c4-017 BorrowOffers do not have a maxDueDate

src/SizeStorage.sol

@@ -6,7 +6,7 @@ import {IERC20Metadata} from "@openzeppelin/contracts/token/ERC20/extensions/IER
 import {IWETH} from "@src/interfaces/IWETH.sol";
 
 import {CreditPosition, DebtPosition} from "@src/libraries/LoanLibrary.sol";
-import {BorrowOffer, LoanOffer} from "@src/libraries/OfferLibrary.sol";
+import {LimitOrder} from "@src/libraries/OfferLibrary.sol";
 
 import {IPriceFeed} from "@src/oracle/IPriceFeed.sol";
 
@@ -15,9 +15,9 @@ import {NonTransferrableToken} from "@src/token/NonTransferrableToken.sol";
 
 struct User {
     // The user's loan offer
-    LoanOffer loanOffer;
+    LimitOrder loanOffer;
     // The user's borrow offer
-    BorrowOffer borrowOffer;
+    LimitOrder borrowOffer;
     // The user-defined opening limit CR. If not set, the protocol's crOpening is used.
     uint256 openingLimitBorrowCR;
     // Whether the user has disabled all credit positions for sale

src/SizeView.sol

@@ -22,7 +22,7 @@ import {DataView, UserView} from "@src/SizeViewData.sol";
 
 import {ISizeView} from "@src/interfaces/ISizeView.sol";
 import {Errors} from "@src/libraries/Errors.sol";
-import {BorrowOffer, LoanOffer, OfferLibrary} from "@src/libraries/OfferLibrary.sol";
+import {LimitOrder, OfferLibrary} from "@src/libraries/OfferLibrary.sol";
 import {
     InitializeDataParams,
     InitializeFeeConfigParams,
@@ -35,8 +35,7 @@ import {
 /// @author Size (https://size.credit/)
 /// @notice View methods for the Size protocol
 abstract contract SizeView is SizeStorage, ISizeView {
-    using OfferLibrary for LoanOffer;
-    using OfferLibrary for BorrowOffer;
+    using OfferLibrary for LimitOrder;
     using LoanLibrary for DebtPosition;
     using LoanLibrary for CreditPosition;
     using LoanLibrary for State;
@@ -139,7 +138,7 @@ abstract contract SizeView is SizeStorage, ISizeView {
 
     /// @inheritdoc ISizeView
     function getBorrowOfferAPR(address borrower, uint256 tenor) external view returns (uint256) {
-        BorrowOffer memory offer = state.data.users[borrower].borrowOffer;
+        LimitOrder memory offer = state.data.users[borrower].borrowOffer;
         if (offer.isNull()) {
             revert Errors.NULL_OFFER();
         }
@@ -155,7 +154,7 @@ abstract contract SizeView is SizeStorage, ISizeView {
 
     /// @inheritdoc ISizeView
     function getLoanOfferAPR(address lender, uint256 tenor) external view returns (uint256) {
-        LoanOffer memory offer = state.data.users[lender].loanOffer;
+        LimitOrder memory offer = state.data.users[lender].loanOffer;
         if (offer.isNull()) {
             revert Errors.NULL_OFFER();
         }

src/libraries/Events.sol

@@ -31,6 +31,7 @@ library Events {
         bool exactAmountIn
     );
     event SellCreditLimit(
+        uint256 indexed maxDueDate,
         uint256[] curveRelativeTimeTenors,
         int256[] curveRelativeTimeAprs,
         uint256[] curveRelativeTimeMarketRateMultipliers

src/libraries/OfferLibrary.sol

@@ -5,75 +5,51 @@ import {Errors} from "@src/libraries/Errors.sol";
 import {Math} from "@src/libraries/Math.sol";
 import {VariablePoolBorrowRateParams, YieldCurve, YieldCurveLibrary} from "@src/libraries/YieldCurveLibrary.sol";
 
-struct LoanOffer {
-    // The maximum due date of the loan offer
-    // Since the yield curve is defined in relative terms, lenders can protect themselves by
+struct LimitOrder {
+    // The maximum due date of the limit order
+    // Since the yield curve is defined in relative terms, users can protect themselves by
     //   setting a maximum timestamp for a loan to be matched
     uint256 maxDueDate;
     // The yield curve in relative terms
     YieldCurve curveRelativeTime;
 }
 
-struct BorrowOffer {
-    // The yield curve in relative terms
-    // Borrowers can protect themselves by setting an opening limit CR for a loan to be matched
-    YieldCurve curveRelativeTime;
-}
-
 /// @title OfferLibrary
 /// @custom:security-contact [email protected]
 /// @author Size (https://size.credit/)
 library OfferLibrary {
     using YieldCurveLibrary for YieldCurve;
 
-    /// @notice Check if the loan offer is null
-    /// @param self The loan offer
-    /// @return True if the loan offer is null, false otherwise
-    function isNull(LoanOffer memory self) internal pure returns (bool) {
+    /// @notice Check if the limit order is null
+    /// @param self The limit order
+    /// @return True if the limit order is null, false otherwise
+    function isNull(LimitOrder memory self) internal pure returns (bool) {
         return self.maxDueDate == 0 && self.curveRelativeTime.isNull();
     }
 
-    /// @notice Check if the borrow offer is null
-    /// @param self The borrow offer
-    /// @return True if the borrow offer is null, false otherwise
-    function isNull(BorrowOffer memory self) internal pure returns (bool) {
-        return self.curveRelativeTime.isNull();
-    }
+    /// @notice Validate the limit order
+    /// @param self The limit order
+    /// @param minTenor The minimum tenor
+    /// @param maxTenor The maximum tenor
+    function validateLimitOrder(LimitOrder memory self, uint256 minTenor, uint256 maxTenor) internal view {
+        // validate maxDueDate
+        if (self.maxDueDate == 0) {
+            revert Errors.NULL_MAX_DUE_DATE();
+        }
+        if (self.maxDueDate < block.timestamp + minTenor) {
+            revert Errors.PAST_MAX_DUE_DATE(self.maxDueDate);
+        }
 
-    /// @notice Get the APR by tenor of a loan offer
-    /// @param self The loan offer
-    /// @param params The variable pool borrow rate params
-    /// @param tenor The tenor
-    /// @return The APR
-    function getAPRByTenor(LoanOffer memory self, VariablePoolBorrowRateParams memory params, uint256 tenor)
-        internal
-        view
-        returns (uint256)
-    {
-        if (tenor == 0) revert Errors.NULL_TENOR();
-        return YieldCurveLibrary.getAPR(self.curveRelativeTime, params, tenor);
-    }
-
-    /// @notice Get the absolute rate per tenor of a loan offer
-    /// @param self The loan offer
-    /// @param params The variable pool borrow rate params
-    /// @param tenor The tenor
-    /// @return The absolute rate
-    function getRatePerTenor(LoanOffer memory self, VariablePoolBorrowRateParams memory params, uint256 tenor)
-        internal
-        view
-        returns (uint256)
-    {
-        uint256 apr = getAPRByTenor(self, params, tenor);
-        return Math.aprToRatePerTenor(apr, tenor);
+        // validate curveRelativeTime
+        YieldCurveLibrary.validateYieldCurve(self.curveRelativeTime, minTenor, maxTenor);
     }
 
-    /// @notice Get the APR by tenor of a borrow offer
-    /// @param self The borrow offer
+    /// @notice Get the APR by tenor of a limit order
+    /// @param self The limit order
     /// @param params The variable pool borrow rate params
     /// @param tenor The tenor
     /// @return The APR
-    function getAPRByTenor(BorrowOffer memory self, VariablePoolBorrowRateParams memory params, uint256 tenor)
+    function getAPRByTenor(LimitOrder memory self, VariablePoolBorrowRateParams memory params, uint256 tenor)
         internal
         view
         returns (uint256)
@@ -82,12 +58,12 @@ library OfferLibrary {
         return YieldCurveLibrary.getAPR(self.curveRelativeTime, params, tenor);
     }
 
-    /// @notice Get the absolute rate per tenor of a borrow offer
-    /// @param self The borrow offer
+    /// @notice Get the absolute rate per tenor of a limit order
+    /// @param self The limit order
     /// @param params The variable pool borrow rate params
     /// @param tenor The tenor
     /// @return The absolute rate
-    function getRatePerTenor(BorrowOffer memory self, VariablePoolBorrowRateParams memory params, uint256 tenor)
+    function getRatePerTenor(LimitOrder memory self, VariablePoolBorrowRateParams memory params, uint256 tenor)
         internal
         view
         returns (uint256)

src/libraries/actions/BuyCreditLimit.sol

@@ -1,12 +1,11 @@
 // SPDX-License-Identifier: MIT
 pragma solidity 0.8.23;
 
-import {LoanOffer, OfferLibrary} from "@src/libraries/OfferLibrary.sol";
-import {YieldCurve, YieldCurveLibrary} from "@src/libraries/YieldCurveLibrary.sol";
+import {LimitOrder, OfferLibrary} from "@src/libraries/OfferLibrary.sol";
+import {YieldCurve} from "@src/libraries/YieldCurveLibrary.sol";
 
 import {State} from "@src/SizeStorage.sol";
 
-import {Errors} from "@src/libraries/Errors.sol";
 import {Events} from "@src/libraries/Events.sol";
 
 struct BuyCreditLimitParams {
@@ -21,32 +20,22 @@ struct BuyCreditLimitParams {
 /// @author Size (https://size.credit/)
 /// @notice Contains the logic for buying credit (lending) as a limit order
 library BuyCreditLimit {
-    using OfferLibrary for LoanOffer;
+    using OfferLibrary for LimitOrder;
 
     /// @notice Validates the input parameters for buying credit as a limit order
     /// @param state The state
     /// @param params The input parameters for buying credit as a limit order
     function validateBuyCreditLimit(State storage state, BuyCreditLimitParams calldata params) external view {
-        LoanOffer memory loanOffer =
-            LoanOffer({maxDueDate: params.maxDueDate, curveRelativeTime: params.curveRelativeTime});
+        LimitOrder memory loanOffer =
+            LimitOrder({maxDueDate: params.maxDueDate, curveRelativeTime: params.curveRelativeTime});
 
         // a null offer mean clearing their limit order
         if (!loanOffer.isNull()) {
             // validate msg.sender
             // N/A
 
-            // validate maxDueDate
-            if (params.maxDueDate == 0) {
-                revert Errors.NULL_MAX_DUE_DATE();
-            }
-            if (params.maxDueDate < block.timestamp + state.riskConfig.minTenor) {
-                revert Errors.PAST_MAX_DUE_DATE(params.maxDueDate);
-            }
-
-            // validate curveRelativeTime
-            YieldCurveLibrary.validateYieldCurve(
-                params.curveRelativeTime, state.riskConfig.minTenor, state.riskConfig.maxTenor
-            );
+            // validate loanOffer
+            loanOffer.validateLimitOrder(state.riskConfig.minTenor, state.riskConfig.maxTenor);
         }
     }
 
@@ -56,7 +45,7 @@ library BuyCreditLimit {
     /// @dev A null offer means clearing a user's loan limit order
     function executeBuyCreditLimit(State storage state, BuyCreditLimitParams calldata params) external {
         state.data.users[msg.sender].loanOffer =
-            LoanOffer({maxDueDate: params.maxDueDate, curveRelativeTime: params.curveRelativeTime});
+            LimitOrder({maxDueDate: params.maxDueDate, curveRelativeTime: params.curveRelativeTime});
         emit Events.BuyCreditLimit(
             params.maxDueDate,
             params.curveRelativeTime.tenors,

src/libraries/actions/BuyCreditMarket.sol

@@ -8,7 +8,7 @@ import {Errors} from "@src/libraries/Errors.sol";
 import {Events} from "@src/libraries/Events.sol";
 import {CreditPosition, DebtPosition, LoanLibrary, RESERVED_ID} from "@src/libraries/LoanLibrary.sol";
 import {Math, PERCENT} from "@src/libraries/Math.sol";
-import {BorrowOffer, OfferLibrary} from "@src/libraries/OfferLibrary.sol";
+import {LimitOrder, OfferLibrary} from "@src/libraries/OfferLibrary.sol";
 
 import {RiskLibrary} from "@src/libraries/RiskLibrary.sol";
 import {VariablePoolBorrowRateParams} from "@src/libraries/YieldCurveLibrary.sol";
@@ -38,7 +38,7 @@ struct BuyCreditMarketParams {
 /// @author Size (https://size.credit/)
 /// @notice Contains the logic for buying credit (lending) as a market order
 library BuyCreditMarket {
-    using OfferLibrary for BorrowOffer;
+    using OfferLibrary for LimitOrder;
     using AccountingLibrary for State;
     using LoanLibrary for State;
     using LoanLibrary for DebtPosition;
@@ -80,7 +80,7 @@ library BuyCreditMarket {
             tenor = debtPosition.dueDate - block.timestamp; // positive since the credit position is transferrable, so the loan must be ACTIVE
         }
 
-        BorrowOffer memory borrowOffer = state.data.users[borrower].borrowOffer;
+        LimitOrder memory borrowOffer = state.data.users[borrower].borrowOffer;
 
         // validate borrower
         if (borrowOffer.isNull()) {
@@ -92,6 +92,11 @@ library BuyCreditMarket {
             revert Errors.CREDIT_LOWER_THAN_MINIMUM_CREDIT(params.amount, state.riskConfig.minimumCreditBorrowAToken);
         }
 
+        // validate tenor
+        if (block.timestamp + tenor > borrowOffer.maxDueDate) {
+            revert Errors.DUE_DATE_GREATER_THAN_MAX_DUE_DATE(block.timestamp + tenor, borrowOffer.maxDueDate);
+        }
+
         // validate deadline
         if (params.deadline < block.timestamp) {
             revert Errors.PAST_DEADLINE(params.deadline);

src/libraries/actions/LiquidateWithReplacement.sol

@@ -6,7 +6,7 @@ import {Math} from "@src/libraries/Math.sol";
 import {PERCENT} from "@src/libraries/Math.sol";
 
 import {CreditPosition, DebtPosition, LoanLibrary, LoanStatus} from "@src/libraries/LoanLibrary.sol";
-import {BorrowOffer, OfferLibrary} from "@src/libraries/OfferLibrary.sol";
+import {LimitOrder, OfferLibrary} from "@src/libraries/OfferLibrary.sol";
 import {VariablePoolBorrowRateParams} from "@src/libraries/YieldCurveLibrary.sol";
 
 import {State} from "@src/SizeStorage.sol";
@@ -35,7 +35,7 @@ struct LiquidateWithReplacementParams {
 /// @notice Contains the logic for liquidating a debt position with a replacement borrower
 library LiquidateWithReplacement {
     using LoanLibrary for CreditPosition;
-    using OfferLibrary for BorrowOffer;
+    using OfferLibrary for LimitOrder;
 
     using LoanLibrary for State;
     using Liquidate for State;
@@ -49,7 +49,7 @@ library LiquidateWithReplacement {
         view
     {
         DebtPosition storage debtPosition = state.getDebtPosition(params.debtPositionId);
-        BorrowOffer storage borrowOffer = state.data.users[params.borrower].borrowOffer;
+        LimitOrder storage borrowOffer = state.data.users[params.borrower].borrowOffer;
 
         // validate liquidate
         state.validateLiquidate(
@@ -59,6 +59,11 @@ library LiquidateWithReplacement {
             })
         );
 
+        // validate borrower
+        if (borrowOffer.isNull()) {
+            revert Errors.INVALID_BORROW_OFFER(params.borrower);
+        }
+
         // validate debtPositionId
         if (state.getLoanStatus(params.debtPositionId) != LoanStatus.ACTIVE) {
             revert Errors.LOAN_NOT_ACTIVE(params.debtPositionId);
@@ -67,10 +72,8 @@ library LiquidateWithReplacement {
         if (tenor < state.riskConfig.minTenor || tenor > state.riskConfig.maxTenor) {
             revert Errors.TENOR_OUT_OF_RANGE(tenor, state.riskConfig.minTenor, state.riskConfig.maxTenor);
         }
-
-        // validate borrower
-        if (borrowOffer.isNull()) {
-            revert Errors.INVALID_BORROW_OFFER(params.borrower);
+        if (block.timestamp + tenor > borrowOffer.maxDueDate) {
+            revert Errors.DUE_DATE_GREATER_THAN_MAX_DUE_DATE(block.timestamp + tenor, borrowOffer.maxDueDate);
         }
 
         // validate deadline
@@ -125,7 +128,7 @@ library LiquidateWithReplacement {
 
         DebtPosition storage debtPosition = state.getDebtPosition(params.debtPositionId);
         DebtPosition memory debtPositionCopy = debtPosition;
-        BorrowOffer storage borrowOffer = state.data.users[params.borrower].borrowOffer;
+        LimitOrder storage borrowOffer = state.data.users[params.borrower].borrowOffer;
         uint256 tenor = debtPositionCopy.dueDate - block.timestamp;
 
         liquidatorProfitCollateralToken = state.executeLiquidate(