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Forked from 1-om/tornadoCore.sol
Created August 12, 2022 09:00
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copy of tornado cash
// SPDX-License-Identifier: MIT
// https://tornado.cash
/*
* d888888P dP a88888b. dP
* 88 88 d8' `88 88
* 88 .d8888b. 88d888b. 88d888b. .d8888b. .d888b88 .d8888b. 88 .d8888b. .d8888b. 88d888b.
* 88 88' `88 88' `88 88' `88 88' `88 88' `88 88' `88 88 88' `88 Y8ooooo. 88' `88
* 88 88. .88 88 88 88 88. .88 88. .88 88. .88 dP Y8. .88 88. .88 88 88 88
* dP `88888P' dP dP dP `88888P8 `88888P8 `88888P' 88 Y88888P' `88888P8 `88888P' dP dP
* ooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo
*/
pragma solidity ^0.7.0;
pragma experimental ABIEncoderV2;
import "@openzeppelin/contracts/utils/ReentrancyGuard.sol";
import { IERC20Receiver, IERC6777, IOmniBridge } from "./interfaces/IBridge.sol";
import { CrossChainGuard } from "./bridge/CrossChainGuard.sol";
import { IVerifier } from "./interfaces/IVerifier.sol";
import "./MerkleTreeWithHistory.sol";
/** @dev This contract(pool) allows deposit of an arbitrary amount to it, shielded transfer to another registered user inside the pool
* and withdrawal from the pool. Project utilizes UTXO model to handle users' funds.
*/
contract TornadoPool is MerkleTreeWithHistory, IERC20Receiver, ReentrancyGuard, CrossChainGuard {
int256 public constant MAX_EXT_AMOUNT = 2**248;
uint256 public constant MAX_FEE = 2**248;
uint256 public constant MIN_EXT_AMOUNT_LIMIT = 0.5 ether;
IVerifier public immutable verifier2;
IVerifier public immutable verifier16;
IERC6777 public immutable token;
address public immutable omniBridge;
address public immutable l1Unwrapper;
address public immutable multisig;
uint256 public lastBalance;
uint256 public __gap; // storage padding to prevent storage collision
uint256 public maximumDepositAmount;
mapping(bytes32 => bool) public nullifierHashes;
struct ExtData {
address recipient;
int256 extAmount;
address relayer;
uint256 fee;
bytes encryptedOutput1;
bytes encryptedOutput2;
bool isL1Withdrawal;
uint256 l1Fee;
}
struct Proof {
bytes proof;
bytes32 root;
bytes32[] inputNullifiers;
bytes32[2] outputCommitments;
uint256 publicAmount;
bytes32 extDataHash;
}
struct Account {
address owner;
bytes publicKey;
}
event NewCommitment(bytes32 commitment, uint256 index, bytes encryptedOutput);
event NewNullifier(bytes32 nullifier);
event PublicKey(address indexed owner, bytes key);
modifier onlyMultisig() {
require(msg.sender == multisig, "only governance");
_;
}
/**
@dev The constructor
@param _verifier2 the address of SNARK verifier for 2 inputs
@param _verifier16 the address of SNARK verifier for 16 inputs
@param _levels hight of the commitments merkle tree
@param _hasher hasher address for the merkle tree
@param _token token address for the pool
@param _omniBridge omniBridge address for specified token
@param _l1Unwrapper address of the L1Helper
@param _governance owner address
@param _l1ChainId chain id of L1
@param _multisig multisig on L2
*/
constructor(
IVerifier _verifier2,
IVerifier _verifier16,
uint32 _levels,
address _hasher,
IERC6777 _token,
address _omniBridge,
address _l1Unwrapper,
address _governance,
uint256 _l1ChainId,
address _multisig
)
MerkleTreeWithHistory(_levels, _hasher)
CrossChainGuard(address(IOmniBridge(_omniBridge).bridgeContract()), _l1ChainId, _governance)
{
verifier2 = _verifier2;
verifier16 = _verifier16;
token = _token;
omniBridge = _omniBridge;
l1Unwrapper = _l1Unwrapper;
multisig = _multisig;
}
function initialize(uint256 _maximumDepositAmount) external initializer {
_configureLimits(_maximumDepositAmount);
super._initialize();
}
/** @dev Main function that allows deposits, transfers and withdrawal.
*/
function transact(Proof memory _args, ExtData memory _extData) public {
if (_extData.extAmount > 0) {
// for deposits from L2
token.transferFrom(msg.sender, address(this), uint256(_extData.extAmount));
require(uint256(_extData.extAmount) <= maximumDepositAmount, "amount is larger than maximumDepositAmount");
}
_transact(_args, _extData);
}
function register(Account memory _account) public {
require(_account.owner == msg.sender, "only owner can be registered");
_register(_account);
}
function registerAndTransact(
Account memory _account,
Proof memory _proofArgs,
ExtData memory _extData
) public {
register(_account);
transact(_proofArgs, _extData);
}
function onTokenBridged(
IERC6777 _token,
uint256 _amount,
bytes calldata _data
) external override {
(Proof memory _args, ExtData memory _extData) = abi.decode(_data, (Proof, ExtData));
require(_token == token, "provided token is not supported");
require(msg.sender == omniBridge, "only omni bridge");
require(_amount >= uint256(_extData.extAmount), "amount from bridge is incorrect");
require(token.balanceOf(address(this)) >= uint256(_extData.extAmount) + lastBalance, "bridge did not send enough tokens");
require(uint256(_extData.extAmount) <= maximumDepositAmount, "amount is larger than maximumDepositAmount");
uint256 sentAmount = token.balanceOf(address(this)) - lastBalance;
try TornadoPool(address(this)).onTransact(_args, _extData) {} catch (bytes memory) {
token.transfer(multisig, sentAmount);
}
}
/**
* @dev Wrapper for the internal func _transact to call it using try-catch from onTokenBridged
*/
function onTransact(Proof memory _args, ExtData memory _extData) external {
require(msg.sender == address(this), "can be called only from onTokenBridged");
_transact(_args, _extData);
}
/// @dev Method to claim junk and accidentally sent tokens
function rescueTokens(
IERC6777 _token,
address payable _to,
uint256 _balance
) external onlyMultisig {
require(_to != address(0), "TORN: can not send to zero address");
require(_token != token, "can not rescue pool asset");
if (_token == IERC6777(0)) {
// for Ether
uint256 totalBalance = address(this).balance;
uint256 balance = _balance == 0 ? totalBalance : _balance;
_to.transfer(balance);
} else {
// any other erc20
uint256 totalBalance = _token.balanceOf(address(this));
uint256 balance = _balance == 0 ? totalBalance : _balance;
require(balance > 0, "TORN: trying to send 0 balance");
_token.transfer(_to, balance);
}
}
function configureLimits(uint256 _maximumDepositAmount) public onlyMultisig {
_configureLimits(_maximumDepositAmount);
}
function calculatePublicAmount(int256 _extAmount, uint256 _fee) public pure returns (uint256) {
require(_fee < MAX_FEE, "Invalid fee");
require(_extAmount > -MAX_EXT_AMOUNT && _extAmount < MAX_EXT_AMOUNT, "Invalid ext amount");
int256 publicAmount = _extAmount - int256(_fee);
return (publicAmount >= 0) ? uint256(publicAmount) : FIELD_SIZE - uint256(-publicAmount);
}
/** @dev whether a note is already spent */
function isSpent(bytes32 _nullifierHash) public view returns (bool) {
return nullifierHashes[_nullifierHash];
}
function verifyProof(Proof memory _args) public view returns (bool) {
if (_args.inputNullifiers.length == 2) {
return
verifier2.verifyProof(
_args.proof,
[
uint256(_args.root),
_args.publicAmount,
uint256(_args.extDataHash),
uint256(_args.inputNullifiers[0]),
uint256(_args.inputNullifiers[1]),
uint256(_args.outputCommitments[0]),
uint256(_args.outputCommitments[1])
]
);
} else if (_args.inputNullifiers.length == 16) {
return
verifier16.verifyProof(
_args.proof,
[
uint256(_args.root),
_args.publicAmount,
uint256(_args.extDataHash),
uint256(_args.inputNullifiers[0]),
uint256(_args.inputNullifiers[1]),
uint256(_args.inputNullifiers[2]),
uint256(_args.inputNullifiers[3]),
uint256(_args.inputNullifiers[4]),
uint256(_args.inputNullifiers[5]),
uint256(_args.inputNullifiers[6]),
uint256(_args.inputNullifiers[7]),
uint256(_args.inputNullifiers[8]),
uint256(_args.inputNullifiers[9]),
uint256(_args.inputNullifiers[10]),
uint256(_args.inputNullifiers[11]),
uint256(_args.inputNullifiers[12]),
uint256(_args.inputNullifiers[13]),
uint256(_args.inputNullifiers[14]),
uint256(_args.inputNullifiers[15]),
uint256(_args.outputCommitments[0]),
uint256(_args.outputCommitments[1])
]
);
} else {
revert("unsupported input count");
}
}
function _register(Account memory _account) internal {
emit PublicKey(_account.owner, _account.publicKey);
}
function _transact(Proof memory _args, ExtData memory _extData) internal nonReentrant {
require(isKnownRoot(_args.root), "Invalid merkle root");
for (uint256 i = 0; i < _args.inputNullifiers.length; i++) {
require(!isSpent(_args.inputNullifiers[i]), "Input is already spent");
}
require(uint256(_args.extDataHash) == uint256(keccak256(abi.encode(_extData))) % FIELD_SIZE, "Incorrect external data hash");
require(_args.publicAmount == calculatePublicAmount(_extData.extAmount, _extData.fee), "Invalid public amount");
require(verifyProof(_args), "Invalid transaction proof");
for (uint256 i = 0; i < _args.inputNullifiers.length; i++) {
nullifierHashes[_args.inputNullifiers[i]] = true;
}
if (_extData.extAmount < 0) {
require(_extData.recipient != address(0), "Can't withdraw to zero address");
if (_extData.isL1Withdrawal) {
token.transferAndCall(
omniBridge,
uint256(-_extData.extAmount),
abi.encodePacked(l1Unwrapper, abi.encode(_extData.recipient, _extData.l1Fee))
);
} else {
token.transfer(_extData.recipient, uint256(-_extData.extAmount));
}
}
if (_extData.fee > 0) {
token.transfer(_extData.relayer, _extData.fee);
}
lastBalance = token.balanceOf(address(this));
_insert(_args.outputCommitments[0], _args.outputCommitments[1]);
emit NewCommitment(_args.outputCommitments[0], nextIndex - 2, _extData.encryptedOutput1);
emit NewCommitment(_args.outputCommitments[1], nextIndex - 1, _extData.encryptedOutput2);
for (uint256 i = 0; i < _args.inputNullifiers.length; i++) {
emit NewNullifier(_args.inputNullifiers[i]);
}
}
function _configureLimits(uint256 _maximumDepositAmount) internal {
maximumDepositAmount = _maximumDepositAmount;
}
}
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