mirror of
https://github.com/tornadocash/tornado-core.git
synced 2024-10-31 23:35:20 +01:00
69 lines
2.4 KiB
Solidity
69 lines
2.4 KiB
Solidity
pragma solidity ^0.5.8;
|
|
|
|
import "./MerkleTreeWithHistory.sol";
|
|
|
|
contract IVerifier {
|
|
function verifyProof(uint256[2] memory a, uint256[2][2] memory b, uint256[2] memory c, uint256[4] memory input) public returns(bool);
|
|
}
|
|
|
|
contract Mixer is MerkleTreeWithHistory {
|
|
uint256 public transferValue;
|
|
mapping(uint256 => bool) public nullifiers;
|
|
IVerifier verifier;
|
|
|
|
event Deposit(address from, uint256 commitment);
|
|
event Withdraw(address to, uint256 nullifier, uint256 fee);
|
|
|
|
/**
|
|
@dev The constructor
|
|
@param _verifier the address of SNARK verifier for this contract
|
|
@param _transferValue the value for all deposits in this contract in wei
|
|
*/
|
|
constructor(
|
|
address _verifier,
|
|
uint256 _transferValue,
|
|
uint8 _merkleTreeHeight,
|
|
uint256 _emptyElement
|
|
) MerkleTreeWithHistory(_merkleTreeHeight, _emptyElement) public {
|
|
verifier = IVerifier(_verifier);
|
|
transferValue = _transferValue;
|
|
}
|
|
|
|
/**
|
|
@dev Deposit funds into mixer. The caller must send value equal to `transferValue` of this mixer.
|
|
@param commitment the note commitment, which is PedersenHash(nullifier + secret)
|
|
*/
|
|
function deposit(uint256 commitment) public payable {
|
|
require(msg.value == transferValue, "Please send `transferValue` ETH along with transaction");
|
|
_insert(commitment);
|
|
emit Deposit(msg.sender, commitment);
|
|
}
|
|
|
|
/**
|
|
@dev Withdraw deposit from the mixer. `a`, `b`, and `c` are zkSNARK proof data, and input is an array of circuit public inputs
|
|
`input` array consists of:
|
|
- merkle root of all deposits in the mixer
|
|
- unique deposit nullifier to prevent double spends
|
|
- the receiver of funds
|
|
- optional fee that goes to the transaction sender (usually a relay)
|
|
*/
|
|
function withdraw(uint256[2] memory a, uint256[2][2] memory b, uint256[2] memory c, uint256[4] memory input) public {
|
|
uint256 root = input[0];
|
|
uint256 nullifier = input[1];
|
|
address payable receiver = address(input[2]);
|
|
uint256 fee = input[3];
|
|
|
|
require(fee < transferValue, "Fee exceeds transfer value");
|
|
require(!nullifiers[nullifier], "The note has been already spent");
|
|
require(isKnownRoot(root), "Cannot find your merkle root"); // Make sure to use a recent one
|
|
require(verifier.verifyProof(a, b, c, input), "Invalid withdraw proof");
|
|
|
|
nullifiers[nullifier] = true;
|
|
receiver.transfer(transferValue - fee);
|
|
if (fee > 0) {
|
|
msg.sender.transfer(fee);
|
|
}
|
|
emit Withdraw(receiver, nullifier, fee);
|
|
}
|
|
}
|