keycard-redeem/contracts/NFTBucket.sol

115 lines
3.3 KiB
Solidity

pragma solidity ^0.6.1;
pragma experimental ABIEncoderV2;
import "./erc721/IERC721.sol";
import "./erc721/IERC721Receiver.sol";
import "./erc721/IERC165.sol";
import "./RedeemUtil.sol";
contract NFTBucket is IERC165, IERC721Receiver {
bool initialized;
address payable public owner;
IERC721 public tokenContract;
uint256 public expirationTime;
uint256 constant maxTxDelayInBlocks = 10;
struct Gift {
address recipient;
uint256 tokenID;
bytes32 code;
}
mapping(address => Gift) public gifts;
bytes4 private constant _ERC721_RECEIVED = 0x150b7a02; //bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))
bytes32 constant EIP712DOMAIN_TYPEHASH = keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)");
bytes32 DOMAIN_SEPARATOR;
modifier onlyOwner() {
require(msg.sender == owner, "owner required");
_;
}
constructor(address _tokenAddress, uint256 _expirationTime) public {
initialize(_tokenAddress, _expirationTime, msg.sender);
}
function initialize(address _tokenAddress, uint256 _expirationTime, address _owner) public {
require(initialized == false, "already initialized");
RedeemUtil.validateExpiryDate(_expirationTime);
tokenContract = IERC721(_tokenAddress);
expirationTime = _expirationTime;
owner = payable(_owner);
DOMAIN_SEPARATOR = keccak256(abi.encode(
EIP712DOMAIN_TYPEHASH,
keccak256("KeycardNFTGift"),
keccak256("1"),
RedeemUtil.getChainID(),
address(this)
));
initialized = true;
}
function redeem(RedeemUtil.Redeem calldata _redeem, bytes calldata _sig) external {
RedeemUtil.validateRedeem(_redeem, maxTxDelayInBlocks, expirationTime, 0);
address recipient = RedeemUtil.recoverSigner(DOMAIN_SEPARATOR, _redeem, _sig);
Gift storage gift = gifts[recipient];
require(gift.recipient == recipient, "not found");
RedeemUtil.validateCode(_redeem, gift.code);
tokenContract.safeTransferFrom(address(this), _redeem.receiver, gift.tokenID);
}
function kill() external onlyOwner {
RedeemUtil.validateExpired(expirationTime);
tokenContract.setApprovalForAll(owner, true);
assert(tokenContract.isApprovedForAll(address(this), owner));
selfdestruct(owner);
}
function supportsInterface(bytes4 interfaceID) external override(IERC165) view returns (bool) {
return interfaceID == _ERC721_RECEIVED;
}
function onERC721Received(address _operator, address _from, uint256 _tokenID, bytes calldata _data) external override(IERC721Receiver) returns(bytes4) {
require(msg.sender == address(tokenContract), "only the NFT contract can call this");
require((_operator == owner) || (_from == owner), "only the owner can create gifts");
require(_data.length == 52, "invalid data field");
bytes memory d = _data;
bytes32 tmp;
bytes32 code;
assembly {
// tmp is 12 bytes of padding (taken from the array length) + 20 bytes of address
tmp := mload(add(d, 20))
code := mload(add(d, 52))
}
address recipient = address(uint160(uint256(tmp)));
Gift storage gift = gifts[recipient];
require(gift.recipient == address(0), "recipient already used");
gift.recipient = recipient;
gift.tokenID = _tokenID;
gift.code = code;
return _ERC721_RECEIVED;
}
}