tornado-core/contracts/ERC20Mixer.sol
2019-11-02 13:06:10 +03:00

89 lines
2.9 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,
uint8 _merkleTreeHeight,
uint256 _emptyElement,
address _operator,
address _token
) Mixer(_verifier, _denomination, _merkleTreeHeight, _emptyElement, _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;
bytes4 transferFromSelector = 0x23b872dd;
(success, data) = token.call(
abi.encodeWithSelector(
transferFromSelector,
from, to, amount
)
);
require(success, "not enough allowed tokens");
// if contract returns some data let's make sure that is `true` according to standard
if (data.length > 0) {
assembly {
success := mload(add(data, 0x20))
}
require(success, "not enough allowed tokens");
}
}
function safeErc20Transfer(address to, uint256 amount) internal {
bool success;
bytes memory data;
bytes4 transferSelector = 0xa9059cbb;
(success, data) = token.call(
abi.encodeWithSelector(
transferSelector,
to, amount
)
);
require(success, "not enough tokens");
// if contract returns some data let's make sure that is `true` according to standard
if (data.length > 0) {
assembly {
success := mload(add(data, 0x20))
}
require(success, "not enough tokens");
}
}
}