tornado-core/contracts/ERC20Mixer.sol

70 lines
2.8 KiB
Solidity

// https://tornado.cash
/*
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*/
pragma solidity ^0.5.8;
import "./Mixer.sol";
contract ERC20Mixer is Mixer {
address public token;
constructor(
IVerifier _verifier,
uint256 _denomination,
uint32 _merkleTreeHeight,
address _operator,
address _token
) Mixer(_verifier, _denomination, _merkleTreeHeight, _operator) public {
token = _token;
}
function _processDeposit() internal {
require(msg.value == 0, "ETH value is supposed to be 0 for ETH mixer");
_safeErc20TransferFrom(msg.sender, address(this), denomination);
}
function _processWithdraw(address payable _receiver, address payable _relayer, uint256 _fee, uint256 _refund) internal {
require(msg.value == _refund, "Incorrect refund amount received by the contract");
_safeErc20Transfer(_receiver, denomination - _fee);
if (_fee > 0) {
_safeErc20Transfer(_relayer, _fee);
}
if (_refund > 0) {
_receiver.transfer(_refund);
}
}
function _safeErc20TransferFrom(address _from, address _to, uint256 _amount) internal {
(bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x23b872dd /* transferFrom */, _from, _to, _amount));
require(success, "not enough allowed tokens");
// if contract returns some data lets make sure that is `true` according to standard
if (data.length > 0) {
require(data.length == 32, "data length should be either 0 or 32 bytes");
success = abi.decode(data, (bool));
require(success, "not enough allowed tokens. Token returns false.");
}
}
function _safeErc20Transfer(address _to, uint256 _amount) internal {
(bool success, bytes memory data) = token.call(abi.encodeWithSelector(0xa9059cbb /* transfer */, _to, _amount));
require(success, "not enough tokens");
// if contract returns some data lets make sure that is `true` according to standard
if (data.length > 0) {
require(data.length == 32, "data length should be either 0 or 32 bytes");
success = abi.decode(data, (bool));
require(success, "not enough tokens. Token returns false.");
}
}
}