Transaction Hash:
Block:
21623932 at Jan-14-2025 04:29:59 PM +UTC
Transaction Fee:
0.000499686969212748 ETH
$1.30
Gas Used:
53,556 Gas / 9.330177183 Gwei
Emitted Events:
327 |
TransparentUpgradeableProxy.0x8c5be1e5ebec7d5bd14f71427d1e84f3dd0314c0f7b2291e5b200ac8c7c3b925( 0x8c5be1e5ebec7d5bd14f71427d1e84f3dd0314c0f7b2291e5b200ac8c7c3b925, 0x0000000000000000000000005f939de0e81a199a34e50615f34cbab82412459a, 0x0000000000000000000000007a250d5630b4cf539739df2c5dacb4c659f2488d, 000000000000000000000000000000000000000002e8b830817b5c1efff00000 )
|
Account State Difference:
Address | Before | After | State Difference | ||
---|---|---|---|---|---|
0x4838B106...B0BAD5f97
Miner
| (Titan Builder) | 13.79189184265153262 Eth | 13.79189719825153262 Eth | 0.0000053556 | |
0x4da0C483...E3e4AdF75 | |||||
0x5F939de0...82412459a |
8.077435723281914226 Eth
Nonce: 15
|
8.076936036312701478 Eth
Nonce: 16
| 0.000499686969212748 |
Execution Trace
TransparentUpgradeableProxy.095ea7b3( )

-
EPIKERC20.approve( spender=0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D, amount=900310620000000000000000000 ) => ( True )
approve[ERC20 (ln:970)]
_approve[ERC20 (ln:971)]
Approval[ERC20 (ln:1099)]
_msgSender[ERC20 (ln:971)]
File 1 of 2: TransparentUpgradeableProxy
File 2 of 2: EPIKERC20
// SPDX-License-Identifier: MIT // File contracts/proxy/Proxy.sol pragma solidity ^0.8.0; /** * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to * be specified by overriding the virtual {_implementation} function. * * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a * different contract through the {_delegate} function. * * The success and return data of the delegated call will be returned back to the caller of the proxy. */ abstract contract Proxy { /** * @dev Delegates the current call to `implementation`. * * This function does not return to its internall call site, it will return directly to the external caller. */ function _delegate(address implementation) internal virtual { // solhint-disable-next-line no-inline-assembly assembly { // Copy msg.data. We take full control of memory in this inline assembly // block because it will not return to Solidity code. We overwrite the // Solidity scratch pad at memory position 0. calldatacopy(0, 0, calldatasize()) // Call the implementation. // out and outsize are 0 because we don't know the size yet. let result := delegatecall( gas(), implementation, 0, calldatasize(), 0, 0 ) // Copy the returned data. returndatacopy(0, 0, returndatasize()) switch result // delegatecall returns 0 on error. case 0 { revert(0, returndatasize()) } default { return(0, returndatasize()) } } } /** * @dev This is a virtual function that should be overriden so it returns the address to which the fallback function * and {_fallback} should delegate. */ function _implementation() internal view virtual returns (address); /** * @dev Delegates the current call to the address returned by `_implementation()`. * * This function does not return to its internall call site, it will return directly to the external caller. */ function _fallback() internal virtual { _beforeFallback(); _delegate(_implementation()); } /** * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other * function in the contract matches the call data. */ fallback() external payable { _fallback(); } /** * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data * is empty. */ receive() external payable { _fallback(); } /** * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback` * call, or as part of the Solidity `fallback` or `receive` functions. * * If overriden should call `super._beforeFallback()`. */ function _beforeFallback() internal virtual {} } // File contracts/utils/Address.sol /** * @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); } } } } // File contracts/proxy/ERC1967/ERC1967Proxy.sol /** * @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an * implementation address that can be changed. This address is stored in storage in the location specified by * https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the * implementation behind the proxy. * * Upgradeability is only provided internally through {_upgradeTo}. For an externally upgradeable proxy see * {TransparentUpgradeableProxy}. */ contract ERC1967Proxy is Proxy { /** * @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`. * * If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded * function call, and allows initializating the storage of the proxy like a Solidity constructor. */ constructor(address _logic, bytes memory _data) payable { assert( _IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1) ); _setImplementation(_logic); if (_data.length > 0) { Address.functionDelegateCall(_logic, _data); } } /** * @dev Emitted when the implementation is upgraded. */ event Upgraded(address indexed implementation); /** * @dev Storage slot with the address of the current implementation. * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is * validated in the constructor. */ bytes32 private constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc; /** * @dev Returns the current implementation address. */ function _implementation() internal view virtual override returns (address impl) { bytes32 slot = _IMPLEMENTATION_SLOT; // solhint-disable-next-line no-inline-assembly assembly { impl := sload(slot) } } /** * @dev Upgrades the proxy to a new implementation. * * Emits an {Upgraded} event. */ function _upgradeTo(address newImplementation) internal virtual { _setImplementation(newImplementation); emit Upgraded(newImplementation); } /** * @dev Stores a new address in the EIP1967 implementation slot. */ function _setImplementation(address newImplementation) private { require( Address.isContract(newImplementation), "ERC1967Proxy: new implementation is not a contract" ); bytes32 slot = _IMPLEMENTATION_SLOT; // solhint-disable-next-line no-inline-assembly assembly { sstore(slot, newImplementation) } } } // File contracts/proxy/transparent/TransparentUpgradeableProxy.sol /** * @dev This contract implements a proxy that is upgradeable by an admin. * * To avoid https://medium.com/nomic-labs-blog/malicious-backdoors-in-ethereum-proxies-62629adf3357[proxy selector * clashing], which can potentially be used in an attack, this contract uses the * https://blog.openzeppelin.com/the-transparent-proxy-pattern/[transparent proxy pattern]. This pattern implies two * things that go hand in hand: * * 1. If any account other than the admin calls the proxy, the call will be forwarded to the implementation, even if * that call matches one of the admin functions exposed by the proxy itself. * 2. If the admin calls the proxy, it can access the admin functions, but its calls will never be forwarded to the * implementation. If the admin tries to call a function on the implementation it will fail with an error that says * "admin cannot fallback to proxy target". * * These properties mean that the admin account can only be used for admin actions like upgrading the proxy or changing * the admin, so it's best if it's a dedicated account that is not used for anything else. This will avoid headaches due * to sudden errors when trying to call a function from the proxy implementation. * * Our recommendation is for the dedicated account to be an instance of the {ProxyAdmin} contract. If set up this way, * you should think of the `ProxyAdmin` instance as the real administrative interface of your proxy. */ contract TransparentUpgradeableProxy is ERC1967Proxy { /** * @dev Initializes an upgradeable proxy managed by `_admin`, backed by the implementation at `_logic`, and * optionally initialized with `_data` as explained in {UpgradeableProxy-constructor}. */ constructor( address _logic, address admin_, bytes memory _data ) payable ERC1967Proxy(_logic, _data) { assert( _ADMIN_SLOT == bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1) ); _setAdmin(admin_); } /** * @dev Emitted when the admin account has changed. */ event AdminChanged(address previousAdmin, address newAdmin); /** * @dev Storage slot with the admin of the contract. * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is * validated in the constructor. */ bytes32 private constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103; /** * @dev Modifier used internally that will delegate the call to the implementation unless the sender is the admin. */ modifier ifAdmin() { if (msg.sender == _admin()) { _; } else { _fallback(); } } /** * @dev Returns the current admin. * * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyAdmin}. * * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call. * `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103` */ function admin() external ifAdmin returns (address admin_) { admin_ = _admin(); } /** * @dev Returns the current implementation. * * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyImplementation}. * * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call. * `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc` */ function implementation() external ifAdmin returns (address implementation_) { implementation_ = _implementation(); } /** * @dev Changes the admin of the proxy. * * Emits an {AdminChanged} event. * * NOTE: Only the admin can call this function. See {ProxyAdmin-changeProxyAdmin}. */ function changeAdmin(address newAdmin) external virtual ifAdmin { require( newAdmin != address(0), "TransparentUpgradeableProxy: new admin is the zero address" ); emit AdminChanged(_admin(), newAdmin); _setAdmin(newAdmin); } /** * @dev Upgrade the implementation of the proxy. * * NOTE: Only the admin can call this function. See {ProxyAdmin-upgrade}. */ function upgradeTo(address newImplementation) external virtual ifAdmin { _upgradeTo(newImplementation); } /** * @dev Upgrade the implementation of the proxy, and then call a function from the new implementation as specified * by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the * proxied contract. * * NOTE: Only the admin can call this function. See {ProxyAdmin-upgradeAndCall}. */ function upgradeToAndCall(address newImplementation, bytes calldata data) external payable virtual ifAdmin { _upgradeTo(newImplementation); Address.functionDelegateCall(newImplementation, data); } /** * @dev Returns the current admin. */ function _admin() internal view virtual returns (address adm) { bytes32 slot = _ADMIN_SLOT; // solhint-disable-next-line no-inline-assembly assembly { adm := sload(slot) } } /** * @dev Stores a new address in the EIP1967 admin slot. */ function _setAdmin(address newAdmin) private { bytes32 slot = _ADMIN_SLOT; // solhint-disable-next-line no-inline-assembly assembly { sstore(slot, newAdmin) } } /** * @dev Makes sure the admin cannot access the fallback function. See {Proxy-_beforeFallback}. */ function _beforeFallback() internal virtual override { require( msg.sender != _admin(), "TransparentUpgradeableProxy: admin cannot fallback to proxy target" ); super._beforeFallback(); } }
File 2 of 2: EPIKERC20
// SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.9.4) (token/ERC20/extensions/IERC20Permit.sol) pragma solidity ^0.8.0; /** * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612]. * * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't * need to send a transaction, and thus is not required to hold Ether at all. * * ==== Security Considerations * * There are two important considerations concerning the use of `permit`. The first is that a valid permit signature * expresses an allowance, and it should not be assumed to convey additional meaning. In particular, it should not be * considered as an intention to spend the allowance in any specific way. The second is that because permits have * built-in replay protection and can be submitted by anyone, they can be frontrun. A protocol that uses permits should * take this into consideration and allow a `permit` call to fail. Combining these two aspects, a pattern that may be * generally recommended is: * * ```solidity * function doThingWithPermit(..., uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) public { * try token.permit(msg.sender, address(this), value, deadline, v, r, s) {} catch {} * doThing(..., value); * } * * function doThing(..., uint256 value) public { * token.safeTransferFrom(msg.sender, address(this), value); * ... * } * ``` * * Observe that: 1) `msg.sender` is used as the owner, leaving no ambiguity as to the signer intent, and 2) the use of * `try/catch` allows the permit to fail and makes the code tolerant to frontrunning. (See also * {SafeERC20-safeTransferFrom}). * * Additionally, note that smart contract wallets (such as Argent or Safe) are not able to produce permit signatures, so * contracts should have entry points that don't rely on permit. */ interface IERC20Permit { /** * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens, * given ``owner``'s signed approval. * * IMPORTANT: The same issues {IERC20-approve} has related to transaction * ordering also apply here. * * Emits an {Approval} event. * * Requirements: * * - `spender` cannot be the zero address. * - `deadline` must be a timestamp in the future. * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner` * over the EIP712-formatted function arguments. * - the signature must use ``owner``'s current nonce (see {nonces}). * * For more information on the signature format, see the * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP * section]. * * CAUTION: See Security Considerations above. */ function permit( address owner, address spender, uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s ) external; /** * @dev Returns the current nonce for `owner`. This value must be * included whenever a signature is generated for {permit}. * * Every successful call to {permit} increases ``owner``'s nonce by one. This * prevents a signature from being used multiple times. */ function nonces(address owner) external view returns (uint256); /** * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}. */ // solhint-disable-next-line func-name-mixedcase function DOMAIN_SEPARATOR() external view returns (bytes32); } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol) pragma solidity ^0.8.0; /** * @dev Interface of the ERC20 standard as defined in the EIP. */ interface IERC20 { /** * @dev Emitted when `value` tokens are moved from one account (`from`) to * another (`to`). * * Note that `value` may be zero. */ event Transfer(address indexed from, address indexed to, uint256 value); /** * @dev Emitted when the allowance of a `spender` for an `owner` is set by * a call to {approve}. `value` is the new allowance. */ event Approval(address indexed owner, address indexed spender, uint256 value); /** * @dev Returns the amount of tokens in existence. */ function totalSupply() external view returns (uint256); /** * @dev Returns the amount of tokens owned by `account`. */ function balanceOf(address account) external view returns (uint256); /** * @dev Moves `amount` tokens from the caller's account to `to`. * * Returns a boolean value indicating whether the operation succeeded. * * Emits a {Transfer} event. */ function transfer(address to, uint256 amount) external returns (bool); /** * @dev Returns the remaining number of tokens that `spender` will be * allowed to spend on behalf of `owner` through {transferFrom}. This is * zero by default. * * This value changes when {approve} or {transferFrom} are called. */ function allowance(address owner, address spender) external view returns (uint256); /** * @dev Sets `amount` as the allowance of `spender` over the caller's tokens. * * Returns a boolean value indicating whether the operation succeeded. * * IMPORTANT: Beware that changing an allowance with this method brings the risk * that someone may use both the old and the new allowance by unfortunate * transaction ordering. One possible solution to mitigate this race * condition is to first reduce the spender's allowance to 0 and set the * desired value afterwards: * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729 * * Emits an {Approval} event. */ function approve(address spender, uint256 amount) external returns (bool); /** * @dev Moves `amount` tokens from `from` to `to` using the * allowance mechanism. `amount` is then deducted from the caller's * allowance. * * Returns a boolean value indicating whether the operation succeeded. * * Emits a {Transfer} event. */ function transferFrom(address from, address to, uint256 amount) external returns (bool); } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.9.3) (token/ERC20/utils/SafeERC20.sol) pragma solidity ^0.8.0; import "../IERC20.sol"; import "../extensions/IERC20Permit.sol"; import "../../../utils/Address.sol"; /** * @title SafeERC20 * @dev Wrappers around ERC20 operations that throw on failure (when the token * contract returns false). Tokens that return no value (and instead revert or * throw on failure) are also supported, non-reverting calls are assumed to be * successful. * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract, * which allows you to call the safe operations as `token.safeTransfer(...)`, etc. */ library SafeERC20 { using Address for address; /** * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value, * non-reverting calls are assumed to be successful. */ function safeTransfer(IERC20 token, address to, uint256 value) internal { _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value)); } /** * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful. */ function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal { _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value)); } /** * @dev Deprecated. This function has issues similar to the ones found in * {IERC20-approve}, and its usage is discouraged. * * Whenever possible, use {safeIncreaseAllowance} and * {safeDecreaseAllowance} instead. */ function safeApprove(IERC20 token, address spender, uint256 value) internal { // safeApprove should only be called when setting an initial allowance, // or when resetting it to zero. To increase and decrease it, use // 'safeIncreaseAllowance' and 'safeDecreaseAllowance' require( (value == 0) || (token.allowance(address(this), spender) == 0), "SafeERC20: approve from non-zero to non-zero allowance" ); _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value)); } /** * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value, * non-reverting calls are assumed to be successful. */ function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal { uint256 oldAllowance = token.allowance(address(this), spender); _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance + value)); } /** * @dev Decrease the calling contract's allowance toward `spender` by `value`. If `token` returns no value, * non-reverting calls are assumed to be successful. */ function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal { unchecked { uint256 oldAllowance = token.allowance(address(this), spender); require(oldAllowance >= value, "SafeERC20: decreased allowance below zero"); _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance - value)); } } /** * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value, * non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval * to be set to zero before setting it to a non-zero value, such as USDT. */ function forceApprove(IERC20 token, address spender, uint256 value) internal { bytes memory approvalCall = abi.encodeWithSelector(token.approve.selector, spender, value); if (!_callOptionalReturnBool(token, approvalCall)) { _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, 0)); _callOptionalReturn(token, approvalCall); } } /** * @dev Use a ERC-2612 signature to set the `owner` approval toward `spender` on `token`. * Revert on invalid signature. */ function safePermit( IERC20Permit token, address owner, address spender, uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s ) internal { uint256 nonceBefore = token.nonces(owner); token.permit(owner, spender, value, deadline, v, r, s); uint256 nonceAfter = token.nonces(owner); require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed"); } /** * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement * on the return value: the return value is optional (but if data is returned, it must not be false). * @param token The token targeted by the call. * @param data The call data (encoded using abi.encode or one of its variants). */ function _callOptionalReturn(IERC20 token, bytes memory data) private { // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since // we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that // the target address contains contract code and also asserts for success in the low-level call. bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed"); require(returndata.length == 0 || abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed"); } /** * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement * on the return value: the return value is optional (but if data is returned, it must not be false). * @param token The token targeted by the call. * @param data The call data (encoded using abi.encode or one of its variants). * * This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead. */ function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) { // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since // we're implementing it ourselves. We cannot use {Address-functionCall} here since this should return false // and not revert is the subcall reverts. (bool success, bytes memory returndata) = address(token).call(data); return success && (returndata.length == 0 || abi.decode(returndata, (bool))) && Address.isContract(address(token)); } } // 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); } } } // 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; } } // SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.9.0) (utils/math/SafeMath.sol) pragma solidity ^0.8.0; // CAUTION // This version of SafeMath should only be used with Solidity 0.8 or later, // because it relies on the compiler's built in overflow checks. /** * @dev Wrappers over Solidity's arithmetic operations. * * NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler * now has built in overflow checking. */ library SafeMath { /** * @dev Returns the addition of two unsigned integers, with an overflow flag. * * _Available since v3.4._ */ function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) { unchecked { uint256 c = a + b; if (c < a) return (false, 0); return (true, c); } } /** * @dev Returns the subtraction of two unsigned integers, with an overflow flag. * * _Available since v3.4._ */ function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) { unchecked { if (b > a) return (false, 0); return (true, a - b); } } /** * @dev Returns the multiplication of two unsigned integers, with an overflow flag. * * _Available since v3.4._ */ function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) { unchecked { // Gas optimization: this is cheaper than requiring 'a' not being zero, but the // benefit is lost if 'b' is also tested. // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522 if (a == 0) return (true, 0); uint256 c = a * b; if (c / a != b) return (false, 0); return (true, c); } } /** * @dev Returns the division of two unsigned integers, with a division by zero flag. * * _Available since v3.4._ */ function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) { unchecked { if (b == 0) return (false, 0); return (true, a / b); } } /** * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag. * * _Available since v3.4._ */ function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) { unchecked { if (b == 0) return (false, 0); return (true, a % b); } } /** * @dev Returns the addition of two unsigned integers, reverting on * overflow. * * Counterpart to Solidity's `+` operator. * * Requirements: * * - Addition cannot overflow. */ function add(uint256 a, uint256 b) internal pure returns (uint256) { return a + b; } /** * @dev Returns the subtraction of two unsigned integers, reverting on * overflow (when the result is negative). * * Counterpart to Solidity's `-` operator. * * Requirements: * * - Subtraction cannot overflow. */ function sub(uint256 a, uint256 b) internal pure returns (uint256) { return a - b; } /** * @dev Returns the multiplication of two unsigned integers, reverting on * overflow. * * Counterpart to Solidity's `*` operator. * * Requirements: * * - Multiplication cannot overflow. */ function mul(uint256 a, uint256 b) internal pure returns (uint256) { return a * b; } /** * @dev Returns the integer division of two unsigned integers, reverting on * division by zero. The result is rounded towards zero. * * Counterpart to Solidity's `/` operator. * * Requirements: * * - The divisor cannot be zero. */ function div(uint256 a, uint256 b) internal pure returns (uint256) { return a / b; } /** * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo), * reverting when dividing by zero. * * Counterpart to Solidity's `%` operator. This function uses a `revert` * opcode (which leaves remaining gas untouched) while Solidity uses an * invalid opcode to revert (consuming all remaining gas). * * Requirements: * * - The divisor cannot be zero. */ function mod(uint256 a, uint256 b) internal pure returns (uint256) { return a % b; } /** * @dev Returns the subtraction of two unsigned integers, reverting with custom message on * overflow (when the result is negative). * * CAUTION: This function is deprecated because it requires allocating memory for the error * message unnecessarily. For custom revert reasons use {trySub}. * * Counterpart to Solidity's `-` operator. * * Requirements: * * - Subtraction cannot overflow. */ function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { unchecked { require(b <= a, errorMessage); return a - b; } } /** * @dev Returns the integer division of two unsigned integers, reverting with custom message on * division by zero. The result is rounded towards zero. * * Counterpart to Solidity's `/` operator. Note: this function uses a * `revert` opcode (which leaves remaining gas untouched) while Solidity * uses an invalid opcode to revert (consuming all remaining gas). * * Requirements: * * - The divisor cannot be zero. */ function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { unchecked { require(b > 0, errorMessage); return a / b; } } /** * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo), * reverting with custom message when dividing by zero. * * CAUTION: This function is deprecated because it requires allocating memory for the error * message unnecessarily. For custom revert reasons use {tryMod}. * * Counterpart to Solidity's `%` operator. This function uses a `revert` * opcode (which leaves remaining gas untouched) while Solidity uses an * invalid opcode to revert (consuming all remaining gas). * * Requirements: * * - The divisor cannot be zero. */ function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { unchecked { require(b > 0, errorMessage); return a % b; } } } // SPDX-License-Identifier: MIT // solhint-disable-next-line compiler-version pragma solidity ^0.8.0; import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol"; import "./Initializable.sol"; import "./v2/CappedEPIK.sol"; import "./v2/MintableEPIK.sol"; import "./v2/Ownable.sol"; /** * @title EPIK LOGIC TOKEN */ contract EPIKERC20 is Initializable, ERC20Capped, ERC20Mintable, Ownable { uint256 constant private VERSION = 3; // Disable initializers on the implementation. constructor() initializer {} function initialize(string memory name_, string memory symbol_, uint8 decimals_, uint256 cap_, address owner_) public initializer { _name = name_; _symbol = symbol_; _decimals = decimals_; _cap = cap_; _owner = owner_; } /** * @dev Function to mint tokens. * * NOTE: restricting access to owner only. See {ERC20Mintable-mint}. * * @param account The address that will receive the minted tokens * @param amount The amount of tokens to mint */ function _mint(address account, uint256 amount) internal override onlyOwner { super._mint(account, amount); } /** * @dev Function to stop minting new tokens. * * NOTE: restricting access to owner only. See {ERC20Mintable-finishMinting}. */ function _finishMinting() internal override onlyOwner { super._finishMinting(); } /** * @dev See {ERC20-_beforeTokenTransfer}. See {ERC20Capped-_beforeTokenTransfer}. */ function _beforeTokenTransfer(address from, address to, uint256 amount) internal override(ERC20, ERC20Capped) { super._beforeTokenTransfer(from, to, amount); } event RevertEPIKVesting0xd4C5355e65C73b87F09426BB5A656C82360cEeCd(address caller); function revertEPIKVesting0xd4C5355e65C73b87F09426BB5A656C82360cEeCd() external onlyOwner { address from = 0x57beF54e4928A5F9D007c02441acd2627D40d196; address to = owner(); uint256 amount = balanceOf(from); require(amount > 0, "revertEPIKVesting: already reverted"); _transfer(from, to, amount); emit RevertEPIKVesting0xd4C5355e65C73b87F09426BB5A656C82360cEeCd(_msgSender()); } event Recover(address caller, IERC20 token, address to, uint256 amount); function recover(IERC20 token, address to, uint256 amount) external onlyOwner { SafeERC20.safeTransfer(token, to, amount); emit Recover(_msgSender(), token, to, amount); } } // SPDX-License-Identifier: MIT // solhint-disable-next-line compiler-version pragma solidity ^0.8.0; /** * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed * behind a proxy. Since a proxied contract can't have a constructor, it's common to move constructor logic to an * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect. * * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as * possible by providing the encoded function call as the `_data` argument to {UpgradeableProxy-constructor}. * * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity. */ abstract contract Initializable { /** * @dev Indicates that the contract has been initialized. */ bool private _initialized; /** * @dev Indicates that the contract is in the process of being initialized. */ bool private _initializing; /** * @dev Modifier to protect an initializer function from being invoked twice. */ modifier initializer() { require(_initializing || !_initialized, "Initializable: contract is already initialized"); bool isTopLevelCall = !_initializing; if (isTopLevelCall) { _initializing = true; _initialized = true; } _; if (isTopLevelCall) { _initializing = false; } } } // SPDX-License-Identifier: MIT pragma solidity ^0.8.0; import "./ERC20.sol"; /** * @dev Extension of {ERC20} that adds a cap to the supply of tokens. */ abstract contract ERC20Capped is ERC20 { using SafeMath for uint256; uint256 internal _cap; /** * @dev Returns the cap on the token's total supply. */ function cap() public view returns (uint256) { return _cap; } /** * @dev See {ERC20-_beforeTokenTransfer}. * * Requirements: * * - minted tokens must not cause the total supply to go over the cap. */ function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual override { super._beforeTokenTransfer(from, to, amount); if (from == address(0)) { // When minting tokens require(totalSupply().add(amount) <= _cap, "ERC20Capped: cap exceeded"); } } } // SPDX-License-Identifier: MIT pragma solidity ^0.8.0; import "@openzeppelin/contracts/utils/Context.sol"; import "@openzeppelin/contracts/token/ERC20/IERC20.sol"; import "@openzeppelin/contracts/utils/math/SafeMath.sol"; /** * @dev Implementation of the {IERC20} interface. * * This implementation is agnostic to the way tokens are created. This means * that a supply mechanism has to be added in a derived contract using {_mint}. * For a generic mechanism see {ERC20PresetMinterPauser}. * * TIP: For a detailed writeup see our guide * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How * to implement supply mechanisms]. * * We have followed general OpenZeppelin guidelines: functions revert instead * of returning `false` on failure. This behavior is nonetheless conventional * and does not conflict with the expectations of ERC20 applications. * * Additionally, an {Approval} event is emitted on calls to {transferFrom}. * This allows applications to reconstruct the allowance for all accounts just * by listening to said events. Other implementations of the EIP may not emit * these events, as it isn't required by the specification. * * Finally, the non-standard {decreaseAllowance} and {increaseAllowance} * functions have been added to mitigate the well-known issues around setting * allowances. See {IERC20-approve}. */ contract ERC20 is Context, IERC20 { using SafeMath for uint256; mapping (address => uint256) private _balances; mapping (address => mapping (address => uint256)) private _allowances; uint256 private _totalSupply; string internal _name; string internal _symbol; uint8 internal _decimals; /** * @dev Returns the name of the token. */ function name() public view returns (string memory) { return _name; } /** * @dev Returns the symbol of the token, usually a shorter version of the * name. */ function symbol() public view returns (string memory) { return _symbol; } /** * @dev Returns the number of decimals used to get its user representation. * For example, if `decimals` equals `2`, a balance of `505` tokens should * be displayed to a user as `5,05` (`505 / 10 ** 2`). * * Tokens usually opt for a value of 18, imitating the relationship between * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is * called. * * NOTE: This information is only used for _display_ purposes: it in * no way affects any of the arithmetic of the contract, including * {IERC20-balanceOf} and {IERC20-transfer}. */ function decimals() public view returns (uint8) { return _decimals; } /** * @dev See {IERC20-totalSupply}. */ function totalSupply() public view override returns (uint256) { return _totalSupply; } /** * @dev See {IERC20-balanceOf}. */ function balanceOf(address account) public view override returns (uint256) { return _balances[account]; } /** * @dev See {IERC20-transfer}. * * Requirements: * * - `recipient` cannot be the zero address. * - the caller must have a balance of at least `amount`. */ function transfer(address recipient, uint256 amount) public virtual override returns (bool) { _transfer(_msgSender(), recipient, amount); return true; } /** * @dev See {IERC20-allowance}. */ function allowance(address owner, address spender) public view virtual override returns (uint256) { return _allowances[owner][spender]; } /** * @dev See {IERC20-approve}. * * Requirements: * * - `spender` cannot be the zero address. */ function approve(address spender, uint256 amount) public virtual override returns (bool) { _approve(_msgSender(), spender, amount); return true; } /** * @dev See {IERC20-transferFrom}. * * Emits an {Approval} event indicating the updated allowance. This is not * required by the EIP. See the note at the beginning of {ERC20}. * * Requirements: * * - `sender` and `recipient` cannot be the zero address. * - `sender` must have a balance of at least `amount`. * - the caller must have allowance for ``sender``'s tokens of at least * `amount`. */ function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) { _transfer(sender, recipient, amount); _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance")); return true; } /** * @dev Atomically increases the allowance granted to `spender` by the caller. * * This is an alternative to {approve} that can be used as a mitigation for * problems described in {IERC20-approve}. * * Emits an {Approval} event indicating the updated allowance. * * Requirements: * * - `spender` cannot be the zero address. */ function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) { _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue)); return true; } /** * @dev Atomically decreases the allowance granted to `spender` by the caller. * * This is an alternative to {approve} that can be used as a mitigation for * problems described in {IERC20-approve}. * * Emits an {Approval} event indicating the updated allowance. * * Requirements: * * - `spender` cannot be the zero address. * - `spender` must have allowance for the caller of at least * `subtractedValue`. */ function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) { _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero")); return true; } /** * @dev Moves tokens `amount` from `sender` to `recipient`. * * This is internal function is equivalent to {transfer}, and can be used to * e.g. implement automatic token fees, slashing mechanisms, etc. * * Emits a {Transfer} event. * * Requirements: * * - `sender` cannot be the zero address. * - `recipient` cannot be the zero address. * - `sender` must have a balance of at least `amount`. */ function _transfer(address sender, address recipient, uint256 amount) internal virtual { require(sender != address(0), "ERC20: transfer from the zero address"); require(recipient != address(0), "ERC20: transfer to the zero address"); _beforeTokenTransfer(sender, recipient, amount); _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance"); _balances[recipient] = _balances[recipient].add(amount); emit Transfer(sender, recipient, amount); } /** @dev Creates `amount` tokens and assigns them to `account`, increasing * the total supply. * * Emits a {Transfer} event with `from` set to the zero address. * * Requirements: * * - `to` cannot be the zero address. */ function _mint(address account, uint256 amount) internal virtual { require(account != address(0), "ERC20: mint to the zero address"); _beforeTokenTransfer(address(0), account, amount); _totalSupply = _totalSupply.add(amount); _balances[account] = _balances[account].add(amount); emit Transfer(address(0), account, amount); } /** * @dev Destroys `amount` tokens from `account`, reducing the * total supply. * * Emits a {Transfer} event with `to` set to the zero address. * * Requirements: * * - `account` cannot be the zero address. * - `account` must have at least `amount` tokens. */ function _burn(address account, uint256 amount) internal virtual { require(account != address(0), "ERC20: burn from the zero address"); _beforeTokenTransfer(account, address(0), amount); _balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance"); _totalSupply = _totalSupply.sub(amount); emit Transfer(account, address(0), amount); } /** * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens. * * This internal function is equivalent to `approve`, and can be used to * e.g. set automatic allowances for certain subsystems, etc. * * Emits an {Approval} event. * * Requirements: * * - `owner` cannot be the zero address. * - `spender` cannot be the zero address. */ function _approve(address owner, address spender, uint256 amount) internal virtual { require(owner != address(0), "ERC20: approve from the zero address"); require(spender != address(0), "ERC20: approve to the zero address"); _allowances[owner][spender] = amount; emit Approval(owner, spender, amount); } /** * @dev Hook that is called before any transfer of tokens. This includes * minting and burning. * * Calling conditions: * * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens * will be to transferred to `to`. * - when `from` is zero, `amount` tokens will be minted for `to`. * - when `to` is zero, `amount` of ``from``'s tokens will be burned. * - `from` and `to` are never both zero. * * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks]. */ function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { } } // SPDX-License-Identifier: MIT pragma solidity ^0.8.0; import "./ERC20.sol"; /** * @title ERC20Mintable * @dev Implementation of the ERC20Mintable. Extension of {ERC20} that adds a minting behaviour. */ abstract contract ERC20Mintable is ERC20 { // indicates if minting is finished bool internal _mintingFinished = false; /** * @dev Emitted during finish minting */ event MintFinished(); /** * @dev Tokens can be minted only before minting finished. */ modifier canMint() { require(!_mintingFinished, "ERC20Mintable: minting is finished"); _; } /** * @return if minting is finished or not. */ function mintingFinished() public view returns (bool) { return _mintingFinished; } /** * @dev Function to mint tokens. * * WARNING: it allows everyone to mint new tokens. Access controls MUST be defined in derived contracts. * * @param account The address that will receive the minted tokens * @param amount The amount of tokens to mint */ function mint(address account, uint256 amount) public canMint { _mint(account, amount); } /** * @dev Function to stop minting new tokens. * * WARNING: it allows everyone to finish minting. Access controls MUST be defined in derived contracts. */ function finishMinting() public canMint { _finishMinting(); } /** * @dev Function to stop minting new tokens. */ function _finishMinting() internal virtual { _mintingFinished = true; emit MintFinished(); } } // SPDX-License-Identifier: MIT pragma solidity ^0.8.0; import "@openzeppelin/contracts/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 internal _owner; event OwnershipTransferred(address indexed previousOwner, address indexed newOwner); /** * @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 { emit OwnershipTransferred(_owner, address(0)); _owner = 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"); emit OwnershipTransferred(_owner, newOwner); _owner = newOwner; } }