You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
346 lines
13 KiB
346 lines
13 KiB
// SPDX-License-Identifier: MIT OR Apache-2.0
|
|
pragma solidity >=0.6.11;
|
|
|
|
// ============ Internal Imports ============
|
|
import {Version0} from "./Version0.sol";
|
|
import {Common} from "./Common.sol";
|
|
import {QueueLib} from "../libs/Queue.sol";
|
|
import {MerkleLib} from "../libs/Merkle.sol";
|
|
import {Message} from "../libs/Message.sol";
|
|
import {MerkleTreeManager} from "./Merkle.sol";
|
|
import {IUpdaterManager} from "../interfaces/IUpdaterManager.sol";
|
|
// ============ External Imports ============
|
|
import {Address} from "@openzeppelin/contracts/utils/Address.sol";
|
|
import {OwnableUpgradeable} from "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
|
|
|
|
/**
|
|
* @title Home
|
|
* @author Celo Labs Inc.
|
|
* @notice Accepts messages to be dispatched to remote chains,
|
|
* constructs a Merkle tree of the messages,
|
|
* and accepts signatures from a bonded Updater
|
|
* which notarize the Merkle tree roots.
|
|
* Accepts submissions of fraudulent signatures
|
|
* by the Updater and slashes the Updater in this case.
|
|
*/
|
|
contract Home is Version0, MerkleTreeManager, Common, OwnableUpgradeable {
|
|
// ============ Libraries ============
|
|
|
|
using QueueLib for QueueLib.Queue;
|
|
using MerkleLib for MerkleLib.Tree;
|
|
|
|
// ============ Constants ============
|
|
|
|
// Maximum bytes per message = 2 KiB
|
|
// (somewhat arbitrarily set to begin)
|
|
uint256 public constant MAX_MESSAGE_BODY_BYTES = 2 * 2**10;
|
|
|
|
// ============ Public Storage Variables ============
|
|
|
|
// domain => next available nonce
|
|
mapping(uint32 => uint32) public sequences;
|
|
// contract responsible for Updater bonding, slashing and rotation
|
|
IUpdaterManager public updaterManager;
|
|
|
|
// ============ Upgrade Gap ============
|
|
|
|
// gap for upgrade safety
|
|
uint256[48] private __GAP;
|
|
|
|
// ============ Events ============
|
|
|
|
/**
|
|
* @notice Emitted when a new message is enqueued
|
|
* @param leafIndex Index of message's leaf in merkle tree
|
|
* @param destinationAndSequence Destination and destination-specific
|
|
* sequence combined in single field ((destination << 32) & sequence)
|
|
* @param leaf Hash of formatted message; the leaf inserted to the Merkle tree for the message
|
|
* @param current the latest notarized root submitted in the last signed Update
|
|
* @param message Raw bytes of enqueued message
|
|
*/
|
|
event Dispatch(
|
|
uint256 indexed leafIndex,
|
|
uint64 indexed destinationAndSequence,
|
|
bytes32 indexed leaf,
|
|
bytes32 current,
|
|
bytes message
|
|
);
|
|
|
|
/**
|
|
* @notice Emitted when proof of an improper update is submitted,
|
|
* which sets the contract to FAILED state
|
|
* @param oldRoot Old root of the improper update
|
|
* @param newRoot New root of the improper update
|
|
* @param signature Signature on `oldRoot` and `newRoot
|
|
*/
|
|
event ImproperUpdate(bytes32 oldRoot, bytes32 newRoot, bytes signature);
|
|
|
|
/**
|
|
* @notice Emitted when the Updater is slashed
|
|
* (should be paired with ImproperUpdater or DoubleUpdate event)
|
|
* @param updater The address of the updater
|
|
* @param reporter The address of the entity that reported the updater misbehavior
|
|
*/
|
|
event UpdaterSlashed(address indexed updater, address indexed reporter);
|
|
|
|
/**
|
|
* @notice Emitted when Updater is rotated by the UpdaterManager
|
|
* @param updater The address of the new updater
|
|
*/
|
|
event NewUpdater(address updater);
|
|
|
|
/**
|
|
* @notice Emitted when the UpdaterManager contract is changed
|
|
* @param updaterManager The address of the new updaterManager
|
|
*/
|
|
event NewUpdaterManager(address updaterManager);
|
|
|
|
// ============ Constructor ============
|
|
|
|
constructor(uint32 _localDomain) Common(_localDomain) {} // solhint-disable-line no-empty-blocks
|
|
|
|
// ============ Initializer ============
|
|
|
|
function initialize(IUpdaterManager _updaterManager) public initializer {
|
|
// initialize owner
|
|
__Ownable_init();
|
|
// set Updater Manager contract and initialize Updater
|
|
_setUpdaterManager(_updaterManager);
|
|
address _updater = updaterManager.updater();
|
|
__Common_initialize(_updater);
|
|
emit NewUpdater(_updater);
|
|
}
|
|
|
|
// ============ Modifiers ============
|
|
|
|
/**
|
|
* @notice Ensures that function is called by the UpdaterManager contract
|
|
*/
|
|
modifier onlyUpdaterManager() {
|
|
require(msg.sender == address(updaterManager), "!updaterManager");
|
|
_;
|
|
}
|
|
|
|
// ============ External: Updater & UpdaterManager Configuration ============
|
|
|
|
/**
|
|
* @notice Set a new Updater
|
|
* @param _updater the new Updater
|
|
*/
|
|
function setUpdater(address _updater) external onlyUpdaterManager {
|
|
_setUpdater(_updater);
|
|
}
|
|
|
|
/**
|
|
* @notice Set a new UpdaterManager contract
|
|
* @dev Home(s) will initially be initialized using a trusted UpdaterManager contract;
|
|
* we will progressively decentralize by swapping the trusted contract with a new implementation
|
|
* that implements Updater bonding & slashing, and rules for Updater selection & rotation
|
|
* @param _updaterManager the new UpdaterManager contract
|
|
*/
|
|
function setUpdaterManager(address _updaterManager) external onlyOwner {
|
|
_setUpdaterManager(IUpdaterManager(_updaterManager));
|
|
}
|
|
|
|
// ============ External Functions ============
|
|
|
|
/**
|
|
* @notice Dispatch the message it to the destination domain & recipient
|
|
* @dev Format the message, insert its hash into Merkle tree,
|
|
* enqueue the new Merkle root, and emit `Dispatch` event with message information.
|
|
* @param _destinationDomain Domain of destination chain
|
|
* @param _recipientAddress Address of recipient on destination chain as bytes32
|
|
* @param _messageBody Raw bytes content of message
|
|
*/
|
|
function enqueue(
|
|
uint32 _destinationDomain,
|
|
bytes32 _recipientAddress,
|
|
bytes memory _messageBody
|
|
) external notFailed {
|
|
require(_messageBody.length <= MAX_MESSAGE_BODY_BYTES, "msg too long");
|
|
// get the next sequence for the destination domain, then increment it
|
|
uint32 _sequence = sequences[_destinationDomain];
|
|
sequences[_destinationDomain] = _sequence + 1;
|
|
// format the message into packed bytes
|
|
bytes memory _message = Message.formatMessage(
|
|
localDomain,
|
|
bytes32(uint256(uint160(msg.sender))),
|
|
_sequence,
|
|
_destinationDomain,
|
|
_recipientAddress,
|
|
_messageBody
|
|
);
|
|
// insert the hashed message into the Merkle tree
|
|
bytes32 _messageHash = keccak256(_message);
|
|
tree.insert(_messageHash);
|
|
// enqueue the new Merkle root after inserting the message
|
|
queue.enqueue(root());
|
|
// Emit Dispatch event with message information
|
|
// note: leafIndex is count() - 1 since new leaf has already been inserted
|
|
emit Dispatch(
|
|
count() - 1,
|
|
_destinationAndSequence(_destinationDomain, _sequence),
|
|
_messageHash,
|
|
current,
|
|
_message
|
|
);
|
|
}
|
|
|
|
/**
|
|
* @notice Submit a signature from the Updater "notarizing" an enqueued root,
|
|
* which updates the Home contract's `current` root,
|
|
* and publishes the signature which will be relayed to Replica contracts
|
|
* @dev emits Update event
|
|
* @dev If _newRoot is not contained in the queue,
|
|
* the Update is a fraudulent Improper Update, so
|
|
* the Updater is slashed & Home is set to FAILED state
|
|
* @param _currentRoot Current updated merkle root which the update is building off of
|
|
* @param _newRoot New merkle root to update the contract state to
|
|
* @param _signature Updater signature on `_currentRoot` and `_newRoot`
|
|
*/
|
|
function update(
|
|
bytes32 _currentRoot,
|
|
bytes32 _newRoot,
|
|
bytes memory _signature
|
|
) external notFailed {
|
|
// check that the update is not fraudulent;
|
|
// if fraud is detected, Updater is slashed & Home is set to FAILED state
|
|
if (improperUpdate(_currentRoot, _newRoot, _signature)) return;
|
|
// clear all of the intermediate roots contained in this update from the queue
|
|
while (true) {
|
|
bytes32 _next = queue.dequeue();
|
|
if (_next == _newRoot) break;
|
|
}
|
|
// update the Home state with the latest signed root & emit event
|
|
current = _newRoot;
|
|
emit Update(localDomain, _currentRoot, _newRoot, _signature);
|
|
}
|
|
|
|
/**
|
|
* @notice Suggest an update for the Updater to sign and submit.
|
|
* @dev If queue is empty, null bytes returned for both
|
|
* (No update is necessary because no messages have been dispatched since the last update)
|
|
* @return _current Latest updated root
|
|
* @return _new Latest enqueued root
|
|
*/
|
|
function suggestUpdate()
|
|
external
|
|
view
|
|
returns (bytes32 _current, bytes32 _new)
|
|
{
|
|
if (queue.length() != 0) {
|
|
_current = current;
|
|
_new = queue.lastItem();
|
|
}
|
|
}
|
|
|
|
// ============ Public Functions ============
|
|
|
|
/**
|
|
* @notice Hash of Home domain concatenated with "OPTICS"
|
|
*/
|
|
function homeDomainHash() public view override returns (bytes32) {
|
|
return _homeDomainHash(localDomain);
|
|
}
|
|
|
|
/**
|
|
* @notice Check if an Update is an Improper Update;
|
|
* if so, slash the Updater and set the contract to FAILED state.
|
|
*
|
|
* An Improper Update is an update building off of the Home's `current` root
|
|
* for which the `_newRoot` does not currently exist in the Home's queue.
|
|
* This would mean that message(s) that were not truly
|
|
* dispatched on Home were falsely included in the signed root.
|
|
*
|
|
* An Improper Update will only be accepted as valid by the Replica
|
|
* If an Improper Update is attempted on Home,
|
|
* the Updater will be slashed immediately.
|
|
* If an Improper Update is submitted to the Replica,
|
|
* it should be relayed to the Home contract using this function
|
|
* in order to slash the Updater with an Improper Update.
|
|
*
|
|
* An Improper Update submitted to the Replica is only valid
|
|
* while the `_oldRoot` is still equal to the `current` root on Home;
|
|
* if the `current` root on Home has already been updated with a valid Update,
|
|
* then the Updater should be slashed with a Double Update.
|
|
* @dev Reverts (and doesn't slash updater) if signature is invalid or
|
|
* update not current
|
|
* @param _oldRoot Old merkle tree root (should equal home's current root)
|
|
* @param _newRoot New merkle tree root
|
|
* @param _signature Updater signature on `_oldRoot` and `_newRoot`
|
|
* @return TRUE if update was an Improper Update (implying Updater was slashed)
|
|
*/
|
|
function improperUpdate(
|
|
bytes32 _oldRoot,
|
|
bytes32 _newRoot,
|
|
bytes memory _signature
|
|
) public notFailed returns (bool) {
|
|
require(
|
|
_isUpdaterSignature(_oldRoot, _newRoot, _signature),
|
|
"!updater sig"
|
|
);
|
|
require(_oldRoot == current, "not a current update");
|
|
// if the _newRoot is not currently contained in the queue,
|
|
// slash the Updater and set the contract to FAILED state
|
|
if (!queue.contains(_newRoot)) {
|
|
_fail();
|
|
emit ImproperUpdate(_oldRoot, _newRoot, _signature);
|
|
return true;
|
|
}
|
|
// if the _newRoot is contained in the queue,
|
|
// this is not an improper update
|
|
return false;
|
|
}
|
|
|
|
// ============ Internal Functions ============
|
|
|
|
/**
|
|
* @notice Set the UpdaterManager
|
|
* @param _updaterManager Address of the UpdaterManager
|
|
*/
|
|
function _setUpdaterManager(IUpdaterManager _updaterManager) internal {
|
|
require(
|
|
Address.isContract(address(_updaterManager)),
|
|
"!contract updaterManager"
|
|
);
|
|
updaterManager = IUpdaterManager(_updaterManager);
|
|
emit NewUpdaterManager(address(_updaterManager));
|
|
}
|
|
|
|
/**
|
|
* @notice Set the Updater
|
|
* @param _updater Address of the Updater
|
|
*/
|
|
function _setUpdater(address _updater) internal {
|
|
updater = _updater;
|
|
emit NewUpdater(_updater);
|
|
}
|
|
|
|
/**
|
|
* @notice Slash the Updater and set contract state to FAILED
|
|
* @dev Called when fraud is proven (Improper Update or Double Update)
|
|
*/
|
|
function _fail() internal override {
|
|
// set contract to FAILED
|
|
_setFailed();
|
|
// slash Updater
|
|
updaterManager.slashUpdater(msg.sender);
|
|
emit UpdaterSlashed(updater, msg.sender);
|
|
}
|
|
|
|
/**
|
|
* @notice Internal utility function that combines
|
|
* `_destination` and `_sequence`.
|
|
* @dev Both destination and sequence should be less than 2^32 - 1
|
|
* @param _destination Domain of destination chain
|
|
* @param _sequence Current sequence for given destination chain
|
|
* @return Returns (`_destination` << 32) & `_sequence`
|
|
*/
|
|
function _destinationAndSequence(uint32 _destination, uint32 _sequence)
|
|
internal
|
|
pure
|
|
returns (uint64)
|
|
{
|
|
return (uint64(_destination) << 32) | _sequence;
|
|
}
|
|
}
|
|
|