Add isValidSignature() to pools (#120)

* Add isValidSignature

* Add tests

* Fix lint

* Update scripts

* Update contracts/testing/MockSigner.sol

Co-authored-by: Oleksii Matiiasevych <[email protected]>

---------

Co-authored-by: Oleksii Matiiasevych <[email protected]>

Author: viatrix

contracts/LiquidityPool.sol

@@ -12,6 +12,7 @@ import {IBorrower} from "./interfaces/IBorrower.sol";
 import {IWrappedNativeToken} from "./interfaces/IWrappedNativeToken.sol";
 import {HelperLib} from "./utils/HelperLib.sol";
 import {NATIVE_TOKEN} from "./utils/Constants.sol";
+import {ISigner} from "./interfaces/ISigner.sol";
 
 /// @title Liquidity pool contract holds the liquidity asset and allows solvers to borrow
 /// the asset from the pool and to perform an external function call upon providing the MPC signature.
@@ -23,7 +24,7 @@ import {NATIVE_TOKEN} from "./utils/Constants.sol";
 /// Borrowing can be paused by the WITHDRAW_PROFIT_ROLE before withdrawing the profit.
 /// The contract is pausable by the PAUSER_ROLE.
 /// @author Tanya Bushenyova <[email protected]>
-contract LiquidityPool is ILiquidityPool, AccessControl, EIP712 {
+contract LiquidityPool is ILiquidityPool, AccessControl, EIP712, ISigner {
     using SafeERC20 for IERC20;
     using ECDSA for bytes32;
     using BitMaps for BitMaps.BitMap;
@@ -64,11 +65,15 @@ contract LiquidityPool is ILiquidityPool, AccessControl, EIP712 {
     bool public borrowPaused;
     address public mpcAddress;
 
-    bytes32 public constant LIQUIDITY_ADMIN_ROLE = "LIQUIDITY_ADMIN_ROLE";
-    bytes32 public constant WITHDRAW_PROFIT_ROLE = "WITHDRAW_PROFIT_ROLE";
-    bytes32 public constant PAUSER_ROLE = "PAUSER_ROLE";
+    bytes32 private constant LIQUIDITY_ADMIN_ROLE = "LIQUIDITY_ADMIN_ROLE";
+    bytes32 private constant WITHDRAW_PROFIT_ROLE = "WITHDRAW_PROFIT_ROLE";
+    bytes32 private constant PAUSER_ROLE = "PAUSER_ROLE";
+    // bytes4(keccak256("isValidSignature(bytes32,bytes)")
+    bytes4 constant internal MAGICVALUE = 0x1626ba7e;
     IWrappedNativeToken immutable public WRAPPED_NATIVE_TOKEN;
 
+    address public signerAddress;
+
     error ZeroAddress();
     error InvalidSignature();
     error NotEnoughToDeposit();
@@ -91,6 +96,7 @@ contract LiquidityPool is ILiquidityPool, AccessControl, EIP712 {
     event BorrowPaused();
     event BorrowUnpaused();
     event MPCAddressSet(address oldMPCAddress, address newMPCAddress);
+    event SignerAddressSet(address oldSignerAddress, address newSignerAddress);
     event Paused(address account);
     event Unpaused(address account);
 
@@ -113,7 +119,8 @@ contract LiquidityPool is ILiquidityPool, AccessControl, EIP712 {
         address liquidityToken,
         address admin,
         address mpcAddress_,
-        address wrappedNativeToken
+        address wrappedNativeToken,
+        address signerAddress_
     ) EIP712("LiquidityPool", "1.0.0") {
         require(liquidityToken != address(0), ZeroAddress());
         ASSETS = IERC20(liquidityToken);
@@ -122,6 +129,8 @@ contract LiquidityPool is ILiquidityPool, AccessControl, EIP712 {
         require(mpcAddress_ != address(0), ZeroAddress());
         mpcAddress = mpcAddress_;
         WRAPPED_NATIVE_TOKEN = IWrappedNativeToken(wrappedNativeToken);
+        require(signerAddress_ != address(0), ZeroAddress());
+        signerAddress = signerAddress_;
     }
 
     receive() external payable {
@@ -309,6 +318,12 @@ contract LiquidityPool is ILiquidityPool, AccessControl, EIP712 {
         emit MPCAddressSet(oldMPCAddress, mpcAddress_);
     }
 
+    function setSignerAddress(address signerAddress_) external onlyRole(DEFAULT_ADMIN_ROLE) {
+        address oldSignerAddress = signerAddress;
+        signerAddress = signerAddress_;
+        emit SignerAddressSet(oldSignerAddress, signerAddress_);
+    }
+
     function pauseBorrow() external override onlyRole(WITHDRAW_PROFIT_ROLE) {
         borrowPaused = true;
         emit BorrowPaused();
@@ -530,4 +545,15 @@ contract LiquidityPool is ILiquidityPool, AccessControl, EIP712 {
     function notPassed(uint256 timestamp) internal view returns (bool) {
         return !passed(timestamp);
     }
+
+    function isValidSignature(bytes32 hash, bytes memory signature) external view returns (bytes4 magicValue) {
+        if (signerAddress.code.length == 0) {
+            // EOA
+            address signerAddressRecovered = ECDSA.recover(hash, signature);
+            if (signerAddressRecovered == signerAddress) return MAGICVALUE;
+            else return 0xffffffff;
+        }
+        // Contract
+        return ISigner(signerAddress).isValidSignature(hash, signature);
+    }
 }

contracts/LiquidityPoolAave.sol

@@ -10,6 +10,7 @@ import {IAavePool, AaveDataTypes, NO_REFERRAL, INTEREST_RATE_MODE_VARIABLE} from
 import {IAaveOracle} from "./interfaces/IAaveOracle.sol";
 import {IAavePoolDataProvider} from "./interfaces/IAavePoolDataProvider.sol";
 import {LiquidityPool} from "./LiquidityPool.sol";
+import {HelperLib} from "./utils/HelperLib.sol";
 
 /// @title A version of the liquidity pool contract that uses Aave pool.
 /// Deposits of the liquidity token are supplied to Aave as collateral.
@@ -58,8 +59,9 @@ contract LiquidityPoolAave is LiquidityPool {
         address mpcAddress_,
         uint32 minHealthFactor_,
         uint32 defaultLTV_,
-        address wrappedNativeToken
-    ) LiquidityPool(liquidityToken, admin, mpcAddress_, wrappedNativeToken) {
+        address wrappedNativeToken,
+        address signerAddress_
+    ) LiquidityPool(liquidityToken, admin, mpcAddress_, wrappedNativeToken, signerAddress_) {
         ASSETS_DECIMALS = IERC20Metadata(liquidityToken).decimals();
         require(aavePoolProvider != address(0), ZeroAddress());
         IAavePoolAddressesProvider provider = IAavePoolAddressesProvider(aavePoolProvider);
@@ -90,8 +92,8 @@ contract LiquidityPoolAave is LiquidityPool {
         address[] calldata tokens,
         uint32[] calldata ltvs
     ) external onlyRole(DEFAULT_ADMIN_ROLE) {
-        require(tokens.length == ltvs.length, InvalidLength());
-        for (uint256 i = 0; i < tokens.length; ++i) {
+        uint256 length = HelperLib.validatePositiveLength(tokens.length, ltvs.length);
+        for (uint256 i = 0; i < length; ++i) {
             address token = tokens[i];
             uint256 ltv = ltvs[i];
             uint256 oldLTV = borrowTokenLTV[token];

contracts/LiquidityPoolAaveLongTerm.sol

@@ -3,16 +3,16 @@ pragma solidity 0.8.28;
 
 import {IERC20} from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
 import {LiquidityPoolAave} from "./LiquidityPoolAave.sol";
-import {AaveDataTypes} from "./interfaces/IAavePool.sol";
 import {ILiquidityPoolLongTerm} from "./interfaces/ILiquidityPoolLongTerm.sol";
+import {HelperLib} from "./utils/HelperLib.sol";
 
 /// @title Same as LiquidityPoolAave, but when borrowing the contract will first try to fulfill
 /// the request with own funds, in which case health factor and ltv are not checked.
 /// If there are not enough funds, the contract will borrow from Aave.
 /// @author Oleksii Matiiasevych <[email protected]>
 contract LiquidityPoolAaveLongTerm is LiquidityPoolAave, ILiquidityPoolLongTerm {
-    bytes32 constant public REPAYER_ROLE = "REPAYER_ROLE";
-    bytes32 constant public BORROW_LONG_TERM_ROLE = "BORROW_LONG_TERM_ROLE";
+    bytes32 private constant REPAYER_ROLE = "REPAYER_ROLE";
+    bytes32 private constant BORROW_LONG_TERM_ROLE = "BORROW_LONG_TERM_ROLE";
 
     error CollateralLongTermBorrowNotAllowed();
 
@@ -25,15 +25,17 @@ contract LiquidityPoolAaveLongTerm is LiquidityPoolAave, ILiquidityPoolLongTerm
         address mpcAddress_,
         uint32 minHealthFactor_,
         uint32 defaultLTV_,
-        address wrappedNativeToken
+        address wrappedNativeToken,
+        address signerAddress_
     ) LiquidityPoolAave(
         liquidityToken,
         aavePoolProvider,
         admin,
         mpcAddress_,
         minHealthFactor_,
         defaultLTV_,
-        wrappedNativeToken
+        wrappedNativeToken,
+        signerAddress_
     ) {}
 
     function _repayAccessCheck() internal view override onlyRole(REPAYER_ROLE) {
@@ -44,9 +46,9 @@ contract LiquidityPoolAaveLongTerm is LiquidityPoolAave, ILiquidityPoolLongTerm
     /// @notice Could be used to increase health factor without full repayment.
     function repayPartial(address[] calldata borrowTokens, uint256[] calldata amounts) external override {
         _repayAccessCheck();
-        require(borrowTokens.length == amounts.length, InvalidLength());
+        uint256 length = HelperLib.validatePositiveLength(borrowTokens.length, amounts.length);
         bool success;
-        for (uint256 i = 0; i < borrowTokens.length; i++) {
+        for (uint256 i = 0; i < length; i++) {
             success = _repay(borrowTokens[i], amounts[i]) || success;
         }
         require(success, NothingToRepay());
@@ -113,9 +115,9 @@ contract LiquidityPoolAaveLongTerm is LiquidityPoolAave, ILiquidityPoolLongTerm
             }
         }
         // If there is debt, subtract it from profit
-        AaveDataTypes.ReserveData memory tokenData = AAVE_POOL.getReserveData(address(token));
-        if (tokenData.variableDebtTokenAddress != address(0)) {
-            uint256 debt = IERC20(tokenData.variableDebtTokenAddress).balanceOf(address(this));
+        address variableDebtTokenAddress = AAVE_POOL.getReserveData(address(token)).variableDebtTokenAddress;
+        if (variableDebtTokenAddress != address(0)) {
+            uint256 debt = IERC20(variableDebtTokenAddress).balanceOf(address(this));
             if (totalBalance > debt) {
                 totalBalance -= debt;
             } else {

contracts/LiquidityPoolStablecoin.sol

@@ -18,9 +18,9 @@ contract LiquidityPoolStablecoin is LiquidityPool {
         address liquidityToken,
         address admin,
         address mpcAddress_,
-        address wrappedNativeToken
-    ) LiquidityPool(liquidityToken, admin, mpcAddress_, wrappedNativeToken) {
-        return;
+        address wrappedNativeToken,
+        address signerAddress_
+    ) LiquidityPool(liquidityToken, admin, mpcAddress_, wrappedNativeToken, signerAddress_) {
     }
 
     function _borrowLogic(address /*borrowToken*/, uint256 /*amount*/, bytes memory context)

contracts/echidna/EchidnaLiquidityPool.sol

@@ -16,9 +16,17 @@ contract EchidnaLiquidityPool {
         liquidityToken = new TestUSDC();
         liquidityToken.mint(address(this), 1e18);
 
-        pool = new LiquidityPool(address(liquidityToken), address(this), address(this), address(new TestWETH()));
-        pool.grantRole(pool.LIQUIDITY_ADMIN_ROLE(), address(this));
-        pool.grantRole(pool.WITHDRAW_PROFIT_ROLE(), address(this));
+        pool = new LiquidityPool(
+            address(liquidityToken),
+            address(this),
+            address(this),
+            address(new TestWETH()),
+            address(this)
+        );
+        bytes32 liquidityAdminRole = "LIQUIDITY_ADMIN_ROLE";
+        bytes32 withdrawProfitRole = "WITHDRAW_PROFIT_ROLE";
+        pool.grantRole(liquidityAdminRole, address(this));
+        pool.grantRole(withdrawProfitRole, address(this));
     }
 
     function deposit(uint256 amountDeposit) public {

contracts/interfaces/ISigner.sol

@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: LGPL-3.0-only
+pragma solidity 0.8.28;
+
+interface ISigner {
+    function isValidSignature(bytes32 hash, bytes memory signature) external view returns (bytes4 magicValue);
+}

contracts/testing/MockSigner.sol

@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: LGPL-3.0-only
+pragma solidity 0.8.28;
+
+import {ISigner} from "../interfaces/ISigner.sol";
+
+contract MockSignerTrue is ISigner{
+    // bytes4(keccak256("isValidSignature(bytes32,bytes)")
+    bytes4 constant internal MAGICVALUE = 0x1626ba7e;
+
+    function isValidSignature(bytes32, bytes calldata) external pure override returns (bytes4) {
+        return MAGICVALUE;
+    }
+}
+
+contract MockSignerFalse is ISigner {
+    function isValidSignature(bytes32, bytes calldata) external pure override returns (bytes4) {
+        return 0xffffffff;
+    }
+}