fix: change messageHash back to only message

packages/contracts/contracts/Home.sol

@@ -65,7 +65,6 @@ contract Home is Version0, QueueManager, MerkleTreeManager, SynapseBase {
         uint256 indexed leafIndex,
         uint64 indexed destinationAndNonce,
         bytes32 committedRoot,
-        uint32 optimisticSeconds,
         bytes message
     );
 
@@ -189,7 +188,7 @@ contract Home is Version0, QueueManager, MerkleTreeManager, SynapseBase {
             _messageBody
         );
         // insert the hashed message into the Merkle tree
-        bytes32 _messageHash = keccak256(abi.encodePacked(_message, _optimisticSeconds));
+        bytes32 _messageHash = keccak256(_message);
         tree.insert(_messageHash);
         // enqueue the new Merkle root after inserting the message
         queue.enqueue(root());
@@ -200,7 +199,6 @@ contract Home is Version0, QueueManager, MerkleTreeManager, SynapseBase {
             count() - 1,
             _destinationAndNonce(_destinationDomain, _nonce),
             committedRoot,
-            _optimisticSeconds,
             _message
         );
     }

packages/contracts/contracts/ReplicaManager.sol

@@ -247,11 +247,10 @@ contract ReplicaManager is Version0, Initializable, OwnableUpgradeable {
     function proveAndProcess(
         uint32 _remoteDomain,
         bytes memory _message,
-        uint32 _optimisticSeconds,
         bytes32[32] calldata _proof,
         uint256 _index
     ) external {
-        require(prove(_remoteDomain, _message, _optimisticSeconds, _proof, _index), "!prove");
+        require(prove(_remoteDomain, _message, _proof, _index), "!prove");
         process(_message);
     }
 
@@ -404,26 +403,25 @@ contract ReplicaManager is Version0, Initializable, OwnableUpgradeable {
      * @dev For convenience, we allow proving against any previous root.
      * This means that witnesses never need to be updated for the new root
      * @param _message Formatted message
-     * @param _optimisticSeconds Latency period requested by app on Home, included in part of Merkle proof
      * @param _proof Merkle proof of inclusion for leaf
      * @param _index Index of leaf in home's merkle tree
      * @return Returns true if proof was valid and `prove` call succeeded
      **/
     function prove(
         uint32 _remoteDomain,
         bytes memory _message,
-        uint32 _optimisticSeconds,
         bytes32[32] calldata _proof,
         uint256 _index
     ) public returns (bool) {
-        bytes32 _leaf = keccak256(abi.encodePacked(_message, _optimisticSeconds));
+        uint32 optimisticSeconds = _message.ref(0).optimisticSeconds();
+        bytes32 _leaf = keccak256(_message);
         ReplicaLib.Replica storage replica = allReplicas[activeReplicas[_remoteDomain]];
         // ensure that message has not been proven or processed
         require(replica.messages[_leaf] == ReplicaLib.MessageStatus.None, "!MessageStatus.None");
         // calculate the expected root based on the proof
         bytes32 _calculatedRoot = MerkleLib.branchRoot(_leaf, _proof, _index);
         // if the root is valid, change status to Proven
-        if (acceptableRoot(_remoteDomain, _optimisticSeconds, _calculatedRoot)) {
+        if (acceptableRoot(_remoteDomain, optimisticSeconds, _calculatedRoot)) {
             replica.setMessageStatus(_leaf, ReplicaLib.MessageStatus.Processed);
             return true;
         }

packages/contracts/test/Home.t.sol

@@ -85,7 +85,6 @@ contract HomeTest is SynapseTestWithUpdaterManager {
         uint256 indexed leafIndex,
         uint64 indexed destinationAndNonce,
         bytes32 committedRoot,
-        uint32 optimisticSeconds,
         bytes message
     );
 
@@ -104,14 +103,13 @@ contract HomeTest is SynapseTestWithUpdaterManager {
             optimisticSeconds,
             messageBody
         );
-        bytes32 messageHash = keccak256(abi.encodePacked(message, optimisticSeconds));
+        bytes32 messageHash = keccak256(message);
         vm.expectEmit(true, true, true, true);
         emit Dispatch(
             messageHash,
             home.count(),
             (uint64(remoteDomain) << 32) | nonce,
             home.committedRoot(),
-            optimisticSeconds,
             message
         );
         vm.prank(sender);

packages/contracts/test/ReplicaManager.t.sol

@@ -121,7 +121,7 @@ contract ReplicaManagerTest is SynapseTest {
     // Relayer relays a new root signed by updater on Home chain
     function test_successfulUpdate() public {
         bytes memory newMessage = "new root";
-        bytes32 newRoot = keccak256(abi.encodePacked(newMessage, optimisticSeconds));
+        bytes32 newRoot = keccak256(newMessage);
         assertEq(replicaManager.updater(), vm.addr(updaterPK));
         bytes memory sig = signRemoteUpdate(updaterPK, committedRoot, newRoot);
         // Root doesn't exist yet
@@ -144,15 +144,15 @@ contract ReplicaManagerTest is SynapseTest {
 
     function test_updateWithIncorrectSig() public {
         bytes memory newMessage = "new root";
-        bytes32 newRoot = keccak256(abi.encodePacked(newMessage, optimisticSeconds));
+        bytes32 newRoot = keccak256(newMessage);
         bytes memory sig = signRemoteUpdate(fakeUpdaterPK, committedRoot, newRoot);
         vm.expectRevert("!updater sig");
         replicaManager.update(remoteDomain, committedRoot, newRoot, sig);
     }
 
     function test_acceptableRoot() public {
         bytes memory newMessage = "new root";
-        bytes32 newRoot = keccak256(abi.encodePacked(newMessage, optimisticSeconds));
+        bytes32 newRoot = keccak256(newMessage);
         test_successfulUpdate();
         vm.warp(block.timestamp + optimisticSeconds + 1);
         assertTrue(replicaManager.acceptableRoot(remoteDomain, optimisticSeconds, newRoot));