// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol)pragmasolidity ^0.8.1;/**
* @dev Collection of functions related to the address type
*/libraryAddress{
/**
* @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
* ====
*
* [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.
* ====
*/functionisContract(address account) internalviewreturns (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://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].
*/functionsendValue(addresspayable 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._
*/functionfunctionCall(address target, bytesmemory data) internalreturns (bytesmemory) {
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._
*/functionfunctionCall(address target,
bytesmemory data,
stringmemory errorMessage
) internalreturns (bytesmemory) {
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._
*/functionfunctionCallWithValue(address target,
bytesmemory data,
uint256 value
) internalreturns (bytesmemory) {
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._
*/functionfunctionCallWithValue(address target,
bytesmemory data,
uint256 value,
stringmemory errorMessage
) internalreturns (bytesmemory) {
require(address(this).balance>= value, "Address: insufficient balance for call");
(bool success, bytesmemory 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._
*/functionfunctionStaticCall(address target, bytesmemory data) internalviewreturns (bytesmemory) {
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._
*/functionfunctionStaticCall(address target,
bytesmemory data,
stringmemory errorMessage
) internalviewreturns (bytesmemory) {
(bool success, bytesmemory 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._
*/functionfunctionDelegateCall(address target, bytesmemory data) internalreturns (bytesmemory) {
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._
*/functionfunctionDelegateCall(address target,
bytesmemory data,
stringmemory errorMessage
) internalreturns (bytesmemory) {
(bool success, bytesmemory 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._
*/functionverifyCallResultFromTarget(address target,
bool success,
bytesmemory returndata,
stringmemory errorMessage
) internalviewreturns (bytesmemory) {
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 contractrequire(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._
*/functionverifyCallResult(bool success,
bytesmemory returndata,
stringmemory errorMessage
) internalpurereturns (bytesmemory) {
if (success) {
return returndata;
} else {
_revert(returndata, errorMessage);
}
}
function_revert(bytesmemory returndata, stringmemory errorMessage) privatepure{
// Look for revert reason and bubble it up if presentif (returndata.length>0) {
// The easiest way to bubble the revert reason is using memory via assembly/// @solidity memory-safe-assemblyassembly {
let returndata_size :=mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
Contract Source Code
File 2 of 19: BytesLib.sol
// SPDX-License-Identifier: Unlicense/*
* @title Solidity Bytes Arrays Utils
* @author Gonçalo Sá <goncalo.sa@consensys.net>
*
* @dev Bytes tightly packed arrays utility library for ethereum contracts written in Solidity.
* The library lets you concatenate, slice and type cast bytes arrays both in memory and storage.
*/pragmasolidity >=0.8.0 <0.9.0;libraryBytesLib{
functionconcat(bytesmemory _preBytes,
bytesmemory _postBytes
)
internalpurereturns (bytesmemory)
{
bytesmemory tempBytes;
assembly {
// Get a location of some free memory and store it in tempBytes as// Solidity does for memory variables.
tempBytes :=mload(0x40)
// Store the length of the first bytes array at the beginning of// the memory for tempBytes.let length :=mload(_preBytes)
mstore(tempBytes, length)
// Maintain a memory counter for the current write location in the// temp bytes array by adding the 32 bytes for the array length to// the starting location.let mc :=add(tempBytes, 0x20)
// Stop copying when the memory counter reaches the length of the// first bytes array.let end :=add(mc, length)
for {
// Initialize a copy counter to the start of the _preBytes data,// 32 bytes into its memory.let cc :=add(_preBytes, 0x20)
} lt(mc, end) {
// Increase both counters by 32 bytes each iteration.
mc :=add(mc, 0x20)
cc :=add(cc, 0x20)
} {
// Write the _preBytes data into the tempBytes memory 32 bytes// at a time.mstore(mc, mload(cc))
}
// Add the length of _postBytes to the current length of tempBytes// and store it as the new length in the first 32 bytes of the// tempBytes memory.
length :=mload(_postBytes)
mstore(tempBytes, add(length, mload(tempBytes)))
// Move the memory counter back from a multiple of 0x20 to the// actual end of the _preBytes data.
mc := end
// Stop copying when the memory counter reaches the new combined// length of the arrays.
end :=add(mc, length)
for {
let cc :=add(_postBytes, 0x20)
} lt(mc, end) {
mc :=add(mc, 0x20)
cc :=add(cc, 0x20)
} {
mstore(mc, mload(cc))
}
// Update the free-memory pointer by padding our last write location// to 32 bytes: add 31 bytes to the end of tempBytes to move to the// next 32 byte block, then round down to the nearest multiple of// 32. If the sum of the length of the two arrays is zero then add// one before rounding down to leave a blank 32 bytes (the length block with 0).mstore(0x40, and(
add(add(end, iszero(add(length, mload(_preBytes)))), 31),
not(31) // Round down to the nearest 32 bytes.
))
}
return tempBytes;
}
functionconcatStorage(bytesstorage _preBytes, bytesmemory _postBytes) internal{
assembly {
// Read the first 32 bytes of _preBytes storage, which is the length// of the array. (We don't need to use the offset into the slot// because arrays use the entire slot.)let fslot :=sload(_preBytes.slot)
// Arrays of 31 bytes or less have an even value in their slot,// while longer arrays have an odd value. The actual length is// the slot divided by two for odd values, and the lowest order// byte divided by two for even values.// If the slot is even, bitwise and the slot with 255 and divide by// two to get the length. If the slot is odd, bitwise and the slot// with -1 and divide by two.let slength :=div(and(fslot, sub(mul(0x100, iszero(and(fslot, 1))), 1)), 2)
let mlength :=mload(_postBytes)
let newlength :=add(slength, mlength)
// slength can contain both the length and contents of the array// if length < 32 bytes so let's prepare for that// v. http://solidity.readthedocs.io/en/latest/miscellaneous.html#layout-of-state-variables-in-storageswitchadd(lt(slength, 32), lt(newlength, 32))
case2 {
// Since the new array still fits in the slot, we just need to// update the contents of the slot.// uint256(bytes_storage) = uint256(bytes_storage) + uint256(bytes_memory) + new_lengthsstore(
_preBytes.slot,
// all the modifications to the slot are inside this// next blockadd(
// we can just add to the slot contents because the// bytes we want to change are the LSBs
fslot,
add(
mul(
div(
// load the bytes from memorymload(add(_postBytes, 0x20)),
// zero all bytes to the rightexp(0x100, sub(32, mlength))
),
// and now shift left the number of bytes to// leave space for the length in the slotexp(0x100, sub(32, newlength))
),
// increase length by the double of the memory// bytes lengthmul(mlength, 2)
)
)
)
}
case1 {
// The stored value fits in the slot, but the combined value// will exceed it.// get the keccak hash to get the contents of the arraymstore(0x0, _preBytes.slot)
let sc :=add(keccak256(0x0, 0x20), div(slength, 32))
// save new lengthsstore(_preBytes.slot, add(mul(newlength, 2), 1))
// The contents of the _postBytes array start 32 bytes into// the structure. Our first read should obtain the `submod`// bytes that can fit into the unused space in the last word// of the stored array. To get this, we read 32 bytes starting// from `submod`, so the data we read overlaps with the array// contents by `submod` bytes. Masking the lowest-order// `submod` bytes allows us to add that value directly to the// stored value.let submod :=sub(32, slength)
let mc :=add(_postBytes, submod)
let end :=add(_postBytes, mlength)
let mask :=sub(exp(0x100, submod), 1)
sstore(
sc,
add(
and(
fslot,
0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff00
),
and(mload(mc), mask)
)
)
for {
mc :=add(mc, 0x20)
sc :=add(sc, 1)
} lt(mc, end) {
sc :=add(sc, 1)
mc :=add(mc, 0x20)
} {
sstore(sc, mload(mc))
}
mask :=exp(0x100, sub(mc, end))
sstore(sc, mul(div(mload(mc), mask), mask))
}
default {
// get the keccak hash to get the contents of the arraymstore(0x0, _preBytes.slot)
// Start copying to the last used word of the stored array.let sc :=add(keccak256(0x0, 0x20), div(slength, 32))
// save new lengthsstore(_preBytes.slot, add(mul(newlength, 2), 1))
// Copy over the first `submod` bytes of the new data as in// case 1 above.let slengthmod :=mod(slength, 32)
let mlengthmod :=mod(mlength, 32)
let submod :=sub(32, slengthmod)
let mc :=add(_postBytes, submod)
let end :=add(_postBytes, mlength)
let mask :=sub(exp(0x100, submod), 1)
sstore(sc, add(sload(sc), and(mload(mc), mask)))
for {
sc :=add(sc, 1)
mc :=add(mc, 0x20)
} lt(mc, end) {
sc :=add(sc, 1)
mc :=add(mc, 0x20)
} {
sstore(sc, mload(mc))
}
mask :=exp(0x100, sub(mc, end))
sstore(sc, mul(div(mload(mc), mask), mask))
}
}
}
functionslice(bytesmemory _bytes,
uint256 _start,
uint256 _length
)
internalpurereturns (bytesmemory)
{
require(_length +31>= _length, "slice_overflow");
require(_bytes.length>= _start + _length, "slice_outOfBounds");
bytesmemory tempBytes;
assembly {
switchiszero(_length)
case0 {
// Get a location of some free memory and store it in tempBytes as// Solidity does for memory variables.
tempBytes :=mload(0x40)
// The first word of the slice result is potentially a partial// word read from the original array. To read it, we calculate// the length of that partial word and start copying that many// bytes into the array. The first word we copy will start with// data we don't care about, but the last `lengthmod` bytes will// land at the beginning of the contents of the new array. When// we're done copying, we overwrite the full first word with// the actual length of the slice.let lengthmod :=and(_length, 31)
// The multiplication in the next line is necessary// because when slicing multiples of 32 bytes (lengthmod == 0)// the following copy loop was copying the origin's length// and then ending prematurely not copying everything it should.let mc :=add(add(tempBytes, lengthmod), mul(0x20, iszero(lengthmod)))
let end :=add(mc, _length)
for {
// The multiplication in the next line has the same exact purpose// as the one above.let cc :=add(add(add(_bytes, lengthmod), mul(0x20, iszero(lengthmod))), _start)
} lt(mc, end) {
mc :=add(mc, 0x20)
cc :=add(cc, 0x20)
} {
mstore(mc, mload(cc))
}
mstore(tempBytes, _length)
//update free-memory pointer//allocating the array padded to 32 bytes like the compiler does nowmstore(0x40, and(add(mc, 31), not(31)))
}
//if we want a zero-length slice let's just return a zero-length arraydefault {
tempBytes :=mload(0x40)
//zero out the 32 bytes slice we are about to return//we need to do it because Solidity does not garbage collectmstore(tempBytes, 0)
mstore(0x40, add(tempBytes, 0x20))
}
}
return tempBytes;
}
functiontoAddress(bytesmemory _bytes, uint256 _start) internalpurereturns (address) {
require(_bytes.length>= _start +20, "toAddress_outOfBounds");
address tempAddress;
assembly {
tempAddress :=div(mload(add(add(_bytes, 0x20), _start)), 0x1000000000000000000000000)
}
return tempAddress;
}
functiontoUint8(bytesmemory _bytes, uint256 _start) internalpurereturns (uint8) {
require(_bytes.length>= _start +1 , "toUint8_outOfBounds");
uint8 tempUint;
assembly {
tempUint :=mload(add(add(_bytes, 0x1), _start))
}
return tempUint;
}
functiontoUint16(bytesmemory _bytes, uint256 _start) internalpurereturns (uint16) {
require(_bytes.length>= _start +2, "toUint16_outOfBounds");
uint16 tempUint;
assembly {
tempUint :=mload(add(add(_bytes, 0x2), _start))
}
return tempUint;
}
functiontoUint32(bytesmemory _bytes, uint256 _start) internalpurereturns (uint32) {
require(_bytes.length>= _start +4, "toUint32_outOfBounds");
uint32 tempUint;
assembly {
tempUint :=mload(add(add(_bytes, 0x4), _start))
}
return tempUint;
}
functiontoUint64(bytesmemory _bytes, uint256 _start) internalpurereturns (uint64) {
require(_bytes.length>= _start +8, "toUint64_outOfBounds");
uint64 tempUint;
assembly {
tempUint :=mload(add(add(_bytes, 0x8), _start))
}
return tempUint;
}
functiontoUint96(bytesmemory _bytes, uint256 _start) internalpurereturns (uint96) {
require(_bytes.length>= _start +12, "toUint96_outOfBounds");
uint96 tempUint;
assembly {
tempUint :=mload(add(add(_bytes, 0xc), _start))
}
return tempUint;
}
functiontoUint128(bytesmemory _bytes, uint256 _start) internalpurereturns (uint128) {
require(_bytes.length>= _start +16, "toUint128_outOfBounds");
uint128 tempUint;
assembly {
tempUint :=mload(add(add(_bytes, 0x10), _start))
}
return tempUint;
}
functiontoUint256(bytesmemory _bytes, uint256 _start) internalpurereturns (uint256) {
require(_bytes.length>= _start +32, "toUint256_outOfBounds");
uint256 tempUint;
assembly {
tempUint :=mload(add(add(_bytes, 0x20), _start))
}
return tempUint;
}
functiontoBytes32(bytesmemory _bytes, uint256 _start) internalpurereturns (bytes32) {
require(_bytes.length>= _start +32, "toBytes32_outOfBounds");
bytes32 tempBytes32;
assembly {
tempBytes32 :=mload(add(add(_bytes, 0x20), _start))
}
return tempBytes32;
}
functionequal(bytesmemory _preBytes, bytesmemory _postBytes) internalpurereturns (bool) {
bool success =true;
assembly {
let length :=mload(_preBytes)
// if lengths don't match the arrays are not equalswitcheq(length, mload(_postBytes))
case1 {
// cb is a circuit breaker in the for loop since there's// no said feature for inline assembly loops// cb = 1 - don't breaker// cb = 0 - breaklet cb :=1let mc :=add(_preBytes, 0x20)
let end :=add(mc, length)
for {
let cc :=add(_postBytes, 0x20)
// the next line is the loop condition:// while(uint256(mc < end) + cb == 2)
} eq(add(lt(mc, end), cb), 2) {
mc :=add(mc, 0x20)
cc :=add(cc, 0x20)
} {
// if any of these checks fails then arrays are not equalifiszero(eq(mload(mc), mload(cc))) {
// unsuccess:
success :=0
cb :=0
}
}
}
default {
// unsuccess:
success :=0
}
}
return success;
}
functionequalStorage(bytesstorage _preBytes,
bytesmemory _postBytes
)
internalviewreturns (bool)
{
bool success =true;
assembly {
// we know _preBytes_offset is 0let fslot :=sload(_preBytes.slot)
// Decode the length of the stored array like in concatStorage().let slength :=div(and(fslot, sub(mul(0x100, iszero(and(fslot, 1))), 1)), 2)
let mlength :=mload(_postBytes)
// if lengths don't match the arrays are not equalswitcheq(slength, mlength)
case1 {
// slength can contain both the length and contents of the array// if length < 32 bytes so let's prepare for that// v. http://solidity.readthedocs.io/en/latest/miscellaneous.html#layout-of-state-variables-in-storageifiszero(iszero(slength)) {
switchlt(slength, 32)
case1 {
// blank the last byte which is the length
fslot :=mul(div(fslot, 0x100), 0x100)
ifiszero(eq(fslot, mload(add(_postBytes, 0x20)))) {
// unsuccess:
success :=0
}
}
default {
// cb is a circuit breaker in the for loop since there's// no said feature for inline assembly loops// cb = 1 - don't breaker// cb = 0 - breaklet cb :=1// get the keccak hash to get the contents of the arraymstore(0x0, _preBytes.slot)
let sc :=keccak256(0x0, 0x20)
let mc :=add(_postBytes, 0x20)
let end :=add(mc, mlength)
// the next line is the loop condition:// while(uint256(mc < end) + cb == 2)for {} eq(add(lt(mc, end), cb), 2) {
sc :=add(sc, 1)
mc :=add(mc, 0x20)
} {
ifiszero(eq(sload(sc), mload(mc))) {
// unsuccess:
success :=0
cb :=0
}
}
}
}
}
default {
// unsuccess:
success :=0
}
}
return success;
}
}
Contract Source Code
File 3 of 19: Context.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)pragmasolidity ^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.
*/abstractcontractContext{
function_msgSender() internalviewvirtualreturns (address) {
returnmsg.sender;
}
function_msgData() internalviewvirtualreturns (bytescalldata) {
returnmsg.data;
}
}
Contract Source Code
File 4 of 19: ERC165.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)pragmasolidity ^0.8.0;import"./IERC165.sol";
/**
* @dev Implementation of the {IERC165} interface.
*
* Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
* for the additional interface id that will be supported. For example:
*
* ```solidity
* function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
* return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
* }
* ```
*
* Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
*/abstractcontractERC165isIERC165{
/**
* @dev See {IERC165-supportsInterface}.
*/functionsupportsInterface(bytes4 interfaceId) publicviewvirtualoverridereturns (bool) {
return interfaceId ==type(IERC165).interfaceId;
}
}
Contract Source Code
File 5 of 19: ExcessivelySafeCall.sol
// SPDX-License-Identifier: MIT OR Apache-2.0pragmasolidity >=0.7.6;libraryExcessivelySafeCall{
uint256constant LOW_28_MASK =0x00000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffff;
/// @notice Use when you _really_ really _really_ don't trust the called/// contract. This prevents the called contract from causing reversion of/// the caller in as many ways as we can./// @dev The main difference between this and a solidity low-level call is/// that we limit the number of bytes that the callee can cause to be/// copied to caller memory. This prevents stupid things like malicious/// contracts returning 10,000,000 bytes causing a local OOG when copying/// to memory./// @param _target The address to call/// @param _gas The amount of gas to forward to the remote contract/// @param _maxCopy The maximum number of bytes of returndata to copy/// to memory./// @param _calldata The data to send to the remote contract/// @return success and returndata, as `.call()`. Returndata is capped to/// `_maxCopy` bytes.functionexcessivelySafeCall(address _target,
uint256 _gas,
uint16 _maxCopy,
bytesmemory _calldata
) internalreturns (bool, bytesmemory) {
// set up for assembly calluint256 _toCopy;
bool _success;
bytesmemory _returnData =newbytes(_maxCopy);
// dispatch message to recipient// by assembly calling "handle" function// we call via assembly to avoid memcopying a very large returndata// returned by a malicious contractassembly {
_success :=call(
_gas, // gas
_target, // recipient0, // ether valueadd(_calldata, 0x20), // inlocmload(_calldata), // inlen0, // outloc0// outlen
)
// limit our copy to 256 bytes
_toCopy :=returndatasize()
ifgt(_toCopy, _maxCopy) {
_toCopy := _maxCopy
}
// Store the length of the copied bytesmstore(_returnData, _toCopy)
// copy the bytes from returndata[0:_toCopy]returndatacopy(add(_returnData, 0x20), 0, _toCopy)
}
return (_success, _returnData);
}
/// @notice Use when you _really_ really _really_ don't trust the called/// contract. This prevents the called contract from causing reversion of/// the caller in as many ways as we can./// @dev The main difference between this and a solidity low-level call is/// that we limit the number of bytes that the callee can cause to be/// copied to caller memory. This prevents stupid things like malicious/// contracts returning 10,000,000 bytes causing a local OOG when copying/// to memory./// @param _target The address to call/// @param _gas The amount of gas to forward to the remote contract/// @param _maxCopy The maximum number of bytes of returndata to copy/// to memory./// @param _calldata The data to send to the remote contract/// @return success and returndata, as `.call()`. Returndata is capped to/// `_maxCopy` bytes.functionexcessivelySafeStaticCall(address _target,
uint256 _gas,
uint16 _maxCopy,
bytesmemory _calldata
) internalviewreturns (bool, bytesmemory) {
// set up for assembly calluint256 _toCopy;
bool _success;
bytesmemory _returnData =newbytes(_maxCopy);
// dispatch message to recipient// by assembly calling "handle" function// we call via assembly to avoid memcopying a very large returndata// returned by a malicious contractassembly {
_success :=staticcall(
_gas, // gas
_target, // recipientadd(_calldata, 0x20), // inlocmload(_calldata), // inlen0, // outloc0// outlen
)
// limit our copy to 256 bytes
_toCopy :=returndatasize()
ifgt(_toCopy, _maxCopy) {
_toCopy := _maxCopy
}
// Store the length of the copied bytesmstore(_returnData, _toCopy)
// copy the bytes from returndata[0:_toCopy]returndatacopy(add(_returnData, 0x20), 0, _toCopy)
}
return (_success, _returnData);
}
/**
* @notice Swaps function selectors in encoded contract calls
* @dev Allows reuse of encoded calldata for functions with identical
* argument types but different names. It simply swaps out the first 4 bytes
* for the new selector. This function modifies memory in place, and should
* only be used with caution.
* @param _newSelector The new 4-byte selector
* @param _buf The encoded contract args
*/functionswapSelector(bytes4 _newSelector, bytesmemory _buf)
internalpure{
require(_buf.length>=4);
uint256 _mask = LOW_28_MASK;
assembly {
// load the first word oflet _word :=mload(add(_buf, 0x20))
// mask out the top 4 bytes// /x
_word :=and(_word, _mask)
_word :=or(_newSelector, _word)
mstore(add(_buf, 0x20), _word)
}
}
}
Contract Source Code
File 6 of 19: IERC165.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)pragmasolidity ^0.8.0;/**
* @dev Interface of the ERC165 standard, as defined in the
* https://eips.ethereum.org/EIPS/eip-165[EIP].
*
* Implementers can declare support of contract interfaces, which can then be
* queried by others ({ERC165Checker}).
*
* For an implementation, see {ERC165}.
*/interfaceIERC165{
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
* to learn more about how these ids are created.
*
* This function call must use less than 30 000 gas.
*/functionsupportsInterface(bytes4 interfaceId) externalviewreturns (bool);
}
Contract Source Code
File 7 of 19: IERC20.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)pragmasolidity ^0.8.0;/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/interfaceIERC20{
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/eventTransfer(addressindexedfrom, addressindexed 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.
*/eventApproval(addressindexed owner, addressindexed spender, uint256 value);
/**
* @dev Returns the amount of tokens in existence.
*/functiontotalSupply() externalviewreturns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/functionbalanceOf(address account) externalviewreturns (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.
*/functiontransfer(address to, uint256 amount) externalreturns (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.
*/functionallowance(address owner, address spender) externalviewreturns (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.
*/functionapprove(address spender, uint256 amount) externalreturns (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.
*/functiontransferFrom(addressfrom,
address to,
uint256 amount
) externalreturns (bool);
}
Contract Source Code
File 8 of 19: ILayerZeroEndpoint.sol
// SPDX-License-Identifier: MITpragmasolidity >=0.5.0;import"./ILayerZeroUserApplicationConfig.sol";
interfaceILayerZeroEndpointisILayerZeroUserApplicationConfig{
// @notice send a LayerZero message to the specified address at a LayerZero endpoint.// @param _dstChainId - the destination chain identifier// @param _destination - the address on destination chain (in bytes). address length/format may vary by chains// @param _payload - a custom bytes payload to send to the destination contract// @param _refundAddress - if the source transaction is cheaper than the amount of value passed, refund the additional amount to this address// @param _zroPaymentAddress - the address of the ZRO token holder who would pay for the transaction// @param _adapterParams - parameters for custom functionality. e.g. receive airdropped native gas from the relayer on destinationfunctionsend(uint16 _dstChainId, bytescalldata _destination, bytescalldata _payload, addresspayable _refundAddress, address _zroPaymentAddress, bytescalldata _adapterParams) externalpayable;
// @notice used by the messaging library to publish verified payload// @param _srcChainId - the source chain identifier// @param _srcAddress - the source contract (as bytes) at the source chain// @param _dstAddress - the address on destination chain// @param _nonce - the unbound message ordering nonce// @param _gasLimit - the gas limit for external contract execution// @param _payload - verified payload to send to the destination contractfunctionreceivePayload(uint16 _srcChainId, bytescalldata _srcAddress, address _dstAddress, uint64 _nonce, uint _gasLimit, bytescalldata _payload) external;
// @notice get the inboundNonce of a lzApp from a source chain which could be EVM or non-EVM chain// @param _srcChainId - the source chain identifier// @param _srcAddress - the source chain contract addressfunctiongetInboundNonce(uint16 _srcChainId, bytescalldata _srcAddress) externalviewreturns (uint64);
// @notice get the outboundNonce from this source chain which, consequently, is always an EVM// @param _srcAddress - the source chain contract addressfunctiongetOutboundNonce(uint16 _dstChainId, address _srcAddress) externalviewreturns (uint64);
// @notice gets a quote in source native gas, for the amount that send() requires to pay for message delivery// @param _dstChainId - the destination chain identifier// @param _userApplication - the user app address on this EVM chain// @param _payload - the custom message to send over LayerZero// @param _payInZRO - if false, user app pays the protocol fee in native token// @param _adapterParam - parameters for the adapter service, e.g. send some dust native token to dstChainfunctionestimateFees(uint16 _dstChainId, address _userApplication, bytescalldata _payload, bool _payInZRO, bytescalldata _adapterParam) externalviewreturns (uint nativeFee, uint zroFee);
// @notice get this Endpoint's immutable source identifierfunctiongetChainId() externalviewreturns (uint16);
// @notice the interface to retry failed message on this Endpoint destination// @param _srcChainId - the source chain identifier// @param _srcAddress - the source chain contract address// @param _payload - the payload to be retriedfunctionretryPayload(uint16 _srcChainId, bytescalldata _srcAddress, bytescalldata _payload) external;
// @notice query if any STORED payload (message blocking) at the endpoint.// @param _srcChainId - the source chain identifier// @param _srcAddress - the source chain contract addressfunctionhasStoredPayload(uint16 _srcChainId, bytescalldata _srcAddress) externalviewreturns (bool);
// @notice query if the _libraryAddress is valid for sending msgs.// @param _userApplication - the user app address on this EVM chainfunctiongetSendLibraryAddress(address _userApplication) externalviewreturns (address);
// @notice query if the _libraryAddress is valid for receiving msgs.// @param _userApplication - the user app address on this EVM chainfunctiongetReceiveLibraryAddress(address _userApplication) externalviewreturns (address);
// @notice query if the non-reentrancy guard for send() is on// @return true if the guard is on. false otherwisefunctionisSendingPayload() externalviewreturns (bool);
// @notice query if the non-reentrancy guard for receive() is on// @return true if the guard is on. false otherwisefunctionisReceivingPayload() externalviewreturns (bool);
// @notice get the configuration of the LayerZero messaging library of the specified version// @param _version - messaging library version// @param _chainId - the chainId for the pending config change// @param _userApplication - the contract address of the user application// @param _configType - type of configuration. every messaging library has its own convention.functiongetConfig(uint16 _version, uint16 _chainId, address _userApplication, uint _configType) externalviewreturns (bytesmemory);
// @notice get the send() LayerZero messaging library version// @param _userApplication - the contract address of the user applicationfunctiongetSendVersion(address _userApplication) externalviewreturns (uint16);
// @notice get the lzReceive() LayerZero messaging library version// @param _userApplication - the contract address of the user applicationfunctiongetReceiveVersion(address _userApplication) externalviewreturns (uint16);
}
Contract Source Code
File 9 of 19: ILayerZeroReceiver.sol
// SPDX-License-Identifier: MITpragmasolidity >=0.5.0;interfaceILayerZeroReceiver{
// @notice LayerZero endpoint will invoke this function to deliver the message on the destination// @param _srcChainId - the source endpoint identifier// @param _srcAddress - the source sending contract address from the source chain// @param _nonce - the ordered message nonce// @param _payload - the signed payload is the UA bytes has encoded to be sentfunctionlzReceive(uint16 _srcChainId, bytescalldata _srcAddress, uint64 _nonce, bytescalldata _payload) external;
}
Contract Source Code
File 10 of 19: ILayerZeroUserApplicationConfig.sol
// SPDX-License-Identifier: MITpragmasolidity >=0.5.0;interfaceILayerZeroUserApplicationConfig{
// @notice set the configuration of the LayerZero messaging library of the specified version// @param _version - messaging library version// @param _chainId - the chainId for the pending config change// @param _configType - type of configuration. every messaging library has its own convention.// @param _config - configuration in the bytes. can encode arbitrary content.functionsetConfig(uint16 _version, uint16 _chainId, uint _configType, bytescalldata _config) external;
// @notice set the send() LayerZero messaging library version to _version// @param _version - new messaging library versionfunctionsetSendVersion(uint16 _version) external;
// @notice set the lzReceive() LayerZero messaging library version to _version// @param _version - new messaging library versionfunctionsetReceiveVersion(uint16 _version) external;
// @notice Only when the UA needs to resume the message flow in blocking mode and clear the stored payload// @param _srcChainId - the chainId of the source chain// @param _srcAddress - the contract address of the source contract at the source chainfunctionforceResumeReceive(uint16 _srcChainId, bytescalldata _srcAddress) external;
}
Contract Source Code
File 11 of 19: IOFTCore.sol
// SPDX-License-Identifier: MITpragmasolidity >=0.5.0;import"@openzeppelin/contracts/utils/introspection/IERC165.sol";
/**
* @dev Interface of the IOFT core standard
*/interfaceIOFTCoreisIERC165{
/**
* @dev estimate send token `_tokenId` to (`_dstChainId`, `_toAddress`)
* _dstChainId - L0 defined chain id to send tokens too
* _toAddress - dynamic bytes array which contains the address to whom you are sending tokens to on the dstChain
* _amount - amount of the tokens to transfer
* _useZro - indicates to use zro to pay L0 fees
* _adapterParam - flexible bytes array to indicate messaging adapter services in L0
*/functionestimateSendFee(uint16 _dstChainId, bytescalldata _toAddress, uint _amount, bool _useZro, bytescalldata _adapterParams) externalviewreturns (uint nativeFee, uint zroFee);
/**
* @dev send `_amount` amount of token to (`_dstChainId`, `_toAddress`) from `_from`
* `_from` the owner of token
* `_dstChainId` the destination chain identifier
* `_toAddress` can be any size depending on the `dstChainId`.
* `_amount` the quantity of tokens in wei
* `_refundAddress` the address LayerZero refunds if too much message fee is sent
* `_zroPaymentAddress` set to address(0x0) if not paying in ZRO (LayerZero Token)
* `_adapterParams` is a flexible bytes array to indicate messaging adapter services
*/functionsendFrom(address _from, uint16 _dstChainId, bytescalldata _toAddress, uint _amount, addresspayable _refundAddress, address _zroPaymentAddress, bytescalldata _adapterParams) externalpayable;
/**
* @dev returns the circulating amount of tokens on current chain
*/functioncirculatingSupply() externalviewreturns (uint);
/**
* @dev returns the address of the ERC20 token
*/functiontoken() externalviewreturns (address);
/**
* @dev Emitted when `_amount` tokens are moved from the `_sender` to (`_dstChainId`, `_toAddress`)
* `_nonce` is the outbound nonce
*/eventSendToChain(uint16indexed _dstChainId, addressindexed _from, bytes _toAddress, uint _amount);
/**
* @dev Emitted when `_amount` tokens are received from `_srcChainId` into the `_toAddress` on the local chain.
* `_nonce` is the inbound nonce.
*/eventReceiveFromChain(uint16indexed _srcChainId, addressindexed _to, uint _amount);
eventSetUseCustomAdapterParams(bool _useCustomAdapterParams);
}
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)pragmasolidity ^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.
*/abstractcontractOwnableisContext{
addressprivate _owner;
eventOwnershipTransferred(addressindexed previousOwner, addressindexed 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.
*/modifieronlyOwner() {
_checkOwner();
_;
}
/**
* @dev Returns the address of the current owner.
*/functionowner() publicviewvirtualreturns (address) {
return _owner;
}
/**
* @dev Throws if the sender is not the owner.
*/function_checkOwner() internalviewvirtual{
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.
*/functionrenounceOwnership() publicvirtualonlyOwner{
_transferOwnership(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/functiontransferOwnership(address newOwner) publicvirtualonlyOwner{
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) internalvirtual{
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
Contract Source Code
File 17 of 19: PrimeTokenProxy.sol
// SPDX-License-Identifier: MITpragmasolidity 0.8.17;import { OFTCore } from"@layerzerolabs/solidity-examples/contracts/token/oft/OFTCore.sol";
import { SafeERC20, IERC20 } from"@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import { IPrimeTokenProxy } from"./interfaces/IPrimeTokenProxy.sol";
contractPrimeTokenProxyisIPrimeTokenProxy, OFTCore{
usingSafeERC20forIERC20;
/// @notice Prime token contract address
IERC20 publicimmutable prime;
/// @notice Disabled state of the contract through invoke echelonboolpublic isDisabled;
/// @notice Disabled state of send fromboolpublic isSendFromDisabled =true;
constructor(address _lzEndpoint, address _proxyToken) OFTCore(_lzEndpoint) {
prime = IERC20(_proxyToken);
}
receive() externalpayable{}
/**
* @dev returns the address of the ERC20 token
*/functiontoken() externalviewoverridereturns (address) {
returnaddress(prime);
}
/**
* @notice Returns the circulating supply of the token.
*/functioncirculatingSupply()
publicviewvirtualoverridereturns (uint256)
{
unchecked {
return prime.totalSupply() - prime.balanceOf(address(this));
}
}
/** @notice Set the isDisabled state
* @param _isDisabled new isDisabled state
*/functionsetIsDisabled(bool _isDisabled) externalonlyOwner{
isDisabled = _isDisabled;
emit IsDisabledSet(_isDisabled);
}
/** @notice Set send from disabled state
* @param _isSendFromDisabled new dend from disabled state
*/functionsetIsSendFromDisabled(bool _isSendFromDisabled
) externalonlyOwner{
isSendFromDisabled = _isSendFromDisabled;
emit IsSendFromDisabledSet(_isSendFromDisabled);
}
/**
* @notice Identical function to `send` except users can bridge using prime invokeEchelon call.
* This way users do not have to approve PrimeTokenProxy to spend prime and bridge their tokens.
* prime will be sent to a primeDestinationAddress that has already approved PrimeTokenProxy and
* ethDestinationAddress will be the PrimeTokenProxy contract itself so that the nativeFees required for
* lzSend call have already been provided to the contract before the handleInvokeEchelon call.
* @param _from The address of the original msg.sender
* @param _ethDestinationAddress must be address of this contract
* @param _primeDestinationAddress original msg.sender transferred _primeDestinationAddress, we will debitFrom this address on behalf
* of the user.
* @param _primeValue The amount of prime that was sent from the prime token contract
* @param _data remaining params required for layerZero send
*/functionhandleInvokeEchelon(address _from,
address _ethDestinationAddress,
address _primeDestinationAddress,
uint256,
uint256,
uint256 _primeValue,
bytesmemory _data
) publicpayable{
if (isDisabled) {
revert ContractDisabled();
}
if (_msgSender() !=address(prime)) {
revert InvalidCaller();
}
// prime contract needs to set prime/ETH destinations as this addressif (_ethDestinationAddress !=address(this)) {
revert InvalidEthDestination(_ethDestinationAddress);
}
if (_primeDestinationAddress !=address(this)) {
revert InvalidPrimeAddress(_primeDestinationAddress);
}
(
uint16 dstChainId,
uint256 amount,
address refundAddress,
address zroPaymentAddress,
bytesmemory adapterParams
) =abi.decode(_data, (uint16, uint256, address, address, bytes));
if (_primeValue != amount) {
revert InvalidPrimePayment();
}
_checkAdapterParams(dstChainId, PT_SEND, adapterParams, NO_EXTRA_GAS);
bytesmemory lzPayload =abi.encode(
PT_SEND,
abi.encodePacked(_from),
amount
);
_lzSend(
dstChainId,
lzPayload,
payable(refundAddress),
zroPaymentAddress,
adapterParams,
address(this).balance
);
emit SendToChain(dstChainId, _from, abi.encodePacked(_from), amount);
}
/**
* @notice Sends prime over to the other side
* @param _from The address that will have its tokens burned when bridging
* @param _dstChainId The destination chain identifier
* @param _toAddress The address that will receive the tokens
* @param _amount Amount of tokens to bridge
* @param _refundAddress If the source transaction is cheaper than the amount of value passed, refund the additional amount to this address
* @param _zroPaymentAddress The address of the ZRO token holder who would pay for the transaction
* @param _adapterParams parameters for custom functionality. e.g. receive airdropped native gas from the relayer on destination
*/functionsendFrom(address _from,
uint16 _dstChainId,
bytescalldata _toAddress,
uint _amount,
addresspayable _refundAddress,
address _zroPaymentAddress,
bytescalldata _adapterParams
) publicpayablevirtualoverride{
if (isSendFromDisabled) {
revert ContractDisabled();
}
_send(
_from,
_dstChainId,
_toAddress,
_amount,
_refundAddress,
_zroPaymentAddress,
_adapterParams
);
}
/**
* @notice Sends prime over to the other side
* @param _from The address that will have its tokens burned when bridging
* @param _dstChainId The destination chain identifier
* @param _amount Amount of tokens to bridge
* @param _refundAddress If the source transaction is cheaper than the amount of value passed, refund the additional amount to this address
* @param _zroPaymentAddress The address of the ZRO token holder who would pay for the transaction
* @param _adapterParams parameters for custom functionality. e.g. receive airdropped native gas from the relayer on destination
*/functionsend(address _from,
uint16 _dstChainId,
uint256 _amount,
addresspayable _refundAddress,
address _zroPaymentAddress,
bytesmemory _adapterParams
) publicpayablevirtual{
_send(
_from,
_dstChainId,
abi.encodePacked(_from),
_amount,
_refundAddress,
_zroPaymentAddress,
_adapterParams
);
}
/**
* @notice Lock user's token
* @dev User that's getting their token locked must also be the caller
* @param _from The address that will have its tokens locked
* @param _amount Amount of tokens to lock
*/function_debitFrom(address _from,
uint16,
bytesmemory,
uint256 _amount
) internalvirtualoverridereturns (uint256) {
if (_from != _msgSender()) {
revert InvalidCaller();
}
prime.safeTransferFrom(_msgSender(), address(this), _amount);
return _amount;
}
/**
* @notice Unlock tokens for user
* @param _toAddress The address that will have tokens unlocked for
* @param _amount Amount of tokens to unlock
*/function_creditTo(uint16,
address _toAddress,
uint256 _amount
) internalvirtualoverridereturns (uint256) {
prime.safeTransfer(_toAddress, _amount);
return _amount;
}
}
Contract Source Code
File 18 of 19: SafeERC20.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/utils/SafeERC20.sol)pragmasolidity ^0.8.0;import"../IERC20.sol";
import"../extensions/draft-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.
*/librarySafeERC20{
usingAddressforaddress;
functionsafeTransfer(
IERC20 token,
address to,
uint256 value
) internal{
_callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
}
functionsafeTransferFrom(
IERC20 token,
addressfrom,
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.
*/functionsafeApprove(
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));
}
functionsafeIncreaseAllowance(
IERC20 token,
address spender,
uint256 value
) internal{
uint256 newAllowance = token.allowance(address(this), spender) + value;
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
functionsafeDecreaseAllowance(
IERC20 token,
address spender,
uint256 value
) internal{
unchecked {
uint256 oldAllowance = token.allowance(address(this), spender);
require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
uint256 newAllowance = oldAllowance - value;
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
}
functionsafePermit(
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, bytesmemory 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.bytesmemory returndata =address(token).functionCall(data, "SafeERC20: low-level call failed");
if (returndata.length>0) {
// Return data is optionalrequire(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
}
}
}
Contract Source Code
File 19 of 19: draft-IERC20Permit.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-IERC20Permit.sol)pragmasolidity ^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.
*/interfaceIERC20Permit{
/**
* @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].
*/functionpermit(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.
*/functionnonces(address owner) externalviewreturns (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-mixedcasefunctionDOMAIN_SEPARATOR() externalviewreturns (bytes32);
}