feat(multiproposal): implement multiproposal

src/loan/terms/simple/loan/PWNSimpleLoan.sol

@@ -94,11 +94,13 @@ contract PWNSimpleLoan is PWNVault, IERC5646, IPWNLoanMetadataProvider {
      * @notice Loan proposal specification during loan creation.
      * @param proposalContract Address of a loan proposal contract.
      * @param proposalData Encoded proposal data that is passed to the loan proposal contract.
+     * @param proposalInclusionProof Inclusion proof of the proposal in the proposal contract.
      * @param signature Signature of the proposal.
      */
     struct ProposalSpec {
         address proposalContract;
         bytes proposalData;
+        bytes32[] proposalInclusionProof;
         bytes signature;
     }
 
@@ -297,6 +299,7 @@ contract PWNSimpleLoan is PWNVault, IERC5646, IPWNLoanMetadataProvider {
                 acceptor: msg.sender,
                 refinancingLoanId: callerSpec.refinancingLoanId,
                 proposalData: proposalSpec.proposalData,
+                proposalInclusionProof: proposalSpec.proposalInclusionProof,
                 signature: proposalSpec.signature
             });
 

src/loan/terms/simple/proposal/PWNSimpleLoanDutchAuctionProposal.sol

@@ -211,6 +211,7 @@ contract PWNSimpleLoanDutchAuctionProposal is PWNSimpleLoanProposal {
         address acceptor,
         uint256 refinancingLoanId,
         bytes calldata proposalData,
+        bytes32[] calldata proposalInclusionProof,
         bytes calldata signature
     ) override external returns (bytes32 proposalHash, PWNSimpleLoan.Terms memory loanTerms) {
         // Decode proposal data
@@ -252,6 +253,7 @@ contract PWNSimpleLoanDutchAuctionProposal is PWNSimpleLoanProposal {
             acceptor,
             refinancingLoanId,
             proposalHash,
+            proposalInclusionProof,
             signature,
             ProposalBase({
                 collateralAddress: proposal.collateralAddress,

src/loan/terms/simple/proposal/PWNSimpleLoanFungibleProposal.sol

@@ -161,6 +161,7 @@ contract PWNSimpleLoanFungibleProposal is PWNSimpleLoanProposal {
         address acceptor,
         uint256 refinancingLoanId,
         bytes calldata proposalData,
+        bytes32[] calldata proposalInclusionProof,
         bytes calldata signature
     ) override external returns (bytes32 proposalHash, PWNSimpleLoan.Terms memory loanTerms) {
         // Decode proposal data
@@ -188,6 +189,7 @@ contract PWNSimpleLoanFungibleProposal is PWNSimpleLoanProposal {
             acceptor,
             refinancingLoanId,
             proposalHash,
+            proposalInclusionProof,
             signature,
             ProposalBase({
                 collateralAddress: proposal.collateralAddress,

src/loan/terms/simple/proposal/PWNSimpleLoanListProposal.sol

@@ -149,6 +149,7 @@ contract PWNSimpleLoanListProposal is PWNSimpleLoanProposal {
         address acceptor,
         uint256 refinancingLoanId,
         bytes calldata proposalData,
+        bytes32[] calldata proposalInclusionProof,
         bytes calldata signature
     ) override external returns (bytes32 proposalHash, PWNSimpleLoan.Terms memory loanTerms) {
         // Decode proposal data
@@ -176,6 +177,7 @@ contract PWNSimpleLoanListProposal is PWNSimpleLoanProposal {
             acceptor,
             refinancingLoanId,
             proposalHash,
+            proposalInclusionProof,
             signature,
             ProposalBase({
                 collateralAddress: proposal.collateralAddress,

src/loan/terms/simple/proposal/PWNSimpleLoanProposal.sol

@@ -1,6 +1,8 @@
 // SPDX-License-Identifier: GPL-3.0-only
 pragma solidity 0.8.16;
 
+import { MerkleProof } from "openzeppelin-contracts/contracts/utils/cryptography/MerkleProof.sol";
+
 import { PWNConfig, IERC5646 } from "@pwn/config/PWNConfig.sol";
 import { PWNHub } from "@pwn/hub/PWNHub.sol";
 import { PWNHubTags } from "@pwn/hub/PWNHubTags.sol";
@@ -16,11 +18,18 @@ import "@pwn/PWNErrors.sol";
 abstract contract PWNSimpleLoanProposal {
 
     bytes32 public immutable DOMAIN_SEPARATOR;
+    bytes32 public immutable MULTIPROPOSAL_DOMAIN_SEPARATOR;
 
     PWNHub public immutable hub;
     PWNRevokedNonce public immutable revokedNonce;
     PWNConfig public immutable config;
 
+    bytes32 public constant MULTIPROPOSAL_TYPEHASH = keccak256("Multiproposal(bytes32 multiproposalMerkleRoot)");
+
+    struct Multiproposal {
+        bytes32 multiproposalMerkleRoot;
+    }
+
     struct ProposalBase {
         address collateralAddress;
         uint256 collateralId;
@@ -69,13 +78,31 @@ abstract contract PWNSimpleLoanProposal {
             block.chainid,
             address(this)
         ));
+
+        MULTIPROPOSAL_DOMAIN_SEPARATOR = keccak256(abi.encode(
+            keccak256("EIP712Domain(string name)"),
+            keccak256("PWNMultiproposal")
+        ));
     }
 
 
     /*----------------------------------------------------------*|
     |*  # EXTERNALS                                             *|
     |*----------------------------------------------------------*/
 
+    /**
+     * @notice Get a multiproposal hash according to EIP-712.
+     * @param multiproposal Multiproposal struct.
+     * @return Multiproposal hash.
+     */
+    function getMultiproposalHash(Multiproposal memory multiproposal) public view returns (bytes32) {
+        return keccak256(abi.encodePacked(
+            hex"1901", MULTIPROPOSAL_DOMAIN_SEPARATOR, keccak256(abi.encodePacked(
+                MULTIPROPOSAL_TYPEHASH, abi.encode(multiproposal)
+            ))
+        ));
+    }
+
     /**
      * @notice Helper function for revoking a proposal nonce on behalf of a caller.
      * @param nonceSpace Nonce space of a proposal nonce to be revoked.
@@ -91,13 +118,15 @@ abstract contract PWNSimpleLoanProposal {
      * @param acceptor Address of a proposal acceptor.
      * @param refinancingLoanId Id of a loan to be refinanced. 0 if creating a new loan.
      * @param proposalData Encoded proposal data with signature.
+     * @param proposalInclusionProof Multiproposal inclusion proof. Empty if single proposal.
      * @return proposalHash Proposal hash.
      * @return loanTerms Loan terms.
      */
     function acceptProposal(
         address acceptor,
         uint256 refinancingLoanId,
         bytes calldata proposalData,
+        bytes32[] calldata proposalInclusionProof,
         bytes calldata signature
     ) virtual external returns (bytes32 proposalHash, PWNSimpleLoan.Terms memory loanTerms);
 
@@ -141,14 +170,16 @@ abstract contract PWNSimpleLoanProposal {
      * @param acceptor Address of a proposal acceptor.
      * @param refinancingLoanId Refinancing loan ID.
      * @param proposalHash Proposal hash.
+     * @param proposalInclusionProof Multiproposal inclusion proof. Empty if single proposal.
      * @param signature Signature of a proposal.
      * @param proposal Proposal base struct.
      */
     function _acceptProposal(
         address acceptor,
         uint256 refinancingLoanId,
         bytes32 proposalHash,
-        bytes memory signature,
+        bytes32[] calldata proposalInclusionProof,
+        bytes calldata signature,
         ProposalBase memory proposal
     ) internal {
         // Check loan contract
@@ -159,10 +190,26 @@ abstract contract PWNSimpleLoanProposal {
             revert AddressMissingHubTag({ addr: proposal.loanContract, tag: PWNHubTags.ACTIVE_LOAN });
         }
 
-        // Check proposal has been made via on-chain tx, EIP-1271 or signed off-chain
-        if (!proposalsMade[proposalHash]) {
-            if (!PWNSignatureChecker.isValidSignatureNow(proposal.proposer, proposalHash, signature)) {
-                revert InvalidSignature({ signer: proposal.proposer, digest: proposalHash });
+        // Check proposal signature or that it was made on-chain
+        if (proposalInclusionProof.length == 0) {
+            // Single proposal signature
+            if (!proposalsMade[proposalHash]) {
+                if (!PWNSignatureChecker.isValidSignatureNow(proposal.proposer, proposalHash, signature)) {
+                    revert InvalidSignature({ signer: proposal.proposer, digest: proposalHash });
+                }
+            }
+        } else {
+            // Multiproposal signature
+            bytes32 multiproposalHash = getMultiproposalHash(
+                Multiproposal({
+                    multiproposalMerkleRoot: MerkleProof.processProofCalldata({
+                        proof: proposalInclusionProof,
+                        leaf: proposalHash
+                    })
+                })
+            );
+            if (!PWNSignatureChecker.isValidSignatureNow(proposal.proposer, multiproposalHash, signature)) {
+                revert InvalidSignature({ signer: proposal.proposer, digest: multiproposalHash });
             }
         }
 

src/loan/terms/simple/proposal/PWNSimpleLoanSimpleProposal.sol

@@ -129,6 +129,7 @@ contract PWNSimpleLoanSimpleProposal is PWNSimpleLoanProposal {
         address acceptor,
         uint256 refinancingLoanId,
         bytes calldata proposalData,
+        bytes32[] calldata proposalInclusionProof,
         bytes calldata signature
     ) override external returns (bytes32 proposalHash, PWNSimpleLoan.Terms memory loanTerms) {
         // Decode proposal data
@@ -142,6 +143,7 @@ contract PWNSimpleLoanSimpleProposal is PWNSimpleLoanProposal {
             acceptor,
             refinancingLoanId,
             proposalHash,
+            proposalInclusionProof,
             signature,
             ProposalBase({
                 collateralAddress: proposal.collateralAddress,

test/unit/PWNSimpleLoan.t.sol

@@ -32,11 +32,11 @@ abstract contract PWNSimpleLoanTest is Test {
     address borrower = makeAddr("borrower");
     address sourceOfFunds = address(new DummyCompoundPool());
     uint256 loanDurationInDays = 101;
-    PWNSimpleLoan.LenderSpec lenderSpec;
     PWNSimpleLoan.LOAN simpleLoan;
     PWNSimpleLoan.LOAN nonExistingLoan;
     PWNSimpleLoan.Terms simpleLoanTerms;
     PWNSimpleLoan.ProposalSpec proposalSpec;
+    PWNSimpleLoan.LenderSpec lenderSpec;
     PWNSimpleLoan.CallerSpec callerSpec;
     PWNSimpleLoan.ExtensionProposal extension;
     T20 fungibleAsset;
@@ -114,6 +114,7 @@ abstract contract PWNSimpleLoanTest is Test {
         proposalSpec = PWNSimpleLoan.ProposalSpec({
             proposalContract: proposalContract,
             proposalData: proposalData,
+            proposalInclusionProof: new bytes32[](0),
             signature: signature
         });
 
@@ -246,7 +247,7 @@ abstract contract PWNSimpleLoanTest is Test {
     function _mockLoanTerms(PWNSimpleLoan.Terms memory _terms) internal {
         vm.mockCall(
             proposalContract,
-            abi.encodeWithSignature("acceptProposal(address,uint256,bytes,bytes)"),
+            abi.encodeWithSignature("acceptProposal(address,uint256,bytes,bytes32[],bytes)"),
             abi.encode(proposalHash, _terms)
         );
     }
@@ -372,10 +373,19 @@ contract PWNSimpleLoan_CreateLOAN_Test is PWNSimpleLoanTest {
         });
     }
 
-    function testFuzz_shouldCallProposalContract(address caller) external {
+    function testFuzz_shouldCallProposalContract(
+        address caller, bytes memory _proposalData, bytes32[] memory _proposalInclusionProof, bytes memory _signature
+    ) external {
+        proposalSpec.proposalData = _proposalData;
+        proposalSpec.proposalInclusionProof = _proposalInclusionProof;
+        proposalSpec.signature = _signature;
+
         vm.expectCall(
             proposalContract,
-            abi.encodeWithSignature("acceptProposal(address,uint256,bytes,bytes)", caller, 0, proposalData, signature)
+            abi.encodeWithSignature(
+                "acceptProposal(address,uint256,bytes,bytes32[],bytes)",
+                caller, 0, _proposalData, _proposalInclusionProof, _signature
+            )
         );
 
         vm.prank(caller);

test/unit/PWNSimpleLoanDutchAuctionProposal.t.sol

@@ -82,55 +82,46 @@ abstract contract PWNSimpleLoanDutchAuctionProposalTest is PWNSimpleLoanProposal
         ));
     }
 
-    function _updateProposal(Params memory _params) internal {
-        if (_params.base.isOffer) {
-            proposal.minCreditAmount = _params.base.creditAmount;
+    function _updateProposal(PWNSimpleLoanProposal.ProposalBase memory _proposal) internal {
+        if (_proposal.isOffer) {
+            proposal.minCreditAmount = _proposal.creditAmount;
             proposal.maxCreditAmount = proposal.minCreditAmount * 10;
             proposalValues.intendedCreditAmount = proposal.minCreditAmount;
         } else {
-            proposal.maxCreditAmount = _params.base.creditAmount;
+            proposal.maxCreditAmount = _proposal.creditAmount;
             proposal.minCreditAmount = proposal.maxCreditAmount / 10;
             proposalValues.intendedCreditAmount = proposal.maxCreditAmount;
         }
 
-        proposal.collateralAddress = _params.base.collateralAddress;
-        proposal.collateralId = _params.base.collateralId;
-        proposal.checkCollateralStateFingerprint = _params.base.checkCollateralStateFingerprint;
-        proposal.collateralStateFingerprint = _params.base.collateralStateFingerprint;
-        proposal.availableCreditLimit = _params.base.availableCreditLimit;
-        proposal.auctionDuration = _params.base.expiration - proposal.auctionStart - 1 minutes;
-        proposal.allowedAcceptor = _params.base.allowedAcceptor;
-        proposal.proposer = _params.base.proposer;
-        proposal.isOffer = _params.base.isOffer;
-        proposal.refinancingLoanId = _params.base.refinancingLoanId;
-        proposal.nonceSpace = _params.base.nonceSpace;
-        proposal.nonce = _params.base.nonce;
-        proposal.loanContract = _params.base.loanContract;
-    }
-
-    function _proposalSignature(Params memory _params) internal view returns (bytes memory signature) {
-        if (_params.signerPK != 0) {
-            if (_params.compactSignature) {
-                signature = _signProposalHashCompact(_params.signerPK, _proposalHash(proposal));
-            } else {
-                signature = _signProposalHash(_params.signerPK, _proposalHash(proposal));
-            }
-        }
+        proposal.collateralAddress = _proposal.collateralAddress;
+        proposal.collateralId = _proposal.collateralId;
+        proposal.checkCollateralStateFingerprint = _proposal.checkCollateralStateFingerprint;
+        proposal.collateralStateFingerprint = _proposal.collateralStateFingerprint;
+        proposal.availableCreditLimit = _proposal.availableCreditLimit;
+        proposal.auctionDuration = _proposal.expiration - proposal.auctionStart - 1 minutes;
+        proposal.allowedAcceptor = _proposal.allowedAcceptor;
+        proposal.proposer = _proposal.proposer;
+        proposal.isOffer = _proposal.isOffer;
+        proposal.refinancingLoanId = _proposal.refinancingLoanId;
+        proposal.nonceSpace = _proposal.nonceSpace;
+        proposal.nonce = _proposal.nonce;
+        proposal.loanContract = _proposal.loanContract;
     }
 
 
     function _callAcceptProposalWith(Params memory _params) internal override returns (bytes32, PWNSimpleLoan.Terms memory) {
-        _updateProposal(_params);
+        _updateProposal(_params.base);
         return proposalContract.acceptProposal({
             acceptor: _params.acceptor,
             refinancingLoanId: _params.refinancingLoanId,
             proposalData: abi.encode(proposal, proposalValues),
-            signature: _proposalSignature(_params)
+            proposalInclusionProof: _params.proposalInclusionProof,
+            signature: _params.signature
         });
     }
 
     function _getProposalHashWith(Params memory _params) internal override returns (bytes32) {
-        _updateProposal(_params);
+        _updateProposal(_params.base);
         return _proposalHash(proposal);
     }
 
@@ -430,7 +421,8 @@ contract PWNSimpleLoanDutchAuctionProposal_AcceptProposal_Test is PWNSimpleLoanD
             acceptor: acceptor,
             refinancingLoanId: 0,
             proposalData: abi.encode(proposal, proposalValues),
-            signature: _signProposalHash(proposerPK, _proposalHash(proposal))
+            proposalInclusionProof: new bytes32[](0),
+            signature: _sign(proposerPK, _proposalHash(proposal))
         });
     }
 
@@ -464,7 +456,8 @@ contract PWNSimpleLoanDutchAuctionProposal_AcceptProposal_Test is PWNSimpleLoanD
             acceptor: acceptor,
             refinancingLoanId: 0,
             proposalData: abi.encode(proposal, proposalValues),
-            signature: _signProposalHash(proposerPK, _proposalHash(proposal))
+            proposalInclusionProof: new bytes32[](0),
+            signature: _sign(proposerPK, _proposalHash(proposal))
         });
     }
 
@@ -496,7 +489,8 @@ contract PWNSimpleLoanDutchAuctionProposal_AcceptProposal_Test is PWNSimpleLoanD
             acceptor: acceptor,
             refinancingLoanId: 0,
             proposalData: abi.encode(proposal, proposalValues),
-            signature: _signProposalHash(proposerPK, _proposalHash(proposal))
+            proposalInclusionProof: new bytes32[](0),
+            signature: _sign(proposerPK, _proposalHash(proposal))
         });
 
         assertEq(proposalHash, _proposalHash(proposal));