Contract Name:
NFTfiSigningUtils
Contract Source Code:
// 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 (last updated v4.9.0) (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 // Deprecated in v4.8
}
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");
}
}
/**
* @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) {
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.
/// @solidity memory-safe-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 {
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 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 message) {
// 32 is the length in bytes of hash,
// enforced by the type signature above
/// @solidity memory-safe-assembly
assembly {
mstore(0x00, "\x19Ethereum Signed Message:\n32")
mstore(0x1c, hash)
message := keccak256(0x00, 0x3c)
}
}
/**
* @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 data) {
/// @solidity memory-safe-assembly
assembly {
let ptr := mload(0x40)
mstore(ptr, "\x19\x01")
mstore(add(ptr, 0x02), domainSeparator)
mstore(add(ptr, 0x22), structHash)
data := keccak256(ptr, 0x42)
}
}
/**
* @dev Returns an Ethereum Signed Data with intended validator, created from a
* `validator` and `data` according to the version 0 of EIP-191.
*
* See {recover}.
*/
function toDataWithIntendedValidatorHash(address validator, bytes memory data) internal pure returns (bytes32) {
return keccak256(abi.encodePacked("\x19\x00", validator, data));
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/cryptography/SignatureChecker.sol)
pragma solidity ^0.8.0;
import "./ECDSA.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);
return
(error == ECDSA.RecoverError.NoError && recovered == signer) ||
isValidERC1271SignatureNow(signer, hash, signature);
}
/**
* @dev Checks if a signature is valid for a given signer and data hash. The signature is validated
* against the signer smart contract using ERC1271.
*
* 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 isValidERC1271SignatureNow(
address signer,
bytes32 hash,
bytes memory signature
) internal view returns (bool) {
(bool success, bytes memory result) = signer.staticcall(
abi.encodeWithSelector(IERC1271.isValidSignature.selector, hash, signature)
);
return (success &&
result.length >= 32 &&
abi.decode(result, (bytes32)) == bytes32(IERC1271.isValidSignature.selector));
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/math/Math.sol)
pragma solidity ^0.8.0;
/**
* @dev Standard math utilities missing in the Solidity language.
*/
library Math {
enum Rounding {
Down, // Toward negative infinity
Up, // Toward infinity
Zero // Toward zero
}
/**
* @dev Returns the largest of two numbers.
*/
function max(uint256 a, uint256 b) internal pure returns (uint256) {
return a > b ? a : b;
}
/**
* @dev Returns the smallest of two numbers.
*/
function min(uint256 a, uint256 b) internal pure returns (uint256) {
return a < b ? a : b;
}
/**
* @dev Returns the average of two numbers. The result is rounded towards
* zero.
*/
function average(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b) / 2 can overflow.
return (a & b) + (a ^ b) / 2;
}
/**
* @dev Returns the ceiling of the division of two numbers.
*
* This differs from standard division with `/` in that it rounds up instead
* of rounding down.
*/
function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b - 1) / b can overflow on addition, so we distribute.
return a == 0 ? 0 : (a - 1) / b + 1;
}
/**
* @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
* @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv)
* with further edits by Uniswap Labs also under MIT license.
*/
function mulDiv(uint256 x, uint256 y, uint256 denominator) internal pure returns (uint256 result) {
unchecked {
// 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
// use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
// variables such that product = prod1 * 2^256 + prod0.
uint256 prod0; // Least significant 256 bits of the product
uint256 prod1; // Most significant 256 bits of the product
assembly {
let mm := mulmod(x, y, not(0))
prod0 := mul(x, y)
prod1 := sub(sub(mm, prod0), lt(mm, prod0))
}
// Handle non-overflow cases, 256 by 256 division.
if (prod1 == 0) {
// Solidity will revert if denominator == 0, unlike the div opcode on its own.
// The surrounding unchecked block does not change this fact.
// See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
return prod0 / denominator;
}
// Make sure the result is less than 2^256. Also prevents denominator == 0.
require(denominator > prod1, "Math: mulDiv overflow");
///////////////////////////////////////////////
// 512 by 256 division.
///////////////////////////////////////////////
// Make division exact by subtracting the remainder from [prod1 prod0].
uint256 remainder;
assembly {
// Compute remainder using mulmod.
remainder := mulmod(x, y, denominator)
// Subtract 256 bit number from 512 bit number.
prod1 := sub(prod1, gt(remainder, prod0))
prod0 := sub(prod0, remainder)
}
// Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
// See https://cs.stackexchange.com/q/138556/92363.
// Does not overflow because the denominator cannot be zero at this stage in the function.
uint256 twos = denominator & (~denominator + 1);
assembly {
// Divide denominator by twos.
denominator := div(denominator, twos)
// Divide [prod1 prod0] by twos.
prod0 := div(prod0, twos)
// Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
twos := add(div(sub(0, twos), twos), 1)
}
// Shift in bits from prod1 into prod0.
prod0 |= prod1 * twos;
// Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
// that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
// four bits. That is, denominator * inv = 1 mod 2^4.
uint256 inverse = (3 * denominator) ^ 2;
// Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
// in modular arithmetic, doubling the correct bits in each step.
inverse *= 2 - denominator * inverse; // inverse mod 2^8
inverse *= 2 - denominator * inverse; // inverse mod 2^16
inverse *= 2 - denominator * inverse; // inverse mod 2^32
inverse *= 2 - denominator * inverse; // inverse mod 2^64
inverse *= 2 - denominator * inverse; // inverse mod 2^128
inverse *= 2 - denominator * inverse; // inverse mod 2^256
// Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
// This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
// less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
// is no longer required.
result = prod0 * inverse;
return result;
}
}
/**
* @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
*/
function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) {
uint256 result = mulDiv(x, y, denominator);
if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
result += 1;
}
return result;
}
/**
* @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down.
*
* Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
*/
function sqrt(uint256 a) internal pure returns (uint256) {
if (a == 0) {
return 0;
}
// For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
//
// We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
// `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
//
// This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
// → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
// → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
//
// Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
uint256 result = 1 << (log2(a) >> 1);
// At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
// since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
// every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
// into the expected uint128 result.
unchecked {
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
return min(result, a / result);
}
}
/**
* @notice Calculates sqrt(a), following the selected rounding direction.
*/
function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = sqrt(a);
return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
}
}
/**
* @dev Return the log in base 2, rounded down, of a positive value.
* Returns 0 if given 0.
*/
function log2(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >> 128 > 0) {
value >>= 128;
result += 128;
}
if (value >> 64 > 0) {
value >>= 64;
result += 64;
}
if (value >> 32 > 0) {
value >>= 32;
result += 32;
}
if (value >> 16 > 0) {
value >>= 16;
result += 16;
}
if (value >> 8 > 0) {
value >>= 8;
result += 8;
}
if (value >> 4 > 0) {
value >>= 4;
result += 4;
}
if (value >> 2 > 0) {
value >>= 2;
result += 2;
}
if (value >> 1 > 0) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 2, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log2(value);
return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
}
}
/**
* @dev Return the log in base 10, rounded down, of a positive value.
* Returns 0 if given 0.
*/
function log10(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >= 10 ** 64) {
value /= 10 ** 64;
result += 64;
}
if (value >= 10 ** 32) {
value /= 10 ** 32;
result += 32;
}
if (value >= 10 ** 16) {
value /= 10 ** 16;
result += 16;
}
if (value >= 10 ** 8) {
value /= 10 ** 8;
result += 8;
}
if (value >= 10 ** 4) {
value /= 10 ** 4;
result += 4;
}
if (value >= 10 ** 2) {
value /= 10 ** 2;
result += 2;
}
if (value >= 10 ** 1) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 10, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log10(value);
return result + (rounding == Rounding.Up && 10 ** result < value ? 1 : 0);
}
}
/**
* @dev Return the log in base 256, rounded down, of a positive value.
* Returns 0 if given 0.
*
* Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
*/
function log256(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >> 128 > 0) {
value >>= 128;
result += 16;
}
if (value >> 64 > 0) {
value >>= 64;
result += 8;
}
if (value >> 32 > 0) {
value >>= 32;
result += 4;
}
if (value >> 16 > 0) {
value >>= 16;
result += 2;
}
if (value >> 8 > 0) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 256, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log256(value);
return result + (rounding == Rounding.Up && 1 << (result << 3) < value ? 1 : 0);
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/math/SignedMath.sol)
pragma solidity ^0.8.0;
/**
* @dev Standard signed math utilities missing in the Solidity language.
*/
library SignedMath {
/**
* @dev Returns the largest of two signed numbers.
*/
function max(int256 a, int256 b) internal pure returns (int256) {
return a > b ? a : b;
}
/**
* @dev Returns the smallest of two signed numbers.
*/
function min(int256 a, int256 b) internal pure returns (int256) {
return a < b ? a : b;
}
/**
* @dev Returns the average of two signed numbers without overflow.
* The result is rounded towards zero.
*/
function average(int256 a, int256 b) internal pure returns (int256) {
// Formula from the book "Hacker's Delight"
int256 x = (a & b) + ((a ^ b) >> 1);
return x + (int256(uint256(x) >> 255) & (a ^ b));
}
/**
* @dev Returns the absolute unsigned value of a signed value.
*/
function abs(int256 n) internal pure returns (uint256) {
unchecked {
// must be unchecked in order to support `n = type(int256).min`
return uint256(n >= 0 ? n : -n);
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/Strings.sol)
pragma solidity ^0.8.0;
import "./math/Math.sol";
import "./math/SignedMath.sol";
/**
* @dev String operations.
*/
library Strings {
bytes16 private constant _SYMBOLS = "0123456789abcdef";
uint8 private constant _ADDRESS_LENGTH = 20;
/**
* @dev Converts a `uint256` to its ASCII `string` decimal representation.
*/
function toString(uint256 value) internal pure returns (string memory) {
unchecked {
uint256 length = Math.log10(value) + 1;
string memory buffer = new string(length);
uint256 ptr;
/// @solidity memory-safe-assembly
assembly {
ptr := add(buffer, add(32, length))
}
while (true) {
ptr--;
/// @solidity memory-safe-assembly
assembly {
mstore8(ptr, byte(mod(value, 10), _SYMBOLS))
}
value /= 10;
if (value == 0) break;
}
return buffer;
}
}
/**
* @dev Converts a `int256` to its ASCII `string` decimal representation.
*/
function toString(int256 value) internal pure returns (string memory) {
return string(abi.encodePacked(value < 0 ? "-" : "", toString(SignedMath.abs(value))));
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
*/
function toHexString(uint256 value) internal pure returns (string memory) {
unchecked {
return toHexString(value, Math.log256(value) + 1);
}
}
/**
* @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] = _SYMBOLS[value & 0xf];
value >>= 4;
}
require(value == 0, "Strings: hex length insufficient");
return string(buffer);
}
/**
* @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
*/
function toHexString(address addr) internal pure returns (string memory) {
return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
}
/**
* @dev Returns true if the two strings are equal.
*/
function equal(string memory a, string memory b) internal pure returns (bool) {
return keccak256(bytes(a)) == keccak256(bytes(b));
}
}
// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.19;
/**
* @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)
*
* @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)
*
* @param signer - The address of the signer. The borrower for `acceptOffer`
* @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:
* - 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;
}
/**
* inclusive min and max Id ranges for collection offers on collections,
* like ArtBlocks, where multiple collections are defined on one contract differentiated by id-ranges
*/
struct CollectionIdRange {
uint256 minId;
uint256 maxId;
}
/**
* @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;
}
}
// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.19;
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() internal view returns (uint256) {
uint256 id;
// solhint-disable-next-line no-inline-assembly
assembly {
id := chainid()
}
return id;
}
/**
* @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`
* - 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 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`
* - 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 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 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);
}
}