSender());
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
_checkOwner();
_;
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if the sender is not the owner.
*/
function _checkOwner() internal view virtual {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby disabling any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
_transferOwnership(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");
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Internal function without access restriction.
*/
function _transferOwnership(address newOwner) internal virtual {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
"
},
"@openzeppelin/contracts/security/ReentrancyGuard.sol": {
"content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (security/ReentrancyGuard.sol)
pragma solidity ^0.8.0;
/**
* @dev Contract module that helps prevent reentrant calls to a function.
*
* Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
* available, which can be applied to functions to make sure there are no nested
* (reentrant) calls to them.
*
* Note that because there is a single `nonReentrant` guard, functions marked as
* `nonReentrant` may not call one another. This can be worked around by making
* those functions `private`, and then adding `external` `nonReentrant` entry
* points to them.
*
* TIP: If you would like to learn more about reentrancy and alternative ways
* to protect against it, check out our blog post
* https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
*/
abstract contract ReentrancyGuard {
// Booleans are more expensive than uint256 or any type that takes up a full
// word because each write operation emits an extra SLOAD to first read the
// slot's contents, replace the bits taken up by the boolean, and then write
// back. This is the compiler's defense against contract upgrades and
// pointer aliasing, and it cannot be disabled.
// The values being non-zero value makes deployment a bit more expensive,
// but in exchange the refund on every call to nonReentrant will be lower in
// amount. Since refunds are capped to a percentage of the total
// transaction's gas, it is best to keep them low in cases like this one, to
// increase the likelihood of the full refund coming into effect.
uint256 private constant _NOT_ENTERED = 1;
uint256 private constant _ENTERED = 2;
uint256 private _status;
constructor() {
_status = _NOT_ENTERED;
}
/**
* @dev Prevents a contract from calling itself, directly or indirectly.
* Calling a `nonReentrant` function from another `nonReentrant`
* function is not supported. It is possible to prevent this from happening
* by making the `nonReentrant` function external, and making it call a
* `private` function that does the actual work.
*/
modifier nonReentrant() {
_nonReentrantBefore();
_;
_nonReentrantAfter();
}
function _nonReentrantBefore() private {
// On the first call to nonReentrant, _status will be _NOT_ENTERED
require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
// Any calls to nonReentrant after this point will fail
_status = _ENTERED;
}
function _nonReentrantAfter() private {
// By storing the original value once again, a refund is triggered (see
// https://eips.ethereum.org/EIPS/eip-2200)
_status = _NOT_ENTERED;
}
/**
* @dev Returns true if the reentrancy guard is currently set to "entered", which indicates there is a
* `nonReentrant` function in the call stack.
*/
function _reentrancyGuardEntered() internal view returns (bool) {
return _status == _ENTERED;
}
}
"
},
"@openzeppelin/contracts/utils/Address.sol": {
"content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/Address.sol)
pragma solidity ^0.8.1;
/**
* @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
*
* Furthermore, `isContract` will also return true if the target contract within
* the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
* which only has an effect at the end of a transaction.
* ====
*
* [IMPORTANT]
* ====
* You shouldn't rely on `isContract` to protect against flash loan attacks!
*
* Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
* like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
* constructor.
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize/address.code.length, which returns 0
// for contracts in construction, since the code is only stored at the end
// of the constructor execution.
return account.code.length > 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://consensys.net/diligence/blog/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/v0.8.0/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");
(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 functionCallWithValue(target, data, 0, "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");
(bool success, bytes memory returndata) = target.call{value: value}(data);
return verifyCallResultFromTarget(target, 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) {
(bool success, bytes memory returndata) = target.staticcall(data);
return verifyCallResultFromTarget(target, 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) {
(bool success, bytes memory returndata) = target.delegatecall(data);
return verifyCallResultFromTarget(target, success, returndata, errorMessage);
}
/**
* @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
* the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
*
* _Available since v4.8._
*/
function verifyCallResultFromTarget(
address target,
bool success,
bytes memory returndata,
string memory errorMessage
) internal view returns (bytes memory) {
if (success) {
if (returndata.length == 0) {
// only check isContract if the call was successful and the return data is empty
// otherwise we already know that it was a contract
require(isContract(target), "Address: call to non-contract");
}
return returndata;
} else {
_revert(returndata, errorMessage);
}
}
/**
* @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
* revert reason or using the provided one.
*
* _Available since v4.3._
*/
function verifyCallResult(
bool success,
bytes memory returndata,
string memory errorMessage
) internal pure returns (bytes memory) {
if (success) {
return returndata;
} else {
_revert(returndata, errorMessage);
}
}
function _revert(bytes memory returndata, string memory errorMessage) private pure {
// 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
/// @solidity memory-safe-assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
"
},
"@openzeppelin/contracts/utils/Context.sol": {
"content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.4) (utils/Context.sol)
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) {
return msg.data;
}
function _contextSuffixLength() internal view virtual returns (uint256) {
return 0;
}
}
"
},
"@openzeppelin/contracts/utils/math/Math.sol": {
"content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/math/Math.sol)
pragma solidity ^0.8.0;
/**
* @dev Standard math utilities missing in the Solidity language.
*/
library Math {
enum Rounding {
Down, // Toward negative infinity
Up, // Toward infinity
Zero // Toward zero
}
/**
* @dev Returns the largest of two numbers.
*/
function max(uint256 a, uint256 b) internal pure returns (uint256) {
return a > b ? a : b;
}
/**
* @dev Returns the smallest of two numbers.
*/
function min(uint256 a, uint256 b) internal pure returns (uint256) {
return a < b ? a : b;
}
/**
* @dev Returns the average of two numbers. The result is rounded towards
* zero.
*/
function average(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b) / 2 can overflow.
return (a & b) + (a ^ b) / 2;
}
/**
* @dev Returns the ceiling of the division of two numbers.
*
* This differs from standard division with `/` in that it rounds up instead
* of rounding down.
*/
function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b - 1) / b can overflow on addition, so we distribute.
return a == 0 ? 0 : (a - 1) / b + 1;
}
/**
* @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
* @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv)
* with further edits by Uniswap Labs also under MIT license.
*/
function mulDiv(uint256 x, uint256 y, uint256 denominator) internal pure returns (uint256 result) {
unchecked {
// 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
// use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
// variables such that product = prod1 * 2^256 + prod0.
uint256 prod0; // Least significant 256 bits of the product
uint256 prod1; // Most significant 256 bits of the product
assembly {
let mm := mulmod(x, y, not(0))
prod0 := mul(x, y)
prod1 := sub(sub(mm, prod0), lt(mm, prod0))
}
// Handle non-overflow cases, 256 by 256 division.
if (prod1 == 0) {
// Solidity will revert if denominator == 0, unlike the div opcode on its own.
// The surrounding unchecked block does not change this fact.
// See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
return prod0 / denominator;
}
// Make sure the result is less than 2^256. Also prevents denominator == 0.
require(denominator > prod1, "Math: mulDiv overflow");
///////////////////////////////////////////////
// 512 by 256 division.
///////////////////////////////////////////////
// Make division exact by subtracting the remainder from [prod1 prod0].
uint256 remainder;
assembly {
// Compute remainder using mulmod.
remainder := mulmod(x, y, denominator)
// Subtract 256 bit number from 512 bit number.
prod1 := sub(prod1, gt(remainder, prod0))
prod0 := sub(prod0, remainder)
}
// Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
// See https://cs.stackexchange.com/q/138556/92363.
// Does not overflow because the denominator cannot be zero at this stage in the function.
uint256 twos = denominator & (~denominator + 1);
assembly {
// Divide denominator by twos.
denominator := div(denominator, twos)
// Divide [prod1 prod0] by twos.
prod0 := div(prod0, twos)
// Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
twos := add(div(sub(0, twos), twos), 1)
}
// Shift in bits from prod1 into prod0.
prod0 |= prod1 * twos;
// Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
// that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
// four bits. That is, denominator * inv = 1 mod 2^4.
uint256 inverse = (3 * denominator) ^ 2;
// Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
// in modular arithmetic, doubling the correct bits in each step.
inverse *= 2 - denominator * inverse; // inverse mod 2^8
inverse *= 2 - denominator * inverse; // inverse mod 2^16
inverse *= 2 - denominator * inverse; // inverse mod 2^32
inverse *= 2 - denominator * inverse; // inverse mod 2^64
inverse *= 2 - denominator * inverse; // inverse mod 2^128
inverse *= 2 - denominator * inverse; // inverse mod 2^256
// Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
// This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
// less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
// is no longer required.
result = prod0 * inverse;
return result;
}
}
/**
* @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
*/
function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) {
uint256 result = mulDiv(x, y, denominator);
if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
result += 1;
}
return result;
}
/**
* @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down.
*
* Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
*/
function sqrt(uint256 a) internal pure returns (uint256) {
if (a == 0) {
return 0;
}
// For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
//
// We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
// `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
//
// This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
// → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
// → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
//
// Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
uint256 result = 1 << (log2(a) >> 1);
// At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
// since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
// every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
// into the expected uint128 result.
unchecked {
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
return min(result, a / result);
}
}
/**
* @notice Calculates sqrt(a), following the selected rounding direction.
*/
function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = sqrt(a);
return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
}
}
/**
* @dev Return the log in base 2, rounded down, of a positive value.
* Returns 0 if given 0.
*/
function log2(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >> 128 > 0) {
value >>= 128;
result += 128;
}
if (value >> 64 > 0) {
value >>= 64;
result += 64;
}
if (value >> 32 > 0) {
value >>= 32;
result += 32;
}
if (value >> 16 > 0) {
value >>= 16;
result += 16;
}
if (value >> 8 > 0) {
value >>= 8;
result += 8;
}
if (value >> 4 > 0) {
value >>= 4;
result += 4;
}
if (value >> 2 > 0) {
value >>= 2;
result += 2;
}
if (value >> 1 > 0) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 2, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log2(value);
return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
}
}
/**
* @dev Return the log in base 10, rounded down, of a positive value.
* Returns 0 if given 0.
*/
function log10(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >= 10 ** 64) {
value /= 10 ** 64;
result += 64;
}
if (value >= 10 ** 32) {
value /= 10 ** 32;
result += 32;
}
if (value >= 10 ** 16) {
value /= 10 ** 16;
result += 16;
}
if (value >= 10 ** 8) {
value /= 10 ** 8;
result += 8;
}
if (value >= 10 ** 4) {
value /= 10 ** 4;
result += 4;
}
if (value >= 10 ** 2) {
value /= 10 ** 2;
result += 2;
}
if (value >= 10 ** 1) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 10, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log10(value);
return result + (rounding == Rounding.Up && 10 ** result < value ? 1 : 0);
}
}
/**
* @dev Return the log in base 256, rounded down, of a positive value.
* Returns 0 if given 0.
*
* Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
*/
function log256(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >> 128 > 0) {
value >>= 128;
result += 16;
}
if (value >> 64 > 0) {
value >>= 64;
result += 8;
}
if (value >> 32 > 0) {
value >>= 32;
result += 4;
}
if (value >> 16 > 0) {
value >>= 16;
result += 2;
}
if (value >> 8 > 0) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 256, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log256(value);
return result + (rounding == Rounding.Up && 1 << (result << 3) < value ? 1 : 0);
}
}
}
"
},
"@openzeppelin/contracts/utils/math/SignedMath.sol": {
"content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/math/SignedMath.sol)
pragma solidity ^0.8.0;
/**
* @dev Standard signed math utilities missing in the Solidity language.
*/
library SignedMath {
/**
* @dev Returns the largest of two signed numbers.
*/
function max(int256 a, int256 b) internal pure returns (int256) {
return a > b ? a : b;
}
/**
* @dev Returns the smallest of two signed numbers.
*/
function min(int256 a, int256 b) internal pure returns (int256) {
return a < b ? a : b;
}
/**
* @dev Returns the average of two signed numbers without overflow.
* The result is rounded towards zero.
*/
function average(int256 a, int256 b) internal pure returns (int256) {
// Formula from the book "Hacker's Delight"
int256 x = (a & b) + ((a ^ b) >> 1);
return x + (int256(uint256(x) >> 255) & (a ^ b));
}
/**
* @dev Returns the absolute unsigned value of a signed value.
*/
function abs(int256 n) internal pure returns (uint256) {
unchecked {
// must be unchecked in order to support `n = type(int256).min`
return uint256(n >= 0 ? n : -n);
}
}
}
"
},
"@openzeppelin/contracts/utils/Strings.sol": {
"content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/Strings.sol)
pragma solidity ^0.8.0;
import "./math/Math.sol";
import "./math/SignedMath.sol";
/**
* @dev String operations.
*/
library Strings {
bytes16 private constant _SYMBOLS = "0123456789abcdef";
uint8 private constant _ADDRESS_LENGTH = 20;
/**
* @dev Converts a `uint256` to its ASCII `string` decimal representation.
*/
function toString(uint256 value) internal pure returns (string memory) {
unchecked {
uint256 length = Math.log10(value) + 1;
string memory buffer = new string(length);
uint256 ptr;
/// @solidity memory-safe-assembly
assembly {
ptr := add(buffer, add(32, length))
}
while (true) {
ptr--;
/// @solidity memory-safe-assembly
assembly {
mstore8(ptr, byte(mod(value, 10), _SYMBOLS))
}
value /= 10;
if (value == 0) break;
}
return buffer;
}
}
/**
* @dev Converts a `int256` to its ASCII `string` decimal representation.
*/
function toString(int256 value) internal pure returns (string memory) {
return string(abi.encodePacked(value < 0 ? "-" : "", toString(SignedMath.abs(value))));
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
*/
function toHexString(uint256 value) internal pure returns (string memory) {
unchecked {
return toHexString(value, Math.log256(value) + 1);
}
}
/**
* @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] = _SYMBOLS[value & 0xf];
value >>= 4;
}
require(value == 0, "Strings: hex length insufficient");
return string(buffer);
}
/**
* @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
*/
function toHexString(address addr) internal pure returns (string memory) {
return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
}
/**
* @dev Returns true if the two strings are equal.
*/
function equal(string memory a, string memory b) internal pure returns (bool) {
return keccak256(bytes(a)) == keccak256(bytes(b));
}
}
"
},
"contracts/CHADSxPOPO.sol": {
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// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
import "erc721a/contracts/ERC721A.sol";
import "erc721a/contracts/extensions/ERC721AQueryable.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
import "@openzeppelin/contracts/utils/Strings.sol";
import "@openzeppelin/contracts/utils/Address.sol";
/**
* @title CHADS x POPO
* @dev A simple NFT contract using ERC721A for efficient batch minting
*/
contract CHADSxPOPO is ERC721A, ERC721AQueryable, Ownable, ReentrancyGuard {
using Strings for uint256;
using Address for address payable;
// Maximum supply of NFTs
uint256 public constant MAX_SUPPLY = 5000;
// Maximum number of NFTs that can be minted per transaction
uint256 public constant MAX_PER_TX = 20;
// Maximum tier level
uint256 public constant MAX_TIER = 7;
// Price per NFT
uint256 public price = 0.005000 ether;
// Base URI for metadata
string private _baseTokenURI;
// Whether public minting is enabled
bool public publicMintEnabled = false;
// Mapping to track mint timestamp for each token (used for seed generation)
mapping(uint256 => uint256) public tokenMintTimestamp;
// Mapping to track which tier each token belongs to
mapping(uint256 => uint256) public tokenTier;
// Mapping to track payment amount for each token (for refund calculation)
mapping(uint256 => uint256) public tokenPayment;
// Mapping to track if a token has been refunded
mapping(uint256 => bool) public tokenRefunded;
// Mapping to track if a token has ever been Snagged (ineligible for refund)
mapping(uint256 => bool) public tokenEverSnagged;
// Mapping to track if a token is locked
mapping(uint256 => bool) public tokenLocked;
// Mapping to track the locked seed for each token
mapping(uint256 => uint256) public tokenLockedSeed;
// Collection lock state
bool public collectionLocked = false;
uint256 public collectionLockedTimePeriod = 0;
// Address that can call lockCollection function
address public lockCollectionAddress;
// Image change trigger state
uint256 public lastTriggerTime = 0;
uint256 public currentRandomSeed = 0;
// Events
event PublicMintToggled(bool enabled);
event PriceUpdated(uint256 newPrice);
event BaseURIUpdated(string newBaseURI);
event TokenRefunded(
uint256 indexed tokenId,
address indexed owner,
uint256 amount
);
event TokenSnagged(
uint256 indexed tokenId,
address indexed from,
address indexed to,
uint256 newTier,
uint256 snagPrice,
uint256 compensation
);
event TokenUpgraded(
uint256 indexed tokenId,
address indexed owner,
uint256 oldTier,
uint256 newTier,
uint256 upgradeCost
);
event BatchMetadataUpdate(uint256 _fromTokenId, uint256 _toTokenId);
event MetadataUpdate(uint256 _tokenId);
event EtherReceived(address indexed sender, uint256 amount);
event TokenLocked(
uint256 indexed tokenId,
address indexed owner,
uint256 lockedSeed
);
event TokenUnlocked(uint256 indexed tokenId, address indexed owner);
event CollectionLocked(uint256 lockedTimePeriod);
event ImageChangeTriggered(
address indexed triggerer,
uint256 randomSeed,
uint256 triggerTime
);
constructor(
string memory name,
string memory symbol,
string memory baseURI
) ERC721A(name, symbol) {
_baseTokenURI = baseURI;
}
/**
* @dev Public mint function
* @param quantity Number of NFTs to mint
* @param tier Tier level (1-based, where 1 is cheapest)
*/
function mint(
uint256 quantity,
uint256 tier
) external payable nonReentrant {
require(publicMintEnabled, "Public minting is not enabled");
require(
!collectionLocked,
"Minting disabled once collection is locked"
);
require(quantity > 0, "Quantity must be greater than 0");
require(quantity <= MAX_PER_TX, "Exceeds maximum per transaction");
require(tier > 0, "Tier must be greater than 0");
require(tier <= MAX_TIER, "Tier exceeds maximum allowed");
require(
totalSupply() + quantity <= MAX_SUPPLY,
"Exceeds maximum supply"
);
uint256 tierPrice = getTierPrice(tier);
require(msg.value >= tierPrice * quantity, "Insufficient payment");
uint256 startTokenId = _nextTokenId();
uint256 mintTimestamp = block.timestamp;
_mint(msg.sender, quantity);
// Assign tier, payment amount, and mint timestamp to each minted token
for (uint256 i = 0; i < quantity; i++) {
tokenTier[startTokenId + i] = tier;
tokenPayment[startTokenId + i] = tierPrice;
tokenMintTimestamp[startTokenId + i] = mintTimestamp;
}
if (totalSupply() == MAX_SUPPLY) {
triggerImageChange();
}
// Refund excess payment if any using safe transfer
uint256 totalCost = tierPrice * quantity;
uint256 excessPayment = msg.value > totalCost
? msg.value - totalCost
: 0;
if (excessPayment > 0) {
bool refundOk = _safeTransfer(msg.sender, excessPayment);
require(refundOk, "Excess refund failed");
}
}
/**
* @dev Toggle public minting on/off
*/
function togglePublicMint() external onlyOwner {
publicMintEnabled = !publicMintEnabled;
emit PublicMintToggled(publicMintEnabled);
}
/**
* @dev Update the mint price
* @param newPrice New price in wei
*/
function setPrice(uint256 newPrice) external onlyOwner {
// Validate that the new price won't cause overflow at maximum tier
if (newPrice > 0) {
uint256 maxMultiplier = 10 ** (MAX_TIER - 1);
require(
maxMultiplier <= type(uint256).max / newPrice,
"Price too high: would cause overflow at max tier"
);
}
price = newPrice;
emit PriceUpdated(newPrice);
}
/**
* @dev Set the address that can call lockCollection function
* @param newAddress New address that can lock the collection
*/
function setLockCollectionAddress(address newAddress) external onlyOwner {
lockCollectionAddress = newAddress;
}
/**
* @dev Calculate the price for a specific tier
* @param tier Tier level (1-based)
* @return tierPrice Price in wei for the tier
*/
function getTierPrice(
uint256 tier
) public view returns (uint256 tierPrice) {
require(tier > 0, "Tier must be greater than 0");
require(tier <= MAX_TIER, "Tier exceeds maximum allowed");
// Price = basePrice * 10^(tier - 1)
// Tier 1: price * 1 = price
// Tier 2: price * 10
// Tier 3: price * 100
// Tier 4: price * 1000
// Tier 5: price * 10000
// Tier 6: price * 100000
// Tier 7: price * 1000000
// Use unchecked for gas optimization since we verify bounds
uint256 multiplier;
unchecked {
multiplier = 10 ** (tier - 1);
}
// Check for multiplication overflow before performing the operation
// If price * multiplier would overflow, revert
require(
price == 0 || multiplier <= type(uint256).max / price,
"Price calculation would overflow"
);
// Safe to multiply after overflow check
unchecked {
return price * multiplier;
}
}
/**
* @dev Set the base URI for token metadata
* @param baseURI New base URI
*/
function setBaseURI(string calldata baseURI) external onlyOwner {
_baseTokenURI = baseURI;
emit BaseURIUpdated(baseURI);
}
/**
* @dev Claim refund for tokens (burns tokens)
* @param tokenIds Array of token IDs to refund
*/
function claimRefund(uint256[] calldata tokenIds) external nonReentrant {
require(totalSupply() < MAX_SUPPLY, "Refunds disabled after sellout");
require(
!collectionLocked,
"Refunds disabled once collection is locked"
);
uint256 totalRefund = 0;
address refundRecipient = msg.sender; // Cache to prevent changes during execution
for (uint256 i = 0; i < tokenIds.length; i++) {
uint256 tokenId = tokenIds[i];
require(_exists(tokenId), "Token does not exist");
require(ownerOf(tokenId) == refundRecipient, "Not token owner");
require(!tokenRefunded[tokenId], "Token already refunded");
require(
!tokenEverSnagged[tokenId],
"Token not eligible for refund"
);
// EFFECTS: Update state first
tokenRefunded[tokenId] = true;
totalRefund += tokenPayment[tokenId];
// Burn the token
_burn(tokenId);
emit TokenRefunded(tokenId, refundRecipient, tokenPayment[tokenId]);
}
require(totalRefund > 0, "No refund amount");
// Use safe transfer to prevent gas griefing
bool success = _safeTransfer(refundRecipient, totalRefund);
require(success, "Refund transfer failed");
}
/**
* @dev Snag a token by paying a higher tier price
* @param tokenId Token ID to snag
* @param targetTier Target tier level (0 means auto-increment by 1)
*/
function snagToken(
uint256 tokenId,
uint256 targetTier
) external payable nonReentrant {
require(_exists(tokenId), "Token does not exist");
require(!tokenRefunded[tokenId], "Token has been refunded");
require(
totalSupply() == MAX_SUPPLY,
"Snagging only available after sellout"
);
require(
!collectionLocked,
"Snagging disabled once collection is locked"
);
address currentOwner = ownerOf(tokenId);
require(currentOwner != msg.sender, "Cannot snag your own token");
require(currentOwner != address(0), "Token has no owner");
uint256 currentTier = tokenTier[tokenId];
uint256 newTier;
if (targetTier == 0) {
// Auto-increment by 1
newTier = currentTier + 1;
} else {
// Use specified target tier
require(
targetTier > currentTier,
"Target tier must be higher than current tier"
);
newTier = targetTier;
}
require(newTier <= MAX_TIER, "Target tier exceeds maximum allowed");
uint256 snagPrice = getTierPrice(newTier);
require(msg.value >= snagPrice, "Insufficient payment for snag");
// Calculate compensation for current owner (currentTier x current tier price)
uint256 currentTierPrice = getTierPrice(currentTier);
uint256 compensation = currentTierPrice * currentTier;
// Cache addresses to prevent state changes during execution
address snagger = msg.sender;
uint256 excessPayment = msg.value > snagPrice
? msg.value - snagPrice
: 0;
tokenTier[tokenId] = newTier;
tokenPayment[tokenId] = snagPrice;
tokenEverSnagged[tokenId] = true;
// Securely transfer token using internal function (bypasses approvals safely)
_forceTransfer(currentOwner, snagger, tokenId);
emit TokenSnagged(
tokenId,
currentOwner,
snagger,
newTier,
snagPrice,
compensation
);
// Emit metadata update event for the snagged token
emit MetadataUpdate(tokenId);
// Pay compensation to original owner using safe transfer
bool compensationOk = _safeTransfer(currentOwner, compensation);
require(compensationOk, "Compensation transfer failed");
// Refund excess payment to snagger if any using safe transfer
if (excessPayment > 0) {
bool refundOk = _safeTransfer(snagger, excessPayment);
require(refundOk, "Excess refund failed");
}
}
/**
* @dev Upgrade a token to a higher tier by paying the difference
* @param tokenId Token ID to upgrade
* @param newTier New tier level (must be higher than current)
*/
function upgradeToken(
uint256 tokenId,
uint256 newTier
) external payable nonReentrant {
require(_exists(tokenId), "Token does not exist");
require(!tokenRefunded[tokenId], "Token has been refunded");
require(ownerOf(tokenId) == msg.sender, "Not token owner");
require(newTier > 0, "Tier must be greater than 0");
uint256 currentTier = tokenTier[tokenId];
require(
newTier > currentTier,
"New tier must be higher than current tier"
);
require(newTier <= MAX_TIER, "New tier exceeds maximum allowed");
// Calculate upgrade cost (difference between new and current tier prices)
uint256 currentTierPrice = getTierPrice(currentTier);
uint256 newTierPrice = getTierPrice(newTier);
uint256 upgradeCost = newTierPrice - currentTierPrice;
require(msg.value >= upgradeCost, "Insufficient payment for upgrade");
// EFFECTS: Update all state BEFORE external calls
tokenTier[tokenId] = newTier;
tokenPayment[tokenId] = newTierPrice;
emit TokenUpgraded(
tokenId,
msg.sender,
currentTier,
newTier,
upgradeCost
);
// Emit metadata update event for the upgraded token
emit MetadataUpdate(tokenId);
// Refund excess payment if any using safe transfer
uint256 excessPayment = msg.value > upgradeCost
? msg.value - upgradeCost
: 0;
if (excessPayment > 0) {
bool refundOk = _safeTransfer(msg.sender, excessPayment);
require(refundOk, "Refund failed");
}
}
/**
* @dev Withdraw a specific amount of contract balance to the owner
* @param amount Amount in wei to withdraw
*/
function withdraw(uint256 amount) external onlyOwner {
require(amount > 0, "Amount must be greater than 0");
uint256 balance = address(this).balance;
require(balance >= amount, "Insufficient contract balance");
address recipient = owner(); // Cache owner to prevent changes during execution
// INTERACTIONS: External call LAST using safe transfer
bool success = _safeTransfer(recipient, amount);
require(success, "Withdrawal failed");
}
/**
* @dev Check if a token can be locked
* @param tokenId Token ID to check
* @return canLock Whether the token can be locked
* @return reason Reason why it cannot be locked (empty if can be locked)
*/
function canLockToken(
uint256 tokenId
) external view returns (bool canLock, string memory reason) {
if (!_exists(tokenId)) {
return (false, "Token does not exist");
}
if (totalSupply() < MAX_SUPPLY) {
return (false, "Lock after sellout");
}
if (collectionLocked) {
return (false, "Collection is locked");
}
if (tokenLocked[tokenId]) {
return (false, "Token already locked");
}
if (tokenRefunded[tokenId]) {
return (false, "Cannot lock refunded token");
}
return (true, "");
}
/**
* @dev Lock a token to lock its current seed
* @param tokenId Token ID to lock
*/
function lockToken(uint256 tokenId) external {
require(totalSupply() >= MAX_SUPPLY, "Lock after sellout");
require(_exists(tokenId), "Token does not exist");
require(ownerOf(tokenId) == msg.sender, "Not token owner");
require(!collectionLocked, "Collection locked: token lock disabled");
require(!tokenLocked[tokenId], "Token already locked");
require(!tokenRefunded[tokenId], "Cannot lock refunded token");
// Store the current seed as the locked seed
uint256 currentSeed = getTokenSeed(tokenId);
tokenLocked[tokenId] = true;
tokenLockedSeed[tokenId] = currentSeed;
emit TokenLocked(tokenId, msg.sender, currentSeed);
}
/**
* @dev Unlock a token to allow seed changes again
* @param tokenId Token ID to unlock
*/
function unlockToken(uint256 tokenId) external {
require(totalSupply() >= MAX_SUPPLY, "Lock after sellout");
require(_exists(tokenId), "Token does not exist");
require(ownerOf(tokenId) == msg.sender, "Not token owner");
require(!collectionLocked, "Collection locked: token unlock disabled");
require(tokenLocked[tokenId], "Token not locked");
tokenLocked[tokenId] = false;
tokenLockedSeed[tokenId] = 0; // Clear the stored seed
emit TokenUnlocked(tokenId, msg.sender);
}
/**
* @dev Lock the entire collection (owner or authorized address only)
* Locks all tokens to their current time period seed
*/
function lockCollection() external {
require(
msg.sender == owner() || msg.sender == lockCollectionAddress,
"Only owner or authorized address can lock collection"
);
require(!collectionLocked, "Collection already locked");
collectionLocked = true;
collectionLockedTimePeriod = lastTriggerTime;
emit CollectionLocked(lastTriggerTime);
}
/**
* @dev Trigger image change - can only be called once per 12-hour period
* Only works after sellout when images are revealed
*/
function triggerImageChange() public {
require(
!collectionLocked,
"Cannot trigger image change when collection is locked"
);
require(
totalSupply() >= MAX_SUPPLY,
"Image changes only available after sellout"
);
// Check if already triggered for this time period
uint256 currentPeriod = getCurrentTimePeriod();
require(
lastTriggerTime < currentPeriod,
"Already triggered for this period"
);
// Generate new random seed using current block data
uint256 randomSeed = uint256(
keccak256(
abi.encodePacked(
block.timestamp,
block.prevrandao,
msg.sender,
currentPeriod
)
)
);
// Update state
lastTriggerTime = currentPeriod;
currentRandomSeed = randomSeed;
emit BatchMetadataUpdate(1, _totalMinted());
emit ImageChangeTriggered(msg.sender, randomSeed, block.timestamp);
}
/**
* @dev Receive function to accept plain ETH transfers
*/
receive() external payable {
emit EtherReceived(msg.sender, msg.value);
}
/**
* @dev Fallback handler: revert with a clear message for unknown function calls
*/
fallback() external payable {
revert("Function does not exist");
}
/**
* @dev Safe transfer function with gas limit to prevent gas griefing attacks
* @param recipient Address to send ether to
* @param amount Amount of ether to send
* @return success Whether the transfer was successful
*/
function _safeTransfer(
address recipient,
uint256 amount
) private returns (bool success) {
if (amount == 0) return true;
// Use Address.sendValue for safe transfers with built-in gas limits
// This prevents gas griefing and reentrancy attacks
// sendValue reverts on failure, so we use try-catch to return false instead
try this._sendValueWrapper(payable(recipient), amount) {
return true;
} catch {
return false;
}
}
/**
* @dev Wrapper function for Address.sendValue to enable try-catch usage
* @param recipient Address to send ether to
* @param amount Amount of ether to send
*/
function _sendValueWrapper(
address payable recipient,
uint256 amount
) external {
require(msg.sender == address(this), "Only self-call allowed");
Address.sendValue(recipient, amount);
}
/**
* @dev Secure internal transfer function for snagging mechanism
* Uses a self-delegating call to bypass approval requirements safely
*/
function _forceTransfer(
address from,
address to,
uint256 tokenId
) internal {
// Verify the transfer is valid
require(_exists(tokenId), "Token does not exist");
require(ownerOf(tokenId) == from, "From address is not owner");
require(to != address(0), "Transfer to zero address");
// Use a delegated call to the contract itself to perform the transfer
// This way msg.sender will be the contract during the transfer
bytes memory data = abi.encodeWithSignature(
"executeTransfer(address,address,uint256)",
from,
to,
tokenId
);
(bool success, ) = address(this).call(data);
require(success, "Force transfer failed");
}
/**
* @dev Internal function to execute transfer with contract as msg.sender
* Only callable by the contract itself during snagging operations
*/
function executeTransfer(
address from,
address to,
uint256 tokenId
) external {
require(msg.sender == address(this), "Only self-call allowed");
// Temporarily approve this contract to transfer the token
_approve(address(this), tokenId);
// Now transfer the token - msg.sender is the contract
transferFrom(from, to, tokenId);
}
/**
* @dev Returns the starting token ID (ERC721A starts at 0 by default, this changes it to 1)
*/
function _startTokenId() internal pure override returns (uint256) {
return 1;
}
/**
* @dev Returns the base URI for tokens
*/
function _baseURI() internal view override returns (string memory) {
return _baseTokenURI;
}
/**
* @dev Returns the token URI for a given token ID
* @param tokenId Token ID to get URI for
*/
function tokenURI(
uint256 tokenId
) public view override(ERC721A, IERC721A) returns (string memory) {
if (!_exists(tokenId)) revert URIQueryForNonexistentToken();
string memory baseURI = _baseURI();
if (totalSupply() < MAX_SUPPLY) {
// Before sellout, return placeholder metadata
return
bytes(baseURI).length != 0
? string(abi.encodePacked(baseURI, tokenId.toString()))
: "";
} else {
// After sellout, include the seed in the URL
uint256 seed = getTokenSeed(tokenId);
return
bytes(baseURI).length != 0
? string(
abi.encodePacked(
baseURI,
tokenId.toString(),
"/",
seed.toString(),
"/",
tokenTier[tokenId].toString()
)
)
: "";
}
}
/**
* @dev Returns total number of tokens minted
*/
function totalMinted() external view returns (uint256) {
return _totalMinted();
}
/**
* @dev Returns the number of tokens minted by a specific address
* @param owner Address to check
*/
function numberMinted(address owner) external view returns (uint256) {
return _numberMinted(owner);
}
/**
* @dev Returns whether a token exists
* @param tokenId Token ID to check
*/
function exists(uint256 tokenId) external view returns (bool) {
return _exists(tokenId);
}
/**
* @dev Get mint info for an address
* @param minter Address to check
*/
function getMintInfo(
address minter
)
external
view
returns (
uint256 numMinted,
uint256 remainingSupply,
uint256 currentPrice,
bool canMint
)
{
numMinted = _numberMinted(minter);
remainingSupply = MAX_SUPPLY - totalSupply();
currentPrice = price;
canMint = publicMintEnabled && remainingSupply > 0 && !collectionLocked;
}
/**
* @dev Get snag info for a token
* @param tokenId Token ID to check
* @param newTier Proposed new tier
*/
function getSnagInfo(
uint256 tokenId,
uint256 newTier
)
external
view
returns (
bool canSnSubmitted on: 2025-09-20 19:57:26
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