Feat: Origination Controller STIRFRY (Set Term Interest Rate Fixed Rate Yield)

contracts/errors/Lending.sol

@@ -276,6 +276,25 @@ error OCM_CollateralMismatch(
  */
 error OCM_LenderIsBorrower();
 
+// ============================ ORIGINATION CONTROLLER INTEREST RATE SWAP ===============================
+/// @notice All errors prefixed with OCIRS_, to separate from other contracts in the protocol.
+
+/**
+ * @notice Zero address passed in where not allowed.
+ *
+ * @param addressType               The name of the parameter for which a zero address was provided.
+ */
+error OCIRS_ZeroAddress(string addressType);
+
+/**
+ * @notice The loan terms payable currency and vaulted currency are not whitelisted as a valid
+ *         currency pair for interest rate swaps.
+ *
+ * @param payableCurrency             The currency of the loan terms.
+ * @param vaultedCurrency             The currency of the vaulted collateral.
+ */
+error OCIRS_InvalidPair(address payableCurrency, address vaultedCurrency);
+
 // ================================== CROSS CURRENCY ROLLOVER ====================================
 /// @notice All errors prefixed with CCR_, to separate from other contracts in the protocol.
 

contracts/interfaces/IOriginationController.sol

@@ -17,7 +17,7 @@ interface IOriginationController is IOriginationControllerBase {
     // ============= Loan Origination =============
 
     function initializeLoan(
-       LoanLibrary.LoanTerms calldata loanTerms,
+        LoanLibrary.LoanTerms calldata loanTerms,
         BorrowerData calldata borrowerData,
         address lender,
         Signature calldata sig,

contracts/interfaces/IOriginationControllerInterestRateSwap.sol

@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity 0.8.18;
+
+import "./IOriginationControllerBase.sol";
+
+import "../libraries/LoanLibrary.sol";
+
+interface IOriginationControllerInterestRateSwap is IOriginationControllerBase {
+
+    // ============= Data Types =============
+
+    struct SwapData {
+        address vaultedCurrency;
+        uint256 payableToVaultedCurrencyRatio;
+    }
+
+    // ============= Loan Origination =============
+
+    function initializeSwap(
+        LoanLibrary.LoanTerms calldata loanTerms,
+        SwapData calldata swapData,
+        address borrower,
+        address lender,
+        Signature calldata sig,
+        SigProperties calldata sigProperties
+    ) external returns (uint256 loanId, uint256 bundleId);
+
+    // ============= Signature Verification =============
+
+    function recoverInterestRateSwapSignature(
+        LoanLibrary.LoanTerms calldata loanTerms,
+        Signature calldata sig,
+        SigProperties calldata sigProperties,
+        address vaultedCurrency,
+        Side side,
+        address signingCounterparty
+    ) external view returns (bytes32 sighash, address signer);
+}

contracts/libraries/OriginationLibrary.sol

@@ -2,9 +2,6 @@
 
 pragma solidity 0.8.18;
 
-import "@openzeppelin/contracts/utils/cryptography/draft-EIP712.sol";
-import "@openzeppelin/contracts/interfaces/IERC1271.sol";
-
 import "../libraries/LoanLibrary.sol";
 
 import "../interfaces/IOriginationController.sol";
@@ -13,7 +10,9 @@ import "../interfaces/IOriginationController.sol";
  * @title OriginationLibrary
  * @author Non-Fungible Technologies, Inc.
  *
- * Library for loan origination functions.
+ * This library is a collection of shared logic used across various origination controller contracts.
+ * It includes constants for EIP712 type hashes, the functions for encoding these type hashes, and
+ * various data structures shared by the origination controller contracts.
  */
 library OriginationLibrary {
     // ======================================= STRUCTS ================================================
@@ -42,21 +41,26 @@ library OriginationLibrary {
     }
 
     // ======================================= CONSTANTS ==============================================
+    // solhint-disable max-line-length
 
     /// @notice EIP712 type hash for bundle-based signatures.
     bytes32 public constant _TOKEN_ID_TYPEHASH =
         keccak256(
-            // solhint-disable-next-line max-line-length
             "LoanTerms(uint32 interestRate,uint64 durationSecs,address collateralAddress,uint96 deadline,address payableCurrency,uint256 principal,uint256 collateralId,bytes32 affiliateCode,SigProperties sigProperties,uint8 side,address signingCounterparty)SigProperties(uint160 nonce,uint96 maxUses)"
         );
 
     /// @notice EIP712 type hash for item-based signatures.
     bytes32 public constant _ITEMS_TYPEHASH =
         keccak256(
-            // solhint-disable max-line-length
             "LoanTermsWithItems(uint32 interestRate,uint64 durationSecs,address collateralAddress,uint96 deadline,address payableCurrency,uint256 principal,bytes32 affiliateCode,Predicate[] items,SigProperties sigProperties,uint8 side,address signingCounterparty)Predicate(bytes data,address verifier)SigProperties(uint160 nonce,uint96 maxUses)"
         );
 
+    /// @notice EIP712 type hash for interest rate swap signatures.
+    bytes32 public constant _INTEREST_RATE_SWAP_TYPEHASH =
+        keccak256(
+            "LoanTermsWithCurrencyPair(uint32 interestRate,uint64 durationSecs,address vaultedCurrency,address collateralAddress,uint96 deadline,address payableCurrency,uint256 principal,uint256 collateralId,bytes32 affiliateCode,SigProperties sigProperties,uint8 side,address signingCounterparty)SigProperties(uint160 nonce,uint96 maxUses)"
+        );
+
     /// @notice EIP712 type hash for Predicate.
     bytes32 public constant _PREDICATE_TYPEHASH =
         keccak256(
@@ -192,33 +196,41 @@ library OriginationLibrary {
         );
     }
 
-    // ==================================== PERMISSION MANAGEMENT =====================================
 
     /**
-     * @notice Reports whether the signer matches the target or is approved by the target.
+     * @notice Hashes a loan with interest rate swap for inclusion in the EIP712 signature.
      *
-     * @param target                        The grantor of permission - should be a smart contract.
-     * @param sig                           A struct containing the signature data (for checking EIP-1271).
-     * @param sighash                       The hash of the signature payload (used for EIP-1271 check).
+     * @param terms                         The loan terms.
+     * @param sigProperties                 The signature properties.
+     * @param vaultedCurrency               The currency to be vaulted.
+     * @param side                          The side of the signature.
+     * @param signingCounterparty           The address of the signing counterparty.
      *
-     * @return bool                         Whether the signer is either the grantor themselves, or approved.
+     * @return loanHash                     The hash of the loan.
      */
-    function isApprovedForContract(
-        address target,
-        IOriginationController.Signature memory sig,
-        bytes32 sighash
-    ) public view returns (bool) {
-        bytes memory signature = abi.encodePacked(sig.r, sig.s, sig.v);
-
-        // Append extra data if it exists
-        if (sig.extraData.length > 0) {
-            signature = bytes.concat(signature, sig.extraData);
-        }
-
-        // Convert sig struct to bytes
-        (bool success, bytes memory result) = target.staticcall(
-            abi.encodeWithSelector(IERC1271.isValidSignature.selector, sighash, signature)
+    function encodeLoanWithInterestRateSwap(
+        LoanLibrary.LoanTerms calldata terms,
+        IOriginationController.SigProperties calldata sigProperties,
+        address vaultedCurrency,
+        uint8 side,
+        address signingCounterparty
+    ) public pure returns (bytes32 loanHash) {
+        loanHash = keccak256(
+            abi.encode(
+                _INTEREST_RATE_SWAP_TYPEHASH,
+                terms.interestRate,
+                terms.durationSecs,
+                vaultedCurrency,
+                terms.collateralAddress,
+                terms.deadline,
+                terms.payableCurrency,
+                terms.principal,
+                terms.collateralId,
+                terms.affiliateCode,
+                encodeSigProperties(sigProperties),
+                uint8(side),
+                signingCounterparty
+            )
         );
-        return (success && result.length == 32 && abi.decode(result, (bytes32)) == bytes32(IERC1271.isValidSignature.selector));
     }
-}
+}

contracts/origination/OriginationController.sol

@@ -9,16 +9,12 @@ import "@openzeppelin/contracts/access/AccessControlEnumerable.sol";
 import "./OriginationControllerBase.sol";
 
 import "../interfaces/IOriginationController.sol";
-
-import "../libraries/FeeLookups.sol";
+import "../interfaces/IFeeController.sol";
+import "../interfaces/IExpressBorrow.sol";
 
 import { OC_InvalidState } from "../errors/Lending.sol";
 
 import {
-    OC_ApprovedOwnLoan,
-    OC_InvalidSignature,
-    OC_CallerNotParticipant,
-    OC_SideMismatch,
     OC_RolloverCurrencyMismatch,
     OC_RolloverCollateralMismatch,
     OC_ZeroAddress
@@ -43,7 +39,12 @@ import {
  * does not move from escrow in LoanCore. Only the payable currency is transferred
  * where applicable.
  */
-contract OriginationController is IOriginationController, OriginationControllerBase, FeeLookups, AccessControlEnumerable, ReentrancyGuard {
+contract OriginationController is
+    IOriginationController,
+    OriginationControllerBase,
+    AccessControlEnumerable,
+    ReentrancyGuard
+{
     using SafeERC20 for IERC20;
 
     // ============================================ STATE ==============================================
@@ -316,44 +317,4 @@ contract OriginationController is IOriginationController, OriginationControllerB
                 newTerms.collateralId
             );
     }
-
-    /**
-     * @dev Ensure that one counterparty has signed the loan terms, and the other
-     *      has initiated the transaction.
-     *
-     * @param signingCounterparty       The address of the counterparty who signed the terms.
-     * @param callingCounterparty       The address on the other side of the loan as the signingCounterparty.
-     * @param caller                    The address initiating the transaction.
-     * @param signer                    The address recovered from the loan terms signature.
-     * @param sig                       A struct containing the signature data (for checking EIP-1271).
-     * @param sighash                   The hash of the signature payload (used for EIP-1271 check).
-     */
-    // solhint-disable-next-line code-complexity
-    function _validateCounterparties(
-        address signingCounterparty,
-        address callingCounterparty,
-        address caller,
-        address signer,
-        Signature calldata sig,
-        bytes32 sighash
-    ) internal view {
-        // Make sure the signer recovered from the loan terms is not the caller,
-        // and even if the caller is approved, the caller is not the signing counterparty
-        if (caller == signer || caller == signingCounterparty) revert OC_ApprovedOwnLoan(caller);
-
-        // Check that caller can actually call this function - neededSide assignment
-        // defaults to BORROW if the signature is not approved by the borrower, but it could
-        // also not be a participant
-        if (!isSelfOrApproved(callingCounterparty, caller)) {
-            revert OC_CallerNotParticipant(msg.sender);
-        }
-
-        // Check signature validity
-        if (!isSelfOrApproved(signingCounterparty, signer) && !OriginationLibrary.isApprovedForContract(signingCounterparty, sig, sighash)) {
-            revert OC_InvalidSignature(signingCounterparty, signer);
-        }
-
-        // Revert if the signer is the calling counterparty
-        if (signer == callingCounterparty) revert OC_SideMismatch(signer);
-    }
 }