// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.0) (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
*
* 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.
* ====
*/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://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].
*/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 11: 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 11: IERC1271.sol
// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;interfaceIERC1271{
/// @dev Should return whether the signature provided is valid for the provided data/// @param hash Hash of the data to be signed/// @param signature Signature byte array associated with _data/// @return magicValue The bytes4 magic value 0x1626ba7efunctionisValidSignature(bytes32 hash, bytesmemory signature) externalviewreturns (bytes4 magicValue);
}
Contract Source Code
File 4 of 11: IERC20.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.0) (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 5 of 11: IERC20Permit.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/extensions/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);
}
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.0) (security/ReentrancyGuard.sol)pragmasolidity ^0.8.0;/**
* @dev Contract module that helps prevent reentrant calls to a function.
*
* Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
* available, which can be applied to functions to make sure there are no nested
* (reentrant) calls to them.
*
* Note that because there is a single `nonReentrant` guard, functions marked as
* `nonReentrant` may not call one another. This can be worked around by making
* those functions `private`, and then adding `external` `nonReentrant` entry
* points to them.
*
* TIP: If you would like to learn more about reentrancy and alternative ways
* to protect against it, check out our blog post
* https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
*/abstractcontractReentrancyGuard{
// Booleans are more expensive than uint256 or any type that takes up a full// word because each write operation emits an extra SLOAD to first read the// slot's contents, replace the bits taken up by the boolean, and then write// back. This is the compiler's defense against contract upgrades and// pointer aliasing, and it cannot be disabled.// The values being non-zero value makes deployment a bit more expensive,// but in exchange the refund on every call to nonReentrant will be lower in// amount. Since refunds are capped to a percentage of the total// transaction's gas, it is best to keep them low in cases like this one, to// increase the likelihood of the full refund coming into effect.uint256privateconstant _NOT_ENTERED =1;
uint256privateconstant _ENTERED =2;
uint256private _status;
constructor() {
_status = _NOT_ENTERED;
}
/**
* @dev Prevents a contract from calling itself, directly or indirectly.
* Calling a `nonReentrant` function from another `nonReentrant`
* function is not supported. It is possible to prevent this from happening
* by making the `nonReentrant` function external, and making it call a
* `private` function that does the actual work.
*/modifiernonReentrant() {
_nonReentrantBefore();
_;
_nonReentrantAfter();
}
function_nonReentrantBefore() private{
// On the first call to nonReentrant, _status will be _NOT_ENTEREDrequire(_status != _ENTERED, "ReentrancyGuard: reentrant call");
// Any calls to nonReentrant after this point will fail
_status = _ENTERED;
}
function_nonReentrantAfter() private{
// By storing the original value once again, a refund is triggered (see// https://eips.ethereum.org/EIPS/eip-2200)
_status = _NOT_ENTERED;
}
/**
* @dev Returns true if the reentrancy guard is currently set to "entered", which indicates there is a
* `nonReentrant` function in the call stack.
*/function_reentrancyGuardEntered() internalviewreturns (bool) {
return _status == _ENTERED;
}
}
Contract Source Code
File 10 of 11: SafeERC20.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.3) (token/ERC20/utils/SafeERC20.sol)pragmasolidity ^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.
*/librarySafeERC20{
usingAddressforaddress;
/**
* @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.
*/functionsafeTransfer(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.
*/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));
}
/**
* @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
* non-reverting calls are assumed to be successful.
*/functionsafeIncreaseAllowance(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.
*/functionsafeDecreaseAllowance(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.
*/functionforceApprove(IERC20 token, address spender, uint256 value) internal{
bytesmemory 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.
*/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");
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, bytesmemory data) privatereturns (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, bytesmemory returndata) =address(token).call(data);
return
success && (returndata.length==0||abi.decode(returndata, (bool))) && Address.isContract(address(token));
}
}
Contract Source Code
File 11 of 11: SignatureVerifier.sol
// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;import {IERC1271} from"../interfaces/IERC1271.sol";
librarySignatureVerifier{
/// @notice Thrown when the passed in signature is not a valid lengtherrorInvalidSignatureLength();
/// @notice Thrown when the recovered signer is equal to the zero addresserrorInvalidSignature();
/// @notice Thrown when the recovered signer does not equal the claimedSignererrorInvalidSigner();
/// @notice Thrown when the recovered contract signature is incorrecterrorInvalidContractSignature();
bytes32constant UPPER_BIT_MASK = (0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
functionverify(bytescalldata signature, bytes32 hash, address claimedSigner) externalview{
bytes32 r;
bytes32 s;
uint8 v;
if (claimedSigner.code.length==0) {
if (signature.length==65) {
(r, s) =abi.decode(signature, (bytes32, bytes32));
v =uint8(signature[64]);
} elseif (signature.length==64) {
// EIP-2098bytes32 vs;
(r, vs) =abi.decode(signature, (bytes32, bytes32));
s = vs & UPPER_BIT_MASK;
v =uint8(uint256(vs >>255)) +27;
} else {
revert InvalidSignatureLength();
}
address signer =ecrecover(hash, v, r, s);
if (signer ==address(0)) revert InvalidSignature();
if (signer != claimedSigner) revert InvalidSigner();
} else {
bytes4 magicValue = IERC1271(claimedSigner).isValidSignature(hash, signature);
if (magicValue != IERC1271.isValidSignature.selector) revert InvalidContractSignature();
}
}
}