Contract Name:
DirectLoanFixedOffer
Contract Source Code:
// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.4;
import "./DirectLoanBaseMinimal.sol";
import "../../../utils/ContractKeys.sol";
/**
* @title DirectLoanFixed
* @author NFTfi
* @notice Main contract for NFTfi Direct Loans Fixed Type. This contract manages the ability to create NFT-backed
* peer-to-peer loans of type Fixed (agreed to be a fixed-repayment loan) where the borrower pays the
* maximumRepaymentAmount regardless of whether they repay early or not.
*
* There are two ways to commence an NFT-backed loan:
*
* a. The borrower accepts a lender's offer by calling `acceptOffer`.
* 1. the borrower calls nftContract.approveAll(NFTfi), approving the NFTfi contract to move their NFT's on their
* be1alf.
* 2. the lender calls erc20Contract.approve(NFTfi), allowing NFTfi to move the lender's ERC20 tokens on their
* behalf.
* 3. the lender signs an off-chain message, proposing its offer terms.
* 4. the borrower calls `acceptOffer` to accept these terms and enter into the loan. The NFT is stored in
* the contract, the borrower receives the loan principal in the specified ERC20 currency, the lender receives an
* NFTfi promissory note (in ERC721 form) that represents the rights to either the principal-plus-interest, or the
* underlying NFT collateral if the borrower does not pay back in time, and the borrower receives obligation receipt
* (in ERC721 form) that gives them the right to pay back the loan and get the collateral back.
*
* b. The lender accepts a borrowe's binding terms by calling `acceptListing`.
* 1. the borrower calls nftContract.approveAll(NFTfi), approving the NFTfi contract to move their NFT's on their
* be1alf.
* 2. the lender calls erc20Contract.approve(NFTfi), allowing NFTfi to move the lender's ERC20 tokens on their
* behalf.
* 3. the borrower signs an off-chain message, proposing its binding terms.
* 4. the lender calls `acceptListing` with an offer matching the binding terms and enter into the loan. The NFT is
* stored in the contract, the borrower receives the loan principal in the specified ERC20 currency, the lender
* receives an NFTfi promissory note (in ERC721 form) that represents the rights to either the principal-plus-interest,
* or the underlying NFT collateral if the borrower does not pay back in time, and the borrower receives obligation
* receipt (in ERC721 form) that gives them the right to pay back the loan and get the collateral back.
*
* The lender can freely transfer and trade this ERC721 promissory note as they wish, with the knowledge that
* transferring the ERC721 promissory note tranfsers the rights to principal-plus-interest and/or collateral, and that
* they will no longer have a claim on the loan. The ERC721 promissory note itself represents that claim.
*
* The borrower can freely transfer and trade this ERC721 obligaiton receipt as they wish, with the knowledge that
* transferring the ERC721 obligaiton receipt tranfsers the rights right to pay back the loan and get the collateral
* back.
*
*
* A loan may end in one of two ways:
* - First, a borrower may call NFTfi.payBackLoan() and pay back the loan plus interest at any time, in which case they
* receive their NFT back in the same transaction.
* - Second, if the loan's duration has passed and the loan has not been paid back yet, a lender can call
* NFTfi.liquidateOverdueLoan(), in which case they receive the underlying NFT collateral and forfeit the rights to the
* principal-plus-interest, which the borrower now keeps.
*/
contract DirectLoanFixedOffer is DirectLoanBaseMinimal {
/* ********** */
/* DATA TYPES */
/* ********** */
bytes32 public constant LOAN_TYPE = bytes32("DIRECT_LOAN_FIXED_OFFER");
/* *********** */
/* CONSTRUCTOR */
/* *********** */
/**
* @dev Sets `hub` and permitted erc20-s
*
* @param _admin - Initial admin of this contract.
* @param _nftfiHub - NFTfiHub address
* @param _permittedErc20s - list of permitted ERC20 token contract addresses
*/
constructor(
address _admin,
address _nftfiHub,
address[] memory _permittedErc20s
)
DirectLoanBaseMinimal(
_admin,
_nftfiHub,
ContractKeys.getIdFromStringKey("DIRECT_LOAN_COORDINATOR"),
_permittedErc20s
)
{
// solhint-disable-previous-line no-empty-blocks
}
/* ********* */
/* FUNCTIONS */
/* ********* */
/**
* @notice This function is called by the borrower when accepting a lender's offer to begin a loan.
*
* @param _offer - The offer made by the lender.
* @param _signature - The components of the lender's signature.
* @param _borrowerSettings - Some extra parameters that the borrower needs to set when accepting an offer.
*/
function acceptOffer(
Offer memory _offer,
Signature memory _signature,
BorrowerSettings memory _borrowerSettings
) external whenNotPaused nonReentrant {
address nftWrapper = _getWrapper(_offer.nftCollateralContract);
_loanSanityChecks(_offer, nftWrapper);
_loanSanityChecksOffer(_offer);
_acceptOffer(
LOAN_TYPE,
_setupLoanTerms(_offer, nftWrapper),
_setupLoanExtras(_borrowerSettings.revenueSharePartner, _borrowerSettings.referralFeeInBasisPoints),
_offer,
_signature
);
}
/* ******************* */
/* READ-ONLY FUNCTIONS */
/* ******************* */
/**
* @notice This function can be used to view the current quantity of the ERC20 currency used in the specified loan
* required by the borrower to repay their loan, measured in the smallest unit of the ERC20 currency.
*
* @param _loanId A unique identifier for this particular loan, sourced from the Loan Coordinator.
*
* @return The amount of the specified ERC20 currency required to pay back this loan, measured in the smallest unit
* of the specified ERC20 currency.
*/
function getPayoffAmount(uint32 _loanId) external view override returns (uint256) {
LoanTerms storage loan = loanIdToLoan[_loanId];
return loan.maximumRepaymentAmount;
}
/* ****************** */
/* INTERNAL FUNCTIONS */
/* ****************** */
/**
* @notice This function is called by the borrower when accepting a lender's offer to begin a loan.
*
* @param _loanType - The loan type being created.
* @param _loanTerms - The main Loan Terms struct. This data is saved upon loan creation on loanIdToLoan.
* @param _loanExtras - The main Loan Terms struct. This data is saved upon loan creation on loanIdToLoanExtras.
* @param _offer - The offer made by the lender.
* @param _signature - The components of the lender's signature.
*/
function _acceptOffer(
bytes32 _loanType,
LoanTerms memory _loanTerms,
LoanExtras memory _loanExtras,
Offer memory _offer,
Signature memory _signature
) internal {
// Check loan nonces. These are different from Ethereum account nonces.
// Here, these are uint256 numbers that should uniquely identify
// each signature for each user (i.e. each user should only create one
// off-chain signature for each nonce, with a nonce being any arbitrary
// uint256 value that they have not used yet for an off-chain NFTfi
// signature).
require(!_nonceHasBeenUsedForUser[_signature.signer][_signature.nonce], "Lender nonce invalid");
_nonceHasBeenUsedForUser[_signature.signer][_signature.nonce] = true;
require(NFTfiSigningUtils.isValidLenderSignature(_offer, _signature), "Lender signature is invalid");
address bundle = hub.getContract(ContractKeys.NFTFI_BUNDLER);
require(_loanTerms.nftCollateralContract != bundle, "Collateral cannot be bundle");
uint32 loanId = _createLoan(_loanType, _loanTerms, _loanExtras, msg.sender, _signature.signer, _offer.referrer);
// Emit an event with all relevant details from this transaction.
emit LoanStarted(loanId, msg.sender, _signature.signer, _loanTerms, _loanExtras);
}
/**
* @dev Creates a `LoanTerms` struct using data sent as the lender's `_offer` on `acceptOffer`.
* This is needed in order to avoid stack too deep issues.
* Since this is a Fixed loan type loanInterestRateForDurationInBasisPoints is ignored.
*/
function _setupLoanTerms(Offer memory _offer, address _nftWrapper) internal view returns (LoanTerms memory) {
return
LoanTerms({
loanERC20Denomination: _offer.loanERC20Denomination,
loanPrincipalAmount: _offer.loanPrincipalAmount,
maximumRepaymentAmount: _offer.maximumRepaymentAmount,
nftCollateralContract: _offer.nftCollateralContract,
nftCollateralWrapper: _nftWrapper,
nftCollateralId: _offer.nftCollateralId,
loanStartTime: uint64(block.timestamp),
loanDuration: _offer.loanDuration,
loanInterestRateForDurationInBasisPoints: uint16(0),
loanAdminFeeInBasisPoints: _offer.loanAdminFeeInBasisPoints,
borrower: msg.sender
});
}
/**
* @dev Calculates the payoff amount and admin fee
*
* @param _loanTerms - Struct containing all the loan's parameters
*/
function _payoffAndFee(LoanTerms memory _loanTerms)
internal
pure
override
returns (uint256 adminFee, uint256 payoffAmount)
{
// Calculate amounts to send to lender and admins
uint256 interestDue = _loanTerms.maximumRepaymentAmount - _loanTerms.loanPrincipalAmount;
adminFee = LoanChecksAndCalculations.computeAdminFee(
interestDue,
uint256(_loanTerms.loanAdminFeeInBasisPoints)
);
payoffAmount = _loanTerms.maximumRepaymentAmount - adminFee;
}
/**
* @dev Function that performs some validation checks over loan parameters when accepting an offer
*
*/
function _loanSanityChecksOffer(LoanData.Offer memory _offer) internal pure {
require(
_offer.maximumRepaymentAmount >= _offer.loanPrincipalAmount,
"Negative interest rate loans are not allowed."
);
}
}
// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.4;
import "./IDirectLoanBase.sol";
import "./LoanData.sol";
import "./LoanChecksAndCalculations.sol";
import "./LoanAirdropUtils.sol";
import "../../BaseLoan.sol";
import "../../../utils/NftReceiver.sol";
import "../../../utils/NFTfiSigningUtils.sol";
import "../../../interfaces/INftfiHub.sol";
import "../../../utils/ContractKeys.sol";
import "../../../interfaces/IDirectLoanCoordinator.sol";
import "../../../interfaces/INftWrapper.sol";
import "../../../interfaces/IPermittedPartners.sol";
import "../../../interfaces/IPermittedERC20s.sol";
import "../../../interfaces/IPermittedNFTs.sol";
import "@openzeppelin/contracts/token/ERC721/IERC721.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC1155/IERC1155.sol";
import "@openzeppelin/contracts/utils/Address.sol";
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
/**
* @title DirectLoanBase
* @author NFTfi
* @notice Main contract for NFTfi Direct Loans Type. This contract manages the ability to create NFT-backed
* peer-to-peer loans.
*
* There are two ways to commence an NFT-backed loan:
*
* a. The borrower accepts a lender's offer by calling `acceptOffer`.
* 1. the borrower calls nftContract.approveAll(NFTfi), approving the NFTfi contract to move their NFT's on their
* be1alf.
* 2. the lender calls erc20Contract.approve(NFTfi), allowing NFTfi to move the lender's ERC20 tokens on their
* behalf.
* 3. the lender signs an off-chain message, proposing its offer terms.
* 4. the borrower calls `acceptOffer` to accept these terms and enter into the loan. The NFT is stored in
* the contract, the borrower receives the loan principal in the specified ERC20 currency, the lender receives an
* NFTfi promissory note (in ERC721 form) that represents the rights to either the principal-plus-interest, or the
* underlying NFT collateral if the borrower does not pay back in time, and the borrower receives obligation receipt
* (in ERC721 form) that gives them the right to pay back the loan and get the collateral back.
*
* b. The lender accepts a borrowe's binding terms by calling `acceptListing`.
* 1. the borrower calls nftContract.approveAll(NFTfi), approving the NFTfi contract to move their NFT's on their
* be1alf.
* 2. the lender calls erc20Contract.approve(NFTfi), allowing NFTfi to move the lender's ERC20 tokens on their
* behalf.
* 3. the borrower signs an off-chain message, proposing its binding terms.
* 4. the lender calls `acceptListing` with an offer matching the binding terms and enter into the loan. The NFT is
* stored in the contract, the borrower receives the loan principal in the specified ERC20 currency, the lender
* receives an NFTfi promissory note (in ERC721 form) that represents the rights to either the principal-plus-interest,
* or the underlying NFT collateral if the borrower does not pay back in time, and the borrower receives obligation
* receipt (in ERC721 form) that gives them the right to pay back the loan and get the collateral back.
*
* The lender can freely transfer and trade this ERC721 promissory note as they wish, with the knowledge that
* transferring the ERC721 promissory note tranfsers the rights to principal-plus-interest and/or collateral, and that
* they will no longer have a claim on the loan. The ERC721 promissory note itself represents that claim.
*
* The borrower can freely transfer and trade this ERC721 obligaiton receipt as they wish, with the knowledge that
* transferring the ERC721 obligaiton receipt tranfsers the rights right to pay back the loan and get the collateral
* back.
*
* A loan may end in one of two ways:
* - First, a borrower may call NFTfi.payBackLoan() and pay back the loan plus interest at any time, in which case they
* receive their NFT back in the same transaction.
* - Second, if the loan's duration has passed and the loan has not been paid back yet, a lender can call
* NFTfi.liquidateOverdueLoan(), in which case they receive the underlying NFT collateral and forfeit the rights to the
* principal-plus-interest, which the borrower now keeps.
*
*
* If the loan was created as a ProRated type loan (pro-rata interest loan), then the user only pays the principal plus
* pro-rata interest if repaid early.
* However, if the loan was was created as a Fixed type loan (agreed to be a fixed-repayment loan), then the borrower
* pays the maximumRepaymentAmount regardless of whether they repay early or not.
*
*/
abstract contract DirectLoanBaseMinimal is IDirectLoanBase, IPermittedERC20s, BaseLoan, NftReceiver, LoanData {
using SafeERC20 for IERC20;
/* ******* */
/* STORAGE */
/* ******* */
uint16 public constant HUNDRED_PERCENT = 10000;
bytes32 public immutable override LOAN_COORDINATOR;
/**
* @notice The maximum duration of any loan started for this loan type, measured in seconds. This is both a
* sanity-check for borrowers and an upper limit on how long admins will have to support v1 of this contract if they
* eventually deprecate it, as well as a check to ensure that the loan duration never exceeds the space alotted for
* it in the loan struct.
*/
uint256 public override maximumLoanDuration = 53 weeks;
/**
* @notice The percentage of interest earned by lenders on this platform that is taken by the contract admin's as a
* fee, measured in basis points (hundreths of a percent). The max allowed value is 10000.
*/
uint16 public override adminFeeInBasisPoints = 25;
/**
* @notice A mapping from a loan's identifier to the loan's details, represted by the loan struct.
*/
mapping(uint32 => LoanTerms) public override loanIdToLoan;
mapping(uint32 => LoanExtras) public loanIdToLoanExtras;
/**
* @notice A mapping tracking whether a loan has either been repaid or liquidated. This prevents an attacker trying
* to repay or liquidate the same loan twice.
*/
mapping(uint32 => bool) public override loanRepaidOrLiquidated;
/**
* @dev keeps track of tokens being held as loan collateral, so we dont allow these
* to be transferred with the aridrop draining functions
*/
mapping(address => mapping(uint256 => uint256)) private _escrowTokens;
/**
* @notice A mapping that takes both a user's address and a loan nonce that was first used when signing an off-chain
* order and checks whether that nonce has previously either been used for a loan, or has been pre-emptively
* cancelled. The nonce referred to here is not the same as an Ethereum account's nonce. We are referring instead to
* nonces that are used by both the lender and the borrower when they are first signing off-chain NFTfi orders.
*
* These nonces can be any uint256 value that the user has not previously used to sign an off-chain order. Each
* nonce can be used at most once per user within NFTfi, regardless of whether they are the lender or the borrower
* in that situation. This serves two purposes. First, it prevents replay attacks where an attacker would submit a
* user's off-chain order more than once. Second, it allows a user to cancel an off-chain order by calling
* NFTfi.cancelLoanCommitmentBeforeLoanHasBegun(), which marks the nonce as used and prevents any future loan from
* using the user's off-chain order that contains that nonce.
*/
mapping(address => mapping(uint256 => bool)) internal _nonceHasBeenUsedForUser;
/**
* @notice A mapping from an ERC20 currency address to whether that currency
* is permitted to be used by this contract.
*/
mapping(address => bool) private erc20Permits;
INftfiHub public immutable hub;
/* ****** */
/* EVENTS */
/* ****** */
/**
* @notice This event is fired whenever the admins change the percent of interest rates earned that they charge as a
* fee. Note that newAdminFee can never exceed 10,000, since the fee is measured in basis points.
*
* @param newAdminFee - The new admin fee measured in basis points. This is a percent of the interest paid upon a
* loan's completion that go to the contract admins.
*/
event AdminFeeUpdated(uint16 newAdminFee);
/**
* @notice This event is fired whenever the admins change the maximum duration of any loan started for this loan
* type.
*
* @param newMaximumLoanDuration - The new maximum duration.
*/
event MaximumLoanDurationUpdated(uint256 newMaximumLoanDuration);
/**
* @notice This event is fired whenever a borrower begins a loan by calling NFTfi.beginLoan(), which can only occur
* after both the lender and borrower have approved their ERC721 and ERC20 contracts to use NFTfi, and when they
* both have signed off-chain messages that agree on the terms of the loan.
*
* @param loanId - A unique identifier for this particular loan, sourced from the Loan Coordinator.
* @param borrower - The address of the borrower.
* @param lender - The address of the lender. The lender can change their address by transferring the NFTfi ERC721
* token that they received when the loan began.
*/
event LoanStarted(
uint32 indexed loanId,
address indexed borrower,
address indexed lender,
LoanTerms loanTerms,
LoanExtras loanExtras
);
/**
* @notice This event is fired whenever a borrower successfully repays their loan, paying
* principal-plus-interest-minus-fee to the lender in loanERC20Denomination, paying fee to owner in
* loanERC20Denomination, and receiving their NFT collateral back.
*
* @param loanId - A unique identifier for this particular loan, sourced from the Loan Coordinator.
* @param borrower - The address of the borrower.
* @param lender - The address of the lender. The lender can change their address by transferring the NFTfi ERC721
* token that they received when the loan began.
* @param loanPrincipalAmount - The original sum of money transferred from lender to borrower at the beginning of
* the loan, measured in loanERC20Denomination's smallest units.
* @param nftCollateralId - The ID within the NFTCollateralContract for the NFT being used as collateral for this
* loan. The NFT is stored within this contract during the duration of the loan.
* @param amountPaidToLender The amount of ERC20 that the borrower paid to the lender, measured in the smalled
* units of loanERC20Denomination.
* @param adminFee The amount of interest paid to the contract admins, measured in the smalled units of
* loanERC20Denomination and determined by adminFeeInBasisPoints. This amount never exceeds the amount of interest
* earned.
* @param revenueShare The amount taken from admin fee amount shared with the partner.
* @param revenueSharePartner - The address of the partner that will receive the revenue share.
* @param nftCollateralContract - The ERC721 contract of the NFT collateral
* @param loanERC20Denomination - The ERC20 contract of the currency being used as principal/interest for this
* loan.
*/
event LoanRepaid(
uint32 indexed loanId,
address indexed borrower,
address indexed lender,
uint256 loanPrincipalAmount,
uint256 nftCollateralId,
uint256 amountPaidToLender,
uint256 adminFee,
uint256 revenueShare,
address revenueSharePartner,
address nftCollateralContract,
address loanERC20Denomination
);
/**
* @notice This event is fired whenever a lender liquidates an outstanding loan that is owned to them that has
* exceeded its duration. The lender receives the underlying NFT collateral, and the borrower no longer needs to
* repay the loan principal-plus-interest.
*
* @param loanId - A unique identifier for this particular loan, sourced from the Loan Coordinator.
* @param borrower - The address of the borrower.
* @param lender - The address of the lender. The lender can change their address by transferring the NFTfi ERC721
* token that they received when the loan began.
* @param loanPrincipalAmount - The original sum of money transferred from lender to borrower at the beginning of
* the loan, measured in loanERC20Denomination's smallest units.
* @param nftCollateralId - The ID within the NFTCollateralContract for the NFT being used as collateral for this
* loan. The NFT is stored within this contract during the duration of the loan.
* @param loanMaturityDate - The unix time (measured in seconds) that the loan became due and was eligible for
* liquidation.
* @param loanLiquidationDate - The unix time (measured in seconds) that liquidation occurred.
* @param nftCollateralContract - The ERC721 contract of the NFT collateral
*/
event LoanLiquidated(
uint32 indexed loanId,
address indexed borrower,
address indexed lender,
uint256 loanPrincipalAmount,
uint256 nftCollateralId,
uint256 loanMaturityDate,
uint256 loanLiquidationDate,
address nftCollateralContract
);
/**
* @notice This event is fired when some of the terms of a loan are being renegotiated.
*
* @param loanId - The unique identifier for the loan to be renegotiated
* @param newLoanDuration - The new amount of time (measured in seconds) that can elapse before the lender can
* liquidate the loan and seize the underlying collateral NFT.
* @param newMaximumRepaymentAmount - The new maximum amount of money that the borrower would be required to
* retrieve their collateral, measured in the smallest units of the ERC20 currency used for the loan. The
* borrower will always have to pay this amount to retrieve their collateral, regardless of whether they repay
* early.
* @param renegotiationFee Agreed upon fee in loan denomination that borrower pays for the lender for the
* renegotiation, has to be paid with an ERC20 transfer loanERC20Denomination token, uses transfer from,
* frontend will have to propmt an erc20 approve for this from the borrower to the lender
* @param renegotiationAdminFee renegotiationFee admin portion based on determined by adminFeeInBasisPoints
*/
event LoanRenegotiated(
uint32 indexed loanId,
address indexed borrower,
address indexed lender,
uint32 newLoanDuration,
uint256 newMaximumRepaymentAmount,
uint256 renegotiationFee,
uint256 renegotiationAdminFee
);
/**
* @notice This event is fired whenever the admin sets a ERC20 permit.
*
* @param erc20Contract - Address of the ERC20 contract.
* @param isPermitted - Signals ERC20 permit.
*/
event ERC20Permit(address indexed erc20Contract, bool isPermitted);
/* *********** */
/* CONSTRUCTOR */
/* *********** */
/**
* @dev Sets `hub`
*
* @param _admin - Initial admin of this contract.
* @param _nftfiHub - NFTfiHub address
* @param _loanCoordinatorKey -
* @param _permittedErc20s -
*/
constructor(
address _admin,
address _nftfiHub,
bytes32 _loanCoordinatorKey,
address[] memory _permittedErc20s
) BaseLoan(_admin) {
hub = INftfiHub(_nftfiHub);
LOAN_COORDINATOR = _loanCoordinatorKey;
for (uint256 i = 0; i < _permittedErc20s.length; i++) {
_setERC20Permit(_permittedErc20s[i], true);
}
}
/* *************** */
/* ADMIN FUNCTIONS */
/* *************** */
/**
* @notice This function can be called by admins to change the maximumLoanDuration. Note that they can never change
* maximumLoanDuration to be greater than UINT32_MAX, since that's the maximum space alotted for the duration in the
* loan struct.
*
* @param _newMaximumLoanDuration - The new maximum loan duration, measured in seconds.
*/
function updateMaximumLoanDuration(uint256 _newMaximumLoanDuration) external onlyOwner {
require(_newMaximumLoanDuration <= uint256(type(uint32).max), "Loan duration overflow");
maximumLoanDuration = _newMaximumLoanDuration;
emit MaximumLoanDurationUpdated(_newMaximumLoanDuration);
}
/**
* @notice This function can be called by admins to change the percent of interest rates earned that they charge as
* a fee. Note that newAdminFee can never exceed 10,000, since the fee is measured in basis points.
*
* @param _newAdminFeeInBasisPoints - The new admin fee measured in basis points. This is a percent of the interest
* paid upon a loan's completion that go to the contract admins.
*/
function updateAdminFee(uint16 _newAdminFeeInBasisPoints) external onlyOwner {
require(_newAdminFeeInBasisPoints <= HUNDRED_PERCENT, "basis points > 10000");
adminFeeInBasisPoints = _newAdminFeeInBasisPoints;
emit AdminFeeUpdated(_newAdminFeeInBasisPoints);
}
/**
* @notice used by the owner account to be able to drain ERC20 tokens received as airdrops
* for the locked collateral NFT-s
* @param _tokenAddress - address of the token contract for the token to be sent out
* @param _receiver - receiver of the token
*/
function drainERC20Airdrop(address _tokenAddress, address _receiver) external onlyOwner {
IERC20 tokenContract = IERC20(_tokenAddress);
uint256 amount = tokenContract.balanceOf(address(this));
require(amount > 0, "no tokens owned");
tokenContract.safeTransfer(_receiver, amount);
}
/**
* @notice This function can be called by admins to change the permitted status of an ERC20 currency. This includes
* both adding an ERC20 currency to the permitted list and removing it.
*
* @param _erc20 - The address of the ERC20 currency whose permit list status changed.
* @param _permit - The new status of whether the currency is permitted or not.
*/
function setERC20Permit(address _erc20, bool _permit) external onlyOwner {
_setERC20Permit(_erc20, _permit);
}
/**
* @notice This function can be called by admins to change the permitted status of a batch of ERC20 currency. This
* includes both adding an ERC20 currency to the permitted list and removing it.
*
* @param _erc20s - The addresses of the ERC20 currencies whose permit list status changed.
* @param _permits - The new statuses of whether the currency is permitted or not.
*/
function setERC20Permits(address[] memory _erc20s, bool[] memory _permits) external onlyOwner {
require(_erc20s.length == _permits.length, "setERC20Permits function information arity mismatch");
for (uint256 i = 0; i < _erc20s.length; i++) {
_setERC20Permit(_erc20s[i], _permits[i]);
}
}
/**
* @notice used by the owner account to be able to drain ERC721 tokens received as airdrops
* for the locked collateral NFT-s
* @param _tokenAddress - address of the token contract for the token to be sent out
* @param _tokenId - id token to be sent out
* @param _receiver - receiver of the token
*/
function drainERC721Airdrop(
address _tokenAddress,
uint256 _tokenId,
address _receiver
) external onlyOwner {
IERC721 tokenContract = IERC721(_tokenAddress);
require(_escrowTokens[_tokenAddress][_tokenId] == 0, "token is collateral");
require(tokenContract.ownerOf(_tokenId) == address(this), "nft not owned");
tokenContract.safeTransferFrom(address(this), _receiver, _tokenId);
}
/**
* @notice used by the owner account to be able to drain ERC1155 tokens received as airdrops
* for the locked collateral NFT-s
* @param _tokenAddress - address of the token contract for the token to be sent out
* @param _tokenId - id token to be sent out
* @param _receiver - receiver of the token
*/
function drainERC1155Airdrop(
address _tokenAddress,
uint256 _tokenId,
address _receiver
) external onlyOwner {
IERC1155 tokenContract = IERC1155(_tokenAddress);
uint256 amount = tokenContract.balanceOf(address(this), _tokenId);
require(_escrowTokens[_tokenAddress][_tokenId] == 0, "token is collateral");
require(amount > 0, "no nfts owned");
tokenContract.safeTransferFrom(address(this), _receiver, _tokenId, amount, "");
}
function mintObligationReceipt(uint32 _loanId) external nonReentrant {
address borrower = loanIdToLoan[_loanId].borrower;
require(msg.sender == borrower, "sender has to be borrower");
IDirectLoanCoordinator loanCoordinator = IDirectLoanCoordinator(hub.getContract(LOAN_COORDINATOR));
loanCoordinator.mintObligationReceipt(_loanId, borrower);
delete loanIdToLoan[_loanId].borrower;
}
/**
* @dev makes possible to change loan duration and max repayment amount, loan duration even can be extended if
* loan was expired but not liquidated.
*
* @param _loanId - The unique identifier for the loan to be renegotiated
* @param _newLoanDuration - The new amount of time (measured in seconds) that can elapse before the lender can
* liquidate the loan and seize the underlying collateral NFT.
* @param _newMaximumRepaymentAmount - The new maximum amount of money that the borrower would be required to
* retrieve their collateral, measured in the smallest units of the ERC20 currency used for the loan. The
* borrower will always have to pay this amount to retrieve their collateral, regardless of whether they repay
* early.
* @param _renegotiationFee Agreed upon fee in ether that borrower pays for the lender for the renegitiation
* @param _lenderNonce - The nonce referred to here is not the same as an Ethereum account's nonce. We are
* referring instead to nonces that are used by both the lender and the borrower when they are first signing
* off-chain NFTfi orders. These nonces can be any uint256 value that the user has not previously used to sign an
* off-chain order. Each nonce can be used at most once per user within NFTfi, regardless of whether they are the
* lender or the borrower in that situation. This serves two purposes:
* - First, it prevents replay attacks where an attacker would submit a user's off-chain order more than once.
* - Second, it allows a user to cancel an off-chain order by calling NFTfi.cancelLoanCommitmentBeforeLoanHasBegun()
* , which marks the nonce as used and prevents any future loan from using the user's off-chain order that contains
* that nonce.
* @param _expiry - The date when the renegotiation offer expires
* @param _lenderSignature - The ECDSA signature of the lender, obtained off-chain ahead of time, signing the
* following combination of parameters:
* - _loanId
* - _newLoanDuration
* - _newMaximumRepaymentAmount
* - _lender
* - _expiry
* - address of this contract
* - chainId
*/
function renegotiateLoan(
uint32 _loanId,
uint32 _newLoanDuration,
uint256 _newMaximumRepaymentAmount,
uint256 _renegotiationFee,
uint256 _lenderNonce,
uint256 _expiry,
bytes memory _lenderSignature
) external whenNotPaused nonReentrant {
_renegotiateLoan(
_loanId,
_newLoanDuration,
_newMaximumRepaymentAmount,
_renegotiationFee,
_lenderNonce,
_expiry,
_lenderSignature
);
}
/**
* @notice This function is called by a anyone to repay a loan. It can be called at any time after the loan has
* begun and before loan expiry.. The caller will pay a pro-rata portion of their interest if the loan is paid off
* early and the loan is pro-rated type, but the complete repayment amount if it is fixed type.
* The the borrower (current owner of the obligation note) will get the collaterl NFT back.
*
* This function is purposefully not pausable in order to prevent an attack where the contract admin's pause the
* contract and hold hostage the NFT's that are still within it.
*
* @param _loanId A unique identifier for this particular loan, sourced from the Loan Coordinator.
*/
function payBackLoan(uint32 _loanId) external nonReentrant {
LoanChecksAndCalculations.payBackChecks(_loanId, hub);
(
address borrower,
address lender,
LoanTerms memory loan,
IDirectLoanCoordinator loanCoordinator
) = _getPartiesAndData(_loanId);
_payBackLoan(_loanId, borrower, lender, loan);
_resolveLoan(_loanId, borrower, loan, loanCoordinator);
// Delete the loan from storage in order to achieve a substantial gas savings and to lessen the burden of
// storage on Ethereum nodes, since we will never access this loan's details again, and the details are still
// available through event data.
delete loanIdToLoan[_loanId];
delete loanIdToLoanExtras[_loanId];
}
/**
* @notice This function is called by a lender once a loan has finished its duration and the borrower still has not
* repaid. The lender can call this function to seize the underlying NFT collateral, although the lender gives up
* all rights to the principal-plus-collateral by doing so.
*
* This function is purposefully not pausable in order to prevent an attack where the contract admin's pause
* the contract and hold hostage the NFT's that are still within it.
*
* We intentionally allow anybody to call this function, although only the lender will end up receiving the seized
* collateral. We are exploring the possbility of incentivizing users to call this function by using some of the
* admin funds.
*
* @param _loanId A unique identifier for this particular loan, sourced from the Loan Coordinator.
*/
function liquidateOverdueLoan(uint32 _loanId) external nonReentrant {
LoanChecksAndCalculations.checkLoanIdValidity(_loanId, hub);
// Sanity check that payBackLoan() and liquidateOverdueLoan() have never been called on this loanId.
// Depending on how the rest of the code turns out, this check may be unnecessary.
require(!loanRepaidOrLiquidated[_loanId], "Loan already repaid/liquidated");
(
address borrower,
address lender,
LoanTerms memory loan,
IDirectLoanCoordinator loanCoordinator
) = _getPartiesAndData(_loanId);
// Ensure that the loan is indeed overdue, since we can only liquidate overdue loans.
uint256 loanMaturityDate = uint256(loan.loanStartTime) + uint256(loan.loanDuration);
require(block.timestamp > loanMaturityDate, "Loan is not overdue yet");
require(msg.sender == lender, "Only lender can liquidate");
_resolveLoan(_loanId, lender, loan, loanCoordinator);
// Emit an event with all relevant details from this transaction.
emit LoanLiquidated(
_loanId,
borrower,
lender,
loan.loanPrincipalAmount,
loan.nftCollateralId,
loanMaturityDate,
block.timestamp,
loan.nftCollateralContract
);
// Delete the loan from storage in order to achieve a substantial gas savings and to lessen the burden of
// storage on Ethereum nodes, since we will never access this loan's details again, and the details are still
// available through event data.
delete loanIdToLoan[_loanId];
delete loanIdToLoanExtras[_loanId];
}
/**
* @notice this function initiates a flashloan to pull an airdrop from a tartget contract
*
* @param _loanId -
* @param _target - address of the airdropping contract
* @param _data - function selector to be called on the airdropping contract
* @param _nftAirdrop - address of the used claiming nft in the drop
* @param _nftAirdropId - id of the used claiming nft in the drop
* @param _is1155 -
* @param _nftAirdropAmount - amount in case of 1155
*/
function pullAirdrop(
uint32 _loanId,
address _target,
bytes calldata _data,
address _nftAirdrop,
uint256 _nftAirdropId,
bool _is1155,
uint256 _nftAirdropAmount
) external nonReentrant {
LoanChecksAndCalculations.checkLoanIdValidity(_loanId, hub);
require(!loanRepaidOrLiquidated[_loanId], "Loan already repaid/liquidated");
LoanTerms memory loan = loanIdToLoan[_loanId];
LoanAirdropUtils.pullAirdrop(
_loanId,
loan,
_target,
_data,
_nftAirdrop,
_nftAirdropId,
_is1155,
_nftAirdropAmount,
hub
);
}
/**
* @notice this function creates a proxy contract wrapping the collateral to be able to catch an expected airdrop
*
* @param _loanId -
*/
function wrapCollateral(uint32 _loanId) external nonReentrant {
LoanChecksAndCalculations.checkLoanIdValidity(_loanId, hub);
require(!loanRepaidOrLiquidated[_loanId], "Loan already repaid/liquidated");
LoanTerms storage loan = loanIdToLoan[_loanId];
_escrowTokens[loan.nftCollateralContract][loan.nftCollateralId] -= 1;
(address instance, uint256 receiverId) = LoanAirdropUtils.wrapCollateral(_loanId, loan, hub);
_escrowTokens[instance][receiverId] += 1;
}
/**
* @notice This function can be called by either a lender or a borrower to cancel all off-chain orders that they
* have signed that contain this nonce. If the off-chain orders were created correctly, there should only be one
* off-chain order that contains this nonce at all.
*
* The nonce referred to here is not the same as an Ethereum account's nonce. We are referring
* instead to nonces that are used by both the lender and the borrower when they are first signing off-chain NFTfi
* orders. These nonces can be any uint256 value that the user has not previously used to sign an off-chain order.
* Each nonce can be used at most once per user within NFTfi, regardless of whether they are the lender or the
* borrower in that situation. This serves two purposes. First, it prevents replay attacks where an attacker would
* submit a user's off-chain order more than once. Second, it allows a user to cancel an off-chain order by calling
* NFTfi.cancelLoanCommitmentBeforeLoanHasBegun(), which marks the nonce as used and prevents any future loan from
* using the user's off-chain order that contains that nonce.
*
* @param _nonce - User nonce
*/
function cancelLoanCommitmentBeforeLoanHasBegun(uint256 _nonce) external {
require(!_nonceHasBeenUsedForUser[msg.sender][_nonce], "Invalid nonce");
_nonceHasBeenUsedForUser[msg.sender][_nonce] = true;
}
/* ******************* */
/* READ-ONLY FUNCTIONS */
/* ******************* */
/**
* @notice This function can be used to view the current quantity of the ERC20 currency used in the specified loan
* required by the borrower to repay their loan, measured in the smallest unit of the ERC20 currency.
*
* @param _loanId A unique identifier for this particular loan, sourced from the Loan Coordinator.
*
* @return The amount of the specified ERC20 currency required to pay back this loan, measured in the smallest unit
* of the specified ERC20 currency.
*/
function getPayoffAmount(uint32 _loanId) external view virtual returns (uint256);
/**
* @notice This function can be used to view whether a particular nonce for a particular user has already been used,
* either from a successful loan or a cancelled off-chain order.
*
* @param _user - The address of the user. This function works for both lenders and borrowers alike.
* @param _nonce - The nonce referred to here is not the same as an Ethereum account's nonce. We are referring
* instead to nonces that are used by both the lender and the borrower when they are first signing off-chain
* NFTfi orders. These nonces can be any uint256 value that the user has not previously used to sign an off-chain
* order. Each nonce can be used at most once per user within NFTfi, regardless of whether they are the lender or
* the borrower in that situation. This serves two purposes:
* - First, it prevents replay attacks where an attacker would submit a user's off-chain order more than once.
* - Second, it allows a user to cancel an off-chain order by calling NFTfi.cancelLoanCommitmentBeforeLoanHasBegun()
* , which marks the nonce as used and prevents any future loan from using the user's off-chain order that contains
* that nonce.
*
* @return A bool representing whether or not this nonce has been used for this user.
*/
function getWhetherNonceHasBeenUsedForUser(address _user, uint256 _nonce) external view override returns (bool) {
return _nonceHasBeenUsedForUser[_user][_nonce];
}
/**
* @notice This function can be called by anyone to get the permit associated with the erc20 contract.
*
* @param _erc20 - The address of the erc20 contract.
*
* @return Returns whether the erc20 is permitted
*/
function getERC20Permit(address _erc20) public view override returns (bool) {
return erc20Permits[_erc20];
}
/* ****************** */
/* INTERNAL FUNCTIONS */
/* ****************** */
/**
* @dev makes possible to change loan duration and max repayment amount, loan duration even can be extended if
* loan was expired but not liquidated. IMPORTANT: Frontend will have to propt the caller to do an ERC20 approve for
* the fee amount from themselves (borrower/obligation reciept holder) to the lender (promissory note holder)
*
* @param _loanId - The unique identifier for the loan to be renegotiated
* @param _newLoanDuration - The new amount of time (measured in seconds) that can elapse before the lender can
* liquidate the loan and seize the underlying collateral NFT.
* @param _newMaximumRepaymentAmount - The new maximum amount of money that the borrower would be required to
* retrieve their collateral, measured in the smallest units of the ERC20 currency used for the loan. The
* borrower will always have to pay this amount to retrieve their collateral, regardless of whether they repay
* early.
* @param _renegotiationFee Agreed upon fee in loan denomination that borrower pays for the lender and
* the admin for the renegotiation, has to be paid with an ERC20 transfer loanERC20Denomination token,
* uses transfer from, frontend will have to propmt an erc20 approve for this from the borrower to the lender,
* admin fee is calculated by the loan's loanAdminFeeInBasisPoints value
* @param _lenderNonce - The nonce referred to here is not the same as an Ethereum account's nonce. We are
* referring instead to nonces that are used by both the lender and the borrower when they are first signing
* off-chain NFTfi orders. These nonces can be any uint256 value that the user has not previously used to sign an
* off-chain order. Each nonce can be used at most once per user within NFTfi, regardless of whether they are the
* lender or the borrower in that situation. This serves two purposes:
* - First, it prevents replay attacks where an attacker would submit a user's off-chain order more than once.
* - Second, it allows a user to cancel an off-chain order by calling NFTfi.cancelLoanCommitmentBeforeLoanHasBegun()
, which marks the nonce as used and prevents any future loan from using the user's off-chain order that contains
* that nonce.
* @param _expiry - The date when the renegotiation offer expires
* @param _lenderSignature - The ECDSA signature of the lender, obtained off-chain ahead of time, signing the
* following combination of parameters:
* - _loanId
* - _newLoanDuration
* - _newMaximumRepaymentAmount
* - _lender
* - _expiry
* - address of this contract
* - chainId
*/
function _renegotiateLoan(
uint32 _loanId,
uint32 _newLoanDuration,
uint256 _newMaximumRepaymentAmount,
uint256 _renegotiationFee,
uint256 _lenderNonce,
uint256 _expiry,
bytes memory _lenderSignature
) internal {
LoanTerms storage loan = loanIdToLoan[_loanId];
(address borrower, address lender) = LoanChecksAndCalculations.renegotiationChecks(
loan,
_loanId,
_newLoanDuration,
_newMaximumRepaymentAmount,
_lenderNonce,
hub
);
_nonceHasBeenUsedForUser[lender][_lenderNonce] = true;
require(
NFTfiSigningUtils.isValidLenderRenegotiationSignature(
_loanId,
_newLoanDuration,
_newMaximumRepaymentAmount,
_renegotiationFee,
Signature({signer: lender, nonce: _lenderNonce, expiry: _expiry, signature: _lenderSignature})
),
"Renegotiation signature is invalid"
);
uint256 renegotiationAdminFee;
/**
* @notice Transfers fee to the lender immediately
* @dev implements Checks-Effects-Interactions pattern by modifying state only after
* the transfer happened successfully, we also add the nonReentrant modifier to
* the pbulic versions
*/
if (_renegotiationFee > 0) {
renegotiationAdminFee = LoanChecksAndCalculations.computeAdminFee(
_renegotiationFee,
loan.loanAdminFeeInBasisPoints
);
// Transfer principal-plus-interest-minus-fees from the caller (always has to be borrower) to lender
IERC20(loan.loanERC20Denomination).safeTransferFrom(
borrower,
lender,
_renegotiationFee - renegotiationAdminFee
);
// Transfer fees from the caller (always has to be borrower) to admins
IERC20(loan.loanERC20Denomination).safeTransferFrom(borrower, owner(), renegotiationAdminFee);
}
loan.loanDuration = _newLoanDuration;
loan.maximumRepaymentAmount = _newMaximumRepaymentAmount;
emit LoanRenegotiated(
_loanId,
borrower,
lender,
_newLoanDuration,
_newMaximumRepaymentAmount,
_renegotiationFee,
renegotiationAdminFee
);
}
/**
* @dev Transfer collateral NFT from borrower to this contract and principal from lender to the borrower and
* registers the new loan through the loan coordinator.
*
* @param _loanType - The type of loan it is being created
* @param _loanTerms - Struct containing the loan's settings
* @param _loanExtras - Struct containing some loan's extra settings, needed to avoid stack too deep
* @param _lender - The address of the lender.
* @param _referrer - The address of the referrer who found the lender matching the listing, Zero address to signal
* that there is no referrer.
*/
function _createLoan(
bytes32 _loanType,
LoanTerms memory _loanTerms,
LoanExtras memory _loanExtras,
address _borrower,
address _lender,
address _referrer
) internal returns (uint32) {
// Transfer collateral from borrower to this contract to be held until
// loan completion.
_transferNFT(_loanTerms, _borrower, address(this));
return _createLoanNoNftTransfer(_loanType, _loanTerms, _loanExtras, _borrower, _lender, _referrer);
}
/**
* @dev Transfer principal from lender to the borrower and
* registers the new loan through the loan coordinator.
*
* @param _loanType - The type of loan it is being created
* @param _loanTerms - Struct containing the loan's settings
* @param _loanExtras - Struct containing some loan's extra settings, needed to avoid stack too deep
* @param _lender - The address of the lender.
* @param _referrer - The address of the referrer who found the lender matching the listing, Zero address to signal
* that there is no referrer.
*/
function _createLoanNoNftTransfer(
bytes32 _loanType,
LoanTerms memory _loanTerms,
LoanExtras memory _loanExtras,
address _borrower,
address _lender,
address _referrer
) internal returns (uint32 loanId) {
_escrowTokens[_loanTerms.nftCollateralContract][_loanTerms.nftCollateralId] += 1;
uint256 referralfee = LoanChecksAndCalculations.computeReferralFee(
_loanTerms.loanPrincipalAmount,
_loanExtras.referralFeeInBasisPoints,
_referrer
);
uint256 principalAmount = _loanTerms.loanPrincipalAmount - referralfee;
if (referralfee > 0) {
// Transfer the referral fee from lender to referrer.
IERC20(_loanTerms.loanERC20Denomination).safeTransferFrom(_lender, _referrer, referralfee);
}
// Transfer principal from lender to borrower.
IERC20(_loanTerms.loanERC20Denomination).safeTransferFrom(_lender, _borrower, principalAmount);
// Issue an ERC721 promissory note to the lender that gives them the
// right to either the principal-plus-interest or the collateral,
// and an obligation note to the borrower that gives them the
// right to pay back the loan and get the collateral back.
IDirectLoanCoordinator loanCoordinator = IDirectLoanCoordinator(hub.getContract(LOAN_COORDINATOR));
loanId = loanCoordinator.registerLoan(_lender, _loanType);
// Add the loan to storage before moving collateral/principal to follow
// the Checks-Effects-Interactions pattern.
loanIdToLoan[loanId] = _loanTerms;
loanIdToLoanExtras[loanId] = _loanExtras;
return loanId;
}
/**
* @dev Transfers several types of NFTs using a wrapper that knows how to handle each case.
*
* @param _loanTerms - Struct containing all the loan's parameters
* @param _sender - Current owner of the NFT
* @param _recipient - Recipient of the transfer
*/
function _transferNFT(
LoanTerms memory _loanTerms,
address _sender,
address _recipient
) internal {
Address.functionDelegateCall(
_loanTerms.nftCollateralWrapper,
abi.encodeWithSelector(
INftWrapper(_loanTerms.nftCollateralWrapper).transferNFT.selector,
_sender,
_recipient,
_loanTerms.nftCollateralContract,
_loanTerms.nftCollateralId
),
"NFT not successfully transferred"
);
}
/**
* @notice This function is called by a anyone to repay a loan. It can be called at any time after the loan has
* begun and before loan expiry.. The caller will pay a pro-rata portion of their interest if the loan is paid off
* early and the loan is pro-rated type, but the complete repayment amount if it is fixed type.
* The the borrower (current owner of the obligation note) will get the collaterl NFT back.
*
* This function is purposefully not pausable in order to prevent an attack where the contract admin's pause the
* contract and hold hostage the NFT's that are still within it.
*
* @param _loanId A unique identifier for this particular loan, sourced from the Loan Coordinator.
*/
function _payBackLoan(
uint32 _loanId,
address _borrower,
address _lender,
LoanTerms memory _loan
) internal {
// Fetch loan details from storage, but store them in memory for the sake of saving gas.
LoanExtras memory loanExtras = loanIdToLoanExtras[_loanId];
(uint256 adminFee, uint256 payoffAmount) = _payoffAndFee(_loan);
// Transfer principal-plus-interest-minus-fees from the caller to lender
IERC20(_loan.loanERC20Denomination).safeTransferFrom(msg.sender, _lender, payoffAmount);
uint256 revenueShare = LoanChecksAndCalculations.computeRevenueShare(
adminFee,
loanExtras.revenueShareInBasisPoints
);
// PermittedPartners contract doesn't allow to set a revenueShareInBasisPoints for address zero so revenuShare
// > 0 implies that revenueSharePartner ~= address(0), BUT revenueShare can be zero for a partener when the
// adminFee is low
if (revenueShare > 0 && loanExtras.revenueSharePartner != address(0)) {
adminFee -= revenueShare;
// Transfer revenue share from the caller to permitted partner
IERC20(_loan.loanERC20Denomination).safeTransferFrom(
msg.sender,
loanExtras.revenueSharePartner,
revenueShare
);
}
// Transfer fees from the caller to admins
IERC20(_loan.loanERC20Denomination).safeTransferFrom(msg.sender, owner(), adminFee);
// Emit an event with all relevant details from this transaction.
emit LoanRepaid(
_loanId,
_borrower,
_lender,
_loan.loanPrincipalAmount,
_loan.nftCollateralId,
payoffAmount,
adminFee,
revenueShare,
loanExtras.revenueSharePartner, // this could be a non address zero even if revenueShare is 0
_loan.nftCollateralContract,
_loan.loanERC20Denomination
);
}
/**
* @notice A convenience function with shared functionality between `payBackLoan` and `liquidateOverdueLoan`.
*
* @param _loanId A unique identifier for this particular loan, sourced from the Loan Coordinator.
* @param _nftReceiver - The receiver of the collateral nft. The borrower when `payBackLoan` or the lender when
* `liquidateOverdueLoan`.
* @param _loanTerms - The main Loan Terms struct. This data is saved upon loan creation on loanIdToLoan.
* @param _loanCoordinator - The loan coordinator used when creating the loan.
*/
function _resolveLoan(
uint32 _loanId,
address _nftReceiver,
LoanTerms memory _loanTerms,
IDirectLoanCoordinator _loanCoordinator
) internal {
_resolveLoanNoNftTransfer(_loanId, _loanTerms, _loanCoordinator);
// Transfer collateral from this contract to the lender, since the lender is seizing collateral for an overdue
// loan
_transferNFT(_loanTerms, address(this), _nftReceiver);
}
/**
* @notice Resolving the loan without trasferring the nft to provide a base for the bundle
* break up of the bundled loans
*
* @param _loanId A unique identifier for this particular loan, sourced from the Loan Coordinator.
* @param _loanTerms - The main Loan Terms struct. This data is saved upon loan creation on loanIdToLoan.
* @param _loanCoordinator - The loan coordinator used when creating the loan.
*/
function _resolveLoanNoNftTransfer(
uint32 _loanId,
LoanTerms memory _loanTerms,
IDirectLoanCoordinator _loanCoordinator
) internal {
// Mark loan as liquidated before doing any external transfers to follow the Checks-Effects-Interactions design
// pattern
loanRepaidOrLiquidated[_loanId] = true;
_escrowTokens[_loanTerms.nftCollateralContract][_loanTerms.nftCollateralId] -= 1;
// Destroy the lender's promissory note for this loan and borrower obligation receipt
_loanCoordinator.resolveLoan(_loanId);
}
/**
* @notice This function can be called by admins to change the permitted status of an ERC20 currency. This includes
* both adding an ERC20 currency to the permitted list and removing it.
*
* @param _erc20 - The address of the ERC20 currency whose permit list status changed.
* @param _permit - The new status of whether the currency is permitted or not.
*/
function _setERC20Permit(address _erc20, bool _permit) internal {
require(_erc20 != address(0), "erc20 is zero address");
erc20Permits[_erc20] = _permit;
emit ERC20Permit(_erc20, _permit);
}
/**
* @dev Performs some validation checks over loan parameters
*
*/
function _loanSanityChecks(LoanData.Offer memory _offer, address _nftWrapper) internal view {
require(getERC20Permit(_offer.loanERC20Denomination), "Currency denomination is not permitted");
require(_nftWrapper != address(0), "NFT collateral contract is not permitted");
require(uint256(_offer.loanDuration) <= maximumLoanDuration, "Loan duration exceeds maximum loan duration");
require(uint256(_offer.loanDuration) != 0, "Loan duration cannot be zero");
require(
_offer.loanAdminFeeInBasisPoints == adminFeeInBasisPoints,
"The admin fee has changed since this order was signed."
);
}
/**
* @dev reads some variable values of a loan for payback functions, created to reduce code repetition
*/
function _getPartiesAndData(uint32 _loanId)
internal
view
returns (
address borrower,
address lender,
LoanTerms memory loan,
IDirectLoanCoordinator loanCoordinator
)
{
loanCoordinator = IDirectLoanCoordinator(hub.getContract(LOAN_COORDINATOR));
IDirectLoanCoordinator.Loan memory loanCoordinatorData = loanCoordinator.getLoanData(_loanId);
uint256 smartNftId = loanCoordinatorData.smartNftId;
// Fetch loan details from storage, but store them in memory for the sake of saving gas.
loan = loanIdToLoan[_loanId];
if (loan.borrower != address(0)) {
borrower = loan.borrower;
} else {
// Fetch current owner of loan obligation note.
borrower = IERC721(loanCoordinator.obligationReceiptToken()).ownerOf(smartNftId);
}
lender = IERC721(loanCoordinator.promissoryNoteToken()).ownerOf(smartNftId);
}
/**
* @dev Creates a `LoanExtras` struct using data sent as the borrower's extra settings.
* This is needed in order to avoid stack too deep issues.
*/
function _setupLoanExtras(address _revenueSharePartner, uint16 _referralFeeInBasisPoints)
internal
view
returns (LoanExtras memory)
{
// Save loan details to a struct in memory first, to save on gas if any
// of the below checks fail, and to avoid the "Stack Too Deep" error by
// clumping the parameters together into one struct held in memory.
return
LoanExtras({
revenueSharePartner: _revenueSharePartner,
revenueShareInBasisPoints: LoanChecksAndCalculations.getRevenueSharePercent(_revenueSharePartner, hub),
referralFeeInBasisPoints: _referralFeeInBasisPoints
});
}
/**
* @dev Calculates the payoff amount and admin fee
*/
function _payoffAndFee(LoanTerms memory _loanTerms) internal view virtual returns (uint256, uint256);
/**
* @dev Checks that the collateral is a supported contracts and returns what wrapper to use for the loan's NFT
* collateral contract.
*
* @param _nftCollateralContract - The address of the the NFT collateral contract.
*
* @return Address of the NftWrapper to use for the loan's NFT collateral.
*/
function _getWrapper(address _nftCollateralContract) internal view returns (address) {
return IPermittedNFTs(hub.getContract(ContractKeys.PERMITTED_NFTS)).getNFTWrapper(_nftCollateralContract);
}
}
// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.4;
/**
* @title ContractKeys
* @author NFTfi
* @dev Common library for contract keys
*/
library ContractKeys {
bytes32 public constant PERMITTED_ERC20S = bytes32("PERMITTED_ERC20S");
bytes32 public constant PERMITTED_NFTS = bytes32("PERMITTED_NFTS");
bytes32 public constant PERMITTED_PARTNERS = bytes32("PERMITTED_PARTNERS");
bytes32 public constant NFT_TYPE_REGISTRY = bytes32("NFT_TYPE_REGISTRY");
bytes32 public constant LOAN_REGISTRY = bytes32("LOAN_REGISTRY");
bytes32 public constant PERMITTED_SNFT_RECEIVER = bytes32("PERMITTED_SNFT_RECEIVER");
bytes32 public constant PERMITTED_BUNDLE_ERC20S = bytes32("PERMITTED_BUNDLE_ERC20S");
bytes32 public constant PERMITTED_AIRDROPS = bytes32("PERMITTED_AIRDROPS");
bytes32 public constant AIRDROP_RECEIVER = bytes32("AIRDROP_RECEIVER");
bytes32 public constant AIRDROP_FACTORY = bytes32("AIRDROP_FACTORY");
bytes32 public constant AIRDROP_FLASH_LOAN = bytes32("AIRDROP_FLASH_LOAN");
bytes32 public constant NFTFI_BUNDLER = bytes32("NFTFI_BUNDLER");
string public constant AIRDROP_WRAPPER_STRING = "AirdropWrapper";
/**
* @notice Returns the bytes32 representation of a string
* @param _key the string key
* @return id bytes32 representation
*/
function getIdFromStringKey(string memory _key) external pure returns (bytes32 id) {
require(bytes(_key).length <= 32, "invalid key");
// solhint-disable-next-line no-inline-assembly
assembly {
id := mload(add(_key, 32))
}
}
}
// SPDX-License-Identifier: BUSL-1.1
import "./LoanData.sol";
pragma solidity 0.8.4;
interface IDirectLoanBase {
function maximumLoanDuration() external view returns (uint256);
function adminFeeInBasisPoints() external view returns (uint16);
// solhint-disable-next-line func-name-mixedcase
function LOAN_COORDINATOR() external view returns (bytes32);
function loanIdToLoan(uint32)
external
view
returns (
uint256,
uint256,
uint256,
address,
uint32,
uint16,
uint16,
address,
uint64,
address,
address
);
function loanRepaidOrLiquidated(uint32) external view returns (bool);
function getWhetherNonceHasBeenUsedForUser(address _user, uint256 _nonce) external view returns (bool);
}
// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.4;
/**
* @title LoanData
* @author NFTfi
* @notice An interface containg the main Loan struct shared by Direct Loans types.
*/
interface LoanData {
/* ********** */
/* DATA TYPES */
/* ********** */
/**
* @notice The main Loan Terms struct. This data is saved upon loan creation.
*
* @param loanERC20Denomination - The address of the ERC20 contract of the currency being used as principal/interest
* for this loan.
* @param loanPrincipalAmount - The original sum of money transferred from lender to borrower at the beginning of
* the loan, measured in loanERC20Denomination's smallest units.
* @param maximumRepaymentAmount - The maximum amount of money that the borrower would be required to retrieve their
* collateral, measured in the smallest units of the ERC20 currency used for the loan. The borrower will always have
* to pay this amount to retrieve their collateral, regardless of whether they repay early.
* @param nftCollateralContract - The address of the the NFT collateral contract.
* @param nftCollateralWrapper - The NFTfi wrapper of the NFT collateral contract.
* @param nftCollateralId - The ID within the NFTCollateralContract for the NFT being used as collateral for this
* loan. The NFT is stored within this contract during the duration of the loan.
* @param loanStartTime - The block.timestamp when the loan first began (measured in seconds).
* @param loanDuration - The amount of time (measured in seconds) that can elapse before the lender can liquidate
* the loan and seize the underlying collateral NFT.
* @param loanInterestRateForDurationInBasisPoints - This is the interest rate (measured in basis points, e.g.
* hundreths of a percent) for the loan, that must be repaid pro-rata by the borrower at the conclusion of the loan
* or risk seizure of their nft collateral. Note if the type of the loan is fixed then this value is not used and
* is irrelevant so it should be set to 0.
* @param loanAdminFeeInBasisPoints - The percent (measured in basis points) of the interest earned that will be
* taken as a fee by the contract admins when the loan is repaid. The fee is stored in the loan struct to prevent an
* attack where the contract admins could adjust the fee right before a loan is repaid, and take all of the interest
* earned.
* @param borrower
*/
struct LoanTerms {
uint256 loanPrincipalAmount;
uint256 maximumRepaymentAmount;
uint256 nftCollateralId;
address loanERC20Denomination;
uint32 loanDuration;
uint16 loanInterestRateForDurationInBasisPoints;
uint16 loanAdminFeeInBasisPoints;
address nftCollateralWrapper;
uint64 loanStartTime;
address nftCollateralContract;
address borrower;
}
/**
* @notice Some extra Loan's settings struct. This data is saved upon loan creation.
* We need this to avoid stack too deep errors.
*
* @param revenueSharePartner - The address of the partner that will receive the revenue share.
* @param revenueShareInBasisPoints - The percent (measured in basis points) of the admin fee amount that will be
* taken as a revenue share for a t
* @param referralFeeInBasisPoints - The percent (measured in basis points) of the loan principal amount that will
* be taken as a fee to pay to the referrer, 0 if the lender is not paying referral fee.he partner, at the moment
* the loan is begun.
*/
struct LoanExtras {
address revenueSharePartner;
uint16 revenueShareInBasisPoints;
uint16 referralFeeInBasisPoints;
}
/**
* @notice The offer made by the lender. Used as parameter on both acceptOffer (initiated by the borrower) and
* acceptListing (initiated by the lender).
*
* @param loanERC20Denomination - The address of the ERC20 contract of the currency being used as principal/interest
* for this loan.
* @param loanPrincipalAmount - The original sum of money transferred from lender to borrower at the beginning of
* the loan, measured in loanERC20Denomination's smallest units.
* @param maximumRepaymentAmount - The maximum amount of money that the borrower would be required to retrieve their
* collateral, measured in the smallest units of the ERC20 currency used for the loan. The borrower will always
* have to pay this amount to retrieve their collateral, regardless of whether they repay early.
* @param nftCollateralContract - The address of the ERC721 contract of the NFT collateral.
* @param nftCollateralId - The ID within the NFTCollateralContract for the NFT being used as collateral for this
* loan. The NFT is stored within this contract during the duration of the loan.
* @param referrer - The address of the referrer who found the lender matching the listing, Zero address to signal
* this there is no referrer.
* @param loanDuration - The amount of time (measured in seconds) that can elapse before the lender can liquidate
* the loan and seize the underlying collateral NFT.
* @param loanAdminFeeInBasisPoints - The percent (measured in basis points) of the interest earned that will be
* taken as a fee by the contract admins when the loan is repaid. The fee is stored in the loan struct to prevent an
* attack where the contract admins could adjust the fee right before a loan is repaid, and take all of the interest
* earned.
*/
struct Offer {
uint256 loanPrincipalAmount;
uint256 maximumRepaymentAmount;
uint256 nftCollateralId;
address nftCollateralContract;
uint32 loanDuration;
uint16 loanAdminFeeInBasisPoints;
address loanERC20Denomination;
address referrer;
}
/**
* @notice Signature related params. Used as parameter on both acceptOffer (containing borrower signature) and
* acceptListing (containing lender signature).
*
* @param signer - The address of the signer. The borrower for `acceptOffer` the lender for `acceptListing`.
* @param nonce - The nonce referred here is not the same as an Ethereum account's nonce.
* We are referring instead to a nonce that is used by the lender or the borrower when they are first signing
* off-chain NFTfi orders. These nonce can be any uint256 value that the user has not previously used to sign an
* off-chain order. Each nonce can be used at most once per user within NFTfi, regardless of whether they are the
* lender or the borrower in that situation. This serves two purposes:
* - First, it prevents replay attacks where an attacker would submit a user's off-chain order more than once.
* - Second, it allows a user to cancel an off-chain order by calling NFTfi.cancelLoanCommitmentBeforeLoanHasBegun()
* , which marks the nonce as used and prevents any future loan from using the user's off-chain order that contains
* that nonce.
* @param expiry - Date when the signature expires
* @param signature - The ECDSA signature of the borrower or the lender, obtained off-chain ahead of time, signing
* the following combination of parameters:
* - Borrower
* - ListingTerms.loanERC20Denomination,
* - ListingTerms.minLoanPrincipalAmount,
* - ListingTerms.maxLoanPrincipalAmount,
* - ListingTerms.nftCollateralContract,
* - ListingTerms.nftCollateralId,
* - ListingTerms.revenueSharePartner,
* - ListingTerms.minLoanDuration,
* - ListingTerms.maxLoanDuration,
* - ListingTerms.maxInterestRateForDurationInBasisPoints,
* - ListingTerms.referralFeeInBasisPoints,
* - Signature.signer,
* - Signature.nonce,
* - Signature.expiry,
* - address of the loan type contract
* - chainId
* - Lender:
* - Offer.loanERC20Denomination
* - Offer.loanPrincipalAmount
* - Offer.maximumRepaymentAmount
* - Offer.nftCollateralContract
* - Offer.nftCollateralId
* - Offer.referrer
* - Offer.loanDuration
* - Offer.loanAdminFeeInBasisPoints
* - Signature.signer,
* - Signature.nonce,
* - Signature.expiry,
* - address of the loan type contract
* - chainId
*/
struct Signature {
uint256 nonce;
uint256 expiry;
address signer;
bytes signature;
}
/**
* @notice Some extra parameters that the borrower needs to set when accepting an offer.
*
* @param revenueSharePartner - The address of the partner that will receive the revenue share.
* @param referralFeeInBasisPoints - The percent (measured in basis points) of the loan principal amount that will
* be taken as a fee to pay to the referrer, 0 if the lender is not paying referral fee.
*/
struct BorrowerSettings {
address revenueSharePartner;
uint16 referralFeeInBasisPoints;
}
/**
* @notice Terms the borrower set off-chain and is willing to accept automatically when fulfiled by a lender's
* offer.
*
* @param loanERC20Denomination - The address of the ERC20 contract of the currency being used as principal/interest
* for this loan.
* @param minLoanPrincipalAmount - The minumum sum of money transferred from lender to borrower at the beginning of
* the loan, measured in loanERC20Denomination's smallest units.
* @param maxLoanPrincipalAmount - The sum of money transferred from lender to borrower at the beginning of
* the loan, measured in loanERC20Denomination's smallest units.
* @param maximumRepaymentAmount - The maximum amount of money that the borrower would be required to retrieve their
* collateral, measured in the smallest units of the ERC20 currency used for the loan. The borrower will always have
* to pay this amount to retrieve their collateral, regardless of whether they repay early.
* @param nftCollateralContract - The address of the ERC721 contract of the NFT collateral.
* @param nftCollateralId - The ID within the NFTCollateralContract for the NFT being used as collateral for this
* loan. The NFT is stored within this contract during the duration of the loan.
* @param revenueSharePartner - The address of the partner that will receive the revenue share.
* @param minLoanDuration - The minumum amount of time (measured in seconds) that can elapse before the lender can
* liquidate the loan and seize the underlying collateral NFT.
* @param maxLoanDuration - The maximum amount of time (measured in seconds) that can elapse before the lender can
* liquidate the loan and seize the underlying collateral NFT.
* @param maxInterestRateForDurationInBasisPoints - This is maximum the interest rate (measured in basis points,
* e.g. hundreths of a percent) for the loan.
* @param referralFeeInBasisPoints - The percent (measured in basis points) of the loan principal amount that will
* be taken as a fee to pay to the referrer, 0 if the lender is not paying referral fee.
*/
struct ListingTerms {
uint256 minLoanPrincipalAmount;
uint256 maxLoanPrincipalAmount;
uint256 nftCollateralId;
address nftCollateralContract;
uint32 minLoanDuration;
uint32 maxLoanDuration;
uint16 maxInterestRateForDurationInBasisPoints;
uint16 referralFeeInBasisPoints;
address revenueSharePartner;
address loanERC20Denomination;
}
}
// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.4;
import "./IDirectLoanBase.sol";
import "./LoanData.sol";
import "../../../interfaces/IDirectLoanCoordinator.sol";
import "../../../utils/ContractKeys.sol";
import "../../../interfaces/INftfiHub.sol";
import "../../../interfaces/IPermittedPartners.sol";
import "../../../interfaces/IPermittedERC20s.sol";
import "@openzeppelin/contracts/token/ERC721/IERC721.sol";
/**
* @title LoanChecksAndCalculations
* @author NFTfi
* @notice Helper library for LoanBase
*/
library LoanChecksAndCalculations {
uint16 private constant HUNDRED_PERCENT = 10000;
/**
* @dev Function that performs some validation checks before trying to repay a loan
*
* @param _loanId - The id of the loan being repaid
*/
function payBackChecks(uint32 _loanId, INftfiHub _hub) external view {
checkLoanIdValidity(_loanId, _hub);
// Sanity check that payBackLoan() and liquidateOverdueLoan() have never been called on this loanId.
// Depending on how the rest of the code turns out, this check may be unnecessary.
require(!IDirectLoanBase(address(this)).loanRepaidOrLiquidated(_loanId), "Loan already repaid/liquidated");
// Fetch loan details from storage, but store them in memory for the sake of saving gas.
(, , , , uint32 loanDuration, , , , uint64 loanStartTime, , ) = IDirectLoanBase(address(this)).loanIdToLoan(
_loanId
);
// When a loan exceeds the loan term, it is expired. At this stage the Lender can call Liquidate Loan to resolve
// the loan.
require(block.timestamp <= (uint256(loanStartTime) + uint256(loanDuration)), "Loan is expired");
}
function checkLoanIdValidity(uint32 _loanId, INftfiHub _hub) public view {
require(
IDirectLoanCoordinator(_hub.getContract(IDirectLoanBase(address(this)).LOAN_COORDINATOR())).isValidLoanId(
_loanId,
address(this)
),
"invalid loanId"
);
}
/**
* @dev Function that the partner is permitted and returns its shared percent.
*
* @param _revenueSharePartner - Partner's address
*
* @return The revenue share percent for the partner.
*/
function getRevenueSharePercent(address _revenueSharePartner, INftfiHub _hub) external view returns (uint16) {
// return soon if no partner is set to avoid a public call
if (_revenueSharePartner == address(0)) {
return 0;
}
uint16 revenueSharePercent = IPermittedPartners(_hub.getContract(ContractKeys.PERMITTED_PARTNERS))
.getPartnerPermit(_revenueSharePartner);
return revenueSharePercent;
}
/**
* @dev Performs some validation checks before trying to renegotiate a loan.
* Needed to avoid stack too deep.
*
* @param _loan - The main Loan Terms struct.
* @param _loanId - The unique identifier for the loan to be renegotiated
* @param _newLoanDuration - The new amount of time (measured in seconds) that can elapse before the lender can
* liquidate the loan and seize the underlying collateral NFT.
* @param _newMaximumRepaymentAmount - The new maximum amount of money that the borrower would be required to
* retrieve their collateral, measured in the smallest units of the ERC20 currency used for the loan. The
* borrower will always have to pay this amount to retrieve their collateral, regardless of whether they repay
* early.
* @param _lenderNonce - The nonce referred to here is not the same as an Ethereum account's nonce. We are
* referring instead to nonces that are used by both the lender and the borrower when they are first signing
* off-chain NFTfi orders. These nonces can be any uint256 value that the user has not previously used to sign an
* off-chain order. Each nonce can be used at most once per user within NFTfi, regardless of whether they are the
* lender or the borrower in that situation. This serves two purposes:
* - First, it prevents replay attacks where an attacker would submit a user's off-chain order more than once.
* - Second, it allows a user to cancel an off-chain order by calling NFTfi.cancelLoanCommitmentBeforeLoanHasBegun()
, which marks the nonce as used and prevents any future loan from using the user's off-chain order that contains
* that nonce.
* @return Borrower and Lender addresses
*/
function renegotiationChecks(
LoanData.LoanTerms memory _loan,
uint32 _loanId,
uint32 _newLoanDuration,
uint256 _newMaximumRepaymentAmount,
uint256 _lenderNonce,
INftfiHub _hub
) external view returns (address, address) {
checkLoanIdValidity(_loanId, _hub);
IDirectLoanCoordinator loanCoordinator = IDirectLoanCoordinator(
_hub.getContract(IDirectLoanBase(address(this)).LOAN_COORDINATOR())
);
uint256 smartNftId = loanCoordinator.getLoanData(_loanId).smartNftId;
address borrower;
if (_loan.borrower != address(0)) {
borrower = _loan.borrower;
} else {
borrower = IERC721(loanCoordinator.obligationReceiptToken()).ownerOf(smartNftId);
}
require(msg.sender == borrower, "Only borrower can initiate");
require(block.timestamp <= (uint256(_loan.loanStartTime) + _newLoanDuration), "New duration already expired");
require(
uint256(_newLoanDuration) <= IDirectLoanBase(address(this)).maximumLoanDuration(),
"New duration exceeds maximum loan duration"
);
require(!IDirectLoanBase(address(this)).loanRepaidOrLiquidated(_loanId), "Loan already repaid/liquidated");
require(
_newMaximumRepaymentAmount >= _loan.loanPrincipalAmount,
"Negative interest rate loans are not allowed."
);
// Fetch current owner of loan promissory note.
address lender = IERC721(loanCoordinator.promissoryNoteToken()).ownerOf(smartNftId);
require(
!IDirectLoanBase(address(this)).getWhetherNonceHasBeenUsedForUser(lender, _lenderNonce),
"Lender nonce invalid"
);
return (borrower, lender);
}
/**
* @dev Performs some validation checks over loan parameters when accepting a listing
*
*/
function bindingTermsSanityChecks(LoanData.ListingTerms memory _listingTerms, LoanData.Offer memory _offer)
external
pure
{
// offer vs listing validations
require(_offer.loanERC20Denomination == _listingTerms.loanERC20Denomination, "Invalid loanERC20Denomination");
require(
_offer.loanPrincipalAmount >= _listingTerms.minLoanPrincipalAmount &&
_offer.loanPrincipalAmount <= _listingTerms.maxLoanPrincipalAmount,
"Invalid loanPrincipalAmount"
);
uint256 maxRepaymentLimit = _offer.loanPrincipalAmount +
(_offer.loanPrincipalAmount * _listingTerms.maxInterestRateForDurationInBasisPoints) /
HUNDRED_PERCENT;
require(_offer.maximumRepaymentAmount <= maxRepaymentLimit, "maxInterestRateForDurationInBasisPoints violated");
require(
_offer.loanDuration >= _listingTerms.minLoanDuration &&
_offer.loanDuration <= _listingTerms.maxLoanDuration,
"Invalid loanDuration"
);
}
/**
* @notice A convenience function computing the revenue share taken from the admin fee to transferr to the permitted
* partner.
*
* @param _adminFee - The quantity of ERC20 currency (measured in smalled units of that ERC20 currency) that is due
* as an admin fee.
* @param _revenueShareInBasisPoints - The percent (measured in basis points) of the admin fee amount that will be
* taken as a revenue share for a the partner, at the moment the loan is begun.
*
* @return The quantity of ERC20 currency (measured in smalled units of that ERC20 currency) that should be sent to
* the `revenueSharePartner`.
*/
function computeRevenueShare(uint256 _adminFee, uint256 _revenueShareInBasisPoints)
external
pure
returns (uint256)
{
return (_adminFee * _revenueShareInBasisPoints) / HUNDRED_PERCENT;
}
/**
* @notice A convenience function computing the adminFee taken from a specified quantity of interest.
*
* @param _interestDue - The amount of interest due, measured in the smallest quantity of the ERC20 currency being
* used to pay the interest.
* @param _adminFeeInBasisPoints - The percent (measured in basis points) of the interest earned that will be taken
* as a fee by the contract admins when the loan is repaid. The fee is stored in the loan struct to prevent an
* attack where the contract admins could adjust the fee right before a loan is repaid, and take all of the interest
* earned.
*
* @return The quantity of ERC20 currency (measured in smalled units of that ERC20 currency) that is due as an admin
* fee.
*/
function computeAdminFee(uint256 _interestDue, uint256 _adminFeeInBasisPoints) external pure returns (uint256) {
return (_interestDue * _adminFeeInBasisPoints) / HUNDRED_PERCENT;
}
/**
* @notice A convenience function computing the referral fee taken from the loan principal amount to transferr to
* the referrer.
*
* @param _loanPrincipalAmount - The original sum of money transferred from lender to borrower at the beginning of
* the loan, measured in loanERC20Denomination's smallest units.
* @param _referralFeeInBasisPoints - The percent (measured in basis points) of the loan principal amount that will
* be taken as a fee to pay to the referrer, 0 if the lender is not paying referral fee.
* @param _referrer - The address of the referrer who found the lender matching the listing, Zero address to signal
* that there is no referrer.
*
* @return The quantity of ERC20 currency (measured in smalled units of that ERC20 currency) that should be sent to
* the referrer.
*/
function computeReferralFee(
uint256 _loanPrincipalAmount,
uint256 _referralFeeInBasisPoints,
address _referrer
) external pure returns (uint256) {
if (_referralFeeInBasisPoints == 0 || _referrer == address(0)) {
return 0;
}
return (_loanPrincipalAmount * _referralFeeInBasisPoints) / HUNDRED_PERCENT;
}
}
// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.4;
import "./IDirectLoanBase.sol";
import "./LoanData.sol";
import "../../../interfaces/IDirectLoanCoordinator.sol";
import "../../../utils/ContractKeys.sol";
import "../../../interfaces/INftfiHub.sol";
import "../../../interfaces/IPermittedPartners.sol";
import "../../../interfaces/IPermittedERC20s.sol";
import "../../../interfaces/IAirdropFlashLoan.sol";
import "../../../interfaces/INftWrapper.sol";
import "../../../airdrop/IAirdropReceiverFactory.sol";
import "@openzeppelin/contracts/token/ERC721/IERC721.sol";
import "@openzeppelin/contracts/utils/Address.sol";
/**
* @title LoanAirdropUtils
* @author NFTfi
* @notice Helper library for LoanBase
*/
library LoanAirdropUtils {
/**
* @notice This event is fired whenever a flashloan is initiated to pull an airdrop
*
* @param loanId - A unique identifier for this particular loan, sourced from the Loan Coordinator.
* @param borrower - The address of the borrower.
* @param nftCollateralId - The ID within the AirdropReceiver for the NFT being used as collateral for this
* loan.
* @param nftCollateralContract - The ERC721 contract of the NFT collateral
* @param target - address of the airdropping contract
* @param data - function selector to be called
*/
event AirdropPulledFlashloan(
uint256 indexed loanId,
address indexed borrower,
uint256 nftCollateralId,
address nftCollateralContract,
address target,
bytes data
);
/**
* @notice This event is fired whenever the collateral gets wrapped in an airdrop receiver
*
* @param loanId - A unique identifier for this particular loan, sourced from the Loan Coordinator.
* @param borrower - The address of the borrower.
* @param nftCollateralId - The ID within the AirdropReceiver for the NFT being used as collateral for this
* loan.
* @param nftCollateralContract - The contract of the NFT collateral
* @param receiverId - id of the created AirdropReceiver, takes the place of nftCollateralId on the loan
* @param receiverInstance - address of the created AirdropReceiver
*/
event CollateralWrapped(
uint256 indexed loanId,
address indexed borrower,
uint256 nftCollateralId,
address nftCollateralContract,
uint256 receiverId,
address receiverInstance
);
function pullAirdrop(
uint32 _loanId,
LoanData.LoanTerms memory _loan,
address _target,
bytes calldata _data,
address _nftAirdrop,
uint256 _nftAirdropId,
bool _is1155,
uint256 _nftAirdropAmount,
INftfiHub _hub
) external {
IDirectLoanCoordinator loanCoordinator = IDirectLoanCoordinator(
_hub.getContract(IDirectLoanBase(address(this)).LOAN_COORDINATOR())
);
address borrower;
// scoped to aviod stack too deep
{
IDirectLoanCoordinator.Loan memory loanCoordinatorData = loanCoordinator.getLoanData(_loanId);
uint256 smartNftId = loanCoordinatorData.smartNftId;
if (_loan.borrower != address(0)) {
borrower = _loan.borrower;
} else {
borrower = IERC721(loanCoordinator.obligationReceiptToken()).ownerOf(smartNftId);
}
}
require(msg.sender == borrower, "Only borrower can airdrop");
{
IAirdropFlashLoan airdropFlashLoan = IAirdropFlashLoan(_hub.getContract(ContractKeys.AIRDROP_FLASH_LOAN));
_transferNFT(_loan, address(this), address(airdropFlashLoan));
airdropFlashLoan.pullAirdrop(
_loan.nftCollateralContract,
_loan.nftCollateralId,
_loan.nftCollateralWrapper,
_target,
_data,
_nftAirdrop,
_nftAirdropId,
_is1155,
_nftAirdropAmount,
borrower
);
}
// revert if the collateral hasn't been transferred back before it ends
require(
INftWrapper(_loan.nftCollateralWrapper).isOwner(
address(this),
_loan.nftCollateralContract,
_loan.nftCollateralId
),
"Collateral should be returned"
);
emit AirdropPulledFlashloan(
_loanId,
borrower,
_loan.nftCollateralId,
_loan.nftCollateralContract,
_target,
_data
);
}
function wrapCollateral(
uint32 _loanId,
LoanData.LoanTerms storage _loan,
INftfiHub _hub
) external returns (address instance, uint256 receiverId) {
IDirectLoanCoordinator loanCoordinator = IDirectLoanCoordinator(
_hub.getContract(IDirectLoanBase(address(this)).LOAN_COORDINATOR())
);
// Fetch the current lender of the promissory note corresponding to this overdue loan.
IDirectLoanCoordinator.Loan memory loanCoordinatorData = loanCoordinator.getLoanData(_loanId);
uint256 smartNftId = loanCoordinatorData.smartNftId;
address borrower;
if (_loan.borrower != address(0)) {
borrower = _loan.borrower;
} else {
borrower = IERC721(loanCoordinator.obligationReceiptToken()).ownerOf(smartNftId);
}
require(msg.sender == borrower, "Only borrower can wrapp");
IAirdropReceiverFactory factory = IAirdropReceiverFactory(_hub.getContract(ContractKeys.AIRDROP_FACTORY));
(instance, receiverId) = factory.createAirdropReceiver(address(this));
// transfer collateral to airdrop receiver wrapper
_transferNFTtoAirdropReceiver(_loan, instance, borrower);
emit CollateralWrapped(
_loanId,
borrower,
_loan.nftCollateralId,
_loan.nftCollateralContract,
receiverId,
instance
);
// set the receiver as the new collateral
_loan.nftCollateralContract = instance;
_loan.nftCollateralId = receiverId;
}
/**
* @dev Transfers several types of NFTs using a wrapper that knows how to handle each case.
*
* @param _loan -
* @param _sender - Current owner of the NFT
* @param _recipient - Recipient of the transfer
*/
function _transferNFT(
LoanData.LoanTerms memory _loan,
address _sender,
address _recipient
) internal {
Address.functionDelegateCall(
_loan.nftCollateralWrapper,
abi.encodeWithSelector(
INftWrapper(_loan.nftCollateralWrapper).transferNFT.selector,
_sender,
_recipient,
_loan.nftCollateralContract,
_loan.nftCollateralId
),
"NFT not successfully transferred"
);
}
/**
* @dev Transfers several types of NFTs to an airdrop receiver with an airdrop beneficiary
* address attached as supplementing data using a wrapper that knows how to handle each case.
*
* @param _loan -
* @param _airdropReceiverInstance - Recipient of the transfer
* @param _airdropBeneficiary - Beneficiary of the future airdops
*/
function _transferNFTtoAirdropReceiver(
LoanData.LoanTerms memory _loan,
address _airdropReceiverInstance,
address _airdropBeneficiary
) internal {
Address.functionDelegateCall(
_loan.nftCollateralWrapper,
abi.encodeWithSelector(
INftWrapper(_loan.nftCollateralWrapper).wrapAirdropReceiver.selector,
_airdropReceiverInstance,
_loan.nftCollateralContract,
_loan.nftCollateralId,
_airdropBeneficiary
),
"NFT was not successfully migrated"
);
}
}
// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.4;
import "../utils/Ownable.sol";
import "@openzeppelin/contracts/security/Pausable.sol";
import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
/**
* @title BaseLoan
* @author NFTfi
* @dev Implements base functionalities common to all Loan types.
* Mostly related to governance and security.
*/
abstract contract BaseLoan is Ownable, Pausable, ReentrancyGuard {
/* *********** */
/* CONSTRUCTOR */
/* *********** */
/**
* @notice Sets the admin of the contract.
*
* @param _admin - Initial admin of this contract.
*/
constructor(address _admin) Ownable(_admin) {
// solhint-disable-previous-line no-empty-blocks
}
/* ********* */
/* FUNCTIONS */
/* ********* */
/**
* @dev Triggers stopped state.
*
* Requirements:
*
* - Only the owner can call this method.
* - The contract must not be paused.
*/
function pause() external onlyOwner {
_pause();
}
/**
* @dev Returns to normal state.
*
* Requirements:
*
* - Only the owner can call this method.
* - The contract must be paused.
*/
function unpause() external onlyOwner {
_unpause();
}
}
// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.4;
import "@openzeppelin/contracts/token/ERC1155/IERC1155Receiver.sol";
import "@openzeppelin/contracts/token/ERC721/utils/ERC721Holder.sol";
/**
* @title NftReceiver
* @author NFTfi
* @dev Base contract with capabilities for receiving ERC1155 and ERC721 tokens
*/
abstract contract NftReceiver is IERC1155Receiver, ERC721Holder {
/**
* @dev Handles the receipt of a single ERC1155 token type. This function is called at the end of a
* `safeTransferFrom` after the balance has been updated.
* @return `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))` if allowed
*/
function onERC1155Received(
address,
address,
uint256,
uint256,
bytes calldata
) external virtual override returns (bytes4) {
return this.onERC1155Received.selector;
}
/**
* @dev Handles the receipt of a multiple ERC1155 token types. This function is called at the end of a
* `safeBatchTransferFrom` after the balances have been updated.
* @return `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))` if allowed
*/
function onERC1155BatchReceived(
address,
address,
uint256[] calldata,
uint256[] calldata,
bytes calldata
) external virtual override returns (bytes4) {
revert("ERC1155 batch not supported");
}
/**
* @dev Checks whether this contract implements the interface defined by `interfaceId`.
* @param _interfaceId Id of the interface
* @return true if this contract implements the interface
*/
function supportsInterface(bytes4 _interfaceId) public view virtual override returns (bool) {
return
_interfaceId == type(IERC1155Receiver).interfaceId ||
_interfaceId == type(IERC721Receiver).interfaceId ||
_interfaceId == type(IERC165).interfaceId;
}
}
// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.4;
import "../interfaces/IBundleBuilder.sol";
import "../loans/direct/loanTypes/LoanData.sol";
import "@openzeppelin/contracts/utils/cryptography/SignatureChecker.sol";
/**
* @title NFTfiSigningUtils
* @author NFTfi
* @notice Helper contract for NFTfi. This contract manages verifying signatures from off-chain NFTfi orders.
* Based on the version of this same contract used on NFTfi V1
*/
library NFTfiSigningUtils {
/* ********* */
/* FUNCTIONS */
/* ********* */
/**
* @dev This function gets the current chain ID.
*/
function getChainID() public view returns (uint256) {
uint256 id;
// solhint-disable-next-line no-inline-assembly
assembly {
id := chainid()
}
return id;
}
/**
* @notice This function is when the lender accepts a borrower's binding listing terms, to validate the lender's
* signature that the borrower provided off-chain to verify that it did indeed made such listing.
*
* @param _listingTerms - The listing terms struct containing:
* - loanERC20Denomination: The address of the ERC20 contract of the currency being used as principal/interest
* for this loan.
* - minLoanPrincipalAmount: The minumum sum of money transferred from lender to borrower at the beginning of
* the loan, measured in loanERC20Denomination's smallest units.
* - maxLoanPrincipalAmount: The sum of money transferred from lender to borrower at the beginning of
* the loan, measured in loanERC20Denomination's smallest units.
* - maximumRepaymentAmount: The maximum amount of money that the borrower would be required to retrieve their
* collateral, measured in the smallest units of the ERC20 currency used for the loan. The borrower will always have
* to pay this amount to retrieve their collateral, regardless of whether they repay early.
* - nftCollateralContract: The address of the ERC721 contract of the NFT collateral.
* - nftCollateralId: The ID within the NFTCollateralContract for the NFT being used as collateral for this
* loan. The NFT is stored within this contract during the duration of the loan.
* - revenueSharePartner: The address of the partner that will receive the revenue share.
* - minLoanDuration: The minumum amount of time (measured in seconds) that can elapse before the lender can
* liquidate the loan and seize the underlying collateral NFT.
* - maxLoanDuration: The maximum amount of time (measured in seconds) that can elapse before the lender can
* liquidate the loan and seize the underlying collateral NFT.
* - maxInterestRateForDurationInBasisPoints: This is maximum the interest rate (measured in basis points, e.g.
* hundreths of a percent) for the loan, that must be repaid pro-rata by the borrower at the conclusion of the loan
* or risk seizure of their nft collateral. Note if the type of the loan is fixed then this value is not used and
* is irrelevant so it should be set to 0.
* - referralFeeInBasisPoints: The percent (measured in basis points) of the loan principal amount that will be
* taken as a fee to pay to the referrer, 0 if the lender is not paying referral fee.
* @param _signature - The offer struct containing:
* - signer: The address of the signer. The borrower for `acceptOffer` the lender for `acceptListing`.
* - nonce: The nonce referred here is not the same as an Ethereum account's nonce.
* We are referring instead to a nonce that is used by the lender or the borrower when they are first signing
* off-chain NFTfi orders. These nonce can be any uint256 value that the user has not previously used to sign an
* off-chain order. Each nonce can be used at most once per user within NFTfi, regardless of whether they are the
* lender or the borrower in that situation. This serves two purposes:
* - First, it prevents replay attacks where an attacker would submit a user's off-chain order more than once.
* - Second, it allows a user to cancel an off-chain order by calling
* NFTfi.cancelLoanCommitmentBeforeLoanHasBegun(), which marks the nonce as used and prevents any future loan from
* using the user's off-chain order that contains that nonce.
* - expiry: Date when the signature expires
* - signature: The ECDSA signature of the borrower, obtained off-chain ahead of time, signing the following
* combination of parameters:
* - listingTerms.loanERC20Denomination,
* - listingTerms.minLoanPrincipalAmount,
* - listingTerms.maxLoanPrincipalAmount,
* - listingTerms.nftCollateralContract,
* - listingTerms.nftCollateralId,
* - listingTerms.revenueSharePartner,
* - listingTerms.minLoanDuration,
* - listingTerms.maxLoanDuration,
* - listingTerms.maxInterestRateForDurationInBasisPoints,
* - listingTerms.referralFeeInBasisPoints,
* - signature.signer,
* - signature.nonce,
* - signature.expiry,
* - address of this contract
* - chainId
*/
function isValidBorrowerSignature(LoanData.ListingTerms memory _listingTerms, LoanData.Signature memory _signature)
external
view
returns (bool)
{
return isValidBorrowerSignature(_listingTerms, _signature, address(this));
}
/**
* @dev This function overload the previous function to allow the caller to specify the address of the contract
*
*/
function isValidBorrowerSignature(
LoanData.ListingTerms memory _listingTerms,
LoanData.Signature memory _signature,
address _loanContract
) public view returns (bool) {
require(block.timestamp <= _signature.expiry, "Borrower Signature has expired");
require(_loanContract != address(0), "Loan is zero address");
if (_signature.signer == address(0)) {
return false;
} else {
bytes32 message = keccak256(
abi.encodePacked(
getEncodedListing(_listingTerms),
getEncodedSignature(_signature),
_loanContract,
getChainID()
)
);
return
SignatureChecker.isValidSignatureNow(
_signature.signer,
ECDSA.toEthSignedMessageHash(message),
_signature.signature
);
}
}
/**
* @notice This function is when the lender accepts a borrower's binding listing terms, to validate the lender's
* signature that the borrower provided off-chain to verify that it did indeed made such listing.
*
* @param _listingTerms - The listing terms struct containing:
* - loanERC20Denomination: The address of the ERC20 contract of the currency being used as principal/interest
* for this loan.
* - minLoanPrincipalAmount: The minumum sum of money transferred from lender to borrower at the beginning of
* the loan, measured in loanERC20Denomination's smallest units.
* - maxLoanPrincipalAmount: The sum of money transferred from lender to borrower at the beginning of
* the loan, measured in loanERC20Denomination's smallest units.
* - maximumRepaymentAmount: The maximum amount of money that the borrower would be required to retrieve their
* collateral, measured in the smallest units of the ERC20 currency used for the loan. The borrower will always have
* to pay this amount to retrieve their collateral, regardless of whether they repay early.
* - nftCollateralContract: The address of the ERC721 contract of the NFT collateral.
* - nftCollateralId: The ID within the NFTCollateralContract for the NFT being used as collateral for this
* loan. The NFT is stored within this contract during the duration of the loan.
* - revenueSharePartner: The address of the partner that will receive the revenue share.
* - minLoanDuration: The minumum amount of time (measured in seconds) that can elapse before the lender can
* liquidate the loan and seize the underlying collateral NFT.
* - maxLoanDuration: The maximum amount of time (measured in seconds) that can elapse before the lender can
* liquidate the loan and seize the underlying collateral NFT.
* - maxInterestRateForDurationInBasisPoints: This is maximum the interest rate (measured in basis points, e.g.
* hundreths of a percent) for the loan, that must be repaid pro-rata by the borrower at the conclusion of the loan
* or risk seizure of their nft collateral. Note if the type of the loan is fixed then this value is not used and
* is irrelevant so it should be set to 0.
* - referralFeeInBasisPoints: The percent (measured in basis points) of the loan principal amount that will be
* taken as a fee to pay to the referrer, 0 if the lender is not paying referral fee.
* @param _bundleElements - the lists of erc721-20-1155 tokens that are to be bundled
* @param _signature - The offer struct containing:
* - signer: The address of the signer. The borrower for `acceptOffer` the lender for `acceptListing`.
* - nonce: The nonce referred here is not the same as an Ethereum account's nonce.
* We are referring instead to a nonce that is used by the lender or the borrower when they are first signing
* off-chain NFTfi orders. These nonce can be any uint256 value that the user has not previously used to sign an
* off-chain order. Each nonce can be used at most once per user within NFTfi, regardless of whether they are the
* lender or the borrower in that situation. This serves two purposes:
* - First, it prevents replay attacks where an attacker would submit a user's off-chain order more than once.
* - Second, it allows a user to cancel an off-chain order by calling
* NFTfi.cancelLoanCommitmentBeforeLoanHasBegun(), which marks the nonce as used and prevents any future loan from
* using the user's off-chain order that contains that nonce.
* - expiry: Date when the signature expires
* - signature: The ECDSA signature of the borrower, obtained off-chain ahead of time, signing the following
* combination of parameters:
* - listingTerms.loanERC20Denomination,
* - listingTerms.minLoanPrincipalAmount,
* - listingTerms.maxLoanPrincipalAmount,
* - listingTerms.nftCollateralContract,
* - listingTerms.nftCollateralId,
* - listingTerms.revenueSharePartner,
* - listingTerms.minLoanDuration,
* - listingTerms.maxLoanDuration,
* - listingTerms.maxInterestRateForDurationInBasisPoints,
* - listingTerms.referralFeeInBasisPoints,
* - bundleElements
* - signature.signer,
* - signature.nonce,
* - signature.expiry,
* - address of this contract
* - chainId
*/
function isValidBorrowerSignatureBundle(
LoanData.ListingTerms memory _listingTerms,
IBundleBuilder.BundleElements memory _bundleElements,
LoanData.Signature memory _signature
) external view returns (bool) {
return isValidBorrowerSignatureBundle(_listingTerms, _bundleElements, _signature, address(this));
}
/**
* @dev This function overload the previous function to allow the caller to specify the address of the contract
*
*/
function isValidBorrowerSignatureBundle(
LoanData.ListingTerms memory _listingTerms,
IBundleBuilder.BundleElements memory _bundleElements,
LoanData.Signature memory _signature,
address _loanContract
) public view returns (bool) {
require(block.timestamp <= _signature.expiry, "Borrower Signature has expired");
require(_loanContract != address(0), "Loan is zero address");
if (_signature.signer == address(0)) {
return false;
} else {
bytes32 message = keccak256(
abi.encodePacked(
getEncodedListing(_listingTerms),
abi.encode(_bundleElements),
getEncodedSignature(_signature),
_loanContract,
getChainID()
)
);
return
SignatureChecker.isValidSignatureNow(
_signature.signer,
ECDSA.toEthSignedMessageHash(message),
_signature.signature
);
}
}
/**
* @notice This function is when the borrower accepts a lender's offer, to validate the lender's signature that the
* lender provided off-chain to verify that it did indeed made such offer.
*
* @param _offer - The offer struct containing:
* - loanERC20Denomination: The address of the ERC20 contract of the currency being used as principal/interest
* for this loan.
* - loanPrincipalAmount: The original sum of money transferred from lender to borrower at the beginning of
* the loan, measured in loanERC20Denomination's smallest units.
* - maximumRepaymentAmount: The maximum amount of money that the borrower would be required to retrieve their
* collateral, measured in the smallest units of the ERC20 currency used for the loan. The borrower will always have
* to pay this amount to retrieve their collateral, regardless of whether they repay early.
* - nftCollateralContract: The address of the ERC721 contract of the NFT collateral.
* - nftCollateralId: The ID within the NFTCollateralContract for the NFT being used as collateral for this
* loan. The NFT is stored within this contract during the duration of the loan.
* - referrer: The address of the referrer who found the lender matching the listing, Zero address to signal
* this there is no referrer.
* - loanDuration: The amount of time (measured in seconds) that can elapse before the lender can liquidate the
* loan and seize the underlying collateral NFT.
* - loanInterestRateForDurationInBasisPoints: This is the interest rate (measured in basis points, e.g.
* hundreths of a percent) for the loan, that must be repaid pro-rata by the borrower at the conclusion of the loan
* or risk seizure of their nft collateral. Note if the type of the loan is fixed then this value is not used and
* is irrelevant so it should be set to 0.
* - loanAdminFeeInBasisPoints: The percent (measured in basis points) of the interest earned that will be
* taken as a fee by the contract admins when the loan is repaid. The fee is stored in the loan struct to prevent an
* attack where the contract admins could adjust the fee right before a loan is repaid, and take all of the interest
* earned.
* @param _signature - The signature structure containing:
* - signer: The address of the signer. The borrower for `acceptOffer` the lender for `acceptListing`.
* - nonce: The nonce referred here is not the same as an Ethereum account's nonce.
* We are referring instead to a nonce that is used by the lender or the borrower when they are first signing
* off-chain NFTfi orders. These nonce can be any uint256 value that the user has not previously used to sign an
* off-chain order. Each nonce can be used at most once per user within NFTfi, regardless of whether they are the
* lender or the borrower in that situation. This serves two purposes:
* - First, it prevents replay attacks where an attacker would submit a user's off-chain order more than once.
* - Second, it allows a user to cancel an off-chain order by calling
* NFTfi.cancelLoanCommitmentBeforeLoanHasBegun(), which marks the nonce as used and prevents any future loan from
* using the user's off-chain order that contains that nonce.
* - expiry: Date when the signature expires
* - signature: The ECDSA signature of the lender, obtained off-chain ahead of time, signing the following
* combination of parameters:
* - offer.loanERC20Denomination
* - offer.loanPrincipalAmount
* - offer.maximumRepaymentAmount
* - offer.nftCollateralContract
* - offer.nftCollateralId
* - offer.referrer
* - offer.loanDuration
* - offer.loanAdminFeeInBasisPoints
* - signature.signer,
* - signature.nonce,
* - signature.expiry,
* - address of this contract
* - chainId
*/
function isValidLenderSignature(LoanData.Offer memory _offer, LoanData.Signature memory _signature)
external
view
returns (bool)
{
return isValidLenderSignature(_offer, _signature, address(this));
}
/**
* @dev This function overload the previous function to allow the caller to specify the address of the contract
*
*/
function isValidLenderSignature(
LoanData.Offer memory _offer,
LoanData.Signature memory _signature,
address _loanContract
) public view returns (bool) {
require(block.timestamp <= _signature.expiry, "Lender Signature has expired");
require(_loanContract != address(0), "Loan is zero address");
if (_signature.signer == address(0)) {
return false;
} else {
bytes32 message = keccak256(
abi.encodePacked(getEncodedOffer(_offer), getEncodedSignature(_signature), _loanContract, getChainID())
);
return
SignatureChecker.isValidSignatureNow(
_signature.signer,
ECDSA.toEthSignedMessageHash(message),
_signature.signature
);
}
}
/**
* @notice This function is when the borrower accepts a lender's offer, to validate the lender's signature that the
* lender provided off-chain to verify that it did indeed made such offer.
*
* @param _offer - The offer struct containing:
* - loanERC20Denomination: The address of the ERC20 contract of the currency being used as principal/interest
* for this loan.
* - loanPrincipalAmount: The original sum of money transferred from lender to borrower at the beginning of
* the loan, measured in loanERC20Denomination's smallest units.
* - maximumRepaymentAmount: The maximum amount of money that the borrower would be required to retrieve their
* collateral, measured in the smallest units of the ERC20 currency used for the loan. The borrower will always have
* to pay this amount to retrieve their collateral, regardless of whether they repay early.
* - nftCollateralContract: The address of the ERC721 contract of the NFT collateral.
* - nftCollateralId: The ID within the NFTCollateralContract for the NFT being used as collateral for this
* loan. The NFT is stored within this contract during the duration of the loan.
* - referrer: The address of the referrer who found the lender matching the listing, Zero address to signal
* this there is no referrer.
* - loanDuration: The amount of time (measured in seconds) that can elapse before the lender can liquidate the
* loan and seize the underlying collateral NFT.
* - loanInterestRateForDurationInBasisPoints: This is the interest rate (measured in basis points, e.g.
* hundreths of a percent) for the loan, that must be repaid pro-rata by the borrower at the conclusion of the loan
* or risk seizure of their nft collateral. Note if the type of the loan is fixed then this value is not used and
* is irrelevant so it should be set to 0.
* - loanAdminFeeInBasisPoints: The percent (measured in basis points) of the interest earned that will be
* taken as a fee by the contract admins when the loan is repaid. The fee is stored in the loan struct to prevent an
* attack where the contract admins could adjust the fee right before a loan is repaid, and take all of the interest
* earned.
* @param _bundleElements - the lists of erc721-20-1155 tokens that are to be bundled
* @param _signature - The signature structure containing:
* - signer: The address of the signer. The borrower for `acceptOffer` the lender for `acceptListing`.
* - nonce: The nonce referred here is not the same as an Ethereum account's nonce.
* We are referring instead to a nonce that is used by the lender or the borrower when they are first signing
* off-chain NFTfi orders. These nonce can be any uint256 value that the user has not previously used to sign an
* off-chain order. Each nonce can be used at most once per user within NFTfi, regardless of whether they are the
* lender or the borrower in that situation. This serves two purposes:
* - First, it prevents replay attacks where an attacker would submit a user's off-chain order more than once.
* - Second, it allows a user to cancel an off-chain order by calling
* NFTfi.cancelLoanCommitmentBeforeLoanHasBegun(), which marks the nonce as used and prevents any future loan from
* using the user's off-chain order that contains that nonce.
* - expiry: Date when the signature expires
* - signature: The ECDSA signature of the lender, obtained off-chain ahead of time, signing the following
* combination of parameters:
* - offer.loanERC20Denomination
* - offer.loanPrincipalAmount
* - offer.maximumRepaymentAmount
* - offer.nftCollateralContract
* - offer.nftCollateralId
* - offer.referrer
* - offer.loanDuration
* - offer.loanAdminFeeInBasisPoints
* - bundleElements
* - signature.signer,
* - signature.nonce,
* - signature.expiry,
* - address of this contract
* - chainId
*/
function isValidLenderSignatureBundle(
LoanData.Offer memory _offer,
IBundleBuilder.BundleElements memory _bundleElements,
LoanData.Signature memory _signature
) external view returns (bool) {
return isValidLenderSignatureBundle(_offer, _bundleElements, _signature, address(this));
}
/**
* @dev This function overload the previous function to allow the caller to specify the address of the contract
*
*/
function isValidLenderSignatureBundle(
LoanData.Offer memory _offer,
IBundleBuilder.BundleElements memory _bundleElements,
LoanData.Signature memory _signature,
address _loanContract
) public view returns (bool) {
require(block.timestamp <= _signature.expiry, "Lender Signature has expired");
require(_loanContract != address(0), "Loan is zero address");
if (_signature.signer == address(0)) {
return false;
} else {
bytes32 message = keccak256(
abi.encodePacked(
getEncodedOffer(_offer),
abi.encode(_bundleElements),
getEncodedSignature(_signature),
_loanContract,
getChainID()
)
);
return
SignatureChecker.isValidSignatureNow(
_signature.signer,
ECDSA.toEthSignedMessageHash(message),
_signature.signature
);
}
}
/**
* @notice This function is called in renegotiateLoan() to validate the lender's signature that the lender provided
* off-chain to verify that they did indeed want to agree to this loan renegotiation according to these terms.
*
* @param _loanId - The unique identifier for the loan to be renegotiated
* @param _newLoanDuration - The new amount of time (measured in seconds) that can elapse before the lender can
* liquidate the loan and seize the underlying collateral NFT.
* @param _newMaximumRepaymentAmount - The new maximum amount of money that the borrower would be required to
* retrieve their collateral, measured in the smallest units of the ERC20 currency used for the loan. The
* borrower will always have to pay this amount to retrieve their collateral, regardless of whether they repay
* early.
* @param _renegotiationFee Agreed upon fee in ether that borrower pays for the lender for the renegitiation
* @param _signature - The signature structure containing:
* - signer: The address of the signer. The borrower for `acceptOffer` the lender for `acceptListing`.
* - nonce: The nonce referred here is not the same as an Ethereum account's nonce.
* We are referring instead to a nonce that is used by the lender or the borrower when they are first signing
* off-chain NFTfi orders. These nonce can be any uint256 value that the user has not previously used to sign an
* off-chain order. Each nonce can be used at most once per user within NFTfi, regardless of whether they are the
* lender or the borrower in that situation. This serves two purposes:
* - First, it prevents replay attacks where an attacker would submit a user's off-chain order more than once.
* - Second, it allows a user to cancel an off-chain order by calling NFTfi.cancelLoanCommitmentBeforeLoanHasBegun()
* , which marks the nonce as used and prevents any future loan from using the user's off-chain order that contains
* that nonce.
* - expiry - The date when the renegotiation offer expires
* - lenderSignature - The ECDSA signature of the lender, obtained off-chain ahead of time, signing the
* following combination of parameters:
* - _loanId
* - _newLoanDuration
* - _newMaximumRepaymentAmount
* - _lender
* - _lenderNonce
* - _expiry
* - address of this contract
* - chainId
*/
function isValidLenderRenegotiationSignature(
uint256 _loanId,
uint32 _newLoanDuration,
uint256 _newMaximumRepaymentAmount,
uint256 _renegotiationFee,
LoanData.Signature memory _signature
) external view returns (bool) {
return
isValidLenderRenegotiationSignature(
_loanId,
_newLoanDuration,
_newMaximumRepaymentAmount,
_renegotiationFee,
_signature,
address(this)
);
}
/**
* @dev This function overload the previous function to allow the caller to specify the address of the contract
*
*/
function isValidLenderRenegotiationSignature(
uint256 _loanId,
uint32 _newLoanDuration,
uint256 _newMaximumRepaymentAmount,
uint256 _renegotiationFee,
LoanData.Signature memory _signature,
address _loanContract
) public view returns (bool) {
require(block.timestamp <= _signature.expiry, "Renegotiation Signature has expired");
require(_loanContract != address(0), "Loan is zero address");
if (_signature.signer == address(0)) {
return false;
} else {
bytes32 message = keccak256(
abi.encodePacked(
_loanId,
_newLoanDuration,
_newMaximumRepaymentAmount,
_renegotiationFee,
getEncodedSignature(_signature),
_loanContract,
getChainID()
)
);
return
SignatureChecker.isValidSignatureNow(
_signature.signer,
ECDSA.toEthSignedMessageHash(message),
_signature.signature
);
}
}
/**
* @dev We need this to avoid stack too deep errors.
*/
function getEncodedListing(LoanData.ListingTerms memory _listingTerms) internal pure returns (bytes memory) {
return
abi.encodePacked(
_listingTerms.loanERC20Denomination,
_listingTerms.minLoanPrincipalAmount,
_listingTerms.maxLoanPrincipalAmount,
_listingTerms.nftCollateralContract,
_listingTerms.nftCollateralId,
_listingTerms.revenueSharePartner,
_listingTerms.minLoanDuration,
_listingTerms.maxLoanDuration,
_listingTerms.maxInterestRateForDurationInBasisPoints,
_listingTerms.referralFeeInBasisPoints
);
}
/**
* @dev We need this to avoid stack too deep errors.
*/
function getEncodedOffer(LoanData.Offer memory _offer) internal pure returns (bytes memory) {
return
abi.encodePacked(
_offer.loanERC20Denomination,
_offer.loanPrincipalAmount,
_offer.maximumRepaymentAmount,
_offer.nftCollateralContract,
_offer.nftCollateralId,
_offer.referrer,
_offer.loanDuration,
_offer.loanAdminFeeInBasisPoints
);
}
/**
* @dev We need this to avoid stack too deep errors.
*/
function getEncodedSignature(LoanData.Signature memory _signature) internal pure returns (bytes memory) {
return abi.encodePacked(_signature.signer, _signature.nonce, _signature.expiry);
}
}
// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.4;
/**
* @title INftfiHub
* @author NFTfi
* @dev NftfiHub interface
*/
interface INftfiHub {
function setContract(string calldata _contractKey, address _contractAddress) external;
function getContract(bytes32 _contractKey) external view returns (address);
}
// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.4;
/**
* @title IDirectLoanCoordinator
* @author NFTfi
* @dev DirectLoanCoordinator interface.
*/
interface IDirectLoanCoordinator {
enum StatusType {
NOT_EXISTS,
NEW,
RESOLVED
}
/**
* @notice This struct contains data related to a loan
*
* @param smartNftId - The id of both the promissory note and obligation receipt.
* @param status - The status in which the loan currently is.
* @param loanContract - Address of the LoanType contract that created the loan.
*/
struct Loan {
address loanContract;
uint64 smartNftId;
StatusType status;
}
function registerLoan(address _lender, bytes32 _loanType) external returns (uint32);
function mintObligationReceipt(uint32 _loanId, address _borrower) external;
function resolveLoan(uint32 _loanId) external;
function promissoryNoteToken() external view returns (address);
function obligationReceiptToken() external view returns (address);
function getLoanData(uint32 _loanId) external view returns (Loan memory);
function isValidLoanId(uint32 _loanId, address _loanContract) external view returns (bool);
}
// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.4;
/**
* @title INftTypeRegistry
* @author NFTfi
* @dev Interface for NFT Wrappers.
*/
interface INftWrapper {
function transferNFT(
address from,
address to,
address nftContract,
uint256 tokenId
) external returns (bool);
function isOwner(
address owner,
address nftContract,
uint256 tokenId
) external view returns (bool);
function wrapAirdropReceiver(
address _recipient,
address _nftContract,
uint256 _nftId,
address _beneficiary
) external returns (bool);
}
// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.4;
interface IPermittedPartners {
function getPartnerPermit(address _partner) external view returns (uint16);
}
// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.4;
interface IPermittedERC20s {
function getERC20Permit(address _erc20) external view returns (bool);
}
// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.4;
interface IPermittedNFTs {
function setNFTPermit(address _nftContract, string memory _nftType) external;
function getNFTPermit(address _nftContract) external view returns (bytes32);
function getNFTWrapper(address _nftContract) external view returns (address);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721.sol)
pragma solidity ^0.8.0;
import "../../utils/introspection/IERC165.sol";
/**
* @dev Required interface of an ERC721 compliant contract.
*/
interface IERC721 is IERC165 {
/**
* @dev Emitted when `tokenId` token is transferred from `from` to `to`.
*/
event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
*/
event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
*/
event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
/**
* @dev Returns the number of tokens in ``owner``'s account.
*/
function balanceOf(address owner) external view returns (uint256 balance);
/**
* @dev Returns the owner of the `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function ownerOf(uint256 tokenId) external view returns (address owner);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
* are aware of the ERC721 protocol to prevent tokens from being forever locked.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId
) external;
/**
* @dev Transfers `tokenId` token from `from` to `to`.
*
* WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
*
* Emits a {Transfer} event.
*/
function transferFrom(
address from,
address to,
uint256 tokenId
) external;
/**
* @dev Gives permission to `to` to transfer `tokenId` token to another account.
* The approval is cleared when the token is transferred.
*
* Only a single account can be approved at a time, so approving the zero address clears previous approvals.
*
* Requirements:
*
* - The caller must own the token or be an approved operator.
* - `tokenId` must exist.
*
* Emits an {Approval} event.
*/
function approve(address to, uint256 tokenId) external;
/**
* @dev Returns the account approved for `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function getApproved(uint256 tokenId) external view returns (address operator);
/**
* @dev Approve or remove `operator` as an operator for the caller.
* Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
*
* Requirements:
*
* - The `operator` cannot be the caller.
*
* Emits an {ApprovalForAll} event.
*/
function setApprovalForAll(address operator, bool _approved) external;
/**
* @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
*
* See {setApprovalForAll}
*/
function isApprovedForAll(address owner, address operator) external view returns (bool);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId,
bytes calldata data
) external;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/IERC20.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `to`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address to, uint256 amount) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: Beware that changing an allowance with this method brings the risk
* that someone may use both the old and the new allowance by unfortunate
* transaction ordering. One possible solution to mitigate this race
* condition is to first reduce the spender's allowance to 0 and set the
* desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* Emits an {Approval} event.
*/
function approve(address spender, uint256 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `from` to `to` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(
address from,
address to,
uint256 amount
) external returns (bool);
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC1155/IERC1155.sol)
pragma solidity ^0.8.0;
import "../../utils/introspection/IERC165.sol";
/**
* @dev Required interface of an ERC1155 compliant contract, as defined in the
* https://eips.ethereum.org/EIPS/eip-1155[EIP].
*
* _Available since v3.1._
*/
interface IERC1155 is IERC165 {
/**
* @dev Emitted when `value` tokens of token type `id` are transferred from `from` to `to` by `operator`.
*/
event TransferSingle(address indexed operator, address indexed from, address indexed to, uint256 id, uint256 value);
/**
* @dev Equivalent to multiple {TransferSingle} events, where `operator`, `from` and `to` are the same for all
* transfers.
*/
event TransferBatch(
address indexed operator,
address indexed from,
address indexed to,
uint256[] ids,
uint256[] values
);
/**
* @dev Emitted when `account` grants or revokes permission to `operator` to transfer their tokens, according to
* `approved`.
*/
event ApprovalForAll(address indexed account, address indexed operator, bool approved);
/**
* @dev Emitted when the URI for token type `id` changes to `value`, if it is a non-programmatic URI.
*
* If an {URI} event was emitted for `id`, the standard
* https://eips.ethereum.org/EIPS/eip-1155#metadata-extensions[guarantees] that `value` will equal the value
* returned by {IERC1155MetadataURI-uri}.
*/
event URI(string value, uint256 indexed id);
/**
* @dev Returns the amount of tokens of token type `id` owned by `account`.
*
* Requirements:
*
* - `account` cannot be the zero address.
*/
function balanceOf(address account, uint256 id) external view returns (uint256);
/**
* @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {balanceOf}.
*
* Requirements:
*
* - `accounts` and `ids` must have the same length.
*/
function balanceOfBatch(address[] calldata accounts, uint256[] calldata ids)
external
view
returns (uint256[] memory);
/**
* @dev Grants or revokes permission to `operator` to transfer the caller's tokens, according to `approved`,
*
* Emits an {ApprovalForAll} event.
*
* Requirements:
*
* - `operator` cannot be the caller.
*/
function setApprovalForAll(address operator, bool approved) external;
/**
* @dev Returns true if `operator` is approved to transfer ``account``'s tokens.
*
* See {setApprovalForAll}.
*/
function isApprovedForAll(address account, address operator) external view returns (bool);
/**
* @dev Transfers `amount` tokens of token type `id` from `from` to `to`.
*
* Emits a {TransferSingle} event.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - If the caller is not `from`, it must be have been approved to spend ``from``'s tokens via {setApprovalForAll}.
* - `from` must have a balance of tokens of type `id` of at least `amount`.
* - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155Received} and return the
* acceptance magic value.
*/
function safeTransferFrom(
address from,
address to,
uint256 id,
uint256 amount,
bytes calldata data
) external;
/**
* @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {safeTransferFrom}.
*
* Emits a {TransferBatch} event.
*
* Requirements:
*
* - `ids` and `amounts` must have the same length.
* - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155BatchReceived} and return the
* acceptance magic value.
*/
function safeBatchTransferFrom(
address from,
address to,
uint256[] calldata ids,
uint256[] calldata amounts,
bytes calldata data
) external;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)
pragma solidity ^0.8.1;
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
* ====
*
* [IMPORTANT]
* ====
* You shouldn't rely on `isContract` to protect against flash loan attacks!
*
* Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
* like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
* constructor.
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize/address.code.length, which returns 0
// for contracts in construction, since the code is only stored at the end
// of the constructor execution.
return account.code.length > 0;
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient balance");
(bool success, ) = recipient.call{value: amount}("");
require(success, "Address: unable to send value, recipient may have reverted");
}
/**
* @dev Performs a Solidity function call using a low level `call`. A
* plain `call` is an unsafe replacement for a function call: use this
* function instead.
*
* If `target` reverts with a revert reason, it is bubbled up by this
* function (like regular Solidity function calls).
*
* Returns the raw returned data. To convert to the expected return value,
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
*
* Requirements:
*
* - `target` must be a contract.
* - calling `target` with `data` must not revert.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return functionCall(target, data, "Address: low-level call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
* `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but also transferring `value` wei to `target`.
*
* Requirements:
*
* - the calling contract must have an ETH balance of at least `value`.
* - the called Solidity function must be `payable`.
*
* _Available since v3.1._
*/
function functionCallWithValue(
address target,
bytes memory data,
uint256 value
) internal returns (bytes memory) {
return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
}
/**
* @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
* with `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCallWithValue(
address target,
bytes memory data,
uint256 value,
string memory errorMessage
) internal returns (bytes memory) {
require(address(this).balance >= value, "Address: insufficient balance for call");
require(isContract(target), "Address: call to non-contract");
(bool success, bytes memory returndata) = target.call{value: value}(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
return functionStaticCall(target, data, "Address: low-level static call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(
address target,
bytes memory data,
string memory errorMessage
) internal view returns (bytes memory) {
require(isContract(target), "Address: static call to non-contract");
(bool success, bytes memory returndata) = target.staticcall(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
return functionDelegateCall(target, data, "Address: low-level delegate call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
require(isContract(target), "Address: delegate call to non-contract");
(bool success, bytes memory returndata) = target.delegatecall(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
* revert reason using the provided one.
*
* _Available since v4.3._
*/
function verifyCallResult(
bool success,
bytes memory returndata,
string memory errorMessage
) internal pure returns (bytes memory) {
if (success) {
return returndata;
} else {
// Look for revert reason and bubble it up if present
if (returndata.length > 0) {
// The easiest way to bubble the revert reason is using memory via assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)
pragma solidity ^0.8.0;
import "../IERC20.sol";
import "../../../utils/Address.sol";
/**
* @title SafeERC20
* @dev Wrappers around ERC20 operations that throw on failure (when the token
* contract returns false). Tokens that return no value (and instead revert or
* throw on failure) are also supported, non-reverting calls are assumed to be
* successful.
* To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
* which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
*/
library SafeERC20 {
using Address for address;
function safeTransfer(
IERC20 token,
address to,
uint256 value
) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
}
function safeTransferFrom(
IERC20 token,
address from,
address to,
uint256 value
) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
}
/**
* @dev Deprecated. This function has issues similar to the ones found in
* {IERC20-approve}, and its usage is discouraged.
*
* Whenever possible, use {safeIncreaseAllowance} and
* {safeDecreaseAllowance} instead.
*/
function safeApprove(
IERC20 token,
address spender,
uint256 value
) internal {
// safeApprove should only be called when setting an initial allowance,
// or when resetting it to zero. To increase and decrease it, use
// 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
require(
(value == 0) || (token.allowance(address(this), spender) == 0),
"SafeERC20: approve from non-zero to non-zero allowance"
);
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
}
function safeIncreaseAllowance(
IERC20 token,
address spender,
uint256 value
) internal {
uint256 newAllowance = token.allowance(address(this), spender) + value;
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
function safeDecreaseAllowance(
IERC20 token,
address spender,
uint256 value
) internal {
unchecked {
uint256 oldAllowance = token.allowance(address(this), spender);
require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
uint256 newAllowance = oldAllowance - value;
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
}
/**
* @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
* on the return value: the return value is optional (but if data is returned, it must not be false).
* @param token The token targeted by the call.
* @param data The call data (encoded using abi.encode or one of its variants).
*/
function _callOptionalReturn(IERC20 token, bytes memory data) private {
// We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
// we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
// the target address contains contract code and also asserts for success in the low-level call.
bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
if (returndata.length > 0) {
// Return data is optional
require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC165 standard, as defined in the
* https://eips.ethereum.org/EIPS/eip-165[EIP].
*
* Implementers can declare support of contract interfaces, which can then be
* queried by others ({ERC165Checker}).
*
* For an implementation, see {ERC165}.
*/
interface IERC165 {
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
* to learn more about how these ids are created.
*
* This function call must use less than 30 000 gas.
*/
function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.4;
interface IAirdropFlashLoan {
function pullAirdrop(
address _nftCollateralContract,
uint256 _nftCollateralId,
address _nftWrapper,
address _target,
bytes calldata _data,
address _nftAirdrop,
uint256 _nftAirdropId,
bool _is1155,
uint256 _nftAirdropAmount,
address _beneficiary
) external;
}
// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.4;
/**
* @title IAirdropReceiver
* @author NFTfi
* @dev
*/
interface IAirdropReceiverFactory {
function createAirdropReceiver(address _to) external returns (address, uint256);
}
// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.4;
import "@openzeppelin/contracts/utils/Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*
* Modified version from openzeppelin/contracts/access/Ownable.sol that allows to
* initialize the owner using a parameter in the constructor
*/
abstract contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
_;
}
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor(address _initialOwner) {
_setOwner(_initialOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address _newOwner) public virtual onlyOwner {
require(_newOwner != address(0), "Ownable: new owner is the zero address");
_setOwner(_newOwner);
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Sets the owner.
*/
function _setOwner(address _newOwner) private {
address oldOwner = _owner;
_owner = _newOwner;
emit OwnershipTransferred(oldOwner, _newOwner);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (security/Pausable.sol)
pragma solidity ^0.8.0;
import "../utils/Context.sol";
/**
* @dev Contract module which allows children to implement an emergency stop
* mechanism that can be triggered by an authorized account.
*
* This module is used through inheritance. It will make available the
* modifiers `whenNotPaused` and `whenPaused`, which can be applied to
* the functions of your contract. Note that they will not be pausable by
* simply including this module, only once the modifiers are put in place.
*/
abstract contract Pausable is Context {
/**
* @dev Emitted when the pause is triggered by `account`.
*/
event Paused(address account);
/**
* @dev Emitted when the pause is lifted by `account`.
*/
event Unpaused(address account);
bool private _paused;
/**
* @dev Initializes the contract in unpaused state.
*/
constructor() {
_paused = false;
}
/**
* @dev Returns true if the contract is paused, and false otherwise.
*/
function paused() public view virtual returns (bool) {
return _paused;
}
/**
* @dev Modifier to make a function callable only when the contract is not paused.
*
* Requirements:
*
* - The contract must not be paused.
*/
modifier whenNotPaused() {
require(!paused(), "Pausable: paused");
_;
}
/**
* @dev Modifier to make a function callable only when the contract is paused.
*
* Requirements:
*
* - The contract must be paused.
*/
modifier whenPaused() {
require(paused(), "Pausable: not paused");
_;
}
/**
* @dev Triggers stopped state.
*
* Requirements:
*
* - The contract must not be paused.
*/
function _pause() internal virtual whenNotPaused {
_paused = true;
emit Paused(_msgSender());
}
/**
* @dev Returns to normal state.
*
* Requirements:
*
* - The contract must be paused.
*/
function _unpause() internal virtual whenPaused {
_paused = false;
emit Unpaused(_msgSender());
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)
pragma solidity ^0.8.0;
/**
* @dev Contract module that helps prevent reentrant calls to a function.
*
* Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
* available, which can be applied to functions to make sure there are no nested
* (reentrant) calls to them.
*
* Note that because there is a single `nonReentrant` guard, functions marked as
* `nonReentrant` may not call one another. This can be worked around by making
* those functions `private`, and then adding `external` `nonReentrant` entry
* points to them.
*
* TIP: If you would like to learn more about reentrancy and alternative ways
* to protect against it, check out our blog post
* https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
*/
abstract contract ReentrancyGuard {
// Booleans are more expensive than uint256 or any type that takes up a full
// word because each write operation emits an extra SLOAD to first read the
// slot's contents, replace the bits taken up by the boolean, and then write
// back. This is the compiler's defense against contract upgrades and
// pointer aliasing, and it cannot be disabled.
// The values being non-zero value makes deployment a bit more expensive,
// but in exchange the refund on every call to nonReentrant will be lower in
// amount. Since refunds are capped to a percentage of the total
// transaction's gas, it is best to keep them low in cases like this one, to
// increase the likelihood of the full refund coming into effect.
uint256 private constant _NOT_ENTERED = 1;
uint256 private constant _ENTERED = 2;
uint256 private _status;
constructor() {
_status = _NOT_ENTERED;
}
/**
* @dev Prevents a contract from calling itself, directly or indirectly.
* Calling a `nonReentrant` function from another `nonReentrant`
* function is not supported. It is possible to prevent this from happening
* by making the `nonReentrant` function external, and making it call a
* `private` function that does the actual work.
*/
modifier nonReentrant() {
// On the first call to nonReentrant, _notEntered will be true
require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
// Any calls to nonReentrant after this point will fail
_status = _ENTERED;
_;
// By storing the original value once again, a refund is triggered (see
// https://eips.ethereum.org/EIPS/eip-2200)
_status = _NOT_ENTERED;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC1155/IERC1155Receiver.sol)
pragma solidity ^0.8.0;
import "../../utils/introspection/IERC165.sol";
/**
* @dev _Available since v3.1._
*/
interface IERC1155Receiver is IERC165 {
/**
* @dev Handles the receipt of a single ERC1155 token type. This function is
* called at the end of a `safeTransferFrom` after the balance has been updated.
*
* NOTE: To accept the transfer, this must return
* `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))`
* (i.e. 0xf23a6e61, or its own function selector).
*
* @param operator The address which initiated the transfer (i.e. msg.sender)
* @param from The address which previously owned the token
* @param id The ID of the token being transferred
* @param value The amount of tokens being transferred
* @param data Additional data with no specified format
* @return `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))` if transfer is allowed
*/
function onERC1155Received(
address operator,
address from,
uint256 id,
uint256 value,
bytes calldata data
) external returns (bytes4);
/**
* @dev Handles the receipt of a multiple ERC1155 token types. This function
* is called at the end of a `safeBatchTransferFrom` after the balances have
* been updated.
*
* NOTE: To accept the transfer(s), this must return
* `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))`
* (i.e. 0xbc197c81, or its own function selector).
*
* @param operator The address which initiated the batch transfer (i.e. msg.sender)
* @param from The address which previously owned the token
* @param ids An array containing ids of each token being transferred (order and length must match values array)
* @param values An array containing amounts of each token being transferred (order and length must match ids array)
* @param data Additional data with no specified format
* @return `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))` if transfer is allowed
*/
function onERC1155BatchReceived(
address operator,
address from,
uint256[] calldata ids,
uint256[] calldata values,
bytes calldata data
) external returns (bytes4);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/utils/ERC721Holder.sol)
pragma solidity ^0.8.0;
import "../IERC721Receiver.sol";
/**
* @dev Implementation of the {IERC721Receiver} interface.
*
* Accepts all token transfers.
* Make sure the contract is able to use its token with {IERC721-safeTransferFrom}, {IERC721-approve} or {IERC721-setApprovalForAll}.
*/
contract ERC721Holder is IERC721Receiver {
/**
* @dev See {IERC721Receiver-onERC721Received}.
*
* Always returns `IERC721Receiver.onERC721Received.selector`.
*/
function onERC721Received(
address,
address,
uint256,
bytes memory
) public virtual override returns (bytes4) {
return this.onERC721Received.selector;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721Receiver.sol)
pragma solidity ^0.8.0;
/**
* @title ERC721 token receiver interface
* @dev Interface for any contract that wants to support safeTransfers
* from ERC721 asset contracts.
*/
interface IERC721Receiver {
/**
* @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
* by `operator` from `from`, this function is called.
*
* It must return its Solidity selector to confirm the token transfer.
* If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
*
* The selector can be obtained in Solidity with `IERC721.onERC721Received.selector`.
*/
function onERC721Received(
address operator,
address from,
uint256 tokenId,
bytes calldata data
) external returns (bytes4);
}
// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.4;
interface IBundleBuilder {
/**
* @notice data of a erc721 bundle element
*
* @param tokenContract - address of the token contract
* @param id - id of the token
* @param safeTransferable - wether the implementing token contract has a safeTransfer function or not
*/
struct BundleElementERC721 {
address tokenContract;
uint256 id;
bool safeTransferable;
}
/**
* @notice data of a erc20 bundle element
*
* @param tokenContract - address of the token contract
* @param amount - amount of the token
*/
struct BundleElementERC20 {
address tokenContract;
uint256 amount;
}
/**
* @notice data of a erc20 bundle element
*
* @param tokenContract - address of the token contract
* @param ids - list of ids of the tokens
* @param amounts - list amounts of the tokens
*/
struct BundleElementERC1155 {
address tokenContract;
uint256[] ids;
uint256[] amounts;
}
/**
* @notice the lists of erc721-20-1155 tokens that are to be bundled
*
* @param erc721s list of erc721 tokens
* @param erc20s list of erc20 tokens
* @param erc1155s list of erc1155 tokens
*/
struct BundleElements {
BundleElementERC721[] erc721s;
BundleElementERC20[] erc20s;
BundleElementERC1155[] erc1155s;
}
/**
* @notice used by the loan contract to build a bundle from the BundleElements struct at the beginning of a loan,
* returns the id of the created bundle
*
* @param _bundleElements - the lists of erc721-20-1155 tokens that are to be bundled
* @param _sender sender of the tokens in the bundle - the borrower
* @param _receiver receiver of the created bundle, normally the loan contract
*/
function buildBundle(
BundleElements memory _bundleElements,
address _sender,
address _receiver
) external returns (uint256);
/**
* @notice Remove all the children from the bundle
* @dev This method may run out of gas if the list of children is too big. In that case, children can be removed
* individually.
* @param _tokenId the id of the bundle
* @param _receiver address of the receiver of the children
*/
function decomposeBundle(uint256 _tokenId, address _receiver) external;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/cryptography/SignatureChecker.sol)
pragma solidity ^0.8.0;
import "./ECDSA.sol";
import "../Address.sol";
import "../../interfaces/IERC1271.sol";
/**
* @dev Signature verification helper that can be used instead of `ECDSA.recover` to seamlessly support both ECDSA
* signatures from externally owned accounts (EOAs) as well as ERC1271 signatures from smart contract wallets like
* Argent and Gnosis Safe.
*
* _Available since v4.1._
*/
library SignatureChecker {
/**
* @dev Checks if a signature is valid for a given signer and data hash. If the signer is a smart contract, the
* signature is validated against that smart contract using ERC1271, otherwise it's validated using `ECDSA.recover`.
*
* NOTE: Unlike ECDSA signatures, contract signatures are revocable, and the outcome of this function can thus
* change through time. It could return true at block N and false at block N+1 (or the opposite).
*/
function isValidSignatureNow(
address signer,
bytes32 hash,
bytes memory signature
) internal view returns (bool) {
(address recovered, ECDSA.RecoverError error) = ECDSA.tryRecover(hash, signature);
if (error == ECDSA.RecoverError.NoError && recovered == signer) {
return true;
}
(bool success, bytes memory result) = signer.staticcall(
abi.encodeWithSelector(IERC1271.isValidSignature.selector, hash, signature)
);
return (success && result.length == 32 && abi.decode(result, (bytes4)) == IERC1271.isValidSignature.selector);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/cryptography/ECDSA.sol)
pragma solidity ^0.8.0;
import "../Strings.sol";
/**
* @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
*
* These functions can be used to verify that a message was signed by the holder
* of the private keys of a given address.
*/
library ECDSA {
enum RecoverError {
NoError,
InvalidSignature,
InvalidSignatureLength,
InvalidSignatureS,
InvalidSignatureV
}
function _throwError(RecoverError error) private pure {
if (error == RecoverError.NoError) {
return; // no error: do nothing
} else if (error == RecoverError.InvalidSignature) {
revert("ECDSA: invalid signature");
} else if (error == RecoverError.InvalidSignatureLength) {
revert("ECDSA: invalid signature length");
} else if (error == RecoverError.InvalidSignatureS) {
revert("ECDSA: invalid signature 's' value");
} else if (error == RecoverError.InvalidSignatureV) {
revert("ECDSA: invalid signature 'v' value");
}
}
/**
* @dev Returns the address that signed a hashed message (`hash`) with
* `signature` or error string. This address can then be used for verification purposes.
*
* The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
* this function rejects them by requiring the `s` value to be in the lower
* half order, and the `v` value to be either 27 or 28.
*
* IMPORTANT: `hash` _must_ be the result of a hash operation for the
* verification to be secure: it is possible to craft signatures that
* recover to arbitrary addresses for non-hashed data. A safe way to ensure
* this is by receiving a hash of the original message (which may otherwise
* be too long), and then calling {toEthSignedMessageHash} on it.
*
* Documentation for signature generation:
* - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
* - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
*
* _Available since v4.3._
*/
function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError) {
// Check the signature length
// - case 65: r,s,v signature (standard)
// - case 64: r,vs signature (cf https://eips.ethereum.org/EIPS/eip-2098) _Available since v4.1._
if (signature.length == 65) {
bytes32 r;
bytes32 s;
uint8 v;
// ecrecover takes the signature parameters, and the only way to get them
// currently is to use assembly.
assembly {
r := mload(add(signature, 0x20))
s := mload(add(signature, 0x40))
v := byte(0, mload(add(signature, 0x60)))
}
return tryRecover(hash, v, r, s);
} else if (signature.length == 64) {
bytes32 r;
bytes32 vs;
// ecrecover takes the signature parameters, and the only way to get them
// currently is to use assembly.
assembly {
r := mload(add(signature, 0x20))
vs := mload(add(signature, 0x40))
}
return tryRecover(hash, r, vs);
} else {
return (address(0), RecoverError.InvalidSignatureLength);
}
}
/**
* @dev Returns the address that signed a hashed message (`hash`) with
* `signature`. This address can then be used for verification purposes.
*
* The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
* this function rejects them by requiring the `s` value to be in the lower
* half order, and the `v` value to be either 27 or 28.
*
* IMPORTANT: `hash` _must_ be the result of a hash operation for the
* verification to be secure: it is possible to craft signatures that
* recover to arbitrary addresses for non-hashed data. A safe way to ensure
* this is by receiving a hash of the original message (which may otherwise
* be too long), and then calling {toEthSignedMessageHash} on it.
*/
function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
(address recovered, RecoverError error) = tryRecover(hash, signature);
_throwError(error);
return recovered;
}
/**
* @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
*
* See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
*
* _Available since v4.3._
*/
function tryRecover(
bytes32 hash,
bytes32 r,
bytes32 vs
) internal pure returns (address, RecoverError) {
bytes32 s = vs & bytes32(0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
uint8 v = uint8((uint256(vs) >> 255) + 27);
return tryRecover(hash, v, r, s);
}
/**
* @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
*
* _Available since v4.2._
*/
function recover(
bytes32 hash,
bytes32 r,
bytes32 vs
) internal pure returns (address) {
(address recovered, RecoverError error) = tryRecover(hash, r, vs);
_throwError(error);
return recovered;
}
/**
* @dev Overload of {ECDSA-tryRecover} that receives the `v`,
* `r` and `s` signature fields separately.
*
* _Available since v4.3._
*/
function tryRecover(
bytes32 hash,
uint8 v,
bytes32 r,
bytes32 s
) internal pure returns (address, RecoverError) {
// EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
// unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
// the valid range for s in (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): v ∈ {27, 28}. Most
// signatures from current libraries generate a unique signature with an s-value in the lower half order.
//
// If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
// with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
// vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
// these malleable signatures as well.
if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {
return (address(0), RecoverError.InvalidSignatureS);
}
if (v != 27 && v != 28) {
return (address(0), RecoverError.InvalidSignatureV);
}
// If the signature is valid (and not malleable), return the signer address
address signer = ecrecover(hash, v, r, s);
if (signer == address(0)) {
return (address(0), RecoverError.InvalidSignature);
}
return (signer, RecoverError.NoError);
}
/**
* @dev Overload of {ECDSA-recover} that receives the `v`,
* `r` and `s` signature fields separately.
*/
function recover(
bytes32 hash,
uint8 v,
bytes32 r,
bytes32 s
) internal pure returns (address) {
(address recovered, RecoverError error) = tryRecover(hash, v, r, s);
_throwError(error);
return recovered;
}
/**
* @dev Returns an Ethereum Signed Message, created from a `hash`. This
* produces hash corresponding to the one signed with the
* https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
* JSON-RPC method as part of EIP-191.
*
* See {recover}.
*/
function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) {
// 32 is the length in bytes of hash,
// enforced by the type signature above
return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n32", hash));
}
/**
* @dev Returns an Ethereum Signed Message, created from `s`. This
* produces hash corresponding to the one signed with the
* https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
* JSON-RPC method as part of EIP-191.
*
* See {recover}.
*/
function toEthSignedMessageHash(bytes memory s) internal pure returns (bytes32) {
return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n", Strings.toString(s.length), s));
}
/**
* @dev Returns an Ethereum Signed Typed Data, created from a
* `domainSeparator` and a `structHash`. This produces hash corresponding
* to the one signed with the
* https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]
* JSON-RPC method as part of EIP-712.
*
* See {recover}.
*/
function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32) {
return keccak256(abi.encodePacked("\x19\x01", domainSeparator, structHash));
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (interfaces/IERC1271.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC1271 standard signature validation method for
* contracts as defined in https://eips.ethereum.org/EIPS/eip-1271[ERC-1271].
*
* _Available since v4.1._
*/
interface IERC1271 {
/**
* @dev Should return whether the signature provided is valid for the provided data
* @param hash Hash of the data to be signed
* @param signature Signature byte array associated with _data
*/
function isValidSignature(bytes32 hash, bytes memory signature) external view returns (bytes4 magicValue);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)
pragma solidity ^0.8.0;
/**
* @dev String operations.
*/
library Strings {
bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
/**
* @dev Converts a `uint256` to its ASCII `string` decimal representation.
*/
function toString(uint256 value) internal pure returns (string memory) {
// Inspired by OraclizeAPI's implementation - MIT licence
// https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
if (value == 0) {
return "0";
}
uint256 temp = value;
uint256 digits;
while (temp != 0) {
digits++;
temp /= 10;
}
bytes memory buffer = new bytes(digits);
while (value != 0) {
digits -= 1;
buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
value /= 10;
}
return string(buffer);
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
*/
function toHexString(uint256 value) internal pure returns (string memory) {
if (value == 0) {
return "0x00";
}
uint256 temp = value;
uint256 length = 0;
while (temp != 0) {
length++;
temp >>= 8;
}
return toHexString(value, length);
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
*/
function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
bytes memory buffer = new bytes(2 * length + 2);
buffer[0] = "0";
buffer[1] = "x";
for (uint256 i = 2 * length + 1; i > 1; --i) {
buffer[i] = _HEX_SYMBOLS[value & 0xf];
value >>= 4;
}
require(value == 0, "Strings: hex length insufficient");
return string(buffer);
}
}