WIP More contract work, c2t

contracts/Create2Transfer.sol

@@ -23,6 +23,7 @@ contract Create2Transfer {
      * */
     function processCreate2TransferCommit(
         bytes32 stateRoot,
+        bytes32[] memory stateHashes,
         uint256 maxTxSize,
         uint256 feeReceiver,
         bytes memory txs,
@@ -32,6 +33,11 @@ contract Create2Transfer {
             return (stateRoot, Types.Result.BadCompression);
         uint256 size = txs.create2TransferSize();
         if (size > maxTxSize) return (stateRoot, Types.Result.TooManyTx);
+        // TODO This modulo check could be wrong if hashes is 2x, 3x etc tx size. Rethink.
+        require(
+            stateHashes.length % size == 1,
+            "stateHashes size mismatch with txs"
+        );
 
         uint256 fees = 0;
         // tokenID should be the same for all states in this commit
@@ -42,6 +48,7 @@ contract Create2Transfer {
             _tx = txs.create2TransferDecode(i);
             (stateRoot, result) = Transition.processCreate2Transfer(
                 stateRoot,
+                stateHashes[i],
                 _tx,
                 tokenID,
                 proofs[i * 2],
@@ -53,6 +60,7 @@ contract Create2Transfer {
         }
         (stateRoot, result) = Transition.processReceiver(
             stateRoot,
+            stateHashes[size + 1],
             feeReceiver,
             tokenID,
             fees,

contracts/Transfer.sol

@@ -24,6 +24,7 @@ contract Transfer {
      * */
     function processTransferCommit(
         bytes32 stateRoot,
+        bytes32[2][] memory stateHashes,
         uint256 maxTxSize,
         uint256 feeReceiver,
         bytes memory txs,
@@ -34,6 +35,10 @@ contract Transfer {
 
         uint256 size = txs.transferSize();
         if (size > maxTxSize) return (stateRoot, Types.Result.TooManyTx);
+        require(
+            stateHashes.length % size == size + 1,
+            "stateHashes size mismatch with txs"
+        );
 
         uint256 fees = 0;
         // tokenID should be the same for all states in this commit
@@ -44,8 +49,8 @@ contract Transfer {
             _tx = txs.transferDecode(i);
             (stateRoot, result) = Transition.processTransfer(
                 stateRoot,
-                stateHashFrom,
-                stateHashTo,
+                stateHashes[i * 2][0], // stateHashFrom
+                stateHashes[i * 2 + 1][1], // stateHashTo
                 _tx,
                 tokenID,
                 proofs[i * 2],
@@ -57,6 +62,7 @@ contract Transfer {
         }
         (stateRoot, result) = Transition.processReceiver(
             stateRoot,
+            stateHashes[size * 2][0],
             feeReceiver,
             tokenID,
             fees,

contracts/client/FrontendCreate2Transfer.sol

@@ -162,6 +162,7 @@ contract FrontendCreate2Transfer {
 
     function process(
         bytes32 stateRoot,
+        bytes32 stateHashFrom,
         bytes memory encodedTx,
         uint256 tokenID,
         Types.StateMerkleProof memory from,
@@ -180,6 +181,7 @@ contract FrontendCreate2Transfer {
         return
             Transition.processCreate2Transfer(
                 stateRoot,
+                stateHashFrom,
                 _tx,
                 tokenID,
                 from,

contracts/client/FrontendTransfer.sol

@@ -132,6 +132,8 @@ contract FrontendTransfer {
 
     function process(
         bytes32 stateRoot,
+        bytes32 stateHashFrom,
+        bytes32 stateHashTo,
         bytes memory encodedTx,
         uint256 tokenID,
         Types.StateMerkleProof memory from,
@@ -146,7 +148,16 @@ contract FrontendTransfer {
                 offchainTx.amount,
                 offchainTx.fee
             );
-        return Transition.processTransfer(stateRoot, _tx, tokenID, from, to);
+        return
+            Transition.processTransfer(
+                stateRoot,
+                stateHashFrom,
+                stateHashTo,
+                _tx,
+                tokenID,
+                from,
+                to
+            );
     }
 
     function checkSignature(

contracts/libs/Transition.sol

@@ -46,6 +46,7 @@ library Transition {
 
     function processMassMigration(
         bytes32 stateRoot,
+        bytes32 stateHashFrom,
         Tx.MassMigration memory _tx,
         uint256 tokenID,
         Types.StateMerkleProof memory from
@@ -60,6 +61,7 @@ library Transition {
     {
         (newRoot, result) = processSender(
             stateRoot,
+            stateHashFrom,
             _tx.fromIndex,
             tokenID,
             _tx.amount,
@@ -74,13 +76,15 @@ library Transition {
 
     function processCreate2Transfer(
         bytes32 stateRoot,
+        bytes32 stateHashFrom,
         Tx.Create2Transfer memory _tx,
         uint256 tokenID,
         Types.StateMerkleProof memory from,
         Types.StateMerkleProof memory to
     ) internal pure returns (bytes32 newRoot, Types.Result result) {
         (newRoot, result) = processSender(
             stateRoot,
+            stateHashFrom,
             _tx.fromIndex,
             tokenID,
             _tx.amount,
@@ -136,12 +140,17 @@ library Transition {
                 stateHash,
                 senderStateIndex,
                 proof.witness
-            )
-        , "Transition: Sender does not exist");
+            ),
+            "Transition: Sender does not exist"
+        );
         // check if sender is empty
-        if (stateHash == Types.ZERO_BYTES32) return Types.Result.BadFromIndex;
+        if (stateHash == Types.ZERO_BYTES32)
+            return (bytes32(0), Types.Result.BadFromIndex);
         // sender is non-empty, the disputer now has to justify the preimage of the state
-        require(stateHash == keccak256(proof.state.encode()), "stateHash mismatch");
+        require(
+            stateHash == keccak256(proof.state.encode()),
+            "stateHash mismatch"
+        );
 
         (Types.UserState memory newSender, Types.Result result) =
             validateAndApplySender(tokenID, amount, fee, proof.state);
@@ -169,12 +178,17 @@ library Transition {
                 stateHash,
                 receiverStateIndex,
                 proof.witness
-            )
-        , "Transition: receiver does not exist");
+            ),
+            "Transition: receiver does not exist"
+        );
         // check if receiver is empty
-        if (stateHash == Types.ZERO_BYTES32) return Types.Result.BadFromIndex;
+        if (stateHash == Types.ZERO_BYTES32)
+            return (bytes32(0), Types.Result.BadFromIndex);
         // receiver is non-empty, the disputer now has to justify the preimage of the state
-        require(stateHash == keccak256(proof.state.encode()), "stateHash mismatch");
+        require(
+            stateHash == keccak256(proof.state.encode()),
+            "stateHash mismatch"
+        );
 
         (Types.UserState memory newReceiver, Types.Result result) =
             validateAndApplyReceiver(tokenID, amount, proof.state);

contracts/rollup/Rollup.sol

@@ -28,11 +28,11 @@ contract Rollup is BatchManager, EIP712, IEIP712 {
     string public constant DOMAIN_NAME = "Hubble";
     string public constant DOMAIN_VERSION = "1";
 
-    /** 
+    /**
      * @dev If this is not being externally consumed,
      * it can be removed and refs replaced with Types.ZERO_BYTES32
      */
-    bytes32 public constant ZERO_BYTES32 = Types.ZERO_BYTES32;
+    bytes32 public immutable ZERO_BYTES32;
 
     // External contracts
     BLSAccountRegistry public immutable accountRegistry;
@@ -72,6 +72,8 @@ contract Rollup is BatchManager, EIP712, IEIP712 {
         )
         EIP712(DOMAIN_NAME, DOMAIN_VERSION)
     {
+        ZERO_BYTES32 = Types.ZERO_BYTES32;
+
         accountRegistry = _accountRegistry;
         transfer = _transfer;
         massMigration = _massMigration;
@@ -369,8 +371,8 @@ contract Rollup is BatchManager, EIP712, IEIP712 {
         uint256 batchID,
         Types.CommitmentInclusionProof memory previous,
         Types.TransferCommitmentInclusionProof memory target,
-        Types.StateMerkleProof[] memory proofs
-
+        Types.StateMerkleProof[] memory proofs,
+        bytes32[2][] memory stateHashes
     )
         public
         isDisputable(batchID)
@@ -384,6 +386,7 @@ contract Rollup is BatchManager, EIP712, IEIP712 {
         (bytes32 processedStateRoot, Types.Result result) =
             transfer.processTransferCommit(
                 previous.commitment.stateRoot,
+                stateHashes,
                 paramMaxTxsPerCommit,
                 target.commitment.body.feeReceiver,
                 target.commitment.body.txs,
@@ -429,7 +432,8 @@ contract Rollup is BatchManager, EIP712, IEIP712 {
         uint256 batchID,
         Types.CommitmentInclusionProof memory previous,
         Types.TransferCommitmentInclusionProof memory target,
-        Types.StateMerkleProof[] memory proofs
+        Types.StateMerkleProof[] memory proofs,
+        bytes32[] memory stateHashes
     )
         public
         isDisputable(batchID)
@@ -443,6 +447,7 @@ contract Rollup is BatchManager, EIP712, IEIP712 {
         (bytes32 processedStateRoot, Types.Result result) =
             create2Transfer.processCreate2TransferCommit(
                 previous.commitment.stateRoot,
+                stateHashes,
                 paramMaxTxsPerCommit,
                 target.commitment.body.feeReceiver,
                 target.commitment.body.txs,

contracts/test/TestCreate2Transfer.sol

@@ -31,6 +31,7 @@ contract TestCreate2Transfer is Create2Transfer {
 
     function testProcessCreate2Transfer(
         bytes32 _balanceRoot,
+        bytes32 stateHashFrom,
         Tx.Create2Transfer memory _tx,
         uint256 tokenID,
         Types.StateMerkleProof memory from,
@@ -39,6 +40,7 @@ contract TestCreate2Transfer is Create2Transfer {
         return
             Transition.processCreate2Transfer(
                 _balanceRoot,
+                stateHashFrom,
                 _tx,
                 tokenID,
                 from,
@@ -48,6 +50,7 @@ contract TestCreate2Transfer is Create2Transfer {
 
     function testProcessCreate2TransferCommit(
         bytes32 stateRoot,
+        bytes32[] memory stateHashes,
         uint256 maxTxSize,
         uint256 feeReceiver,
         bytes memory txs,
@@ -57,6 +60,7 @@ contract TestCreate2Transfer is Create2Transfer {
         uint256 operationCost = gasleft();
         (newRoot, ) = processCreate2TransferCommit(
             stateRoot,
+            stateHashes,
             maxTxSize,
             feeReceiver,
             txs,

contracts/test/TestTransfer.sol

@@ -31,16 +31,28 @@ contract TestTransfer is Transfer {
 
     function testProcessTransfer(
         bytes32 _balanceRoot,
+        bytes32 stateHashFrom,
+        bytes32 stateHashTo,
         Tx.Transfer memory _tx,
         uint256 tokenID,
         Types.StateMerkleProof memory from,
         Types.StateMerkleProof memory to
     ) public pure returns (bytes32, Types.Result) {
-        return Transition.processTransfer(_balanceRoot, _tx, tokenID, from, to);
+        return
+            Transition.processTransfer(
+                _balanceRoot,
+                stateHashFrom,
+                stateHashTo,
+                _tx,
+                tokenID,
+                from,
+                to
+            );
     }
 
     function testProcessTransferCommit(
         bytes32 stateRoot,
+        bytes32[2][] memory stateHashes,
         uint256 maxTxSize,
         uint256 feeReceiver,
         bytes memory txs,
@@ -50,6 +62,7 @@ contract TestTransfer is Transfer {
         uint256 operationCost = gasleft();
         (newRoot, ) = processTransferCommit(
             stateRoot,
+            stateHashes,
             maxTxSize,
             feeReceiver,
             txs,