[Provers L02] Check for non-zero target commitments

docs/provers/ARBITRUM.md

@@ -180,7 +180,7 @@ function getTargetStateCommitment(bytes calldata input)
     targetStateCommitment = IOutbox(outbox).roots(sendRoot);
 
     if (targetStateCommitment == bytes32(0)) {
-        revert TargetBlockHashNotFound();
+        revert InvalidTargetStateCommitment();
     }
 }
 ```
@@ -213,7 +213,7 @@ function verifyTargetStateCommitment(bytes32 homeBlockHash, bytes calldata input
     );
 
     if (targetStateCommitment == bytes32(0)) {
-        revert TargetBlockHashNotFound();
+        revert InvalidTargetStateCommitment();
     }
 }
 ```

docs/provers/TAIKO.md

@@ -101,7 +101,7 @@ function getTargetStateCommitment(bytes calldata input)
     targetStateCommitment = checkpoint.blockHash;
 
     if (targetStateCommitment == bytes32(0)) {
-        revert TargetBlockHashNotFound();
+        revert InvalidTargetStateCommitment();
     }
 }
 ```
@@ -136,7 +136,7 @@ function verifyTargetStateCommitment(bytes32 homeBlockHash, bytes calldata input
     );
 
     if (targetStateCommitment == bytes32(0)) {
-        revert TargetBlockHashNotFound();
+        revert InvalidTargetStateCommitment();
     }
 }
 ```
@@ -206,7 +206,7 @@ function getTargetStateCommitment(bytes calldata input)
     targetStateCommitment = checkpoint.blockHash;
 
     if (targetStateCommitment == bytes32(0)) {
-        revert TargetBlockHashNotFound();
+        revert InvalidTargetStateCommitment();
     }
 }
 ```
@@ -239,7 +239,7 @@ function verifyTargetStateCommitment(bytes32 homeBlockHash, bytes calldata input
     );
 
     if (targetStateCommitment == bytes32(0)) {
-        revert TargetBlockHashNotFound();
+        revert InvalidTargetStateCommitment();
     }
 }
 ```

snapshots/verifyBroadcastMessage.json

@@ -1,9 +1,9 @@
 {
   "EthereumToOptimism": "1639239",
-  "EthereumToTaikoL2": "1052214",
-  "LineaL2ToEthereum": "2551776",
-  "ScrollL2ToEthereum": "1361940",
+  "EthereumToTaikoL2": "1052244",
+  "LineaL2ToEthereum": "2551806",
+  "ScrollL2ToEthereum": "1361970",
   "ScrollToOptimism": "1348710",
-  "TaikoL2ToEthereum": "1022277",
-  "ZkSyncL2ToEthereum": "125663"
+  "TaikoL2ToEthereum": "1022307",
+  "ZkSyncL2ToEthereum": "125693"
 }

src/contracts/provers/arbitrum/ChildToParentProver.sol

@@ -23,6 +23,7 @@ contract ChildToParentProver is IStateProver {
 
     error CallNotOnHomeChain();
     error CallOnHomeChain();
+    error InvalidTargetStateCommitment();
 
     constructor(uint256 _homeChainId) {
         homeChainId = _homeChainId;
@@ -51,6 +52,8 @@ contract ChildToParentProver is IStateProver {
         targetStateCommitment = ProverUtils.getSlotFromBlockHeader(
             homeBlockHash, rlpBlockHeader, BLOCK_HASH_BUFFER, slot, accountProof, storageProof
         );
+
+        require(targetStateCommitment != bytes32(0), InvalidTargetStateCommitment());
     }
 
     /// @notice Get a parent chain block hash from the buffer at `BLOCK_HASH_BUFFER`.
@@ -64,6 +67,7 @@ contract ChildToParentProver is IStateProver {
 
         // get the block hash from the buffer
         targetStateCommitment = IBuffer(BLOCK_HASH_BUFFER).parentChainBlockHash(targetBlockNumber);
+        require(targetStateCommitment != bytes32(0), InvalidTargetStateCommitment());
     }
 
     /// @notice Verify a storage slot given a target chain block hash and a proof.

src/contracts/provers/arbitrum/ParentToChildProver.sol

@@ -22,7 +22,7 @@ contract ParentToChildProver is IStateProver {
 
     error CallNotOnHomeChain();
     error CallOnHomeChain();
-    error TargetBlockHashNotFound();
+    error InvalidTargetStateCommitment();
 
     constructor(address _outbox, uint256 _rootsSlot, uint256 _homeChainId) {
         outbox = _outbox;
@@ -54,9 +54,7 @@ contract ParentToChildProver is IStateProver {
         targetStateCommitment =
             ProverUtils.getSlotFromBlockHeader(homeBlockHash, rlpBlockHeader, outbox, slot, accountProof, storageProof);
 
-        if (targetStateCommitment == bytes32(0)) {
-            revert TargetBlockHashNotFound();
-        }
+        require(targetStateCommitment != bytes32(0), InvalidTargetStateCommitment());
     }
 
     /// @notice Get a target chain block hash given a target chain sendRoot
@@ -71,9 +69,7 @@ contract ParentToChildProver is IStateProver {
         // get the target block hash from the outbox
         targetStateCommitment = IOutbox(outbox).roots(sendRoot);
 
-        if (targetStateCommitment == bytes32(0)) {
-            revert TargetBlockHashNotFound();
-        }
+        require(targetStateCommitment != bytes32(0), InvalidTargetStateCommitment());
     }
 
     /// @notice Verify a storage slot given a target chain block hash and a proof.

src/contracts/provers/linea/ChildToParentProver.sol

@@ -21,6 +21,7 @@ contract ChildToParentProver is IStateProver {
 
     error CallNotOnHomeChain();
     error CallOnHomeChain();
+    error InvalidTargetStateCommitment();
 
     constructor(address _blockHashBuffer, uint256 _homeChainId) {
         blockHashBuffer = _blockHashBuffer;
@@ -50,6 +51,7 @@ contract ChildToParentProver is IStateProver {
         targetStateCommitment = ProverUtils.getSlotFromBlockHeader(
             homeBlockHash, rlpBlockHeader, blockHashBuffer, slot, accountProof, storageProof
         );
+        require(targetStateCommitment != bytes32(0), InvalidTargetStateCommitment());
     }
 
     /// @notice Get a parent chain block hash from the buffer at `blockHashBuffer`.
@@ -63,6 +65,7 @@ contract ChildToParentProver is IStateProver {
 
         // get the block hash from the buffer
         targetStateCommitment = IBuffer(blockHashBuffer).parentChainBlockHash(targetBlockNumber);
+        require(targetStateCommitment != bytes32(0), InvalidTargetStateCommitment());
     }
 
     /// @notice Verify a storage slot given a target chain block hash and a proof.

src/contracts/provers/linea/ParentToChildProver.sol

@@ -36,6 +36,7 @@ contract ParentToChildProver is IStateProver {
     error AccountKeyMismatch();
     error AccountValueMismatch();
     error StorageKeyMismatch();
+    error InvalidTargetStateCommitment();
 
     constructor(address _lineaRollup, uint256 _stateRootHashesSlot, uint256 _homeChainId) {
         lineaRollup = _lineaRollup;
@@ -71,9 +72,7 @@ contract ParentToChildProver is IStateProver {
             homeStateCommitment, rlpBlockHeader, lineaRollup, slot, accountProof, storageProof
         );
 
-        if (targetStateCommitment == bytes32(0)) {
-            revert TargetStateRootNotFound();
-        }
+        require(targetStateCommitment != bytes32(0), InvalidTargetStateCommitment());
     }
 
     /// @notice Get L2 state root directly from L1 LineaRollup
@@ -91,9 +90,7 @@ contract ParentToChildProver is IStateProver {
         // Get the state root from LineaRollup
         targetStateCommitment = ZkEvmV2(lineaRollup).stateRootHashes(l2BlockNumber);
 
-        if (targetStateCommitment == bytes32(0)) {
-            revert TargetStateRootNotFound();
-        }
+        require(targetStateCommitment != bytes32(0), TargetStateRootNotFound());
     }
 
     /// @notice Verify a storage slot given a target chain state root and a Sparse Merkle Tree proof

src/contracts/provers/optimism/ChildToParentProver.sol

@@ -25,6 +25,7 @@ contract ChildToParentProver is IStateProver {
 
     error CallNotOnHomeChain();
     error CallOnHomeChain();
+    error InvalidTargetStateCommitment();
 
     constructor(uint256 _homeChainId) {
         homeChainId = _homeChainId;
@@ -52,6 +53,7 @@ contract ChildToParentProver is IStateProver {
         targetStateCommitment = ProverUtils.getSlotFromBlockHeader(
             homeBlockHash, rlpBlockHeader, L1_BLOCK_PREDEPLOY, L1_BLOCK_HASH_SLOT, accountProof, storageProof
         );
+        require(targetStateCommitment != bytes32(0), InvalidTargetStateCommitment());
     }
 
     /// @notice Get the latest parent chain block hash from the L1Block predeploy. Bytes argument is ignored.

src/contracts/provers/optimism/ParentToChildProver.sol

@@ -41,6 +41,7 @@ contract ParentToChildProver is IStateProver {
     error InvalidGameProxyCode();
     error InvalidRootClaimPreimage();
     error InvalidGameProxy();
+    error InvalidTargetStateCommitment();
 
     constructor(address _anchorStateRegistry, uint256 _homeChainId) {
         anchorStateRegistry = _anchorStateRegistry;
@@ -118,7 +119,8 @@ contract ParentToChildProver is IStateProver {
         }
 
         // return the target block hash from the root claim preimage
-        return rootClaimPreimage.latestBlockhash;
+        targetStateCommitment = rootClaimPreimage.latestBlockhash;
+        require(targetStateCommitment != bytes32(0), InvalidTargetStateCommitment());
     }
 
     /// @notice Return the blockhash from a valid fault dispute game's root claim. The game's claim must be considered valid by the anchor state registry.

src/contracts/provers/scroll/ChildToParentProver.sol

@@ -22,6 +22,7 @@ contract ChildToParentProver is IStateProver {
 
     error CallNotOnHomeChain();
     error CallOnHomeChain();
+    error InvalidTargetStateCommitment();
 
     constructor(address _blockHashBuffer, uint256 _homeChainId) {
         blockHashBuffer = _blockHashBuffer;
@@ -51,6 +52,7 @@ contract ChildToParentProver is IStateProver {
         targetStateCommitment = ProverUtils.getSlotFromBlockHeader(
             homeBlockHash, rlpBlockHeader, blockHashBuffer, slot, accountProof, storageProof
         );
+        require(targetStateCommitment != bytes32(0), InvalidTargetStateCommitment());
     }
 
     /// @notice Get a parent chain block hash from the buffer at `blockHashBuffer`.
@@ -64,6 +66,7 @@ contract ChildToParentProver is IStateProver {
 
         // get the block hash from the buffer
         targetStateCommitment = IBuffer(blockHashBuffer).parentChainBlockHash(targetBlockNumber);
+        require(targetStateCommitment != bytes32(0), InvalidTargetStateCommitment());
     }
 
     /// @notice Verify a storage slot given a target chain block hash and a proof.

src/contracts/provers/scroll/ParentToChildProver.sol

@@ -30,7 +30,7 @@ contract ParentToChildProver is IStateProver {
 
     error CallNotOnHomeChain();
     error CallOnHomeChain();
-    error StateRootNotFound();
+    error InvalidTargetStateCommitment();
 
     /// @param _scrollChain Address of the ScrollChain contract on L1
     /// @param _finalizedStateRootsSlot Storage slot of the finalizedStateRoots mapping
@@ -68,9 +68,7 @@ contract ParentToChildProver is IStateProver {
             homeBlockHash, rlpBlockHeader, scrollChain, slot, accountProof, storageProof
         );
 
-        if (targetStateCommitment == bytes32(0)) {
-            revert StateRootNotFound();
-        }
+        require(targetStateCommitment != bytes32(0), InvalidTargetStateCommitment());
     }
 
     /// @notice Get L2 state root directly from L1 ScrollChain
@@ -88,9 +86,7 @@ contract ParentToChildProver is IStateProver {
         // Get the state root from ScrollChain
         targetStateCommitment = IScrollChain(scrollChain).finalizedStateRoots(batchIndex);
 
-        if (targetStateCommitment == bytes32(0)) {
-            revert StateRootNotFound();
-        }
+        require(targetStateCommitment != bytes32(0), InvalidTargetStateCommitment());
     }
 
     /// @notice Verify a storage slot given an L2 state root and a proof

src/contracts/provers/taiko/ChildToParentProver.sol

@@ -34,7 +34,7 @@ contract ChildToParentProver is IStateProver {
 
     error CallNotOnHomeChain();
     error CallOnHomeChain();
-    error TargetBlockHashNotFound();
+    error InvalidTargetStateCommitment();
 
     constructor(address _signalService, uint256 _checkpointsSlot, uint256 _homeChainId) {
         signalService = _signalService;
@@ -70,9 +70,7 @@ contract ChildToParentProver is IStateProver {
             homeBlockHash, rlpBlockHeader, signalService, slot, accountProof, storageProof
         );
 
-        if (targetStateCommitment == bytes32(0)) {
-            revert TargetBlockHashNotFound();
-        }
+        require(targetStateCommitment != bytes32(0), InvalidTargetStateCommitment());
     }
 
     /// @notice Get L1 block hash directly from L2 SignalService
@@ -92,9 +90,7 @@ contract ChildToParentProver is IStateProver {
 
         targetStateCommitment = checkpoint.blockHash;
 
-        if (targetStateCommitment == bytes32(0)) {
-            revert TargetBlockHashNotFound();
-        }
+        require(targetStateCommitment != bytes32(0), InvalidTargetStateCommitment());
     }
 
     /// @notice Verify a storage slot given a target chain block hash and a proof

src/contracts/provers/taiko/ParentToChildProver.sol

@@ -34,7 +34,7 @@ contract ParentToChildProver is IStateProver {
 
     error CallNotOnHomeChain();
     error CallOnHomeChain();
-    error TargetBlockHashNotFound();
+    error InvalidTargetStateCommitment();
 
     constructor(address _signalService, uint256 _checkpointsSlot, uint256 _homeChainId) {
         signalService = _signalService;
@@ -70,9 +70,7 @@ contract ParentToChildProver is IStateProver {
             homeBlockHash, rlpBlockHeader, signalService, slot, accountProof, storageProof
         );
 
-        if (targetStateCommitment == bytes32(0)) {
-            revert TargetBlockHashNotFound();
-        }
+        require(targetStateCommitment != bytes32(0), InvalidTargetStateCommitment());
     }
 
     /// @notice Get L2 block hash directly from L1 SignalService
@@ -92,9 +90,7 @@ contract ParentToChildProver is IStateProver {
 
         targetStateCommitment = checkpoint.blockHash;
 
-        if (targetStateCommitment == bytes32(0)) {
-            revert TargetBlockHashNotFound();
-        }
+        require(targetStateCommitment != bytes32(0), InvalidTargetStateCommitment());
     }
 
     /// @notice Verify a storage slot given a target chain block hash and a proof

src/contracts/provers/zksync/ChildToParentProver.sol

@@ -22,6 +22,7 @@ contract ChildToParentProver is IStateProver {
 
     error CallNotOnHomeChain();
     error CallOnHomeChain();
+    error InvalidTargetStateCommitment();
 
     constructor(address _blockHashBuffer, uint256 _homeChainId) {
         blockHashBuffer = _blockHashBuffer;
@@ -51,6 +52,7 @@ contract ChildToParentProver is IStateProver {
         targetStateCommitment = ProverUtils.getSlotFromBlockHeader(
             homeBlockHash, rlpBlockHeader, blockHashBuffer, slot, accountProof, storageProof
         );
+        require(targetStateCommitment != bytes32(0), InvalidTargetStateCommitment());
     }
 
     /// @notice Get a parent chain block hash from the buffer at `blockHashBuffer`.
@@ -64,6 +66,7 @@ contract ChildToParentProver is IStateProver {
 
         // get the block hash from the buffer
         targetStateCommitment = IBuffer(blockHashBuffer).parentChainBlockHash(targetBlockNumber);
+        require(targetStateCommitment != bytes32(0), InvalidTargetStateCommitment());
     }
 
     /// @notice Verify a storage slot given a target chain block hash and a proof.

src/contracts/provers/zksync/ParentToChildProver.sol

@@ -97,6 +97,9 @@ contract ParentToChildProver is IStateProver {
     /// @notice Error thrown when the slot does not match the expected slot.
     error SlotMismatch();
 
+    /// @notice Error thrown when the target state commitment is invalid.
+    error InvalidTargetStateCommitment();
+
     constructor(
         address _gatewayZkChain,
         uint256 _l2LogsRootHashSlot,
@@ -138,6 +141,7 @@ contract ParentToChildProver is IStateProver {
         targetStateCommitment = ProverUtils.getSlotFromBlockHeader(
             homeStateCommitment, rlpBlockHeader, address(gatewayZkChain), slot, accountProof, storageProof
         );
+        require(targetStateCommitment != bytes32(0), InvalidTargetStateCommitment());
     }
 
     /// @notice Get a target chain L2 logs root hash given a batch number.
@@ -154,9 +158,7 @@ contract ParentToChildProver is IStateProver {
         uint256 batchNumber = abi.decode(input, (uint256));
         targetStateCommitment = gatewayZkChain.l2LogsRootHash(batchNumber);
 
-        if (targetStateCommitment == bytes32(0)) {
-            revert L2LogsRootHashNotFound();
-        }
+        require(targetStateCommitment != bytes32(0), L2LogsRootHashNotFound());
     }
 
     /// @notice Verify a storage slot given a target chain L2 logs root hash and a proof.

test/provers/scroll/ParentToChildProver.t.sol

@@ -122,7 +122,7 @@ contract ScrollChainMock is IScrollChain {
 
             bytes memory input = abi.encode(batchIndex);
 
-            vm.expectRevert(ParentToChildProver.StateRootNotFound.selector);
+            vm.expectRevert(ParentToChildProver.InvalidTargetStateCommitment.selector);
             parentToChildProver.getTargetStateCommitment(input);
         }