feat: add unique receipts for cross-subnet transactions (#125)

Signed-off-by: Jawad Tariq <[email protected]>

contracts/interfaces/IToposCore.sol

@@ -25,7 +25,7 @@ interface IToposCore {
 
     event CertStored(CertificateId certId, bytes32 receiptRoot);
 
-    event CrossSubnetMessageSent(SubnetId indexed targetSubnetId);
+    event CrossSubnetMessageSent(SubnetId indexed targetSubnetId, SubnetId sourceSubnetId, uint256 nonce);
 
     event Upgraded(address indexed implementation);
 

contracts/interfaces/IToposMessaging.sol

@@ -27,7 +27,7 @@ interface IToposMessaging {
     function validateMerkleProof(
         bytes memory proofBlob,
         bytes32 receiptRoot
-    ) external returns (bytes memory receiptRaw);
+    ) external returns (bytes memory receiptTrieNodeRaw);
 
     function toposCore() external view returns (address);
 }

contracts/topos-core/CodeHash.sol

@@ -4,10 +4,10 @@ pragma solidity ^0.8.9;
 contract CodeHash {
     /// @notice gets the codehash of a contract address
     /// @param contractAddr a contract address
-    function getCodeHash(address contractAddr) public view returns (bytes32) {
+    function getCodeHash(address contractAddr) public view returns (bytes32 codeHash) {
         // does not fail with wallet addresses
         if (contractAddr.codehash.length != 0) {
-            return contractAddr.codehash;
+            codeHash = contractAddr.codehash;
         }
     }
 }

contracts/topos-core/ToposCore.sol

@@ -18,6 +18,10 @@ contract ToposCore is IToposCore, AdminMultisigBase, Initializable {
     /// @notice The subnet ID of the subnet this contract is to be deployed on
     SubnetId public networkSubnetId;
 
+    /// @notice Nonce for cross subnet message, meant to be used in combination with `sourceSubnetId`
+    /// so that the message can be uniquely identified per subnet
+    uint256 private nonce;
+
     /// @notice Set of certificate IDs
     Bytes32SetsLib.Set certificateSet;
 
@@ -113,7 +117,8 @@ contract ToposCore is IToposCore, AdminMultisigBase, Initializable {
     /// @notice Emits an event to signal a cross subnet message has been sent
     /// @param targetSubnetId The subnet ID of the target subnet
     function emitCrossSubnetMessage(SubnetId targetSubnetId) external {
-        emit CrossSubnetMessageSent(targetSubnetId);
+        nonce += 1;
+        emit CrossSubnetMessageSent(targetSubnetId, networkSubnetId, nonce);
     }
 
     /// @notice Returns the admin epoch

contracts/topos-core/ToposMessaging.sol

@@ -37,11 +37,11 @@ contract ToposMessaging is IToposMessaging, EternalStorage {
         if (!IToposCore(_toposCoreAddr).certificateExists(certId)) revert CertNotPresent();
 
         // the raw receipt bytes are taken out of the proof
-        bytes memory receiptRaw = validateMerkleProof(proofBlob, receiptRoot);
-        if (receiptRaw.length == uint256(0)) revert InvalidMerkleProof();
+        bytes memory receiptTrieNodeRaw = validateMerkleProof(proofBlob, receiptRoot);
+        if (receiptTrieNodeRaw.length == uint256(0)) revert InvalidMerkleProof();
 
-        bytes32 receiptHash = keccak256(abi.encodePacked(receiptRaw));
-        if (_isTxExecuted(receiptHash, receiptRoot)) revert TransactionAlreadyExecuted();
+        bytes32 receiptTrieNodeHash = keccak256(abi.encodePacked(receiptTrieNodeRaw));
+        if (_isTxExecuted(receiptTrieNodeHash, receiptRoot)) revert TransactionAlreadyExecuted();
 
         (
             uint256 status, // uint256 cumulativeGasUsed // bytes memory logsBloom
@@ -50,7 +50,7 @@ contract ToposMessaging is IToposMessaging, EternalStorage {
             address[] memory logsAddress,
             bytes32[][] memory logsTopics,
             bytes[] memory logsData
-        ) = _decodeReceipt(receiptRaw);
+        ) = _decodeReceipt(receiptTrieNodeRaw);
         if (status != 1) revert InvalidTransactionStatus();
 
         // verify that provided indexes are within the range of the number of event logs
@@ -61,7 +61,7 @@ contract ToposMessaging is IToposMessaging, EternalStorage {
         SubnetId networkSubnetId = IToposCore(_toposCoreAddr).networkSubnetId();
 
         // prevent re-entrancy
-        _setTxExecuted(receiptHash, receiptRoot);
+        _setTxExecuted(receiptTrieNodeHash, receiptRoot);
         _execute(logIndexes, logsAddress, logsData, logsTopics, networkSubnetId);
     }
 
@@ -76,10 +76,10 @@ contract ToposMessaging is IToposMessaging, EternalStorage {
     function validateMerkleProof(
         bytes memory proofBlob,
         bytes32 receiptRoot
-    ) public pure override returns (bytes memory receiptRaw) {
+    ) public pure override returns (bytes memory receiptTrieNodeRaw) {
         Proof memory proof = _decodeProofBlob(proofBlob);
         if (proof.kind != 1) revert UnsupportedProofKind();
-        receiptRaw = MerklePatriciaProofVerifier.extractProofValue(receiptRoot, proof.mptKey, proof.stack);
+        receiptTrieNodeRaw = MerklePatriciaProofVerifier.extractProofValue(receiptRoot, proof.mptKey, proof.stack);
     }
 
     /// @notice Execute the message on a target subnet
@@ -103,18 +103,18 @@ contract ToposMessaging is IToposMessaging, EternalStorage {
     }
 
     /// @notice Set a flag to indicate that the asset transfer transaction has been executed
-    /// @param receiptHash receipt hash
+    /// @param receiptTrieNodeHash receipt hash
     /// @param receiptRoot receipt root
-    function _setTxExecuted(bytes32 receiptHash, bytes32 receiptRoot) internal {
-        bytes32 suffix = keccak256(abi.encodePacked(receiptHash, receiptRoot));
+    function _setTxExecuted(bytes32 receiptTrieNodeHash, bytes32 receiptRoot) internal {
+        bytes32 suffix = keccak256(abi.encodePacked(receiptTrieNodeHash, receiptRoot));
         _setBool(_getTxExecutedKey(suffix), true);
     }
 
     /// @notice Get the flag to indicate that the transaction has been executed
-    /// @param receiptHash receipt hash
+    /// @param receiptTrieNodeHash receipt hash
     /// @param receiptRoot receipt root
-    function _isTxExecuted(bytes32 receiptHash, bytes32 receiptRoot) internal view returns (bool) {
-        bytes32 suffix = keccak256(abi.encodePacked(receiptHash, receiptRoot));
+    function _isTxExecuted(bytes32 receiptTrieNodeHash, bytes32 receiptRoot) internal view returns (bool) {
+        bytes32 suffix = keccak256(abi.encodePacked(receiptTrieNodeHash, receiptRoot));
         return getBool(_getTxExecutedKey(suffix));
     }
 
@@ -171,9 +171,9 @@ contract ToposMessaging is IToposMessaging, EternalStorage {
     }
 
     /// @notice Decode the receipt into its components
-    /// @param receiptRaw RLP encoded receipt
+    /// @param receiptTrieNodeRaw RLP encoded receipt
     function _decodeReceipt(
-        bytes memory receiptRaw
+        bytes memory receiptTrieNodeRaw
     )
         internal
         pure
@@ -186,7 +186,7 @@ contract ToposMessaging is IToposMessaging, EternalStorage {
             bytes[] memory logsData
         )
     {
-        RLPReader.RLPItem[] memory receipt = receiptRaw.toRlpItem().toList();
+        RLPReader.RLPItem[] memory receipt = receiptTrieNodeRaw.toRlpItem().toList();
 
         status = receipt[0].toUint();
         cumulativeGasUsed = receipt[1].toUint();

test/topos-core/ToposMessaging.test.ts

@@ -82,10 +82,7 @@ describe('ToposMessaging', () => {
     await toposCoreProxy.waitForDeployment()
     const toposCoreProxyAddress = await toposCoreProxy.getAddress()
 
-    const toposCore = await ToposCore__factory.connect(
-      toposCoreProxyAddress,
-      admin
-    )
+    const toposCore = ToposCore__factory.connect(toposCoreProxyAddress, admin)
     await toposCore.initialize(adminAddresses, adminThreshold)
 
     const erc20Messaging = await new ERC20Messaging__factory(admin).deploy(
@@ -214,7 +211,7 @@ describe('ToposMessaging', () => {
         (l) => (l as EventLog).eventName === 'TokenDeployed'
       ) as EventLog
       const tokenAddress = log.args.tokenAddress
-      const erc20 = await ERC20__factory.connect(tokenAddress, admin)
+      const erc20 = ERC20__factory.connect(tokenAddress, admin)
       await erc20.approve(erc20MessagingAddress, tc.SEND_AMOUNT_50)
 
       const sendToken = await sendTokenTx(
@@ -223,7 +220,8 @@ describe('ToposMessaging', () => {
         receiver.address,
         admin,
         cc.SOURCE_SUBNET_ID_2,
-        tc.TOKEN_SYMBOL_X
+        tc.TOKEN_SYMBOL_X,
+        tc.SEND_AMOUNT_50
       )
 
       const { proofBlob, receiptsRoot } = await getReceiptMptProof(
@@ -498,7 +496,7 @@ describe('ToposMessaging', () => {
       const deployedToken = await erc20Messaging.getTokenBySymbol(
         tc.TOKEN_SYMBOL_X
       )
-      const erc20 = await ERC20__factory.connect(deployedToken.addr, admin)
+      const erc20 = ERC20__factory.connect(deployedToken.addr, admin)
       await erc20.approve(erc20MessagingAddress, tc.SEND_AMOUNT_50)
 
       const sendToken = await sendTokenTx(
@@ -507,7 +505,8 @@ describe('ToposMessaging', () => {
         receiver.address,
         admin,
         cc.SOURCE_SUBNET_ID_2,
-        tc.TOKEN_SYMBOL_X
+        tc.TOKEN_SYMBOL_X,
+        tc.SEND_AMOUNT_50
       )
 
       const { proofBlob, receiptsRoot } = await getReceiptMptProof(
@@ -547,7 +546,7 @@ describe('ToposMessaging', () => {
       const deployedToken = await erc20Messaging.getTokenBySymbol(
         tc.TOKEN_SYMBOL_X
       )
-      const erc20 = await ERC20__factory.connect(deployedToken.addr, admin)
+      const erc20 = ERC20__factory.connect(deployedToken.addr, admin)
       await erc20.approve(erc20MessagingAddress, tc.SEND_AMOUNT_50)
 
       const sendToken = await sendTokenTx(
@@ -556,7 +555,8 @@ describe('ToposMessaging', () => {
         ethers.ZeroAddress, // sending to a zero address
         admin,
         cc.SOURCE_SUBNET_ID_2,
-        tc.TOKEN_SYMBOL_X
+        tc.TOKEN_SYMBOL_X,
+        tc.SEND_AMOUNT_50
       )
 
       const { proofBlob, receiptsRoot } = await getReceiptMptProof(
@@ -582,6 +582,80 @@ describe('ToposMessaging', () => {
       ).to.be.revertedWith('ERC20: mint to the zero address')
     })
 
+    it('can execute a transaction with same inputs twice', async () => {
+      const { admin, receiver, defaultToken, toposCore, erc20Messaging } =
+        await loadFixture(deployERC20MessagingFixture)
+      await toposCore.setNetworkSubnetId(cc.SOURCE_SUBNET_ID_2)
+      // first transaction
+      const { erc20, proofBlob, receiptsRoot } = await deployDefaultToken(
+        admin,
+        receiver,
+        defaultToken,
+        erc20Messaging
+      )
+      const certificate = testUtils.encodeCertParam(
+        cc.PREV_CERT_ID_0,
+        cc.SOURCE_SUBNET_ID_1,
+        cc.STATE_ROOT_MAX,
+        cc.TX_ROOT_MAX,
+        receiptsRoot,
+        [cc.SOURCE_SUBNET_ID_2],
+        cc.VERIFIER,
+        cc.CERT_ID_1,
+        cc.DUMMY_STARK_PROOF,
+        cc.DUMMY_SIGNATURE
+      )
+      await toposCore.pushCertificate(certificate, cc.CERT_POS_1)
+      await expect(
+        erc20Messaging.execute([tc.TOKEN_SENT_INDEX_2], proofBlob, receiptsRoot)
+      )
+        .to.emit(erc20, 'Transfer')
+        .withArgs(ethers.ZeroAddress, receiver.address, tc.SEND_AMOUNT_50)
+      await expect(erc20.balanceOf(receiver.address)).to.eventually.equal(
+        tc.SEND_AMOUNT_50
+      )
+
+      // second transaction
+      await erc20.approve(await erc20Messaging.getAddress(), tc.SEND_AMOUNT_50)
+      const sendToken = await sendTokenTx(
+        erc20Messaging,
+        ethers.provider,
+        await receiver.getAddress(),
+        admin,
+        cc.SOURCE_SUBNET_ID_2,
+        await erc20.symbol(),
+        tc.SEND_AMOUNT_50
+      )
+
+      const { proofBlob: proofBlob2, receiptsRoot: receiptsRoot2 } =
+        await getReceiptMptProof(sendToken, ethers.provider)
+      const certificate2 = testUtils.encodeCertParam(
+        cc.CERT_ID_1,
+        cc.SOURCE_SUBNET_ID_1,
+        cc.STATE_ROOT_MAX,
+        cc.TX_ROOT_MAX,
+        receiptsRoot2,
+        [cc.SOURCE_SUBNET_ID_2],
+        cc.VERIFIER,
+        cc.CERT_ID_2,
+        cc.DUMMY_STARK_PROOF,
+        cc.DUMMY_SIGNATURE
+      )
+      await toposCore.pushCertificate(certificate2, cc.CERT_POS_2)
+      await expect(
+        erc20Messaging.execute(
+          [tc.TOKEN_SENT_INDEX_2],
+          proofBlob2,
+          receiptsRoot2
+        )
+      )
+        .to.emit(erc20, 'Transfer')
+        .withArgs(ethers.ZeroAddress, receiver.address, tc.SEND_AMOUNT_50)
+      await expect(erc20.balanceOf(receiver.address)).to.eventually.equal(
+        tc.SEND_AMOUNT_50 * 2
+      )
+    })
+
     it('emits the Transfer success event', async () => {
       const { admin, receiver, defaultToken, toposCore, erc20Messaging } =
         await loadFixture(deployERC20MessagingFixture)
@@ -680,7 +754,7 @@ describe('ToposMessaging', () => {
         (l) => (l as EventLog).eventName === 'TokenDeployed'
       ) as EventLog
       const tokenAddress = log.args.tokenAddress
-      const erc20 = await ERC20__factory.connect(tokenAddress, admin)
+      const erc20 = ERC20__factory.connect(tokenAddress, admin)
       await erc20.approve(erc20MessagingAddress, tc.SEND_AMOUNT_50)
 
       await expect(
@@ -702,7 +776,7 @@ describe('ToposMessaging', () => {
           tc.SEND_AMOUNT_50
         )
         .to.emit(toposCore, 'CrossSubnetMessageSent')
-        .withArgs(cc.TARGET_SUBNET_ID_4)
+        .withArgs(cc.TARGET_SUBNET_ID_4, cc.SOURCE_SUBNET_ID_2, 1)
     })
   })
 
@@ -719,7 +793,7 @@ describe('ToposMessaging', () => {
       (l) => (l as EventLog).eventName === 'TokenDeployed'
     ) as EventLog
     const tokenAddress = log.args.tokenAddress
-    const erc20 = await ERC20__factory.connect(tokenAddress, admin)
+    const erc20 = ERC20__factory.connect(tokenAddress, admin)
     await erc20.approve(erc20MessagingAddress, tc.SEND_AMOUNT_50)
 
     const receiverAddress = await receiver.getAddress()
@@ -730,7 +804,8 @@ describe('ToposMessaging', () => {
       receiverAddress,
       admin,
       cc.SOURCE_SUBNET_ID_2,
-      await erc20.symbol()
+      await erc20.symbol(),
+      tc.SEND_AMOUNT_50
     )
 
     const { proofBlob, receiptsRoot } = await getReceiptMptProof(
@@ -746,20 +821,21 @@ describe('ToposMessaging', () => {
     receiver: string,
     signer: Signer,
     targetSubnetId: string,
-    symbol: string
+    symbol: string,
+    amount: number
   ) {
     const estimatedGasLimit = await erc20Messaging.sendToken.estimateGas(
       targetSubnetId,
       symbol,
       receiver,
-      tc.SEND_AMOUNT_50,
+      amount,
       { gasLimit: 4_000_000 }
     )
     const TxUnsigned = await erc20Messaging.sendToken.populateTransaction(
       targetSubnetId,
       symbol,
       receiver,
-      tc.SEND_AMOUNT_50,
+      amount,
       { gasLimit: 4_000_000 }
     )
     TxUnsigned.chainId = BigInt(31337) // Hardcoded chainId for Hardhat local testing