Comment on page
Contract
// SPDX-License-Identifier: BSD-3-Clause-Clear
pragma solidity >=0.8.13 <0.9.0;
import "../lib/TFHE.sol";
import "./abstract/EIP712WithModifier.sol";
import "./EncryptedERC20.sol";
contract BlindAuction is EIP712WithModifier {
uint public endTime;
address public beneficiary;
// Current highest bid.
euint32 internal highestBid;
// Mapping from bidder to their bid value.
mapping(address => euint32) public bids;
// Number of bid
uint public bidCounter;
// The token contract used for encrypted bids.
EncryptedERC20 public tokenContract;
// Whether the auction object has been claimed.
bool public objectClaimed;
// If the token has been transferred to the beneficiary
bool public tokenTransferred;
bool public stoppable;
bool public manuallyStopped = false;
// The function has been called too early.
// Try again at `time`.
error TooEarly(uint time);
// The function has been called too late.
// It cannot be called after `time`.
error TooLate(uint time);
event Winner(address who);
constructor(
address _beneficiary,
EncryptedERC20 _tokenContract,
uint biddingTime,
bool isStoppable
) EIP712WithModifier("Authorization token", "1") {
beneficiary = _beneficiary;
tokenContract = _tokenContract;
endTime = block.timestamp + biddingTime;
objectClaimed = false;
tokenTransferred = false;
bidCounter = 0;
stoppable = isStoppable;
}
// Bid an `encryptedValue`.
function bid(bytes calldata encryptedValue) public onlyBeforeEnd {
euint32 value = TFHE.asEuint32(encryptedValue);
euint32 existingBid = bids[msg.sender];
if (TFHE.isInitialized(existingBid)) {
euint32 isHigher = TFHE.lt(existingBid, value);
// Update bid with value
bids[msg.sender] = TFHE.cmux(isHigher, value, existingBid);
// Transfer only the difference between existing and value
euint32 toTransfer = TFHE.sub(value, existingBid);
// Transfer only if bid is higher
euint32 amount = TFHE.mul(isHigher, toTransfer);
tokenContract.transferFrom(msg.sender, address(this), amount);
} else {
bidCounter++;
bids[msg.sender] = value;
tokenContract.transferFrom(msg.sender, address(this), value);
}
euint32 currentBid = bids[msg.sender];
if (!TFHE.isInitialized(highestBid)) {
highestBid = currentBid;
} else {
highestBid = TFHE.cmux(
TFHE.lt(highestBid, currentBid),
currentBid,
highestBid
);
}
}
function getBid(
bytes32 publicKey,
bytes calldata signature
)
public
view
onlySignedPublicKey(publicKey, signature)
returns (bytes memory)
{
return TFHE.reencrypt(bids[msg.sender], publicKey, 0);
}
// Returns the user bid
function stop() public {
require(stoppable);
manuallyStopped = true;
}
// Returns an encrypted value of 0 or 1 under the caller's public key, indicating
// if the caller has the highest bid.
function doIHaveHighestBid(
bytes32 publicKey,
bytes calldata signature
)
public
view
onlyAfterEnd
onlySignedPublicKey(publicKey, signature)
returns (bytes memory)
{
if (
TFHE.isInitialized(highestBid) &&
TFHE.isInitialized(bids[msg.sender])
) {
return
TFHE.reencrypt(
TFHE.le(highestBid, bids[msg.sender]),
publicKey
);
} else {
return TFHE.reencrypt(TFHE.asEuint32(0), publicKey);
}
}
// Claim the object. Succeeds only if the caller has the highest bid.
function claim() public onlyAfterEnd {
require(!objectClaimed);
TFHE.req(TFHE.le(highestBid, bids[msg.sender]));
objectClaimed = true;
bids[msg.sender] = euint32.wrap(0);
emit Winner(msg.sender);
}
// Transfer token to beneficiary
function auctionEnd() public onlyAfterEnd {
require(!tokenTransferred);
tokenTransferred = true;
tokenContract.transfer(beneficiary, highestBid);
}
// Withdraw a bid from the auction to the caller once the auction has stopped.
function withdraw() public onlyAfterEnd {
euint32 bidValue = bids[msg.sender];
if (!objectClaimed) {
TFHE.req(TFHE.lt(bidValue, highestBid));
}
tokenContract.transfer(msg.sender, bidValue);
bids[msg.sender] = euint32.wrap(0);
}
modifier onlyBeforeEnd() {
if (block.timestamp >= endTime || manuallyStopped == true)
revert TooLate(endTime);
_;
}
modifier onlyAfterEnd() {
if (block.timestamp <= endTime && manuallyStopped == false)
revert TooEarly(endTime);
_;
}
}
Last modified 4mo ago