Contract Source Code:
// SPDX-License-Identifier: MIT
pragma solidity >=0.5.0;
import "./ILayerZeroUserApplicationConfig.sol";
interface ILayerZeroEndpoint is ILayerZeroUserApplicationConfig {
// @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 destination
function send(uint16 _dstChainId, bytes calldata _destination, bytes calldata _payload, address payable _refundAddress, address _zroPaymentAddress, bytes calldata _adapterParams) external payable;
// @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 contract
function receivePayload(uint16 _srcChainId, bytes calldata _srcAddress, address _dstAddress, uint64 _nonce, uint _gasLimit, bytes calldata _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 address
function getInboundNonce(uint16 _srcChainId, bytes calldata _srcAddress) external view returns (uint64);
// @notice get the outboundNonce from this source chain which, consequently, is always an EVM
// @param _srcAddress - the source chain contract address
function getOutboundNonce(uint16 _dstChainId, address _srcAddress) external view returns (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 dstChain
function estimateFees(uint16 _dstChainId, address _userApplication, bytes calldata _payload, bool _payInZRO, bytes calldata _adapterParam) external view returns (uint nativeFee, uint zroFee);
// @notice get this Endpoint's immutable source identifier
function getChainId() external view returns (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 retried
function retryPayload(uint16 _srcChainId, bytes calldata _srcAddress, bytes calldata _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 address
function hasStoredPayload(uint16 _srcChainId, bytes calldata _srcAddress) external view returns (bool);
// @notice query if the _libraryAddress is valid for sending msgs.
// @param _userApplication - the user app address on this EVM chain
function getSendLibraryAddress(address _userApplication) external view returns (address);
// @notice query if the _libraryAddress is valid for receiving msgs.
// @param _userApplication - the user app address on this EVM chain
function getReceiveLibraryAddress(address _userApplication) external view returns (address);
// @notice query if the non-reentrancy guard for send() is on
// @return true if the guard is on. false otherwise
function isSendingPayload() external view returns (bool);
// @notice query if the non-reentrancy guard for receive() is on
// @return true if the guard is on. false otherwise
function isReceivingPayload() external view returns (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.
function getConfig(uint16 _version, uint16 _chainId, address _userApplication, uint _configType) external view returns (bytes memory);
// @notice get the send() LayerZero messaging library version
// @param _userApplication - the contract address of the user application
function getSendVersion(address _userApplication) external view returns (uint16);
// @notice get the lzReceive() LayerZero messaging library version
// @param _userApplication - the contract address of the user application
function getReceiveVersion(address _userApplication) external view returns (uint16);
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.5.0;
interface ILayerZeroReceiver {
// @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 sent
function lzReceive(uint16 _srcChainId, bytes calldata _srcAddress, uint64 _nonce, bytes calldata _payload) external;
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.5.0;
interface ILayerZeroUserApplicationConfig {
// @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.
function setConfig(uint16 _version, uint16 _chainId, uint _configType, bytes calldata _config) external;
// @notice set the send() LayerZero messaging library version to _version
// @param _version - new messaging library version
function setSendVersion(uint16 _version) external;
// @notice set the lzReceive() LayerZero messaging library version to _version
// @param _version - new messaging library version
function setReceiveVersion(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 chain
function forceResumeReceive(uint16 _srcChainId, bytes calldata _srcAddress) external;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/access/Ownable.sol";
import "../interfaces/ILayerZeroReceiver.sol";
import "../interfaces/ILayerZeroUserApplicationConfig.sol";
import "../interfaces/ILayerZeroEndpoint.sol";
import "../util/BytesLib.sol";
/*
* a generic LzReceiver implementation
*/
abstract contract LzApp is Ownable, ILayerZeroReceiver, ILayerZeroUserApplicationConfig {
using BytesLib for bytes;
// ua can not send payload larger than this by default, but it can be changed by the ua owner
uint constant public DEFAULT_PAYLOAD_SIZE_LIMIT = 10000;
ILayerZeroEndpoint public immutable lzEndpoint;
mapping(uint16 => bytes) public trustedRemoteLookup;
mapping(uint16 => mapping(uint16 => uint)) public minDstGasLookup;
mapping(uint16 => uint) public payloadSizeLimitLookup;
address public precrime;
event SetPrecrime(address precrime);
event SetTrustedRemote(uint16 _remoteChainId, bytes _path);
event SetTrustedRemoteAddress(uint16 _remoteChainId, bytes _remoteAddress);
event SetMinDstGas(uint16 _dstChainId, uint16 _type, uint _minDstGas);
constructor(address _endpoint) {
lzEndpoint = ILayerZeroEndpoint(_endpoint);
}
function lzReceive(uint16 _srcChainId, bytes calldata _srcAddress, uint64 _nonce, bytes calldata _payload) public virtual override {
// lzReceive must be called by the endpoint for security
require(_msgSender() == address(lzEndpoint), "LzApp: invalid endpoint caller");
bytes memory trustedRemote = trustedRemoteLookup[_srcChainId];
// if will still block the message pathway from (srcChainId, srcAddress). should not receive message from untrusted remote.
require(_srcAddress.length == trustedRemote.length && trustedRemote.length > 0 && keccak256(_srcAddress) == keccak256(trustedRemote), "LzApp: invalid source sending contract");
_blockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload);
}
// abstract function - the default behaviour of LayerZero is blocking. See: NonblockingLzApp if you dont need to enforce ordered messaging
function _blockingLzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) internal virtual;
function _lzSend(uint16 _dstChainId, bytes memory _payload, address payable _refundAddress, address _zroPaymentAddress, bytes memory _adapterParams, uint _nativeFee) internal virtual {
bytes memory trustedRemote = trustedRemoteLookup[_dstChainId];
require(trustedRemote.length != 0, "LzApp: destination chain is not a trusted source");
_checkPayloadSize(_dstChainId, _payload.length);
lzEndpoint.send{value: _nativeFee}(_dstChainId, trustedRemote, _payload, _refundAddress, _zroPaymentAddress, _adapterParams);
}
function _checkGasLimit(uint16 _dstChainId, uint16 _type, bytes memory _adapterParams, uint _extraGas) internal view virtual {
uint providedGasLimit = _getGasLimit(_adapterParams);
uint minGasLimit = minDstGasLookup[_dstChainId][_type] + _extraGas;
require(minGasLimit > 0, "LzApp: minGasLimit not set");
require(providedGasLimit >= minGasLimit, "LzApp: gas limit is too low");
}
function _getGasLimit(bytes memory _adapterParams) internal pure virtual returns (uint gasLimit) {
require(_adapterParams.length >= 34, "LzApp: invalid adapterParams");
assembly {
gasLimit := mload(add(_adapterParams, 34))
}
}
function _checkPayloadSize(uint16 _dstChainId, uint _payloadSize) internal view virtual {
uint payloadSizeLimit = payloadSizeLimitLookup[_dstChainId];
if (payloadSizeLimit == 0) { // use default if not set
payloadSizeLimit = DEFAULT_PAYLOAD_SIZE_LIMIT;
}
require(_payloadSize <= payloadSizeLimit, "LzApp: payload size is too large");
}
//---------------------------UserApplication config----------------------------------------
function getConfig(uint16 _version, uint16 _chainId, address, uint _configType) external view returns (bytes memory) {
return lzEndpoint.getConfig(_version, _chainId, address(this), _configType);
}
// generic config for LayerZero user Application
function setConfig(uint16 _version, uint16 _chainId, uint _configType, bytes calldata _config) external override onlyOwner {
lzEndpoint.setConfig(_version, _chainId, _configType, _config);
}
function setSendVersion(uint16 _version) external override onlyOwner {
lzEndpoint.setSendVersion(_version);
}
function setReceiveVersion(uint16 _version) external override onlyOwner {
lzEndpoint.setReceiveVersion(_version);
}
function forceResumeReceive(uint16 _srcChainId, bytes calldata _srcAddress) external override onlyOwner {
lzEndpoint.forceResumeReceive(_srcChainId, _srcAddress);
}
// _path = abi.encodePacked(remoteAddress, localAddress)
// this function set the trusted path for the cross-chain communication
function setTrustedRemote(uint16 _remoteChainId, bytes calldata _path) external onlyOwner {
trustedRemoteLookup[_remoteChainId] = _path;
emit SetTrustedRemote(_remoteChainId, _path);
}
function setTrustedRemoteAddress(uint16 _remoteChainId, bytes calldata _remoteAddress) external onlyOwner {
trustedRemoteLookup[_remoteChainId] = abi.encodePacked(_remoteAddress, address(this));
emit SetTrustedRemoteAddress(_remoteChainId, _remoteAddress);
}
function getTrustedRemoteAddress(uint16 _remoteChainId) external view returns (bytes memory) {
bytes memory path = trustedRemoteLookup[_remoteChainId];
require(path.length != 0, "LzApp: no trusted path record");
return path.slice(0, path.length - 20); // the last 20 bytes should be address(this)
}
function setPrecrime(address _precrime) external onlyOwner {
precrime = _precrime;
emit SetPrecrime(_precrime);
}
function setMinDstGas(uint16 _dstChainId, uint16 _packetType, uint _minGas) external onlyOwner {
require(_minGas > 0, "LzApp: invalid minGas");
minDstGasLookup[_dstChainId][_packetType] = _minGas;
emit SetMinDstGas(_dstChainId, _packetType, _minGas);
}
// if the size is 0, it means default size limit
function setPayloadSizeLimit(uint16 _dstChainId, uint _size) external onlyOwner {
payloadSizeLimitLookup[_dstChainId] = _size;
}
//--------------------------- VIEW FUNCTION ----------------------------------------
function isTrustedRemote(uint16 _srcChainId, bytes calldata _srcAddress) external view returns (bool) {
bytes memory trustedSource = trustedRemoteLookup[_srcChainId];
return keccak256(trustedSource) == keccak256(_srcAddress);
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./LzApp.sol";
import "../util/ExcessivelySafeCall.sol";
/*
* the default LayerZero messaging behaviour is blocking, i.e. any failed message will block the channel
* this abstract class try-catch all fail messages and store locally for future retry. hence, non-blocking
* NOTE: if the srcAddress is not configured properly, it will still block the message pathway from (srcChainId, srcAddress)
*/
abstract contract NonblockingLzApp is LzApp {
using ExcessivelySafeCall for address;
constructor(address _endpoint) LzApp(_endpoint) {}
mapping(uint16 => mapping(bytes => mapping(uint64 => bytes32))) public failedMessages;
event MessageFailed(uint16 _srcChainId, bytes _srcAddress, uint64 _nonce, bytes _payload, bytes _reason);
event RetryMessageSuccess(uint16 _srcChainId, bytes _srcAddress, uint64 _nonce, bytes32 _payloadHash);
// overriding the virtual function in LzReceiver
function _blockingLzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) internal virtual override {
(bool success, bytes memory reason) = address(this).excessivelySafeCall(gasleft(), 150, abi.encodeWithSelector(this.nonblockingLzReceive.selector, _srcChainId, _srcAddress, _nonce, _payload));
// try-catch all errors/exceptions
if (!success) {
_storeFailedMessage(_srcChainId, _srcAddress, _nonce, _payload, reason);
}
}
function _storeFailedMessage(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload, bytes memory _reason) internal virtual {
failedMessages[_srcChainId][_srcAddress][_nonce] = keccak256(_payload);
emit MessageFailed(_srcChainId, _srcAddress, _nonce, _payload, _reason);
}
function nonblockingLzReceive(uint16 _srcChainId, bytes calldata _srcAddress, uint64 _nonce, bytes calldata _payload) public virtual {
// only internal transaction
require(_msgSender() == address(this), "NonblockingLzApp: caller must be LzApp");
_nonblockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload);
}
//@notice override this function
function _nonblockingLzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) internal virtual;
function retryMessage(uint16 _srcChainId, bytes calldata _srcAddress, uint64 _nonce, bytes calldata _payload) public payable virtual {
// assert there is message to retry
bytes32 payloadHash = failedMessages[_srcChainId][_srcAddress][_nonce];
require(payloadHash != bytes32(0), "NonblockingLzApp: no stored message");
require(keccak256(_payload) == payloadHash, "NonblockingLzApp: invalid payload");
// clear the stored message
failedMessages[_srcChainId][_srcAddress][_nonce] = bytes32(0);
// execute the message. revert if it fails again
_nonblockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload);
emit RetryMessageSuccess(_srcChainId, _srcAddress, _nonce, payloadHash);
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../OFT.sol";
contract BasedOFT is OFT {
constructor(string memory _name, string memory _symbol, address _lzEndpoint) OFT(_name, _symbol, _lzEndpoint) {}
function circulatingSupply() public view virtual override returns (uint) {
unchecked {
return totalSupply() - balanceOf(address(this));
}
}
function _debitFrom(address _from, uint16, bytes memory, uint _amount) internal virtual override returns(uint) {
address spender = _msgSender();
if (_from != spender) _spendAllowance(_from, spender, _amount);
_transfer(_from, address(this), _amount);
return _amount;
}
function _creditTo(uint16, address _toAddress, uint _amount) internal virtual override returns(uint) {
_transfer(address(this), _toAddress, _amount);
return _amount;
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.5.0;
import "./IOFTCore.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
/**
* @dev Interface of the OFT standard
*/
interface IOFT is IOFTCore, IERC20 {
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.5.0;
import "@openzeppelin/contracts/utils/introspection/IERC165.sol";
/**
* @dev Interface of the IOFT core standard
*/
interface IOFTCore is IERC165 {
/**
* @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
*/
function estimateSendFee(uint16 _dstChainId, bytes calldata _toAddress, uint _amount, bool _useZro, bytes calldata _adapterParams) external view returns (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
*/
function sendFrom(address _from, uint16 _dstChainId, bytes calldata _toAddress, uint _amount, address payable _refundAddress, address _zroPaymentAddress, bytes calldata _adapterParams) external payable;
/**
* @dev returns the circulating amount of tokens on current chain
*/
function circulatingSupply() external view returns (uint);
/**
* @dev returns the address of the ERC20 token
*/
function token() external view returns (address);
/**
* @dev Emitted when `_amount` tokens are moved from the `_sender` to (`_dstChainId`, `_toAddress`)
* `_nonce` is the outbound nonce
*/
event SendToChain(uint16 indexed _dstChainId, address indexed _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.
*/
event ReceiveFromChain(uint16 indexed _srcChainId, address indexed _to, uint _amount);
event SetUseCustomAdapterParams(bool _useCustomAdapterParams);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/utils/introspection/IERC165.sol";
import "./IOFT.sol";
import "./OFTCore.sol";
// override decimal() function is needed
contract OFT is OFTCore, ERC20, IOFT {
constructor(string memory _name, string memory _symbol, address _lzEndpoint) ERC20(_name, _symbol) OFTCore(_lzEndpoint) {}
function supportsInterface(bytes4 interfaceId) public view virtual override(OFTCore, IERC165) returns (bool) {
return interfaceId == type(IOFT).interfaceId || interfaceId == type(IERC20).interfaceId || super.supportsInterface(interfaceId);
}
function token() public view virtual override returns (address) {
return address(this);
}
function circulatingSupply() public view virtual override returns (uint) {
return totalSupply();
}
function _debitFrom(address _from, uint16, bytes memory, uint _amount) internal virtual override returns(uint) {
address spender = _msgSender();
if (_from != spender) _spendAllowance(_from, spender, _amount);
_burn(_from, _amount);
return _amount;
}
function _creditTo(uint16, address _toAddress, uint _amount) internal virtual override returns(uint) {
_mint(_toAddress, _amount);
return _amount;
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../../lzApp/NonblockingLzApp.sol";
import "./IOFTCore.sol";
import "@openzeppelin/contracts/utils/introspection/ERC165.sol";
abstract contract OFTCore is NonblockingLzApp, ERC165, IOFTCore {
using BytesLib for bytes;
uint public constant NO_EXTRA_GAS = 0;
// packet type
uint16 public constant PT_SEND = 0;
bool public useCustomAdapterParams;
constructor(address _lzEndpoint) NonblockingLzApp(_lzEndpoint) {}
function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
return interfaceId == type(IOFTCore).interfaceId || super.supportsInterface(interfaceId);
}
function estimateSendFee(uint16 _dstChainId, bytes calldata _toAddress, uint _amount, bool _useZro, bytes calldata _adapterParams) public view virtual override returns (uint nativeFee, uint zroFee) {
// mock the payload for sendFrom()
bytes memory payload = abi.encode(PT_SEND, _toAddress, _amount);
return lzEndpoint.estimateFees(_dstChainId, address(this), payload, _useZro, _adapterParams);
}
function sendFrom(address _from, uint16 _dstChainId, bytes calldata _toAddress, uint _amount, address payable _refundAddress, address _zroPaymentAddress, bytes calldata _adapterParams) public payable virtual override {
_send(_from, _dstChainId, _toAddress, _amount, _refundAddress, _zroPaymentAddress, _adapterParams);
}
function setUseCustomAdapterParams(bool _useCustomAdapterParams) public virtual onlyOwner {
useCustomAdapterParams = _useCustomAdapterParams;
emit SetUseCustomAdapterParams(_useCustomAdapterParams);
}
function _nonblockingLzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) internal virtual override {
uint16 packetType;
assembly {
packetType := mload(add(_payload, 32))
}
if (packetType == PT_SEND) {
_sendAck(_srcChainId, _srcAddress, _nonce, _payload);
} else {
revert("OFTCore: unknown packet type");
}
}
function _send(address _from, uint16 _dstChainId, bytes memory _toAddress, uint _amount, address payable _refundAddress, address _zroPaymentAddress, bytes memory _adapterParams) internal virtual {
_checkAdapterParams(_dstChainId, PT_SEND, _adapterParams, NO_EXTRA_GAS);
uint amount = _debitFrom(_from, _dstChainId, _toAddress, _amount);
bytes memory lzPayload = abi.encode(PT_SEND, _toAddress, amount);
_lzSend(_dstChainId, lzPayload, _refundAddress, _zroPaymentAddress, _adapterParams, msg.value);
emit SendToChain(_dstChainId, _from, _toAddress, amount);
}
function _sendAck(uint16 _srcChainId, bytes memory, uint64, bytes memory _payload) internal virtual {
(, bytes memory toAddressBytes, uint amount) = abi.decode(_payload, (uint16, bytes, uint));
address to = toAddressBytes.toAddress(0);
amount = _creditTo(_srcChainId, to, amount);
emit ReceiveFromChain(_srcChainId, to, amount);
}
function _checkAdapterParams(uint16 _dstChainId, uint16 _pkType, bytes memory _adapterParams, uint _extraGas) internal virtual {
if (useCustomAdapterParams) {
_checkGasLimit(_dstChainId, _pkType, _adapterParams, _extraGas);
} else {
require(_adapterParams.length == 0, "OFTCore: _adapterParams must be empty.");
}
}
function _debitFrom(address _from, uint16 _dstChainId, bytes memory _toAddress, uint _amount) internal virtual returns(uint);
function _creditTo(uint16 _srcChainId, address _toAddress, uint _amount) internal virtual returns(uint);
}
// SPDX-License-Identifier: Unlicense
/*
* @title Solidity Bytes Arrays Utils
* @author Gonçalo Sá <[email protected]>
*
* @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.
*/
pragma solidity >=0.8.0 <0.9.0;
library BytesLib {
function concat(
bytes memory _preBytes,
bytes memory _postBytes
)
internal
pure
returns (bytes memory)
{
bytes memory 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;
}
function concatStorage(bytes storage _preBytes, bytes memory _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-storage
switch add(lt(slength, 32), lt(newlength, 32))
case 2 {
// 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_length
sstore(
_preBytes.slot,
// all the modifications to the slot are inside this
// next block
add(
// 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 memory
mload(add(_postBytes, 0x20)),
// zero all bytes to the right
exp(0x100, sub(32, mlength))
),
// and now shift left the number of bytes to
// leave space for the length in the slot
exp(0x100, sub(32, newlength))
),
// increase length by the double of the memory
// bytes length
mul(mlength, 2)
)
)
)
}
case 1 {
// The stored value fits in the slot, but the combined value
// will exceed it.
// get the keccak hash to get the contents of the array
mstore(0x0, _preBytes.slot)
let sc := add(keccak256(0x0, 0x20), div(slength, 32))
// save new length
sstore(_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 array
mstore(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 length
sstore(_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))
}
}
}
function slice(
bytes memory _bytes,
uint256 _start,
uint256 _length
)
internal
pure
returns (bytes memory)
{
require(_length + 31 >= _length, "slice_overflow");
require(_bytes.length >= _start + _length, "slice_outOfBounds");
bytes memory tempBytes;
assembly {
switch iszero(_length)
case 0 {
// 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 now
mstore(0x40, and(add(mc, 31), not(31)))
}
//if we want a zero-length slice let's just return a zero-length array
default {
tempBytes := mload(0x40)
//zero out the 32 bytes slice we are about to return
//we need to do it because Solidity does not garbage collect
mstore(tempBytes, 0)
mstore(0x40, add(tempBytes, 0x20))
}
}
return tempBytes;
}
function toAddress(bytes memory _bytes, uint256 _start) internal pure returns (address) {
require(_bytes.length >= _start + 20, "toAddress_outOfBounds");
address tempAddress;
assembly {
tempAddress := div(mload(add(add(_bytes, 0x20), _start)), 0x1000000000000000000000000)
}
return tempAddress;
}
function toUint8(bytes memory _bytes, uint256 _start) internal pure returns (uint8) {
require(_bytes.length >= _start + 1 , "toUint8_outOfBounds");
uint8 tempUint;
assembly {
tempUint := mload(add(add(_bytes, 0x1), _start))
}
return tempUint;
}
function toUint16(bytes memory _bytes, uint256 _start) internal pure returns (uint16) {
require(_bytes.length >= _start + 2, "toUint16_outOfBounds");
uint16 tempUint;
assembly {
tempUint := mload(add(add(_bytes, 0x2), _start))
}
return tempUint;
}
function toUint32(bytes memory _bytes, uint256 _start) internal pure returns (uint32) {
require(_bytes.length >= _start + 4, "toUint32_outOfBounds");
uint32 tempUint;
assembly {
tempUint := mload(add(add(_bytes, 0x4), _start))
}
return tempUint;
}
function toUint64(bytes memory _bytes, uint256 _start) internal pure returns (uint64) {
require(_bytes.length >= _start + 8, "toUint64_outOfBounds");
uint64 tempUint;
assembly {
tempUint := mload(add(add(_bytes, 0x8), _start))
}
return tempUint;
}
function toUint96(bytes memory _bytes, uint256 _start) internal pure returns (uint96) {
require(_bytes.length >= _start + 12, "toUint96_outOfBounds");
uint96 tempUint;
assembly {
tempUint := mload(add(add(_bytes, 0xc), _start))
}
return tempUint;
}
function toUint128(bytes memory _bytes, uint256 _start) internal pure returns (uint128) {
require(_bytes.length >= _start + 16, "toUint128_outOfBounds");
uint128 tempUint;
assembly {
tempUint := mload(add(add(_bytes, 0x10), _start))
}
return tempUint;
}
function toUint256(bytes memory _bytes, uint256 _start) internal pure returns (uint256) {
require(_bytes.length >= _start + 32, "toUint256_outOfBounds");
uint256 tempUint;
assembly {
tempUint := mload(add(add(_bytes, 0x20), _start))
}
return tempUint;
}
function toBytes32(bytes memory _bytes, uint256 _start) internal pure returns (bytes32) {
require(_bytes.length >= _start + 32, "toBytes32_outOfBounds");
bytes32 tempBytes32;
assembly {
tempBytes32 := mload(add(add(_bytes, 0x20), _start))
}
return tempBytes32;
}
function equal(bytes memory _preBytes, bytes memory _postBytes) internal pure returns (bool) {
bool success = true;
assembly {
let length := mload(_preBytes)
// if lengths don't match the arrays are not equal
switch eq(length, mload(_postBytes))
case 1 {
// 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 - break
let cb := 1
let 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 equal
if iszero(eq(mload(mc), mload(cc))) {
// unsuccess:
success := 0
cb := 0
}
}
}
default {
// unsuccess:
success := 0
}
}
return success;
}
function equalStorage(
bytes storage _preBytes,
bytes memory _postBytes
)
internal
view
returns (bool)
{
bool success = true;
assembly {
// we know _preBytes_offset is 0
let 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 equal
switch eq(slength, mlength)
case 1 {
// 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-storage
if iszero(iszero(slength)) {
switch lt(slength, 32)
case 1 {
// blank the last byte which is the length
fslot := mul(div(fslot, 0x100), 0x100)
if iszero(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 - break
let cb := 1
// get the keccak hash to get the contents of the array
mstore(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)
} {
if iszero(eq(sload(sc), mload(mc))) {
// unsuccess:
success := 0
cb := 0
}
}
}
}
}
default {
// unsuccess:
success := 0
}
}
return success;
}
}
// SPDX-License-Identifier: MIT OR Apache-2.0
pragma solidity >=0.7.6;
library ExcessivelySafeCall {
uint256 constant 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.
function excessivelySafeCall(
address _target,
uint256 _gas,
uint16 _maxCopy,
bytes memory _calldata
) internal returns (bool, bytes memory) {
// set up for assembly call
uint256 _toCopy;
bool _success;
bytes memory _returnData = new bytes(_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 contract
assembly {
_success := call(
_gas, // gas
_target, // recipient
0, // ether value
add(_calldata, 0x20), // inloc
mload(_calldata), // inlen
0, // outloc
0 // outlen
)
// limit our copy to 256 bytes
_toCopy := returndatasize()
if gt(_toCopy, _maxCopy) {
_toCopy := _maxCopy
}
// Store the length of the copied bytes
mstore(_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.
function excessivelySafeStaticCall(
address _target,
uint256 _gas,
uint16 _maxCopy,
bytes memory _calldata
) internal view returns (bool, bytes memory) {
// set up for assembly call
uint256 _toCopy;
bool _success;
bytes memory _returnData = new bytes(_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 contract
assembly {
_success := staticcall(
_gas, // gas
_target, // recipient
add(_calldata, 0x20), // inloc
mload(_calldata), // inlen
0, // outloc
0 // outlen
)
// limit our copy to 256 bytes
_toCopy := returndatasize()
if gt(_toCopy, _maxCopy) {
_toCopy := _maxCopy
}
// Store the length of the copied bytes
mstore(_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
*/
function swapSelector(bytes4 _newSelector, bytes memory _buf)
internal
pure
{
require(_buf.length >= 4);
uint256 _mask = LOW_28_MASK;
assembly {
// load the first word of
let _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)
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable.sol)
pragma solidity ^0.8.0;
import "../utils/Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
abstract contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor() {
_transferOwnership(_msgSender());
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
_checkOwner();
_;
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if the sender is not the owner.
*/
function _checkOwner() internal view virtual {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby disabling any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
_transferOwnership(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Internal function without access restriction.
*/
function _transferOwnership(address newOwner) internal virtual {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (interfaces/IERC5267.sol)
pragma solidity ^0.8.0;
interface IERC5267 {
/**
* @dev MAY be emitted to signal that the domain could have changed.
*/
event EIP712DomainChanged();
/**
* @dev returns the fields and values that describe the domain separator used by this contract for EIP-712
* signature.
*/
function eip712Domain()
external
view
returns (
bytes1 fields,
string memory name,
string memory version,
uint256 chainId,
address verifyingContract,
bytes32 salt,
uint256[] memory extensions
);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/ERC20.sol)
pragma solidity ^0.8.0;
import "./IERC20.sol";
import "./extensions/IERC20Metadata.sol";
import "../../utils/Context.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.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* The default value of {decimals} is 18. To change this, you should override
* this function so it returns a different value.
*
* We have followed general OpenZeppelin Contracts guidelines: functions revert
* instead 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, IERC20Metadata {
mapping(address => uint256) private _balances;
mapping(address => mapping(address => uint256)) private _allowances;
uint256 private _totalSupply;
string private _name;
string private _symbol;
/**
* @dev Sets the values for {name} and {symbol}.
*
* All two of these values are immutable: they can only be set once during
* construction.
*/
constructor(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
}
/**
* @dev Returns the name of the token.
*/
function name() public view virtual override returns (string memory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view virtual override 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 default value returned by this function, unless
* it's overridden.
*
* 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 virtual override returns (uint8) {
return 18;
}
/**
* @dev See {IERC20-totalSupply}.
*/
function totalSupply() public view virtual override returns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/
function balanceOf(address account) public view virtual override returns (uint256) {
return _balances[account];
}
/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/
function transfer(address to, uint256 amount) public virtual override returns (bool) {
address owner = _msgSender();
_transfer(owner, to, 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}.
*
* NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
* `transferFrom`. This is semantically equivalent to an infinite approval.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 amount) public virtual override returns (bool) {
address owner = _msgSender();
_approve(owner, 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}.
*
* NOTE: Does not update the allowance if the current allowance
* is the maximum `uint256`.
*
* Requirements:
*
* - `from` and `to` cannot be the zero address.
* - `from` must have a balance of at least `amount`.
* - the caller must have allowance for ``from``'s tokens of at least
* `amount`.
*/
function transferFrom(address from, address to, uint256 amount) public virtual override returns (bool) {
address spender = _msgSender();
_spendAllowance(from, spender, amount);
_transfer(from, to, amount);
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) {
address owner = _msgSender();
_approve(owner, spender, allowance(owner, spender) + 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) {
address owner = _msgSender();
uint256 currentAllowance = allowance(owner, spender);
require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
unchecked {
_approve(owner, spender, currentAllowance - subtractedValue);
}
return true;
}
/**
* @dev Moves `amount` of tokens from `from` to `to`.
*
* This 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:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `from` must have a balance of at least `amount`.
*/
function _transfer(address from, address to, uint256 amount) internal virtual {
require(from != address(0), "ERC20: transfer from the zero address");
require(to != address(0), "ERC20: transfer to the zero address");
_beforeTokenTransfer(from, to, amount);
uint256 fromBalance = _balances[from];
require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
unchecked {
_balances[from] = fromBalance - amount;
// Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
// decrementing then incrementing.
_balances[to] += amount;
}
emit Transfer(from, to, amount);
_afterTokenTransfer(from, to, 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:
*
* - `account` 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 += amount;
unchecked {
// Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
_balances[account] += amount;
}
emit Transfer(address(0), account, amount);
_afterTokenTransfer(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);
uint256 accountBalance = _balances[account];
require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
unchecked {
_balances[account] = accountBalance - amount;
// Overflow not possible: amount <= accountBalance <= totalSupply.
_totalSupply -= amount;
}
emit Transfer(account, address(0), amount);
_afterTokenTransfer(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 Updates `owner` s allowance for `spender` based on spent `amount`.
*
* Does not update the allowance amount in case of infinite allowance.
* Revert if not enough allowance is available.
*
* Might emit an {Approval} event.
*/
function _spendAllowance(address owner, address spender, uint256 amount) internal virtual {
uint256 currentAllowance = allowance(owner, spender);
if (currentAllowance != type(uint256).max) {
require(currentAllowance >= amount, "ERC20: insufficient allowance");
unchecked {
_approve(owner, spender, currentAllowance - 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 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 {}
/**
* @dev Hook that is called after any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* has been transferred to `to`.
* - when `from` is zero, `amount` tokens have been minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens have been 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 _afterTokenTransfer(address from, address to, uint256 amount) internal virtual {}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/extensions/ERC20Permit.sol)
pragma solidity ^0.8.0;
import "./IERC20Permit.sol";
import "../ERC20.sol";
import "../../../utils/cryptography/ECDSA.sol";
import "../../../utils/cryptography/EIP712.sol";
import "../../../utils/Counters.sol";
/**
* @dev Implementation 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.
*
* _Available since v3.4._
*/
abstract contract ERC20Permit is ERC20, IERC20Permit, EIP712 {
using Counters for Counters.Counter;
mapping(address => Counters.Counter) private _nonces;
// solhint-disable-next-line var-name-mixedcase
bytes32 private constant _PERMIT_TYPEHASH =
keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
/**
* @dev In previous versions `_PERMIT_TYPEHASH` was declared as `immutable`.
* However, to ensure consistency with the upgradeable transpiler, we will continue
* to reserve a slot.
* @custom:oz-renamed-from _PERMIT_TYPEHASH
*/
// solhint-disable-next-line var-name-mixedcase
bytes32 private _PERMIT_TYPEHASH_DEPRECATED_SLOT;
/**
* @dev Initializes the {EIP712} domain separator using the `name` parameter, and setting `version` to `"1"`.
*
* It's a good idea to use the same `name` that is defined as the ERC20 token name.
*/
constructor(string memory name) EIP712(name, "1") {}
/**
* @dev See {IERC20Permit-permit}.
*/
function permit(
address owner,
address spender,
uint256 value,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) public virtual override {
require(block.timestamp <= deadline, "ERC20Permit: expired deadline");
bytes32 structHash = keccak256(abi.encode(_PERMIT_TYPEHASH, owner, spender, value, _useNonce(owner), deadline));
bytes32 hash = _hashTypedDataV4(structHash);
address signer = ECDSA.recover(hash, v, r, s);
require(signer == owner, "ERC20Permit: invalid signature");
_approve(owner, spender, value);
}
/**
* @dev See {IERC20Permit-nonces}.
*/
function nonces(address owner) public view virtual override returns (uint256) {
return _nonces[owner].current();
}
/**
* @dev See {IERC20Permit-DOMAIN_SEPARATOR}.
*/
// solhint-disable-next-line func-name-mixedcase
function DOMAIN_SEPARATOR() external view override returns (bytes32) {
return _domainSeparatorV4();
}
/**
* @dev "Consume a nonce": return the current value and increment.
*
* _Available since v4.1._
*/
function _useNonce(address owner) internal virtual returns (uint256 current) {
Counters.Counter storage nonce = _nonces[owner];
current = nonce.current();
nonce.increment();
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)
pragma solidity ^0.8.0;
import "../IERC20.sol";
/**
* @dev Interface for the optional metadata functions from the ERC20 standard.
*
* _Available since v4.1._
*/
interface IERC20Metadata is IERC20 {
/**
* @dev Returns the name of the token.
*/
function name() external view returns (string memory);
/**
* @dev Returns the symbol of the token.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the decimals places of the token.
*/
function decimals() external view returns (uint8);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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.
*/
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].
*/
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 v4.9.0) (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 v4.4.1 (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;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Counters.sol)
pragma solidity ^0.8.0;
/**
* @title Counters
* @author Matt Condon (@shrugs)
* @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number
* of elements in a mapping, issuing ERC721 ids, or counting request ids.
*
* Include with `using Counters for Counters.Counter;`
*/
library Counters {
struct Counter {
// This variable should never be directly accessed by users of the library: interactions must be restricted to
// the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
// this feature: see https://github.com/ethereum/solidity/issues/4637
uint256 _value; // default: 0
}
function current(Counter storage counter) internal view returns (uint256) {
return counter._value;
}
function increment(Counter storage counter) internal {
unchecked {
counter._value += 1;
}
}
function decrement(Counter storage counter) internal {
uint256 value = counter._value;
require(value > 0, "Counter: decrement overflow");
unchecked {
counter._value = value - 1;
}
}
function reset(Counter storage counter) internal {
counter._value = 0;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/cryptography/ECDSA.sol)
pragma solidity ^0.8.0;
import "../Strings.sol";
/**
* @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
*
* These functions can be used to verify that a message was signed by the holder
* of the private keys of a given address.
*/
library ECDSA {
enum RecoverError {
NoError,
InvalidSignature,
InvalidSignatureLength,
InvalidSignatureS,
InvalidSignatureV // Deprecated in v4.8
}
function _throwError(RecoverError error) private pure {
if (error == RecoverError.NoError) {
return; // no error: do nothing
} else if (error == RecoverError.InvalidSignature) {
revert("ECDSA: invalid signature");
} else if (error == RecoverError.InvalidSignatureLength) {
revert("ECDSA: invalid signature length");
} else if (error == RecoverError.InvalidSignatureS) {
revert("ECDSA: invalid signature 's' value");
}
}
/**
* @dev Returns the address that signed a hashed message (`hash`) with
* `signature` or error string. This address can then be used for verification purposes.
*
* The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
* this function rejects them by requiring the `s` value to be in the lower
* half order, and the `v` value to be either 27 or 28.
*
* IMPORTANT: `hash` _must_ be the result of a hash operation for the
* verification to be secure: it is possible to craft signatures that
* recover to arbitrary addresses for non-hashed data. A safe way to ensure
* this is by receiving a hash of the original message (which may otherwise
* be too long), and then calling {toEthSignedMessageHash} on it.
*
* Documentation for signature generation:
* - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
* - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
*
* _Available since v4.3._
*/
function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError) {
if (signature.length == 65) {
bytes32 r;
bytes32 s;
uint8 v;
// ecrecover takes the signature parameters, and the only way to get them
// currently is to use assembly.
/// @solidity memory-safe-assembly
assembly {
r := mload(add(signature, 0x20))
s := mload(add(signature, 0x40))
v := byte(0, mload(add(signature, 0x60)))
}
return tryRecover(hash, v, r, s);
} else {
return (address(0), RecoverError.InvalidSignatureLength);
}
}
/**
* @dev Returns the address that signed a hashed message (`hash`) with
* `signature`. This address can then be used for verification purposes.
*
* The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
* this function rejects them by requiring the `s` value to be in the lower
* half order, and the `v` value to be either 27 or 28.
*
* IMPORTANT: `hash` _must_ be the result of a hash operation for the
* verification to be secure: it is possible to craft signatures that
* recover to arbitrary addresses for non-hashed data. A safe way to ensure
* this is by receiving a hash of the original message (which may otherwise
* be too long), and then calling {toEthSignedMessageHash} on it.
*/
function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
(address recovered, RecoverError error) = tryRecover(hash, signature);
_throwError(error);
return recovered;
}
/**
* @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
*
* See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
*
* _Available since v4.3._
*/
function tryRecover(bytes32 hash, bytes32 r, bytes32 vs) internal pure returns (address, RecoverError) {
bytes32 s = vs & bytes32(0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
uint8 v = uint8((uint256(vs) >> 255) + 27);
return tryRecover(hash, v, r, s);
}
/**
* @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
*
* _Available since v4.2._
*/
function recover(bytes32 hash, bytes32 r, bytes32 vs) internal pure returns (address) {
(address recovered, RecoverError error) = tryRecover(hash, r, vs);
_throwError(error);
return recovered;
}
/**
* @dev Overload of {ECDSA-tryRecover} that receives the `v`,
* `r` and `s` signature fields separately.
*
* _Available since v4.3._
*/
function tryRecover(bytes32 hash, uint8 v, bytes32 r, bytes32 s) internal pure returns (address, RecoverError) {
// EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
// unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
// the valid range for s in (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): v ∈ {27, 28}. Most
// signatures from current libraries generate a unique signature with an s-value in the lower half order.
//
// If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
// with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
// vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
// these malleable signatures as well.
if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {
return (address(0), RecoverError.InvalidSignatureS);
}
// If the signature is valid (and not malleable), return the signer address
address signer = ecrecover(hash, v, r, s);
if (signer == address(0)) {
return (address(0), RecoverError.InvalidSignature);
}
return (signer, RecoverError.NoError);
}
/**
* @dev Overload of {ECDSA-recover} that receives the `v`,
* `r` and `s` signature fields separately.
*/
function recover(bytes32 hash, uint8 v, bytes32 r, bytes32 s) internal pure returns (address) {
(address recovered, RecoverError error) = tryRecover(hash, v, r, s);
_throwError(error);
return recovered;
}
/**
* @dev Returns an Ethereum Signed Message, created from a `hash`. This
* produces hash corresponding to the one signed with the
* https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
* JSON-RPC method as part of EIP-191.
*
* See {recover}.
*/
function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32 message) {
// 32 is the length in bytes of hash,
// enforced by the type signature above
/// @solidity memory-safe-assembly
assembly {
mstore(0x00, "\x19Ethereum Signed Message:\n32")
mstore(0x1c, hash)
message := keccak256(0x00, 0x3c)
}
}
/**
* @dev Returns an Ethereum Signed Message, created from `s`. This
* produces hash corresponding to the one signed with the
* https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
* JSON-RPC method as part of EIP-191.
*
* See {recover}.
*/
function toEthSignedMessageHash(bytes memory s) internal pure returns (bytes32) {
return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n", Strings.toString(s.length), s));
}
/**
* @dev Returns an Ethereum Signed Typed Data, created from a
* `domainSeparator` and a `structHash`. This produces hash corresponding
* to the one signed with the
* https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]
* JSON-RPC method as part of EIP-712.
*
* See {recover}.
*/
function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32 data) {
/// @solidity memory-safe-assembly
assembly {
let ptr := mload(0x40)
mstore(ptr, "\x19\x01")
mstore(add(ptr, 0x02), domainSeparator)
mstore(add(ptr, 0x22), structHash)
data := keccak256(ptr, 0x42)
}
}
/**
* @dev Returns an Ethereum Signed Data with intended validator, created from a
* `validator` and `data` according to the version 0 of EIP-191.
*
* See {recover}.
*/
function toDataWithIntendedValidatorHash(address validator, bytes memory data) internal pure returns (bytes32) {
return keccak256(abi.encodePacked("\x19\x00", validator, data));
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/cryptography/EIP712.sol)
pragma solidity ^0.8.8;
import "./ECDSA.sol";
import "../ShortStrings.sol";
import "../../interfaces/IERC5267.sol";
/**
* @dev https://eips.ethereum.org/EIPS/eip-712[EIP 712] is a standard for hashing and signing of typed structured data.
*
* The encoding specified in the EIP is very generic, and such a generic implementation in Solidity is not feasible,
* thus this contract does not implement the encoding itself. Protocols need to implement the type-specific encoding
* they need in their contracts using a combination of `abi.encode` and `keccak256`.
*
* This contract implements the EIP 712 domain separator ({_domainSeparatorV4}) that is used as part of the encoding
* scheme, and the final step of the encoding to obtain the message digest that is then signed via ECDSA
* ({_hashTypedDataV4}).
*
* The implementation of the domain separator was designed to be as efficient as possible while still properly updating
* the chain id to protect against replay attacks on an eventual fork of the chain.
*
* NOTE: This contract implements the version of the encoding known as "v4", as implemented by the JSON RPC method
* https://docs.metamask.io/guide/signing-data.html[`eth_signTypedDataV4` in MetaMask].
*
* NOTE: In the upgradeable version of this contract, the cached values will correspond to the address, and the domain
* separator of the implementation contract. This will cause the `_domainSeparatorV4` function to always rebuild the
* separator from the immutable values, which is cheaper than accessing a cached version in cold storage.
*
* _Available since v3.4._
*
* @custom:oz-upgrades-unsafe-allow state-variable-immutable state-variable-assignment
*/
abstract contract EIP712 is IERC5267 {
using ShortStrings for *;
bytes32 private constant _TYPE_HASH =
keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)");
// Cache the domain separator as an immutable value, but also store the chain id that it corresponds to, in order to
// invalidate the cached domain separator if the chain id changes.
bytes32 private immutable _cachedDomainSeparator;
uint256 private immutable _cachedChainId;
address private immutable _cachedThis;
bytes32 private immutable _hashedName;
bytes32 private immutable _hashedVersion;
ShortString private immutable _name;
ShortString private immutable _version;
string private _nameFallback;
string private _versionFallback;
/**
* @dev Initializes the domain separator and parameter caches.
*
* The meaning of `name` and `version` is specified in
* https://eips.ethereum.org/EIPS/eip-712#definition-of-domainseparator[EIP 712]:
*
* - `name`: the user readable name of the signing domain, i.e. the name of the DApp or the protocol.
* - `version`: the current major version of the signing domain.
*
* NOTE: These parameters cannot be changed except through a xref:learn::upgrading-smart-contracts.adoc[smart
* contract upgrade].
*/
constructor(string memory name, string memory version) {
_name = name.toShortStringWithFallback(_nameFallback);
_version = version.toShortStringWithFallback(_versionFallback);
_hashedName = keccak256(bytes(name));
_hashedVersion = keccak256(bytes(version));
_cachedChainId = block.chainid;
_cachedDomainSeparator = _buildDomainSeparator();
_cachedThis = address(this);
}
/**
* @dev Returns the domain separator for the current chain.
*/
function _domainSeparatorV4() internal view returns (bytes32) {
if (address(this) == _cachedThis && block.chainid == _cachedChainId) {
return _cachedDomainSeparator;
} else {
return _buildDomainSeparator();
}
}
function _buildDomainSeparator() private view returns (bytes32) {
return keccak256(abi.encode(_TYPE_HASH, _hashedName, _hashedVersion, block.chainid, address(this)));
}
/**
* @dev Given an already https://eips.ethereum.org/EIPS/eip-712#definition-of-hashstruct[hashed struct], this
* function returns the hash of the fully encoded EIP712 message for this domain.
*
* This hash can be used together with {ECDSA-recover} to obtain the signer of a message. For example:
*
* ```solidity
* bytes32 digest = _hashTypedDataV4(keccak256(abi.encode(
* keccak256("Mail(address to,string contents)"),
* mailTo,
* keccak256(bytes(mailContents))
* )));
* address signer = ECDSA.recover(digest, signature);
* ```
*/
function _hashTypedDataV4(bytes32 structHash) internal view virtual returns (bytes32) {
return ECDSA.toTypedDataHash(_domainSeparatorV4(), structHash);
}
/**
* @dev See {EIP-5267}.
*
* _Available since v4.9._
*/
function eip712Domain()
public
view
virtual
override
returns (
bytes1 fields,
string memory name,
string memory version,
uint256 chainId,
address verifyingContract,
bytes32 salt,
uint256[] memory extensions
)
{
return (
hex"0f", // 01111
_name.toStringWithFallback(_nameFallback),
_version.toStringWithFallback(_versionFallback),
block.chainid,
address(this),
bytes32(0),
new uint256[](0)
);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
pragma solidity ^0.8.0;
import "./IERC165.sol";
/**
* @dev Implementation of the {IERC165} interface.
*
* Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
* for the additional interface id that will be supported. For example:
*
* ```solidity
* function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
* return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
* }
* ```
*
* Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
*/
abstract contract ERC165 is IERC165 {
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
return interfaceId == type(IERC165).interfaceId;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC165 standard, as defined in the
* https://eips.ethereum.org/EIPS/eip-165[EIP].
*
* Implementers can declare support of contract interfaces, which can then be
* queried by others ({ERC165Checker}).
*
* For an implementation, see {ERC165}.
*/
interface IERC165 {
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
* to learn more about how these ids are created.
*
* This function call must use less than 30 000 gas.
*/
function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/math/Math.sol)
pragma solidity ^0.8.0;
/**
* @dev Standard math utilities missing in the Solidity language.
*/
library Math {
enum Rounding {
Down, // Toward negative infinity
Up, // Toward infinity
Zero // Toward zero
}
/**
* @dev Returns the largest of two numbers.
*/
function max(uint256 a, uint256 b) internal pure returns (uint256) {
return a > b ? a : b;
}
/**
* @dev Returns the smallest of two numbers.
*/
function min(uint256 a, uint256 b) internal pure returns (uint256) {
return a < b ? a : b;
}
/**
* @dev Returns the average of two numbers. The result is rounded towards
* zero.
*/
function average(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b) / 2 can overflow.
return (a & b) + (a ^ b) / 2;
}
/**
* @dev Returns the ceiling of the division of two numbers.
*
* This differs from standard division with `/` in that it rounds up instead
* of rounding down.
*/
function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b - 1) / b can overflow on addition, so we distribute.
return a == 0 ? 0 : (a - 1) / b + 1;
}
/**
* @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
* @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv)
* with further edits by Uniswap Labs also under MIT license.
*/
function mulDiv(uint256 x, uint256 y, uint256 denominator) internal pure returns (uint256 result) {
unchecked {
// 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
// use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
// variables such that product = prod1 * 2^256 + prod0.
uint256 prod0; // Least significant 256 bits of the product
uint256 prod1; // Most significant 256 bits of the product
assembly {
let mm := mulmod(x, y, not(0))
prod0 := mul(x, y)
prod1 := sub(sub(mm, prod0), lt(mm, prod0))
}
// Handle non-overflow cases, 256 by 256 division.
if (prod1 == 0) {
// Solidity will revert if denominator == 0, unlike the div opcode on its own.
// The surrounding unchecked block does not change this fact.
// See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
return prod0 / denominator;
}
// Make sure the result is less than 2^256. Also prevents denominator == 0.
require(denominator > prod1, "Math: mulDiv overflow");
///////////////////////////////////////////////
// 512 by 256 division.
///////////////////////////////////////////////
// Make division exact by subtracting the remainder from [prod1 prod0].
uint256 remainder;
assembly {
// Compute remainder using mulmod.
remainder := mulmod(x, y, denominator)
// Subtract 256 bit number from 512 bit number.
prod1 := sub(prod1, gt(remainder, prod0))
prod0 := sub(prod0, remainder)
}
// Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
// See https://cs.stackexchange.com/q/138556/92363.
// Does not overflow because the denominator cannot be zero at this stage in the function.
uint256 twos = denominator & (~denominator + 1);
assembly {
// Divide denominator by twos.
denominator := div(denominator, twos)
// Divide [prod1 prod0] by twos.
prod0 := div(prod0, twos)
// Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
twos := add(div(sub(0, twos), twos), 1)
}
// Shift in bits from prod1 into prod0.
prod0 |= prod1 * twos;
// Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
// that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
// four bits. That is, denominator * inv = 1 mod 2^4.
uint256 inverse = (3 * denominator) ^ 2;
// Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
// in modular arithmetic, doubling the correct bits in each step.
inverse *= 2 - denominator * inverse; // inverse mod 2^8
inverse *= 2 - denominator * inverse; // inverse mod 2^16
inverse *= 2 - denominator * inverse; // inverse mod 2^32
inverse *= 2 - denominator * inverse; // inverse mod 2^64
inverse *= 2 - denominator * inverse; // inverse mod 2^128
inverse *= 2 - denominator * inverse; // inverse mod 2^256
// Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
// This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
// less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
// is no longer required.
result = prod0 * inverse;
return result;
}
}
/**
* @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
*/
function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) {
uint256 result = mulDiv(x, y, denominator);
if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
result += 1;
}
return result;
}
/**
* @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down.
*
* Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
*/
function sqrt(uint256 a) internal pure returns (uint256) {
if (a == 0) {
return 0;
}
// For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
//
// We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
// `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
//
// This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
// → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
// → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
//
// Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
uint256 result = 1 << (log2(a) >> 1);
// At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
// since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
// every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
// into the expected uint128 result.
unchecked {
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
return min(result, a / result);
}
}
/**
* @notice Calculates sqrt(a), following the selected rounding direction.
*/
function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = sqrt(a);
return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
}
}
/**
* @dev Return the log in base 2, rounded down, of a positive value.
* Returns 0 if given 0.
*/
function log2(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >> 128 > 0) {
value >>= 128;
result += 128;
}
if (value >> 64 > 0) {
value >>= 64;
result += 64;
}
if (value >> 32 > 0) {
value >>= 32;
result += 32;
}
if (value >> 16 > 0) {
value >>= 16;
result += 16;
}
if (value >> 8 > 0) {
value >>= 8;
result += 8;
}
if (value >> 4 > 0) {
value >>= 4;
result += 4;
}
if (value >> 2 > 0) {
value >>= 2;
result += 2;
}
if (value >> 1 > 0) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 2, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log2(value);
return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
}
}
/**
* @dev Return the log in base 10, rounded down, of a positive value.
* Returns 0 if given 0.
*/
function log10(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >= 10 ** 64) {
value /= 10 ** 64;
result += 64;
}
if (value >= 10 ** 32) {
value /= 10 ** 32;
result += 32;
}
if (value >= 10 ** 16) {
value /= 10 ** 16;
result += 16;
}
if (value >= 10 ** 8) {
value /= 10 ** 8;
result += 8;
}
if (value >= 10 ** 4) {
value /= 10 ** 4;
result += 4;
}
if (value >= 10 ** 2) {
value /= 10 ** 2;
result += 2;
}
if (value >= 10 ** 1) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 10, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log10(value);
return result + (rounding == Rounding.Up && 10 ** result < value ? 1 : 0);
}
}
/**
* @dev Return the log in base 256, rounded down, of a positive value.
* Returns 0 if given 0.
*
* Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
*/
function log256(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >> 128 > 0) {
value >>= 128;
result += 16;
}
if (value >> 64 > 0) {
value >>= 64;
result += 8;
}
if (value >> 32 > 0) {
value >>= 32;
result += 4;
}
if (value >> 16 > 0) {
value >>= 16;
result += 2;
}
if (value >> 8 > 0) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 256, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log256(value);
return result + (rounding == Rounding.Up && 1 << (result << 3) < value ? 1 : 0);
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/math/SignedMath.sol)
pragma solidity ^0.8.0;
/**
* @dev Standard signed math utilities missing in the Solidity language.
*/
library SignedMath {
/**
* @dev Returns the largest of two signed numbers.
*/
function max(int256 a, int256 b) internal pure returns (int256) {
return a > b ? a : b;
}
/**
* @dev Returns the smallest of two signed numbers.
*/
function min(int256 a, int256 b) internal pure returns (int256) {
return a < b ? a : b;
}
/**
* @dev Returns the average of two signed numbers without overflow.
* The result is rounded towards zero.
*/
function average(int256 a, int256 b) internal pure returns (int256) {
// Formula from the book "Hacker's Delight"
int256 x = (a & b) + ((a ^ b) >> 1);
return x + (int256(uint256(x) >> 255) & (a ^ b));
}
/**
* @dev Returns the absolute unsigned value of a signed value.
*/
function abs(int256 n) internal pure returns (uint256) {
unchecked {
// must be unchecked in order to support `n = type(int256).min`
return uint256(n >= 0 ? n : -n);
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/ShortStrings.sol)
pragma solidity ^0.8.8;
import "./StorageSlot.sol";
// | string | 0xAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA |
// | length | 0x BB |
type ShortString is bytes32;
/**
* @dev This library provides functions to convert short memory strings
* into a `ShortString` type that can be used as an immutable variable.
*
* Strings of arbitrary length can be optimized using this library if
* they are short enough (up to 31 bytes) by packing them with their
* length (1 byte) in a single EVM word (32 bytes). Additionally, a
* fallback mechanism can be used for every other case.
*
* Usage example:
*
* ```solidity
* contract Named {
* using ShortStrings for *;
*
* ShortString private immutable _name;
* string private _nameFallback;
*
* constructor(string memory contractName) {
* _name = contractName.toShortStringWithFallback(_nameFallback);
* }
*
* function name() external view returns (string memory) {
* return _name.toStringWithFallback(_nameFallback);
* }
* }
* ```
*/
library ShortStrings {
// Used as an identifier for strings longer than 31 bytes.
bytes32 private constant _FALLBACK_SENTINEL = 0x00000000000000000000000000000000000000000000000000000000000000FF;
error StringTooLong(string str);
error InvalidShortString();
/**
* @dev Encode a string of at most 31 chars into a `ShortString`.
*
* This will trigger a `StringTooLong` error is the input string is too long.
*/
function toShortString(string memory str) internal pure returns (ShortString) {
bytes memory bstr = bytes(str);
if (bstr.length > 31) {
revert StringTooLong(str);
}
return ShortString.wrap(bytes32(uint256(bytes32(bstr)) | bstr.length));
}
/**
* @dev Decode a `ShortString` back to a "normal" string.
*/
function toString(ShortString sstr) internal pure returns (string memory) {
uint256 len = byteLength(sstr);
// using `new string(len)` would work locally but is not memory safe.
string memory str = new string(32);
/// @solidity memory-safe-assembly
assembly {
mstore(str, len)
mstore(add(str, 0x20), sstr)
}
return str;
}
/**
* @dev Return the length of a `ShortString`.
*/
function byteLength(ShortString sstr) internal pure returns (uint256) {
uint256 result = uint256(ShortString.unwrap(sstr)) & 0xFF;
if (result > 31) {
revert InvalidShortString();
}
return result;
}
/**
* @dev Encode a string into a `ShortString`, or write it to storage if it is too long.
*/
function toShortStringWithFallback(string memory value, string storage store) internal returns (ShortString) {
if (bytes(value).length < 32) {
return toShortString(value);
} else {
StorageSlot.getStringSlot(store).value = value;
return ShortString.wrap(_FALLBACK_SENTINEL);
}
}
/**
* @dev Decode a string that was encoded to `ShortString` or written to storage using {setWithFallback}.
*/
function toStringWithFallback(ShortString value, string storage store) internal pure returns (string memory) {
if (ShortString.unwrap(value) != _FALLBACK_SENTINEL) {
return toString(value);
} else {
return store;
}
}
/**
* @dev Return the length of a string that was encoded to `ShortString` or written to storage using {setWithFallback}.
*
* WARNING: This will return the "byte length" of the string. This may not reflect the actual length in terms of
* actual characters as the UTF-8 encoding of a single character can span over multiple bytes.
*/
function byteLengthWithFallback(ShortString value, string storage store) internal view returns (uint256) {
if (ShortString.unwrap(value) != _FALLBACK_SENTINEL) {
return byteLength(value);
} else {
return bytes(store).length;
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/StorageSlot.sol)
// This file was procedurally generated from scripts/generate/templates/StorageSlot.js.
pragma solidity ^0.8.0;
/**
* @dev Library for reading and writing primitive types to specific storage slots.
*
* Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
* This library helps with reading and writing to such slots without the need for inline assembly.
*
* The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
*
* Example usage to set ERC1967 implementation slot:
* ```solidity
* contract ERC1967 {
* bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
*
* function _getImplementation() internal view returns (address) {
* return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
* }
*
* function _setImplementation(address newImplementation) internal {
* require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
* StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
* }
* }
* ```
*
* _Available since v4.1 for `address`, `bool`, `bytes32`, `uint256`._
* _Available since v4.9 for `string`, `bytes`._
*/
library StorageSlot {
struct AddressSlot {
address value;
}
struct BooleanSlot {
bool value;
}
struct Bytes32Slot {
bytes32 value;
}
struct Uint256Slot {
uint256 value;
}
struct StringSlot {
string value;
}
struct BytesSlot {
bytes value;
}
/**
* @dev Returns an `AddressSlot` with member `value` located at `slot`.
*/
function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
/// @solidity memory-safe-assembly
assembly {
r.slot := slot
}
}
/**
* @dev Returns an `BooleanSlot` with member `value` located at `slot`.
*/
function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
/// @solidity memory-safe-assembly
assembly {
r.slot := slot
}
}
/**
* @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
*/
function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
/// @solidity memory-safe-assembly
assembly {
r.slot := slot
}
}
/**
* @dev Returns an `Uint256Slot` with member `value` located at `slot`.
*/
function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
/// @solidity memory-safe-assembly
assembly {
r.slot := slot
}
}
/**
* @dev Returns an `StringSlot` with member `value` located at `slot`.
*/
function getStringSlot(bytes32 slot) internal pure returns (StringSlot storage r) {
/// @solidity memory-safe-assembly
assembly {
r.slot := slot
}
}
/**
* @dev Returns an `StringSlot` representation of the string storage pointer `store`.
*/
function getStringSlot(string storage store) internal pure returns (StringSlot storage r) {
/// @solidity memory-safe-assembly
assembly {
r.slot := store.slot
}
}
/**
* @dev Returns an `BytesSlot` with member `value` located at `slot`.
*/
function getBytesSlot(bytes32 slot) internal pure returns (BytesSlot storage r) {
/// @solidity memory-safe-assembly
assembly {
r.slot := slot
}
}
/**
* @dev Returns an `BytesSlot` representation of the bytes storage pointer `store`.
*/
function getBytesSlot(bytes storage store) internal pure returns (BytesSlot storage r) {
/// @solidity memory-safe-assembly
assembly {
r.slot := store.slot
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/Strings.sol)
pragma solidity ^0.8.0;
import "./math/Math.sol";
import "./math/SignedMath.sol";
/**
* @dev String operations.
*/
library Strings {
bytes16 private constant _SYMBOLS = "0123456789abcdef";
uint8 private constant _ADDRESS_LENGTH = 20;
/**
* @dev Converts a `uint256` to its ASCII `string` decimal representation.
*/
function toString(uint256 value) internal pure returns (string memory) {
unchecked {
uint256 length = Math.log10(value) + 1;
string memory buffer = new string(length);
uint256 ptr;
/// @solidity memory-safe-assembly
assembly {
ptr := add(buffer, add(32, length))
}
while (true) {
ptr--;
/// @solidity memory-safe-assembly
assembly {
mstore8(ptr, byte(mod(value, 10), _SYMBOLS))
}
value /= 10;
if (value == 0) break;
}
return buffer;
}
}
/**
* @dev Converts a `int256` to its ASCII `string` decimal representation.
*/
function toString(int256 value) internal pure returns (string memory) {
return string(abi.encodePacked(value < 0 ? "-" : "", toString(SignedMath.abs(value))));
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
*/
function toHexString(uint256 value) internal pure returns (string memory) {
unchecked {
return toHexString(value, Math.log256(value) + 1);
}
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
*/
function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
bytes memory buffer = new bytes(2 * length + 2);
buffer[0] = "0";
buffer[1] = "x";
for (uint256 i = 2 * length + 1; i > 1; --i) {
buffer[i] = _SYMBOLS[value & 0xf];
value >>= 4;
}
require(value == 0, "Strings: hex length insufficient");
return string(buffer);
}
/**
* @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
*/
function toHexString(address addr) internal pure returns (string memory) {
return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
}
/**
* @dev Returns true if the two strings are equal.
*/
function equal(string memory a, string memory b) internal pure returns (bool) {
return keccak256(bytes(a)) == keccak256(bytes(b));
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/utils/Address.sol";
import "@openzeppelin/contracts/token/ERC20/extensions/ERC20Permit.sol";
import "@layerzerolabs/solidity-examples/contracts/token/oft/extension/BasedOFT.sol";
contract OmniBotX is BasedOFT, ERC20Permit {
struct Taxes {
uint from; // buy + lp removed
uint to; // sell + lp added
}
mapping(address => bool) public isExcludedFromFee;
mapping(address => Taxes) public taxes;
address public taxReceiver;
uint internal constant MAX_TAX = 9000;
uint internal constant PRECISION = 10000;
event SetExcludedFromFee(address who, bool isExcludedFromFee);
event SetTaxes(address who, uint from, uint to);
event SetTaxReceiver(address who);
constructor(
string memory _name,
string memory _symbol,
uint _totalSupply,
address _multisig,
address _lzEndpoint
)
BasedOFT(_name, _symbol, _lzEndpoint)
ERC20Permit(_name)
{
_mint(_multisig, _totalSupply);
isExcludedFromFee[_msgSender()] = true;
emit SetExcludedFromFee(_msgSender(), true);
isExcludedFromFee[_multisig] = true;
emit SetExcludedFromFee(_multisig, true);
taxReceiver = _multisig;
emit SetTaxReceiver(_multisig);
}
function setIsExcludedFromFee(address _who, bool _value) external onlyOwner {
isExcludedFromFee[_who] = _value;
emit SetExcludedFromFee(_who, _value);
}
function setTaxes(address _who, uint _from, uint _to) external onlyOwner {
require(Address.isContract(_who), "eoa protection");
require(_from <= MAX_TAX && _to <= MAX_TAX, "lower than 90%");
taxes[_who] = Taxes(_from, _to);
emit SetTaxes(_who, _from, _to);
}
function setTaxReceiver(address _who) external onlyOwner {
assert(_who != address(0));
taxReceiver = _who;
emit SetTaxReceiver(_who);
}
function _transfer(address from, address to, uint256 amount) internal override {
uint finalAmount = amount;
if (!isExcludedFromFee[from] && !isExcludedFromFee[to]) {
uint taxFrom = taxes[from].from;
if (taxFrom > 0) finalAmount -= amount * taxFrom / PRECISION;
uint taxTo = taxes[to].to;
if (taxTo > 0) finalAmount -= amount * taxTo / PRECISION;
}
super._transfer(from, to, finalAmount);
if (finalAmount != amount) super._transfer(from, taxReceiver, amount - finalAmount);
}
}