Contract Name:
ValidatorPool
Contract Source Code:
// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;
import {
ReentrancyGuardUpgradeable
} from "@openzeppelin/contracts-upgradeable/security/ReentrancyGuardUpgradeable.sol";
import { Math } from "@openzeppelin/contracts/utils/math/Math.sol";
import { Constants } from "../libraries/Constants.sol";
import { Predeploys } from "../libraries/Predeploys.sol";
import { SafeCall } from "../libraries/SafeCall.sol";
import { Types } from "../libraries/Types.sol";
import { Semver } from "../universal/Semver.sol";
import { ValidatorRewardVault } from "../L2/ValidatorRewardVault.sol";
import { KromaPortal } from "./KromaPortal.sol";
import { L2OutputOracle } from "./L2OutputOracle.sol";
/**
* @custom:proxied
* @title ValidatorPool
* @notice The ValidatorPool determines whether the validator is present and manages the validator's deposit.
*/
contract ValidatorPool is ReentrancyGuardUpgradeable, Semver {
/**
* @notice The gas limit to use when rewarding validator in the ValidatorRewardVault on L2.
* This value is measured through simulation.
*/
uint64 public constant VAULT_REWARD_GAS_LIMIT = 100000;
/**
* @notice The numerator of the tax.
*/
uint128 public constant TAX_NUMERATOR = 20;
/**
* @notice The denominator of the tax.
*/
uint128 public constant TAX_DENOMINATOR = 100;
/**
* @notice The address of the L2OutputOracle contract. Can be updated via upgrade.
*/
L2OutputOracle public immutable L2_ORACLE;
/**
* @notice The address of the KromaPortal contract. Can be updated via upgrade.
*/
KromaPortal public immutable PORTAL;
/**
* @notice The address of the SecurityCouncil contract. Can be updated via upgrade.
*/
address public immutable SECURITY_COUNCIL;
/**
* @notice The address of the trusted validator. Can be updated via upgrade.
*/
address public immutable TRUSTED_VALIDATOR;
/**
* @notice The required bond amount. Can be updated via upgrade.
*/
uint128 public immutable REQUIRED_BOND_AMOUNT;
/**
* @notice The max number of unbonds when trying unbond.
*/
uint256 public immutable MAX_UNBOND;
/**
* @notice The duration of a submission round for one output (in seconds).
* Note that there are two submission rounds for an output: PRIORITY ROUND and PUBLIC ROUND.
*/
uint256 public immutable ROUND_DURATION;
/**
* @notice A mapping of balances.
*/
mapping(address => uint256) internal balances;
/**
* @notice The bond corresponding to a specific output index.
*/
mapping(uint256 => Types.Bond) internal bonds;
/**
* @notice The output index to unbond next.
*/
uint256 internal nextUnbondOutputIndex;
/**
* @notice An array of validator addresses.
*/
address[] internal validators;
/**
* @notice The index of the specific address in the validator array.
*/
mapping(address => uint256) internal validatorIndexes;
/**
* @notice Address of the next validator with priority for submitting output.
*/
address internal nextPriorityValidator;
/**
* @notice A mapping of pending bonds that have not yet been included in a bond.
*/
mapping(uint256 => mapping(address => uint128)) internal pendingBonds;
/**
* @notice Emitted when a validator bonds.
*
* @param submitter Address of submitter.
* @param outputIndex Index of the L2 checkpoint output index.
* @param amount Amount of bonded.
* @param expiresAt The expiration timestamp of bond.
*/
event Bonded(
address indexed submitter,
uint256 indexed outputIndex,
uint128 amount,
uint128 expiresAt
);
/**
* @notice Emitted when the pending bond is added.
*
* @param outputIndex Index of the L2 checkpoint output.
* @param challenger Address of the challenger.
* @param amount Amount of bond added.
*/
event PendingBondAdded(uint256 indexed outputIndex, address indexed challenger, uint128 amount);
/**
* @notice Emitted when the bond is increased.
*
* @param outputIndex Index of the L2 checkpoint output.
* @param challenger Address of the challenger.
* @param amount Amount of bond increased.
*/
event BondIncreased(uint256 indexed outputIndex, address indexed challenger, uint128 amount);
/**
* @notice Emitted when the pending bond is released(refunded).
*
* @param outputIndex Index of the L2 checkpoint output.
* @param challenger Address of the challenger.
* @param recipient Address to receive amount from a pending bond.
* @param amount Amount of bond released.
*/
event PendingBondReleased(
uint256 indexed outputIndex,
address indexed challenger,
address indexed recipient,
uint128 amount
);
/**
* @notice Emitted when a validator unbonds.
*
* @param outputIndex Index of the L2 checkpoint output.
* @param recipient Address of the recipient.
* @param amount Amount of unbonded.
*/
event Unbonded(uint256 indexed outputIndex, address indexed recipient, uint128 amount);
/**
* @notice A modifier that only allows the Colosseum contract to call
*/
modifier onlyColosseum() {
require(msg.sender == L2_ORACLE.COLOSSEUM(), "ValidatorPool: sender is not Colosseum");
_;
}
/**
* @custom:semver 1.0.1
*
* @param _l2OutputOracle Address of the L2OutputOracle.
* @param _portal Address of the KromaPortal.
* @param _securityCouncil Address of the security council.
* @param _trustedValidator Address of the trusted validator.
* @param _requiredBondAmount The required bond amount.
* @param _maxUnbond The max number of unbonds when trying unbond.
* @param _roundDuration The duration of one submission round in seconds.
*/
constructor(
L2OutputOracle _l2OutputOracle,
KromaPortal _portal,
address _securityCouncil,
address _trustedValidator,
uint256 _requiredBondAmount,
uint256 _maxUnbond,
uint256 _roundDuration
) Semver(1, 0, 1) {
L2_ORACLE = _l2OutputOracle;
PORTAL = _portal;
SECURITY_COUNCIL = _securityCouncil;
TRUSTED_VALIDATOR = _trustedValidator;
REQUIRED_BOND_AMOUNT = uint128(_requiredBondAmount);
MAX_UNBOND = _maxUnbond;
// Note that this value MUST be (SUBMISSION_INTERVAL * L2_BLOCK_TIME) / 2.
ROUND_DURATION = _roundDuration;
initialize();
}
/**
* @notice Initializer.
*/
function initialize() public initializer {
__ReentrancyGuard_init_unchained();
}
/**
* @notice Deposit ETH to be used as bond.
*/
function deposit() external payable {
_increaseBalance(msg.sender, msg.value);
}
/**
* @notice Withdraw a given amount.
*
* @param _amount Amount to withdraw.
*/
function withdraw(uint256 _amount) external nonReentrant {
_decreaseBalance(msg.sender, _amount);
bool success = SafeCall.call(msg.sender, gasleft(), _amount, "");
require(success, "ValidatorPool: ETH transfer failed");
}
/**
* @notice Bond asset corresponding to the given output index.
* This function is called when submitting output.
*
* @param _outputIndex Index of the L2 checkpoint output.
* @param _expiresAt The expiration timestamp of bond.
*/
function createBond(uint256 _outputIndex, uint128 _expiresAt) external {
require(msg.sender == address(L2_ORACLE), "ValidatorPool: sender is not L2OutputOracle");
Types.Bond storage bond = bonds[_outputIndex];
require(
bond.expiresAt == 0,
"ValidatorPool: bond of the given output index already exists"
);
// Unbond the bond of nextUnbondOutputIndex if available.
_tryUnbond();
address submitter = L2_ORACLE.getSubmitter(_outputIndex);
_decreaseBalance(submitter, REQUIRED_BOND_AMOUNT);
bond.amount = REQUIRED_BOND_AMOUNT;
bond.expiresAt = _expiresAt;
emit Bonded(submitter, _outputIndex, REQUIRED_BOND_AMOUNT, _expiresAt);
// Select the next priority validator
_updatePriorityValidator();
}
/**
* @notice Adds a pending bond to the challenge corresponding to the given output index and challenger address.
* The pending bond is added to the bond when the challenge is proven or challenger is timed out,
* or refunded when the challenge is canceled.
*
* @param _outputIndex Index of the L2 checkpoint output.
* @param _challenger Address of the challenger.
*/
function addPendingBond(uint256 _outputIndex, address _challenger) external onlyColosseum {
Types.Bond storage bond = bonds[_outputIndex];
require(
bond.expiresAt >= block.timestamp,
"ValidatorPool: the output is already finalized"
);
_decreaseBalance(_challenger, REQUIRED_BOND_AMOUNT);
pendingBonds[_outputIndex][_challenger] = REQUIRED_BOND_AMOUNT;
emit PendingBondAdded(_outputIndex, _challenger, REQUIRED_BOND_AMOUNT);
}
/**
* @notice Releases the corresponding pending bond to the given output index and challenger address
* if a challenge is canceled.
*
* @param _outputIndex Index of the L2 checkpoint output.
* @param _challenger Address of the challenger.
* @param _recipient Address to receive amount from a pending bond.
*/
function releasePendingBond(
uint256 _outputIndex,
address _challenger,
address _recipient
) external onlyColosseum {
uint128 bonded = pendingBonds[_outputIndex][_challenger];
require(bonded > 0, "ValidatorPool: the pending bond does not exist");
delete pendingBonds[_outputIndex][_challenger];
_increaseBalance(_recipient, bonded);
emit PendingBondReleased(_outputIndex, _challenger, _recipient, bonded);
}
/**
* @notice Increases the bond amount corresponding to the given output index by the pending bond amount.
* This is when taxes are charged, and note that taxes are a means of preventing collusive attacks by
* the asserter and challenger.
*
* @param _outputIndex Index of the L2 checkpoint output.
* @param _challenger Address of the challenger.
*/
function increaseBond(uint256 _outputIndex, address _challenger) external onlyColosseum {
Types.Bond storage bond = bonds[_outputIndex];
require(
bond.expiresAt >= block.timestamp,
"ValidatorPool: the output is already finalized"
);
uint128 pendingBond = pendingBonds[_outputIndex][_challenger];
require(pendingBond > 0, "ValidatorPool: the pending bond does not exist");
uint128 tax = (pendingBond * TAX_NUMERATOR) / TAX_DENOMINATOR;
uint128 increased = pendingBond - tax;
delete pendingBonds[_outputIndex][_challenger];
unchecked {
bond.amount += increased;
balances[SECURITY_COUNCIL] += tax;
}
emit BondIncreased(_outputIndex, _challenger, increased);
}
/**
* @notice Attempt to unbond. Reverts if unbond is not possible.
*/
function unbond() external {
bool released = _tryUnbond();
require(released, "ValidatorPool: no bond that can be unbond");
}
/**
* @notice Attempts to unbond starting from nextUnbondOutputIndex and returns whether at least
* one unbond is executed. Tries unbond at most MAX_UNBOND number of bonds and sends
* a reward message to L2 for each unbond.
*
* @return Whether at least one unbond is executed.
*/
function _tryUnbond() private returns (bool) {
uint256 outputIndex = nextUnbondOutputIndex;
uint128 bondAmount;
Types.Bond storage bond;
Types.CheckpointOutput memory output;
uint256 unbondedNum = 0;
for (; unbondedNum < MAX_UNBOND; ) {
bond = bonds[outputIndex];
bondAmount = bond.amount;
if (block.timestamp >= bond.expiresAt && bondAmount > 0) {
delete bonds[outputIndex];
output = L2_ORACLE.getL2Output(outputIndex);
_increaseBalance(output.submitter, bondAmount);
emit Unbonded(outputIndex, output.submitter, bondAmount);
// Send reward message to L2 ValidatorRewardVault.
_sendRewardMessageToL2Vault(output);
unchecked {
++unbondedNum;
++outputIndex;
}
} else {
break;
}
}
if (unbondedNum > 0) {
unchecked {
nextUnbondOutputIndex = outputIndex;
}
return true;
}
return false;
}
/**
* @notice Updates next priority validator address.
*/
function _updatePriorityValidator() private {
uint256 len = validators.length;
if (len > 0 && nextUnbondOutputIndex > 0) {
// TODO(pangssu): improve next validator selection
Types.CheckpointOutput memory output = L2_ORACLE.getL2Output(nextUnbondOutputIndex - 1);
uint256 validatorIndex = uint256(
keccak256(
abi.encodePacked(
output.outputRoot,
block.number,
block.coinbase,
block.difficulty,
blockhash(block.number - 1)
)
)
) % len;
nextPriorityValidator = validators[validatorIndex];
} else {
nextPriorityValidator = address(0);
}
}
/**
* @notice Sends reward message to ValidatorRewardVault contract on L2 using Portal.
*
* @param _output The finalized output.
*/
function _sendRewardMessageToL2Vault(Types.CheckpointOutput memory _output) private {
// Pay out rewards via L2 Vault now that the output is finalized.
PORTAL.depositTransactionByValidatorPool(
Predeploys.VALIDATOR_REWARD_VAULT,
VAULT_REWARD_GAS_LIMIT,
abi.encodeWithSelector(
ValidatorRewardVault.reward.selector,
_output.submitter,
_output.l2BlockNumber
)
);
}
/**
* @notice Increases the balance of the given address. If the balance is greater than the required bond amount,
* add the given address to the validator set.
*
* @param _validator Address to increase the balance.
* @param _amount Amount of balance increased.
*/
function _increaseBalance(address _validator, uint256 _amount) private {
uint256 balance = balances[_validator] + _amount;
if (balance >= REQUIRED_BOND_AMOUNT && !isValidator(_validator)) {
if (_validator != SECURITY_COUNCIL) {
validatorIndexes[_validator] = validators.length;
validators.push(_validator);
}
}
balances[_validator] = balance;
}
/**
* @notice Deceases the balance of the given address. If the balance is less than the required bond amount,
* remove the given address from the validator set.
*
* @param _validator Address to decrease the balance.
* @param _amount Amount of balance decreased.
*/
function _decreaseBalance(address _validator, uint256 _amount) private {
uint256 balance = balances[_validator];
require(balance >= _amount, "ValidatorPool: insufficient balances");
balance = balance - _amount;
if (balance < REQUIRED_BOND_AMOUNT && isValidator(_validator)) {
uint256 lastValidatorIndex = validators.length - 1;
if (lastValidatorIndex > 0) {
uint256 validatorIndex = validatorIndexes[_validator];
address lastValidator = validators[lastValidatorIndex];
validators[validatorIndex] = lastValidator;
validatorIndexes[lastValidator] = validatorIndex;
}
delete validatorIndexes[_validator];
validators.pop();
}
balances[_validator] = balance;
}
/**
* @notice Returns the bond corresponding to the output index. Reverts if the bond does not exist.
*
* @param _outputIndex Index of the L2 checkpoint output.
*
* @return The bond data.
*/
function getBond(uint256 _outputIndex) external view returns (Types.Bond memory) {
Types.Bond storage bond = bonds[_outputIndex];
require(bond.amount > 0 && bond.expiresAt > 0, "ValidatorPool: the bond does not exist");
return bond;
}
/**
* @notice Returns the pending bond corresponding to the output index and challenger address.
* Reverts if the pending bond does not exist.
*
* @param _outputIndex Index of the L2 checkpoint output.
* @param _challenger Address of the challenger.
*
* @return Amount of the pending bond.
*/
function getPendingBond(uint256 _outputIndex, address _challenger)
external
view
returns (uint128)
{
uint128 pendingBond = pendingBonds[_outputIndex][_challenger];
require(pendingBond > 0, "ValidatorPool: the pending bond does not exist");
return pendingBond;
}
/**
* @notice Returns the balance of given address.
*
* @param _addr Address of validator.
*
* @return Balance of given address.
*/
function balanceOf(address _addr) external view returns (uint256) {
return balances[_addr];
}
/**
* @notice Determines whether the given address is an active validator.
*
* @param _addr Address of validator.
*
* @return Whether the given address is an active validator.
*/
function isValidator(address _addr) public view returns (bool) {
if (validators.length == 0) {
return false;
} else if (_addr == address(0)) {
return false;
}
uint256 index = validatorIndexes[_addr];
return validators[index] == _addr;
}
/**
* @notice Returns the number of validators.
*
* @return The number of validators.
*/
function validatorCount() external view returns (uint256) {
return validators.length;
}
/**
* @notice Determines who can submit the L2 output next.
*
* @return The address of the validator.
*/
function nextValidator() public view returns (address) {
if (nextPriorityValidator != address(0)) {
uint256 l2BlockNumber = L2_ORACLE.nextBlockNumber();
uint256 l2Timestamp = L2_ORACLE.computeL2Timestamp(l2BlockNumber + 1);
if (block.timestamp >= l2Timestamp) {
uint256 elapsed = block.timestamp - l2Timestamp;
// If the current time exceeds one round time, it is a public round.
if (elapsed > ROUND_DURATION) {
return Constants.VALIDATOR_PUBLIC_ROUND_ADDRESS;
}
}
return nextPriorityValidator;
} else {
return TRUSTED_VALIDATOR;
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (security/ReentrancyGuard.sol)
pragma solidity ^0.8.0;
import "../proxy/utils/Initializable.sol";
/**
* @dev Contract module that helps prevent reentrant calls to a function.
*
* Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
* available, which can be applied to functions to make sure there are no nested
* (reentrant) calls to them.
*
* Note that because there is a single `nonReentrant` guard, functions marked as
* `nonReentrant` may not call one another. This can be worked around by making
* those functions `private`, and then adding `external` `nonReentrant` entry
* points to them.
*
* TIP: If you would like to learn more about reentrancy and alternative ways
* to protect against it, check out our blog post
* https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
*/
abstract contract ReentrancyGuardUpgradeable is Initializable {
// Booleans are more expensive than uint256 or any type that takes up a full
// word because each write operation emits an extra SLOAD to first read the
// slot's contents, replace the bits taken up by the boolean, and then write
// back. This is the compiler's defense against contract upgrades and
// pointer aliasing, and it cannot be disabled.
// The values being non-zero value makes deployment a bit more expensive,
// but in exchange the refund on every call to nonReentrant will be lower in
// amount. Since refunds are capped to a percentage of the total
// transaction's gas, it is best to keep them low in cases like this one, to
// increase the likelihood of the full refund coming into effect.
uint256 private constant _NOT_ENTERED = 1;
uint256 private constant _ENTERED = 2;
uint256 private _status;
function __ReentrancyGuard_init() internal onlyInitializing {
__ReentrancyGuard_init_unchained();
}
function __ReentrancyGuard_init_unchained() internal onlyInitializing {
_status = _NOT_ENTERED;
}
/**
* @dev Prevents a contract from calling itself, directly or indirectly.
* Calling a `nonReentrant` function from another `nonReentrant`
* function is not supported. It is possible to prevent this from happening
* by making the `nonReentrant` function external, and making it call a
* `private` function that does the actual work.
*/
modifier nonReentrant() {
_nonReentrantBefore();
_;
_nonReentrantAfter();
}
function _nonReentrantBefore() private {
// On the first call to nonReentrant, _status will be _NOT_ENTERED
require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
// Any calls to nonReentrant after this point will fail
_status = _ENTERED;
}
function _nonReentrantAfter() private {
// By storing the original value once again, a refund is triggered (see
// https://eips.ethereum.org/EIPS/eip-2200)
_status = _NOT_ENTERED;
}
/**
* @dev Returns true if the reentrancy guard is currently set to "entered", which indicates there is a
* `nonReentrant` function in the call stack.
*/
function _reentrancyGuardEntered() internal view returns (bool) {
return _status == _ENTERED;
}
/**
* @dev This empty reserved space is put in place to allow future versions to add new
* variables without shifting down storage in the inheritance chain.
* See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
*/
uint256[49] private __gap;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/math/Math.sol)
pragma solidity ^0.8.0;
/**
* @dev Standard math utilities missing in the Solidity language.
*/
library Math {
enum Rounding {
Down, // Toward negative infinity
Up, // Toward infinity
Zero // Toward zero
}
/**
* @dev Returns the largest of two numbers.
*/
function max(uint256 a, uint256 b) internal pure returns (uint256) {
return a > b ? a : b;
}
/**
* @dev Returns the smallest of two numbers.
*/
function min(uint256 a, uint256 b) internal pure returns (uint256) {
return a < b ? a : b;
}
/**
* @dev Returns the average of two numbers. The result is rounded towards
* zero.
*/
function average(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b) / 2 can overflow.
return (a & b) + (a ^ b) / 2;
}
/**
* @dev Returns the ceiling of the division of two numbers.
*
* This differs from standard division with `/` in that it rounds up instead
* of rounding down.
*/
function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b - 1) / b can overflow on addition, so we distribute.
return a == 0 ? 0 : (a - 1) / b + 1;
}
/**
* @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
* @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv)
* with further edits by Uniswap Labs also under MIT license.
*/
function mulDiv(uint256 x, uint256 y, uint256 denominator) internal pure returns (uint256 result) {
unchecked {
// 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
// use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
// variables such that product = prod1 * 2^256 + prod0.
uint256 prod0; // Least significant 256 bits of the product
uint256 prod1; // Most significant 256 bits of the product
assembly {
let mm := mulmod(x, y, not(0))
prod0 := mul(x, y)
prod1 := sub(sub(mm, prod0), lt(mm, prod0))
}
// Handle non-overflow cases, 256 by 256 division.
if (prod1 == 0) {
// Solidity will revert if denominator == 0, unlike the div opcode on its own.
// The surrounding unchecked block does not change this fact.
// See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
return prod0 / denominator;
}
// Make sure the result is less than 2^256. Also prevents denominator == 0.
require(denominator > prod1, "Math: mulDiv overflow");
///////////////////////////////////////////////
// 512 by 256 division.
///////////////////////////////////////////////
// Make division exact by subtracting the remainder from [prod1 prod0].
uint256 remainder;
assembly {
// Compute remainder using mulmod.
remainder := mulmod(x, y, denominator)
// Subtract 256 bit number from 512 bit number.
prod1 := sub(prod1, gt(remainder, prod0))
prod0 := sub(prod0, remainder)
}
// Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
// See https://cs.stackexchange.com/q/138556/92363.
// Does not overflow because the denominator cannot be zero at this stage in the function.
uint256 twos = denominator & (~denominator + 1);
assembly {
// Divide denominator by twos.
denominator := div(denominator, twos)
// Divide [prod1 prod0] by twos.
prod0 := div(prod0, twos)
// Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
twos := add(div(sub(0, twos), twos), 1)
}
// Shift in bits from prod1 into prod0.
prod0 |= prod1 * twos;
// Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
// that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
// four bits. That is, denominator * inv = 1 mod 2^4.
uint256 inverse = (3 * denominator) ^ 2;
// Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
// in modular arithmetic, doubling the correct bits in each step.
inverse *= 2 - denominator * inverse; // inverse mod 2^8
inverse *= 2 - denominator * inverse; // inverse mod 2^16
inverse *= 2 - denominator * inverse; // inverse mod 2^32
inverse *= 2 - denominator * inverse; // inverse mod 2^64
inverse *= 2 - denominator * inverse; // inverse mod 2^128
inverse *= 2 - denominator * inverse; // inverse mod 2^256
// Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
// This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
// less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
// is no longer required.
result = prod0 * inverse;
return result;
}
}
/**
* @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
*/
function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) {
uint256 result = mulDiv(x, y, denominator);
if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
result += 1;
}
return result;
}
/**
* @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down.
*
* Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
*/
function sqrt(uint256 a) internal pure returns (uint256) {
if (a == 0) {
return 0;
}
// For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
//
// We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
// `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
//
// This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
// → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
// → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
//
// Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
uint256 result = 1 << (log2(a) >> 1);
// At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
// since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
// every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
// into the expected uint128 result.
unchecked {
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
return min(result, a / result);
}
}
/**
* @notice Calculates sqrt(a), following the selected rounding direction.
*/
function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = sqrt(a);
return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
}
}
/**
* @dev Return the log in base 2, rounded down, of a positive value.
* Returns 0 if given 0.
*/
function log2(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >> 128 > 0) {
value >>= 128;
result += 128;
}
if (value >> 64 > 0) {
value >>= 64;
result += 64;
}
if (value >> 32 > 0) {
value >>= 32;
result += 32;
}
if (value >> 16 > 0) {
value >>= 16;
result += 16;
}
if (value >> 8 > 0) {
value >>= 8;
result += 8;
}
if (value >> 4 > 0) {
value >>= 4;
result += 4;
}
if (value >> 2 > 0) {
value >>= 2;
result += 2;
}
if (value >> 1 > 0) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 2, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log2(value);
return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
}
}
/**
* @dev Return the log in base 10, rounded down, of a positive value.
* Returns 0 if given 0.
*/
function log10(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >= 10 ** 64) {
value /= 10 ** 64;
result += 64;
}
if (value >= 10 ** 32) {
value /= 10 ** 32;
result += 32;
}
if (value >= 10 ** 16) {
value /= 10 ** 16;
result += 16;
}
if (value >= 10 ** 8) {
value /= 10 ** 8;
result += 8;
}
if (value >= 10 ** 4) {
value /= 10 ** 4;
result += 4;
}
if (value >= 10 ** 2) {
value /= 10 ** 2;
result += 2;
}
if (value >= 10 ** 1) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 10, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log10(value);
return result + (rounding == Rounding.Up && 10 ** result < value ? 1 : 0);
}
}
/**
* @dev Return the log in base 256, rounded down, of a positive value.
* Returns 0 if given 0.
*
* Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
*/
function log256(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >> 128 > 0) {
value >>= 128;
result += 16;
}
if (value >> 64 > 0) {
value >>= 64;
result += 8;
}
if (value >> 32 > 0) {
value >>= 32;
result += 4;
}
if (value >> 16 > 0) {
value >>= 16;
result += 2;
}
if (value >> 8 > 0) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 256, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log256(value);
return result + (rounding == Rounding.Up && 1 << (result << 3) < value ? 1 : 0);
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import { ResourceMetering } from "../L1/ResourceMetering.sol";
/**
* @title Constants
* @notice Constants is a library for storing constants. Simple! Don't put everything in here, just
* the stuff used in multiple contracts. Constants that only apply to a single contract
* should be defined in that contract instead.
*/
library Constants {
/**
* @notice Special address to be used as the tx origin for gas estimation calls in the
* KromaPortal and CrossDomainMessenger calls. You only need to use this address if
* the minimum gas limit specified by the user is not actually enough to execute the
* given message and you're attempting to estimate the actual necessary gas limit. We
* use address(1) because it's the ecrecover precompile and therefore guaranteed to
* never have any code on any EVM chain.
*/
address internal constant ESTIMATION_ADDRESS = address(1);
/**
* @notice Value used for the L2 sender storage slot in both the KromaPortal and the
* CrossDomainMessenger contracts before an actual sender is set. This value is
* non-zero to reduce the gas cost of message passing transactions.
*/
address internal constant DEFAULT_L2_SENDER = 0x000000000000000000000000000000000000dEaD;
/**
* @notice Returns the default values for the ResourceConfig. These are the recommended values
* for a production network.
*/
function DEFAULT_RESOURCE_CONFIG()
internal
pure
returns (ResourceMetering.ResourceConfig memory)
{
ResourceMetering.ResourceConfig memory config = ResourceMetering.ResourceConfig({
maxResourceLimit: 20_000_000,
elasticityMultiplier: 10,
baseFeeMaxChangeDenominator: 8,
minimumBaseFee: 1 gwei,
systemTxMaxGas: 1_000_000,
maximumBaseFee: type(uint128).max
});
return config;
}
/**
* @notice The denominator of the validator reward.
* DO NOT change this value if the L2 chain is already operational.
*/
uint256 internal constant VALIDATOR_REWARD_DENOMINATOR = 10000;
/**
* @notice An address that identifies that current submission round is a public round.
*/
address internal constant VALIDATOR_PUBLIC_ROUND_ADDRESS = address(type(uint160).max);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @title Predeploys
* @notice Contains constant addresses for contracts that are pre-deployed to the L2 system.
*/
library Predeploys {
/**
* @notice Address of the ProxyAdmin predeploy.
*/
address internal constant PROXY_ADMIN = 0x4200000000000000000000000000000000000000;
/**
* @notice Address of the L1Block predeploy.
*/
address internal constant L1_BLOCK_ATTRIBUTES = 0x4200000000000000000000000000000000000002;
/**
* @notice Address of the L2ToL1MessagePasser predeploy.
*/
address internal constant L2_TO_L1_MESSAGE_PASSER = 0x4200000000000000000000000000000000000003;
/**
* @notice Address of the L2CrossDomainMessenger predeploy.
*/
address internal constant L2_CROSS_DOMAIN_MESSENGER =
0x4200000000000000000000000000000000000004;
/**
* @notice Address of the GasPriceOracle predeploy. Includes fee information
* and helpers for computing the L1 portion of the transaction fee.
*/
address internal constant GAS_PRICE_ORACLE = 0x4200000000000000000000000000000000000005;
/**
* @notice Address of the ProtocolVault predeploy.
*/
address internal constant PROTOCOL_VAULT = 0x4200000000000000000000000000000000000006;
/**
* @notice Address of the ProposerRewardVault predeploy.
*/
address internal constant PROPOSER_REWARD_VAULT = 0x4200000000000000000000000000000000000007;
/**
* @notice Address of the ValidatorRewardVault predeploy.
*/
address internal constant VALIDATOR_REWARD_VAULT = 0x4200000000000000000000000000000000000008;
/**
* @notice Address of the L2StandardBridge predeploy.
*/
address internal constant L2_STANDARD_BRIDGE = 0x4200000000000000000000000000000000000009;
/**
* @notice Address of the L2ERC721Bridge predeploy.
*/
address internal constant L2_ERC721_BRIDGE = 0x420000000000000000000000000000000000000A;
/**
* @notice Address of the KromaMintableERC20Factory predeploy.
*/
address internal constant KROMA_MINTABLE_ERC20_FACTORY =
0x420000000000000000000000000000000000000B;
/**
* @notice Address of the KromaMintableERC721Factory predeploy.
*/
address internal constant KROMA_MINTABLE_ERC721_FACTORY =
0x420000000000000000000000000000000000000c;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;
/**
* @title SafeCall
* @notice Perform low level safe calls
*/
library SafeCall {
/**
* @notice Perform a low level call without copying any returndata
*
* @param _target Address to call
* @param _gas Amount of gas to pass to the call
* @param _value Amount of value to pass to the call
* @param _calldata Calldata to pass to the call
*/
function call(
address _target,
uint256 _gas,
uint256 _value,
bytes memory _calldata
) internal returns (bool) {
bool _success;
assembly {
_success := call(
_gas, // gas
_target, // recipient
_value, // ether value
add(_calldata, 32), // inloc
mload(_calldata), // inlen
0, // outloc
0 // outlen
)
}
return _success;
}
/**
* @notice Helper function to determine if there is sufficient gas remaining within the context
* to guarantee that the minimum gas requirement for a call will be met as well as
* optionally reserving a specified amount of gas for after the call has concluded.
*
* @param _minGas The minimum amount of gas that may be passed to the target context.
* @param _reservedGas Optional amount of gas to reserve for the caller after the execution
* of the target context.
*
* @return `true` if there is enough gas remaining to safely supply `_minGas` to the target
* context as well as reserve `_reservedGas` for the caller after the execution of
* the target context.
*
* @dev !!!!! FOOTGUN ALERT !!!!!
* 1.) The 40_000 base buffer is to account for the worst case of the dynamic cost of the
* `CALL` opcode's `address_access_cost`, `positive_value_cost`, and
* `value_to_empty_account_cost` factors with an added buffer of 5,700 gas. It is
* still possible to self-rekt by initiating a withdrawal with a minimum gas limit
* that does not account for the `memory_expansion_cost` & `code_execution_cost`
* factors of the dynamic cost of the `CALL` opcode.
* 2.) This function should *directly* precede the external call if possible. There is an
* added buffer to account for gas consumed between this check and the call, but it
* is only 5,700 gas.
* 3.) Because EIP-150 ensures that a maximum of 63/64ths of the remaining gas in the call
* frame may be passed to a subcontext, we need to ensure that the gas will not be
* truncated.
* 4.) Use wisely. This function is not a silver bullet.
*/
function hasMinGas(uint256 _minGas, uint256 _reservedGas) internal view returns (bool) {
bool _hasMinGas;
assembly {
// Equation: gas × 63 ≥ minGas × 64 + 63(40_000 + reservedGas)
_hasMinGas := iszero(
lt(mul(gas(), 63), add(mul(_minGas, 64), mul(add(40000, _reservedGas), 63)))
)
}
return _hasMinGas;
}
/**
* @notice Perform a low level call without copying any returndata. This function
* will revert if the call cannot be performed with the specified minimum
* gas.
*
* @param _target Address to call
* @param _minGas The minimum amount of gas that may be passed to the call
* @param _value Amount of value to pass to the call
* @param _calldata Calldata to pass to the call
*/
function callWithMinGas(
address _target,
uint256 _minGas,
uint256 _value,
bytes memory _calldata
) internal returns (bool) {
bool _success;
bool _hasMinGas = hasMinGas(_minGas, 0);
assembly {
// Assertion: gasleft() >= (_minGas * 64) / 63 + 40_000
if iszero(_hasMinGas) {
// Store the "Error(string)" selector in scratch space.
mstore(0, 0x08c379a0)
// Store the pointer to the string length in scratch space.
mstore(32, 32)
// Store the string.
//
// SAFETY:
// - We pad the beginning of the string with two zero bytes as well as the
// length (24) to ensure that we override the free memory pointer at offset
// 0x40. This is necessary because the free memory pointer is likely to
// be greater than 1 byte when this function is called, but it is incredibly
// unlikely that it will be greater than 3 bytes. As for the data within
// 0x60, it is ensured that it is 0 due to 0x60 being the zero offset.
// - It's fine to clobber the free memory pointer, we're reverting.
mstore(88, 0x0000185361666543616c6c3a204e6f7420656e6f75676820676173)
// Revert with 'Error("SafeCall: Not enough gas")'
revert(28, 100)
}
// The call will be supplied at least ((_minGas * 64) / 63 + 40_000 - 49) gas due to the
// above assertion. This ensures that, in all circumstances (except for when the
// `_minGas` does not account for the `memory_expansion_cost` and `code_execution_cost`
// factors of the dynamic cost of the `CALL` opcode), the call will receive at least
// the minimum amount of gas specified.
_success := call(
gas(), // gas
_target, // recipient
_value, // ether value
add(_calldata, 32), // inloc
mload(_calldata), // inlen
0x00, // outloc
0x00 // outlen
)
}
return _success;
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;
/**
* @title Types
* @notice Contains various types used throughout the Kroma contract system.
*/
library Types {
/**
* @notice CheckpointOutput represents a commitment to the state of L2 checkpoint. The timestamp
* is the L1 timestamp that the output root is posted. This timestamp is used to verify
* that the finalization period has passed since the output root was submitted.
*
* @custom:field submitter Address of the output submitter.
* @custom:field outputRoot Hash of the L2 output.
* @custom:field timestamp Timestamp of the L1 block that the output root was submitted in.
* @custom:field l2BlockNumber L2 block number that the output corresponds to.
*/
struct CheckpointOutput {
address submitter;
bytes32 outputRoot;
uint128 timestamp;
uint128 l2BlockNumber;
}
/**
* @notice Struct representing the elements that are hashed together to generate an output root
* which itself represents a snapshot of the L2 state.
*
* @custom:field version Version of the output root.
* @custom:field stateRoot Root of the state trie at the block of this output.
* @custom:field messagePasserStorageRoot Root of the message passer storage trie.
* @custom:field blockHash Hash of the block this output was generated from.
* @custom:field nextBlockHash Hash of the next block.
*/
struct OutputRootProof {
bytes32 version;
bytes32 stateRoot;
bytes32 messagePasserStorageRoot;
bytes32 blockHash;
bytes32 nextBlockHash;
}
/**
* @notice Struct representing the elements that are hashed together to generate a public input.
*
* @custom:field blockHash The hash of the block.
* @custom:field parentHash The hash of the previous block.
* @custom:field timestamp The block time.
* @custom:field number The block number.
* @custom:field gasLimit Maximum gas allowed.
* @custom:field baseFee The base fee per gas.
* @custom:field transactionsRoot Root hash of the transactions.
* @custom:field stateRoot Root hash of the state trie.
* @custom:field withdrawalsRoot Root hash of the withdrawals.
* @custom:field txHashes Array of hash of the transaction.
*/
struct PublicInput {
bytes32 blockHash;
bytes32 parentHash;
uint64 timestamp;
uint64 number;
uint64 gasLimit;
uint256 baseFee;
bytes32 transactionsRoot;
bytes32 stateRoot;
bytes32 withdrawalsRoot;
bytes32[] txHashes;
}
/**
* @notice Struct representing the elements that are hashed together to generate a block hash.
* Some of fields that are contained in PublicInput are omitted.
*
* @custom:field uncleHash RLP encoded uncle hash.
* @custom:field coinbase RLP encoded coinbase.
* @custom:field receiptsRoot RLP encoded receipts root.
* @custom:field logsBloom RLP encoded logs bloom.
* @custom:field difficulty RLP encoded difficulty.
* @custom:field gasUsed RLP encoded gas used.
* @custom:field extraData RLP encoded extra data.
* @custom:field mixHash RLP encoded mix hash.
* @custom:field nonce RLP encoded nonce.
*/
struct BlockHeaderRLP {
bytes uncleHash;
bytes coinbase;
bytes receiptsRoot;
bytes logsBloom;
bytes difficulty;
bytes gasUsed;
bytes extraData;
bytes mixHash;
bytes nonce;
}
/**
* @notice Struct representing a deposit transaction (L1 => L2 transaction) created by an end
* user (as opposed to a system deposit transaction generated by the system).
*
* @custom:field from Address of the sender of the transaction.
* @custom:field to Address of the recipient of the transaction.
* @custom:field isCreation True if the transaction is a contract creation.
* @custom:field value Value to send to the recipient.
* @custom:field mint Amount of ETH to mint.
* @custom:field gasLimit Gas limit of the transaction.
* @custom:field data Data of the transaction.
* @custom:field l1BlockHash Hash of the block the transaction was submitted in.
* @custom:field logIndex Index of the log in the block the transaction was submitted in.
*/
struct UserDepositTransaction {
address from;
address to;
bool isCreation;
uint256 value;
uint256 mint;
uint64 gasLimit;
bytes data;
bytes32 l1BlockHash;
uint64 logIndex;
}
/**
* @notice Struct representing a withdrawal transaction.
*
* @custom:field nonce Nonce of the withdrawal transaction
* @custom:field sender Address of the sender of the transaction.
* @custom:field target Address of the recipient of the transaction.
* @custom:field value Value to send to the recipient.
* @custom:field gasLimit Gas limit of the transaction.
* @custom:field data Data of the transaction.
*/
struct WithdrawalTransaction {
uint256 nonce;
address sender;
address target;
uint256 value;
uint256 gasLimit;
bytes data;
}
/**
* @notice Struct representing a challenge.
*
* @custom:field turn The current turn.
* @custom:field timeoutAt Timeout timestamp of the next turn.
* @custom:field asserter Address of the asserter.
* @custom:field challenger Address of the challenger.
* @custom:field segments Array of the segment.
* @custom:field segStart The L2 block number of the first segment.
* @custom:field segSize The number of L2 blocks.
*/
struct Challenge {
uint8 turn;
uint64 timeoutAt;
address asserter;
address challenger;
bytes32[] segments;
uint256 segSize;
uint256 segStart;
}
/**
* @notice Struct representing a validator's bond.
*
* @custom:field amount Amount of the lock.
* @custom:field expiresAt The expiration timestamp of bond.
*/
struct Bond {
uint128 amount;
uint128 expiresAt;
}
/**
* @notice Struct representing multisig transaction data.
*
* @custom:field target The destination address to run the transaction.
* @custom:field executed Record whether a transaction was executed or not.
* @custom:field value The value passed in while executing the transaction.
* @custom:field data Calldata for transaction.
*/
struct MultiSigTransaction {
address target;
bool executed;
uint256 value;
bytes data;
}
/**
* @notice Struct representing multisig confirmation data.
*
* @custom:field confirmationCount The sum of confirmations.
* @custom:field confirmedBy Map data that stores whether confirmation is performed by account.
*/
struct MultiSigConfirmation {
uint256 confirmationCount;
mapping(address => bool) confirmedBy;
}
/**
* @notice Struct representing the data for verifying the public input.
*
* @custom:field srcOutputRootProof Proof of the source output root.
* @custom:field dstOutputRootProof Proof of the destination output root.
* @custom:field publicInput Ingredients to compute the public input used by ZK proof verification.
* @custom:field rlps Pre-encoded RLPs to compute the next block hash
* of the source output root proof.
* @custom:field l2ToL1MessagePasserBalance Balance of the L2ToL1MessagePasser account.
* @custom:field l2ToL1MessagePasserCodeHash Codehash of the L2ToL1MessagePasser account.
* @custom:field merkleProof Merkle proof of L2ToL1MessagePasser account against the state root.
*/
struct PublicInputProof {
OutputRootProof srcOutputRootProof;
OutputRootProof dstOutputRootProof;
PublicInput publicInput;
BlockHeaderRLP rlps;
bytes32 l2ToL1MessagePasserBalance;
bytes32 l2ToL1MessagePasserCodeHash;
bytes[] merkleProof;
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.15;
import { Strings } from "@openzeppelin/contracts/utils/Strings.sol";
/**
* @title Semver
* @notice Semver is a simple contract for managing contract versions.
*/
contract Semver {
/**
* @notice Contract version number (major).
*/
uint256 private immutable MAJOR_VERSION;
/**
* @notice Contract version number (minor).
*/
uint256 private immutable MINOR_VERSION;
/**
* @notice Contract version number (patch).
*/
uint256 private immutable PATCH_VERSION;
/**
* @param _major Version number (major).
* @param _minor Version number (minor).
* @param _patch Version number (patch).
*/
constructor(
uint256 _major,
uint256 _minor,
uint256 _patch
) {
MAJOR_VERSION = _major;
MINOR_VERSION = _minor;
PATCH_VERSION = _patch;
}
/**
* @notice Returns the full semver contract version.
*
* @return Semver contract version as a string.
*/
function version() public view virtual returns (string memory) {
return
string(
abi.encodePacked(
Strings.toString(MAJOR_VERSION),
".",
Strings.toString(MINOR_VERSION),
".",
Strings.toString(PATCH_VERSION)
)
);
}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;
import { L2StandardBridge } from "../L2/L2StandardBridge.sol";
import { Predeploys } from "../libraries/Predeploys.sol";
import { FeeVault } from "../universal/FeeVault.sol";
import { Semver } from "../universal/Semver.sol";
import { AddressAliasHelper } from "../vendor/AddressAliasHelper.sol";
/**
* @custom:proxied
* @custom:predeploy 0x4200000000000000000000000000000000000008
* @title ValidatorRewardVault
* @notice The ValidatorRewardVault accumulates transaction fees and pays rewards to validators.
*/
contract ValidatorRewardVault is FeeVault, Semver {
/**
* @notice Address of the ValidatorPool contract on L1.
*/
address public immutable VALIDATOR_POOL;
/**
* @notice A value to divide the vault balance by when determining the reward amount.
*/
uint256 public immutable REWARD_DIVIDER;
/**
* @notice The reward balance that the validator is eligible to receive.
*/
mapping(address => uint256) internal rewards;
/**
* @notice A mapping of whether the reward corresponding to the L2 block number has been paid.
*/
mapping(uint256 => bool) internal isPaid;
/**
* @notice The amount of determined as rewards.
*/
uint256 public totalReserved;
/**
* @notice Emitted when the balance of a validator has increased.
*
* @param validator Address of the validator.
* @param l2BlockNumber The L2 block number of the output root.
* @param amount Amount of the reward.
*/
event Rewarded(address indexed validator, uint256 indexed l2BlockNumber, uint256 amount);
/**
* @custom:semver 1.0.0
*
* @param _validatorPool Address of the ValidatorPool contract on L1.
* @param _rewardDivider A value to divide the vault balance by when determining the reward amount.
*/
constructor(address _validatorPool, uint256 _rewardDivider)
FeeVault(address(0), 0)
Semver(1, 0, 0)
{
VALIDATOR_POOL = _validatorPool;
REWARD_DIVIDER = _rewardDivider;
}
/**
* @notice Rewards the validator for submitting the output.
* ValidatorPool contract on L1 calls this function over the portal when output is finalized.
*
* @param _validator Address of the validator.
* @param _l2BlockNumber The L2 block number of the output root.
*/
function reward(address _validator, uint256 _l2BlockNumber) external {
require(
AddressAliasHelper.undoL1ToL2Alias(msg.sender) == VALIDATOR_POOL,
"ValidatorRewardVault: function can only be called from the ValidatorPool"
);
require(_validator != address(0), "ValidatorRewardVault: validator address cannot be 0");
require(
!isPaid[_l2BlockNumber],
"ValidatorRewardVault: the reward has already been paid for the L2 block number"
);
uint256 amount = _determineRewardAmount();
unchecked {
totalReserved += amount;
rewards[_validator] += amount;
}
isPaid[_l2BlockNumber] = true;
emit Rewarded(_validator, _l2BlockNumber, amount);
}
/**
* @notice Withdraws all of the sender's balance.
* Reverts if the balance is less than the minimum withdrawal amount.
*/
function withdraw() external override {
uint256 balance = rewards[msg.sender];
require(
balance >= MIN_WITHDRAWAL_AMOUNT,
"ValidatorRewardVault: withdrawal amount must be greater than minimum withdrawal amount"
);
rewards[msg.sender] = 0;
unchecked {
totalReserved -= balance;
totalProcessed += balance;
}
emit Withdrawal(balance, msg.sender, msg.sender);
L2StandardBridge(payable(Predeploys.L2_STANDARD_BRIDGE)).bridgeETHTo{ value: balance }(
msg.sender,
WITHDRAWAL_MIN_GAS,
bytes("")
);
}
/**
* @notice Determines the reward amount.
*
* @return Amount of the reward.
*/
function _determineRewardAmount() internal view returns (uint256) {
return (address(this).balance - totalReserved) / REWARD_DIVIDER;
}
/**
* @notice Returns the reward balance of the given address.
*
* @param _addr Address to lookup.
*
* @return The reward balance of the given address.
*/
function balanceOf(address _addr) external view returns (uint256) {
return rewards[_addr];
}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;
import { Initializable } from "@openzeppelin/contracts/proxy/utils/Initializable.sol";
import { Constants } from "../libraries/Constants.sol";
import { Hashing } from "../libraries/Hashing.sol";
import { SafeCall } from "../libraries/SafeCall.sol";
import { Types } from "../libraries/Types.sol";
import { Semver } from "../universal/Semver.sol";
import { AddressAliasHelper } from "../vendor/AddressAliasHelper.sol";
import { L2OutputOracle } from "./L2OutputOracle.sol";
import { ResourceMetering } from "./ResourceMetering.sol";
import { SystemConfig } from "./SystemConfig.sol";
import { ZKMerkleTrie } from "./ZKMerkleTrie.sol";
/**
* @custom:proxied
* @title KromaPortal
* @notice The KromaPortal is a low-level contract responsible for passing messages between L1
* and L2. Messages sent directly to the KromaPortal have no form of replayability.
* Users are encouraged to use the L1CrossDomainMessenger for a higher-level interface.
*/
contract KromaPortal is Initializable, ResourceMetering, Semver {
/**
* @notice Represents a proven withdrawal.
*
* @custom:field outputRoot Root of the L2 output this was proven against.
* @custom:field timestamp Timestamp at whcih the withdrawal was proven.
* @custom:field l2OutputIndex Index of the output this was proven against.
*/
struct ProvenWithdrawal {
bytes32 outputRoot;
uint128 timestamp;
uint128 l2OutputIndex;
}
/**
* @notice Version of the deposit event.
*/
uint256 internal constant DEPOSIT_VERSION = 0;
/**
* @notice The L2 gas limit set when eth is deposited using the receive() function.
*/
uint64 internal constant RECEIVE_DEFAULT_GAS_LIMIT = 100_000;
/**
* @notice Address of the L2OutputOracle contract.
*/
L2OutputOracle public immutable L2_ORACLE;
/**
* @notice Address of the ValidatorPool contract.
*/
address public immutable VALIDATOR_POOL;
/**
/**
* @notice Address of the SystemConfig contract.
*/
SystemConfig public immutable SYSTEM_CONFIG;
/**
* @notice MultiSig wallet address that has the ability to pause and unpause withdrawals.
*/
address public immutable GUARDIAN;
/**
* @notice Address of the ZKMerkleTrie.
*/
ZKMerkleTrie public immutable ZK_MERKLE_TRIE;
/**
* @notice Address of the L2 account which initiated a withdrawal in this transaction. If the
* of this variable is the default L2 sender address, then we are NOT inside of a call
* to finalizeWithdrawalTransaction.
*/
address public l2Sender;
/**
* @notice A list of withdrawal hashes which have been successfully finalized.
*/
mapping(bytes32 => bool) public finalizedWithdrawals;
/**
* @notice A mapping of withdrawal hashes to `ProvenWithdrawal` data.
*/
mapping(bytes32 => ProvenWithdrawal) public provenWithdrawals;
/**
* @notice Determines if cross domain messaging is paused. When set to true,
* withdrawals are paused. This may be removed in the future.
*/
bool public paused;
/**
* @notice Emitted when a transaction is deposited from L1 to L2. The parameters of this event
* are read by the rollup node and used to derive deposit transactions on L2.
*
* @param from Address that triggered the deposit transaction.
* @param to Address that the deposit transaction is directed to.
* @param version Version of this deposit transaction event.
* @param opaqueData ABI encoded deposit data to be parsed off-chain.
*/
event TransactionDeposited(
address indexed from,
address indexed to,
uint256 indexed version,
bytes opaqueData
);
/**
* @notice Emitted when a withdrawal transaction is proven.
*
* @param withdrawalHash Hash of the withdrawal transaction.
*/
event WithdrawalProven(
bytes32 indexed withdrawalHash,
address indexed from,
address indexed to
);
/**
* @notice Emitted when a withdrawal transaction is finalized.
*
* @param withdrawalHash Hash of the withdrawal transaction.
* @param success Whether the withdrawal transaction was successful.
*/
event WithdrawalFinalized(bytes32 indexed withdrawalHash, bool success);
/**
* @notice Emitted when the pause is triggered.
*
* @param account Address of the account triggering the pause.
*/
event Paused(address account);
/**
* @notice Emitted when the pause is lifted.
*
* @param account Address of the account triggering the unpause.
*/
event Unpaused(address account);
/**
* @notice Reverts when paused.
*/
modifier whenNotPaused() {
require(paused == false, "KromaPortal: paused");
_;
}
/**
* @custom:semver 1.0.0
*
* @param _l2Oracle Address of the L2OutputOracle contract.
* @param _validatorPool Address of the ValidatorPool contract.
* @param _guardian MultiSig wallet address that can pause deposits and withdrawals.
* @param _paused Sets the contract's pausability state.
* @param _config Address of the SystemConfig contract.
* @param _zkMerkleTrie Address of the ZKMerkleTrie contract.
*/
constructor(
L2OutputOracle _l2Oracle,
address _validatorPool,
address _guardian,
bool _paused,
SystemConfig _config,
ZKMerkleTrie _zkMerkleTrie
) Semver(1, 0, 0) {
L2_ORACLE = _l2Oracle;
VALIDATOR_POOL = _validatorPool;
GUARDIAN = _guardian;
SYSTEM_CONFIG = _config;
ZK_MERKLE_TRIE = _zkMerkleTrie;
initialize(_paused);
}
/**
* @notice Initializer.
*/
function initialize(bool _paused) public initializer {
l2Sender = Constants.DEFAULT_L2_SENDER;
paused = _paused;
__ResourceMetering_init();
}
/**
* @notice Pause deposits and withdrawals.
*/
function pause() external {
require(msg.sender == GUARDIAN, "KromaPortal: only guardian can pause");
paused = true;
emit Paused(msg.sender);
}
/**
* @notice Unpause deposits and withdrawals.
*/
function unpause() external {
require(msg.sender == GUARDIAN, "KromaPortal: only guardian can unpause");
paused = false;
emit Unpaused(msg.sender);
}
/**
* @notice Accepts value so that users can send ETH directly to this contract and have the
* funds be deposited to their address on L2. This is intended as a convenience
* function for EOAs. Contracts should call the depositTransaction() function directly
* otherwise any deposited funds will be lost due to address aliasing.
*/
// solhint-disable-next-line ordering
receive() external payable {
depositTransaction(msg.sender, msg.value, RECEIVE_DEFAULT_GAS_LIMIT, false, bytes(""));
}
/**
* @notice Getter for the resource config. Used internally by the ResourceMetering
* contract. The SystemConfig is the source of truth for the resource config.
*
* @return ResourceMetering.ResourceConfig
*/
function _resourceConfig()
internal
view
override
returns (ResourceMetering.ResourceConfig memory)
{
return SYSTEM_CONFIG.resourceConfig();
}
/**
* @notice Proves a withdrawal transaction.
*
* @param _tx Withdrawal transaction to finalize.
* @param _l2OutputIndex L2 output index to prove against.
* @param _outputRootProof Inclusion proof of the L2ToL1MessagePasser contract's storage root.
* @param _withdrawalProof Inclusion proof of the withdrawal in L2ToL1MessagePasser contract.
*/
function proveWithdrawalTransaction(
Types.WithdrawalTransaction memory _tx,
uint256 _l2OutputIndex,
Types.OutputRootProof calldata _outputRootProof,
bytes[] calldata _withdrawalProof
) external whenNotPaused {
// Prevent users from creating a deposit transaction where this address is the message
// sender on L2. Because this is checked here, we do not need to check again in
// `finalizeWithdrawalTransaction`.
require(
_tx.target != address(this),
"KromaPortal: you cannot send messages to the portal contract"
);
// Get the output root and load onto the stack to prevent multiple mloads. This will
// revert if there is no output root for the given block number.
bytes32 outputRoot = L2_ORACLE.getL2Output(_l2OutputIndex).outputRoot;
// Verify that the output root can be generated with the elements in the proof.
require(
outputRoot == Hashing.hashOutputRootProof(_outputRootProof),
"KromaPortal: invalid output root proof"
);
// Load the ProvenWithdrawal into memory, using the withdrawal hash as a unique identifier.
bytes32 withdrawalHash = Hashing.hashWithdrawal(_tx);
ProvenWithdrawal memory provenWithdrawal = provenWithdrawals[withdrawalHash];
// We generally want to prevent users from proving the same withdrawal multiple times
// because each successive proof will update the timestamp. A malicious user can take
// advantage of this to prevent other users from finalizing their withdrawal. However,
// since withdrawals are proven before an output root is finalized, we need to allow users
// to re-prove their withdrawal only in the case that the output root for their specified
// output index has been updated.
require(
provenWithdrawal.timestamp == 0 ||
L2_ORACLE.getL2Output(provenWithdrawal.l2OutputIndex).outputRoot !=
provenWithdrawal.outputRoot,
"KromaPortal: withdrawal hash has already been proven"
);
// Compute the storage slot of the withdrawal hash in the L2ToL1MessagePasser contract.
// Refer to the Solidity documentation for more information on how storage layouts are
// computed for mappings.
bytes32 storageKey = keccak256(
abi.encode(
withdrawalHash,
uint256(0) // The withdrawals mapping is at the first slot in the layout.
)
);
// Verify that the hash of this withdrawal was stored in the L2toL1MessagePasser contract
// on L2. If this is true, under the assumption that the ZKMerkleTrie contract does not have
// bugs, then we know that this withdrawal was actually triggered on L2 and can therefore
// be relayed on L1.
require(
ZK_MERKLE_TRIE.verifyInclusionProof(
storageKey,
hex"0000000000000000000000000000000000000000000000000000000000000001",
_withdrawalProof,
_outputRootProof.messagePasserStorageRoot
),
"KromaPortal: invalid withdrawal inclusion proof"
);
// Designate the withdrawalHash as proven by storing the `outputRoot`, `timestamp`, and
// `l2OutputIndex` in the `provenWithdrawals` mapping. A `withdrawalHash` can only be
// proven once unless it is submitted again with a different outputRoot.
provenWithdrawals[withdrawalHash] = ProvenWithdrawal({
outputRoot: outputRoot,
timestamp: uint128(block.timestamp),
l2OutputIndex: uint128(_l2OutputIndex)
});
// Emit a `WithdrawalProven` event.
emit WithdrawalProven(withdrawalHash, _tx.sender, _tx.target);
}
/**
* @notice Finalizes a withdrawal transaction.
*
* @param _tx Withdrawal transaction to finalize.
*/
function finalizeWithdrawalTransaction(Types.WithdrawalTransaction memory _tx)
external
whenNotPaused
{
// Make sure that the l2Sender has not yet been set. The l2Sender is set to a value other
// than the default value when a withdrawal transaction is being finalized. This check is
// a defacto reentrancy guard.
require(
l2Sender == Constants.DEFAULT_L2_SENDER,
"KromaPortal: can only trigger one withdrawal per transaction"
);
// Grab the proven withdrawal from the `provenWithdrawals` map.
bytes32 withdrawalHash = Hashing.hashWithdrawal(_tx);
ProvenWithdrawal memory provenWithdrawal = provenWithdrawals[withdrawalHash];
// A withdrawal can only be finalized if it has been proven. We know that a withdrawal has
// been proven at least once when its timestamp is non-zero. Unproven withdrawals will have
// a timestamp of zero.
require(provenWithdrawal.timestamp != 0, "KromaPortal: withdrawal has not been proven yet");
// As a sanity check, we make sure that the proven withdrawal's timestamp is greater than
// starting timestamp inside the L2OutputOracle. Not strictly necessary but extra layer of
// safety against weird bugs in the proving step.
require(
provenWithdrawal.timestamp >= L2_ORACLE.startingTimestamp(),
"KromaPortal: withdrawal timestamp less than L2 Oracle starting timestamp"
);
// A proven withdrawal must wait at least the finalization period before it can be
// finalized. This waiting period can elapse in parallel with the waiting period for the
// output the withdrawal was proven against. In effect, this means that the minimum
// withdrawal time is l2 output submission time + finalization period.
require(
_isFinalizationPeriodElapsed(provenWithdrawal.timestamp),
"KromaPortal: proven withdrawal finalization period has not elapsed"
);
// Grab the CheckpointOutput from the L2OutputOracle, will revert if the output that
// corresponds to the given index has not been submitted yet.
Types.CheckpointOutput memory checkpointOutput = L2_ORACLE.getL2Output(
provenWithdrawal.l2OutputIndex
);
// Check that the output root that was used to prove the withdrawal is the same as the
// current output root for the given output index. An output root may change if it is
// deleted by the challenger address and then re-submitted.
require(
checkpointOutput.outputRoot == provenWithdrawal.outputRoot,
"KromaPortal: output root proven is not the same as current output root"
);
// Check that the checkpoint output has also been finalized.
require(
_isFinalizationPeriodElapsed(checkpointOutput.timestamp),
"KromaPortal: checkpoint output finalization period has not elapsed"
);
// Check that this withdrawal has not already been finalized, this is replay protection.
require(
finalizedWithdrawals[withdrawalHash] == false,
"KromaPortal: withdrawal has already been finalized"
);
// Mark the withdrawal as finalized so it can't be replayed.
finalizedWithdrawals[withdrawalHash] = true;
// Set the l2Sender so contracts know who triggered this withdrawal on L2.
l2Sender = _tx.sender;
// Trigger the call to the target contract. We use a custom low level method
// SafeCall.callWithMinGas to ensure two key properties
// 1. Target contracts cannot force this call to run out of gas by returning a very large
// amount of data (and this is OK because we don't care about the returndata here).
// 2. The amount of gas provided to the execution context of the target is at least the
// gas limit specified by the user. If there is not enough gas in the current context
// to accomplish this, `callWithMinGas` will revert.
bool success = SafeCall.callWithMinGas(_tx.target, _tx.gasLimit, _tx.value, _tx.data);
// Reset the l2Sender back to the default value.
l2Sender = Constants.DEFAULT_L2_SENDER;
// All withdrawals are immediately finalized. Replayability can
// be achieved through contracts built on top of this contract
emit WithdrawalFinalized(withdrawalHash, success);
// Reverting here is useful for determining the exact gas cost to successfully execute the
// sub call to the target contract if the minimum gas limit specified by the user would not
// be sufficient to execute the sub call.
if (success == false && tx.origin == Constants.ESTIMATION_ADDRESS) {
revert("KromaPortal: withdrawal failed");
}
}
/**
* @notice Accepts deposits of ETH and data, and emits a TransactionDeposited event for use in
* deriving deposit transactions. Note that if a deposit is made by a contract, its
* address will be aliased when retrieved using `tx.origin` or `msg.sender`. Consider
* using the CrossDomainMessenger contracts for a simpler developer experience.
*
* @param _to Target address on L2.
* @param _value ETH value to send to the recipient.
* @param _gasLimit Minimum L2 gas limit (can be greater than or equal to this value).
* @param _isCreation Whether or not the transaction is a contract creation.
* @param _data Data to trigger the recipient with.
*/
function depositTransaction(
address _to,
uint256 _value,
uint64 _gasLimit,
bool _isCreation,
bytes memory _data
) public payable metered(_gasLimit) {
// Just to be safe, make sure that people specify address(0) as the target when doing
// contract creations.
if (_isCreation) {
require(
_to == address(0),
"KromaPortal: must send to address(0) when creating a contract"
);
}
// Prevent depositing transactions that have too small of a gas limit.
require(_gasLimit >= 21_000, "KromaPortal: gas limit must cover instrinsic gas cost");
// Transform the from-address to its alias if the caller is a contract.
address from = msg.sender;
if (msg.sender != tx.origin) {
from = AddressAliasHelper.applyL1ToL2Alias(msg.sender);
}
// Compute the opaque data that will be emitted as part of the TransactionDeposited event.
// We use opaque data so that we can update the TransactionDeposited event in the future
// without breaking the current interface.
bytes memory opaqueData = abi.encodePacked(
msg.value,
_value,
_gasLimit,
_isCreation,
_data
);
// Emit a TransactionDeposited event so that the rollup node can derive a deposit
// transaction for this deposit.
emit TransactionDeposited(from, _to, DEPOSIT_VERSION, opaqueData);
}
/**
* @notice Accepts deposits of data from ValidatorPool contract, and emits a TransactionDeposited event for use in
* deriving deposit transactions on L2.
*
* @param _to Target address on L2.
* @param _gasLimit Minimum L2 gas limit (can be greater than or equal to this value).
* @param _data Data to trigger the recipient with.
*/
function depositTransactionByValidatorPool(
address _to,
uint64 _gasLimit,
bytes memory _data
) public {
require(
msg.sender == VALIDATOR_POOL,
"KromaPortal: function can only be called from the ValidatorPool"
);
// Transform the from-address to its alias.
address from = AddressAliasHelper.applyL1ToL2Alias(msg.sender);
// Compute the opaque data that will be emitted as part of the TransactionDeposited event.
bytes memory opaqueData = abi.encodePacked(uint256(0), uint256(0), _gasLimit, false, _data);
// Emit a TransactionDeposited event so that the rollup node can derive a deposit
// transaction for this deposit.
emit TransactionDeposited(from, _to, DEPOSIT_VERSION, opaqueData);
}
/**
* @notice Determines if the output at the given index is finalized. Reverts if the call to
* L2_ORACLE.getL2Output reverts. Returns a boolean otherwise.
*
* @param _l2OutputIndex Index of the L2 output to check.
*
* @return Whether or not the output is finalized.
*/
function isOutputFinalized(uint256 _l2OutputIndex) external view returns (bool) {
return _isFinalizationPeriodElapsed(L2_ORACLE.getL2Output(_l2OutputIndex).timestamp);
}
/**
* @notice Determines whether the finalization period has elapsed w/r/t a given timestamp.
*
* @param _timestamp Timestamp to check.
*
* @return Whether or not the finalization period has elapsed.
*/
function _isFinalizationPeriodElapsed(uint256 _timestamp) internal view returns (bool) {
return block.timestamp > _timestamp + L2_ORACLE.FINALIZATION_PERIOD_SECONDS();
}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;
import { Initializable } from "@openzeppelin/contracts/proxy/utils/Initializable.sol";
import { Constants } from "../libraries/Constants.sol";
import { Types } from "../libraries/Types.sol";
import { Semver } from "../universal/Semver.sol";
import { ValidatorPool } from "./ValidatorPool.sol";
/**
* @custom:proxied
* @title L2OutputOracle
* @notice The L2OutputOracle contains an array of L2 state outputs, where each output is a
* commitment to the state of the L2 chain. Other contracts like the KromaPortal use
* these outputs to verify information about the state of L2.
*/
contract L2OutputOracle is Initializable, Semver {
/**
* @notice The address of the validator pool contract. Can be updated via upgrade.
*/
ValidatorPool public immutable VALIDATOR_POOL;
/**
* @notice The address of the colosseum contract. Can be updated via upgrade.
*/
address public immutable COLOSSEUM;
/**
* @notice The interval in L2 blocks at which checkpoints must be submitted. Although this is
* immutable, it can be modified by upgrading the implementation contract.
* Note that nodes that fetch and use this value need to restart when it is modified.
*/
uint256 public immutable SUBMISSION_INTERVAL;
/**
* @notice The time between L2 blocks in seconds. Once set, this value MUST NOT be modified.
*/
uint256 public immutable L2_BLOCK_TIME;
/**
* @notice Minimum time (in seconds) that must elapse before a withdrawal can be finalized.
*/
uint256 public immutable FINALIZATION_PERIOD_SECONDS;
/**
* @notice The number of the first L2 block recorded in this contract.
*/
uint256 public startingBlockNumber;
/**
* @notice The timestamp of the first L2 block recorded in this contract.
*/
uint256 public startingTimestamp;
/**
* @notice Array of L2 checkpoint outputs.
*/
Types.CheckpointOutput[] internal l2Outputs;
/**
* @notice Emitted when an output is submitted.
*
* @param outputRoot The output root.
* @param l2OutputIndex The index of the output in the l2Outputs array.
* @param l2BlockNumber The L2 block number of the output root.
* @param l1Timestamp The L1 timestamp when submitted.
*/
event OutputSubmitted(
bytes32 indexed outputRoot,
uint256 indexed l2OutputIndex,
uint256 indexed l2BlockNumber,
uint256 l1Timestamp
);
/**
* @notice Emitted when an output is replaced.
*
* @param outputIndex Replaced L2 output index.
* @param newOutputRoot L2 output root after replacement.
*/
event OutputReplaced(uint256 indexed outputIndex, bytes32 newOutputRoot);
/**
* @custom:semver 1.0.0
*
* @param _validatorPool The address of the ValidatorPool contract.
* @param _colosseum The address of the Colosseum contract.
* @param _submissionInterval Interval in blocks at which checkpoints must be submitted.
* @param _l2BlockTime The time per L2 block, in seconds.
* @param _startingBlockNumber The number of the first L2 block.
* @param _startingTimestamp The timestamp of the first L2 block.
* @param _finalizationPeriodSeconds Output finalization time in seconds.
*/
constructor(
ValidatorPool _validatorPool,
address _colosseum,
uint256 _submissionInterval,
uint256 _l2BlockTime,
uint256 _startingBlockNumber,
uint256 _startingTimestamp,
uint256 _finalizationPeriodSeconds
) Semver(1, 0, 0) {
require(_l2BlockTime > 0, "L2OutputOracle: L2 block time must be greater than 0");
require(
_submissionInterval > 0,
"L2OutputOracle: submission interval must be greater than 0"
);
VALIDATOR_POOL = _validatorPool;
COLOSSEUM = _colosseum;
SUBMISSION_INTERVAL = _submissionInterval;
L2_BLOCK_TIME = _l2BlockTime;
FINALIZATION_PERIOD_SECONDS = _finalizationPeriodSeconds;
initialize(_startingBlockNumber, _startingTimestamp);
}
/**
* @notice Initializer.
*
* @param _startingBlockNumber Block number for the first recorded L2 block.
* @param _startingTimestamp Timestamp for the first recorded L2 block.
*/
function initialize(uint256 _startingBlockNumber, uint256 _startingTimestamp)
public
initializer
{
require(
_startingTimestamp <= block.timestamp,
"L2OutputOracle: starting L2 timestamp must be less than current time"
);
startingTimestamp = _startingTimestamp;
startingBlockNumber = _startingBlockNumber;
}
/**
* @notice Replaces the output that corresponds to the given output index.
* Only the Colosseum contract can replace an output.
*
* @param _l2OutputIndex Index of the L2 output to be replaced.
* @param _newOutputRoot The L2 output root to replace the existing one.
* @param _submitter Address of the L2 output submitter.
*/
function replaceL2Output(
uint256 _l2OutputIndex,
bytes32 _newOutputRoot,
address _submitter
) external {
require(
msg.sender == COLOSSEUM,
"L2OutputOracle: only the colosseum contract can replace an output"
);
require(_submitter != address(0), "L2OutputOracle: submitter address cannot be zero");
// Make sure we're not *increasing* the length of the array.
require(
_l2OutputIndex < l2Outputs.length,
"L2OutputOracle: cannot replace an output after the latest output index"
);
Types.CheckpointOutput storage output = l2Outputs[_l2OutputIndex];
// Do not allow replacing any outputs that have already been finalized.
require(
block.timestamp - output.timestamp < FINALIZATION_PERIOD_SECONDS,
"L2OutputOracle: cannot replace an output that has already been finalized"
);
output.outputRoot = _newOutputRoot;
output.submitter = _submitter;
emit OutputReplaced(_l2OutputIndex, _newOutputRoot);
}
/**
* @notice Accepts an outputRoot and the block number of the corresponding L2 block.
* The block number must be equal to the current value returned by `nextBlockNumber()`
* in order to be accepted. This function may only be called by the validator.
*
* @param _outputRoot The L2 output of the checkpoint block.
* @param _l2BlockNumber The L2 block number that resulted in _outputRoot.
* @param _l1BlockHash A block hash which must be included in the current chain.
* @param _l1BlockNumber The block number with the specified block hash.
*/
function submitL2Output(
bytes32 _outputRoot,
uint256 _l2BlockNumber,
bytes32 _l1BlockHash,
uint256 _l1BlockNumber
) external payable {
address nextValidator = VALIDATOR_POOL.nextValidator();
// If it's not a public round, only selected validators can submit output.
if (nextValidator != Constants.VALIDATOR_PUBLIC_ROUND_ADDRESS) {
require(
msg.sender == nextValidator,
"L2OutputOracle: only the next selected validator can submit output"
);
}
require(
_l2BlockNumber == nextBlockNumber(),
"L2OutputOracle: block number must be equal to next expected block number"
);
require(
computeL2Timestamp(_l2BlockNumber) < block.timestamp,
"L2OutputOracle: cannot submit L2 output in the future"
);
require(
_outputRoot != bytes32(0),
"L2OutputOracle: L2 checkpoint output cannot be the zero hash"
);
if (_l1BlockHash != bytes32(0) && blockhash(_l1BlockNumber) != bytes32(0)) {
// This check allows the validator to submit an output based on a given L1 block,
// without fear that it will be reorged out.
// It will be skipped if the blockheight provided is more than 256 blocks behind the
// chain tip (as the hash will return as zero).
require(
blockhash(_l1BlockNumber) == _l1BlockHash,
"L2OutputOracle: block hash does not match the hash at the expected height"
);
}
uint256 outputIndex = nextOutputIndex();
l2Outputs.push(
Types.CheckpointOutput({
submitter: msg.sender,
outputRoot: _outputRoot,
timestamp: uint128(block.timestamp),
l2BlockNumber: uint128(_l2BlockNumber)
})
);
emit OutputSubmitted(_outputRoot, outputIndex, _l2BlockNumber, block.timestamp);
VALIDATOR_POOL.createBond(
outputIndex,
uint128(block.timestamp + FINALIZATION_PERIOD_SECONDS)
);
}
/**
* @notice Returns an output by index. Reverts if output is not found at the given index.
*
* @param _l2OutputIndex Index of the output to return.
*
* @return The output at the given index.
*/
function getL2Output(uint256 _l2OutputIndex)
external
view
returns (Types.CheckpointOutput memory)
{
return l2Outputs[_l2OutputIndex];
}
/**
* @notice Returns the index of the L2 output that checkpoints a given L2 block number. Uses a
* binary search to find the first output greater than or equal to the given block.
*
* @param _l2BlockNumber L2 block number to find a checkpoint for.
*
* @return Index of the first checkpoint that commits to the given L2 block number.
*/
function getL2OutputIndexAfter(uint256 _l2BlockNumber) public view returns (uint256) {
// Make sure an output for this block number has actually been submitted.
require(
_l2BlockNumber <= latestBlockNumber(),
"L2OutputOracle: cannot get output for a block that has not been submitted"
);
// Make sure there's at least one output submitted.
require(
l2Outputs.length > 0,
"L2OutputOracle: cannot get output as no outputs have been submitted yet"
);
// Find the output via binary search, guaranteed to exist.
uint256 lo = 0;
uint256 hi = l2Outputs.length;
while (lo < hi) {
uint256 mid = (lo + hi) / 2;
if (l2Outputs[mid].l2BlockNumber < _l2BlockNumber) {
lo = mid + 1;
} else {
hi = mid;
}
}
return lo;
}
/**
* @notice Returns the L2 checkpoint output that checkpoints a given L2 block number.
*
* @param _l2BlockNumber L2 block number to find a checkpoint for.
*
* @return First checkpoint that commits to the given L2 block number.
*/
function getL2OutputAfter(uint256 _l2BlockNumber)
external
view
returns (Types.CheckpointOutput memory)
{
return l2Outputs[getL2OutputIndexAfter(_l2BlockNumber)];
}
/**
* @notice Returns the index of the latest submitted output. Will revert if no outputs
* have been submitted yet.
*
* @return The index of the latest submitted output.
*/
function latestOutputIndex() external view returns (uint256) {
return l2Outputs.length - 1;
}
/**
* @notice Returns the index of the next output to be submitted.
*
* @return The index of the next output to be submitted.
*/
function nextOutputIndex() public view returns (uint256) {
return l2Outputs.length;
}
/**
* @notice Returns the block number of the latest submitted L2 checkpoint output. If no outputs
* have been submitted yet then this function will return the starting block number.
*
* @return Latest submitted L2 block number.
*/
function latestBlockNumber() public view returns (uint256) {
return
l2Outputs.length == 0
? startingBlockNumber
: l2Outputs[l2Outputs.length - 1].l2BlockNumber;
}
/**
* @notice Computes the block number of the next L2 block that needs to be checkpointed. If no
* outputs have been submitted yet then this function will return the latest block
* number, which is the starting block number.
*
* @return Next L2 block number.
*/
function nextBlockNumber() public view returns (uint256) {
return
l2Outputs.length == 0 ? latestBlockNumber() : latestBlockNumber() + SUBMISSION_INTERVAL;
}
/**
* @notice Returns the L2 timestamp corresponding to a given L2 block number.
*
* @param _l2BlockNumber The L2 block number of the target block.
*
* @return L2 timestamp of the given block.
*/
function computeL2Timestamp(uint256 _l2BlockNumber) public view returns (uint256) {
return startingTimestamp + ((_l2BlockNumber - startingBlockNumber) * L2_BLOCK_TIME);
}
/**
* @notice Returns the address of the L2 output submitter.
*
* @param _outputIndex Index of an output.
*
* @return Address of the submitter.
*/
function getSubmitter(uint256 _outputIndex) external view returns (address) {
return l2Outputs[_outputIndex].submitter;
}
/**
* @notice Returns if the output of given index is finalized.
*
* @param _outputIndex Index of an output.
*
* @return If the given output is finalized or not.
*/
function isFinalized(uint256 _outputIndex) external view returns (bool) {
return l2Outputs[_outputIndex].timestamp + FINALIZATION_PERIOD_SECONDS < block.timestamp;
}
/**
* @notice Returns the finalization time of given output index.
*
* @param _outputIndex Index of an output.
*
* @return The finalization time of given output index.
*/
function finalizedAt(uint256 _outputIndex) external view returns (uint256) {
return l2Outputs[_outputIndex].timestamp + FINALIZATION_PERIOD_SECONDS;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (proxy/utils/Initializable.sol)
pragma solidity ^0.8.2;
import "../../utils/AddressUpgradeable.sol";
/**
* @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
* behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an
* external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
* function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
*
* The initialization functions use a version number. Once a version number is used, it is consumed and cannot be
* reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in
* case an upgrade adds a module that needs to be initialized.
*
* For example:
*
* [.hljs-theme-light.nopadding]
* ```solidity
* contract MyToken is ERC20Upgradeable {
* function initialize() initializer public {
* __ERC20_init("MyToken", "MTK");
* }
* }
*
* contract MyTokenV2 is MyToken, ERC20PermitUpgradeable {
* function initializeV2() reinitializer(2) public {
* __ERC20Permit_init("MyToken");
* }
* }
* ```
*
* TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
* possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
*
* CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
* that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
*
* [CAUTION]
* ====
* Avoid leaving a contract uninitialized.
*
* An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
* contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke
* the {_disableInitializers} function in the constructor to automatically lock it when it is deployed:
*
* [.hljs-theme-light.nopadding]
* ```
* /// @custom:oz-upgrades-unsafe-allow constructor
* constructor() {
* _disableInitializers();
* }
* ```
* ====
*/
abstract contract Initializable {
/**
* @dev Indicates that the contract has been initialized.
* @custom:oz-retyped-from bool
*/
uint8 private _initialized;
/**
* @dev Indicates that the contract is in the process of being initialized.
*/
bool private _initializing;
/**
* @dev Triggered when the contract has been initialized or reinitialized.
*/
event Initialized(uint8 version);
/**
* @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,
* `onlyInitializing` functions can be used to initialize parent contracts.
*
* Similar to `reinitializer(1)`, except that functions marked with `initializer` can be nested in the context of a
* constructor.
*
* Emits an {Initialized} event.
*/
modifier initializer() {
bool isTopLevelCall = !_initializing;
require(
(isTopLevelCall && _initialized < 1) || (!AddressUpgradeable.isContract(address(this)) && _initialized == 1),
"Initializable: contract is already initialized"
);
_initialized = 1;
if (isTopLevelCall) {
_initializing = true;
}
_;
if (isTopLevelCall) {
_initializing = false;
emit Initialized(1);
}
}
/**
* @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
* contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
* used to initialize parent contracts.
*
* A reinitializer may be used after the original initialization step. This is essential to configure modules that
* are added through upgrades and that require initialization.
*
* When `version` is 1, this modifier is similar to `initializer`, except that functions marked with `reinitializer`
* cannot be nested. If one is invoked in the context of another, execution will revert.
*
* Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in
* a contract, executing them in the right order is up to the developer or operator.
*
* WARNING: setting the version to 255 will prevent any future reinitialization.
*
* Emits an {Initialized} event.
*/
modifier reinitializer(uint8 version) {
require(!_initializing && _initialized < version, "Initializable: contract is already initialized");
_initialized = version;
_initializing = true;
_;
_initializing = false;
emit Initialized(version);
}
/**
* @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
* {initializer} and {reinitializer} modifiers, directly or indirectly.
*/
modifier onlyInitializing() {
require(_initializing, "Initializable: contract is not initializing");
_;
}
/**
* @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call.
* Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized
* to any version. It is recommended to use this to lock implementation contracts that are designed to be called
* through proxies.
*
* Emits an {Initialized} event the first time it is successfully executed.
*/
function _disableInitializers() internal virtual {
require(!_initializing, "Initializable: contract is initializing");
if (_initialized != type(uint8).max) {
_initialized = type(uint8).max;
emit Initialized(type(uint8).max);
}
}
/**
* @dev Returns the highest version that has been initialized. See {reinitializer}.
*/
function _getInitializedVersion() internal view returns (uint8) {
return _initialized;
}
/**
* @dev Returns `true` if the contract is currently initializing. See {onlyInitializing}.
*/
function _isInitializing() internal view returns (bool) {
return _initializing;
}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;
import { Initializable } from "@openzeppelin/contracts/proxy/utils/Initializable.sol";
import { Math } from "@openzeppelin/contracts/utils/math/Math.sol";
import { Arithmetic } from "../libraries/Arithmetic.sol";
import { Burn } from "../libraries/Burn.sol";
/**
* @custom:upgradeable
* @title ResourceMetering
* @notice ResourceMetering implements an EIP-1559 style resource metering system where pricing
* updates automatically based on current demand.
*/
abstract contract ResourceMetering is Initializable {
/**
* @notice Represents the various parameters that control the way in which resources are
* metered. Corresponds to the EIP-1559 resource metering system.
*
* @custom:field prevBaseFee Base fee from the previous block(s).
* @custom:field prevBoughtGas Amount of gas bought so far in the current block.
* @custom:field prevBlockNum Last block number that the base fee was updated.
*/
struct ResourceParams {
uint128 prevBaseFee;
uint64 prevBoughtGas;
uint64 prevBlockNum;
}
/**
* @notice Represents the configuration for the EIP-1559 based curve for the deposit gas
* market. These values should be set with care as it is possible to set them in
* a way that breaks the deposit gas market. The target resource limit is defined as
* maxResourceLimit / elasticityMultiplier. This struct was designed to fit within a
* single word. There is additional space for additions in the future.
*
* @custom:field maxResourceLimit Represents the maximum amount of deposit gas that
* can be purchased per block.
* @custom:field elasticityMultiplier Determines the target resource limit along with
* the resource limit.
* @custom:field baseFeeMaxChangeDenominator Determines max change on fee per block.
* @custom:field minimumBaseFee The min deposit base fee, it is clamped to this
* value.
* @custom:field systemTxMaxGas The amount of gas supplied to the system
* transaction. This should be set to the same number
* that the kroma-node sets as the gas limit for the
* system transaction.
* @custom:field maximumBaseFee The max deposit base fee, it is clamped to this
* value.
*/
struct ResourceConfig {
uint32 maxResourceLimit;
uint8 elasticityMultiplier;
uint8 baseFeeMaxChangeDenominator;
uint32 minimumBaseFee;
uint32 systemTxMaxGas;
uint128 maximumBaseFee;
}
/**
* @notice EIP-1559 style gas parameters.
*/
ResourceParams public params;
/**
* @notice Reserve extra slots (to a total of 50) in the storage layout for future upgrades.
*/
uint256[48] private __gap;
/**
* @notice Meters access to a function based an amount of a requested resource.
*
* @param _amount Amount of the resource requested.
*/
modifier metered(uint64 _amount) {
// Record initial gas amount so we can refund for it later.
uint256 initialGas = gasleft();
// Run the underlying function.
_;
// Run the metering function.
_metered(_amount, initialGas);
}
/**
* @notice An internal function that holds all of the logic for metering a resource.
*
* @param _amount Amount of the resource requested.
* @param _initialGas The amount of gas before any modifier execution.
*/
function _metered(uint64 _amount, uint256 _initialGas) internal {
// Update block number and base fee if necessary.
uint256 blockDiff = block.number - params.prevBlockNum;
ResourceConfig memory config = _resourceConfig();
int256 targetResourceLimit = int256(uint256(config.maxResourceLimit)) /
int256(uint256(config.elasticityMultiplier));
if (blockDiff > 0) {
// Handle updating EIP-1559 style gas parameters. We use EIP-1559 to restrict the rate
// at which deposits can be created and therefore limit the potential for deposits to
// spam the L2 system. Fee scheme is very similar to EIP-1559 with minor changes.
int256 gasUsedDelta = int256(uint256(params.prevBoughtGas)) - targetResourceLimit;
int256 baseFeeDelta = (int256(uint256(params.prevBaseFee)) * gasUsedDelta) /
(targetResourceLimit * int256(uint256(config.baseFeeMaxChangeDenominator)));
// Update base fee by adding the base fee delta and clamp the resulting value between
// min and max.
int256 newBaseFee = Arithmetic.clamp({
_value: int256(uint256(params.prevBaseFee)) + baseFeeDelta,
_min: int256(uint256(config.minimumBaseFee)),
_max: int256(uint256(config.maximumBaseFee))
});
// If we skipped more than one block, we also need to account for every empty block.
// Empty block means there was no demand for deposits in that block, so we should
// reflect this lack of demand in the fee.
if (blockDiff > 1) {
// Update the base fee by repeatedly applying the exponent 1-(1/change_denominator)
// blockDiff - 1 times. Simulates multiple empty blocks. Clamp the resulting value
// between min and max.
newBaseFee = Arithmetic.clamp({
_value: Arithmetic.cdexp({
_coefficient: newBaseFee,
_denominator: int256(uint256(config.baseFeeMaxChangeDenominator)),
_exponent: int256(blockDiff - 1)
}),
_min: int256(uint256(config.minimumBaseFee)),
_max: int256(uint256(config.maximumBaseFee))
});
}
// Update new base fee, reset bought gas, and update block number.
params.prevBaseFee = uint128(uint256(newBaseFee));
params.prevBoughtGas = 0;
params.prevBlockNum = uint64(block.number);
}
// Make sure we can actually buy the resource amount requested by the user.
params.prevBoughtGas += _amount;
require(
int256(uint256(params.prevBoughtGas)) <= int256(uint256(config.maxResourceLimit)),
"ResourceMetering: cannot buy more gas than available gas limit"
);
// Determine the amount of ETH to be paid.
uint256 resourceCost = uint256(_amount) * uint256(params.prevBaseFee);
// We currently charge for this ETH amount as an L1 gas burn, so we convert the ETH amount
// into gas by dividing by the L1 base fee. We assume a minimum base fee of 1 gwei to avoid
// division by zero for L1s that don't support 1559 or to avoid excessive gas burns during
// periods of extremely low L1 demand. One-day average gas fee hasn't dipped below 1 gwei
// during any 1 day period in the last 5 years, so should be fine.
uint256 gasCost = resourceCost / Math.max(block.basefee, 1 gwei);
// Give the user a refund based on the amount of gas they used to do all of the work up to
// this point. Since we're at the end of the modifier, this should be pretty accurate. Acts
// effectively like a dynamic stipend (with a minimum value).
uint256 usedGas = _initialGas - gasleft();
if (gasCost > usedGas) {
Burn.gas(gasCost - usedGas);
}
}
/**
* @notice Virtual function that returns the resource config. Contracts that inherit this
* contract must implement this function.
*
* @return ResourceConfig
*/
function _resourceConfig() internal virtual returns (ResourceConfig memory);
/**
* @notice Sets initial resource parameter values. This function must either be called by the
* initializer function of an upgradeable child contract.
*/
// solhint-disable-next-line func-name-mixedcase
function __ResourceMetering_init() internal onlyInitializing {
params = ResourceParams({
prevBaseFee: 1 gwei,
prevBoughtGas: 0,
prevBlockNum: uint64(block.number)
});
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/Strings.sol)
pragma solidity ^0.8.0;
import "./math/Math.sol";
import "./math/SignedMath.sol";
/**
* @dev String operations.
*/
library Strings {
bytes16 private constant _SYMBOLS = "0123456789abcdef";
uint8 private constant _ADDRESS_LENGTH = 20;
/**
* @dev Converts a `uint256` to its ASCII `string` decimal representation.
*/
function toString(uint256 value) internal pure returns (string memory) {
unchecked {
uint256 length = Math.log10(value) + 1;
string memory buffer = new string(length);
uint256 ptr;
/// @solidity memory-safe-assembly
assembly {
ptr := add(buffer, add(32, length))
}
while (true) {
ptr--;
/// @solidity memory-safe-assembly
assembly {
mstore8(ptr, byte(mod(value, 10), _SYMBOLS))
}
value /= 10;
if (value == 0) break;
}
return buffer;
}
}
/**
* @dev Converts a `int256` to its ASCII `string` decimal representation.
*/
function toString(int256 value) internal pure returns (string memory) {
return string(abi.encodePacked(value < 0 ? "-" : "", toString(SignedMath.abs(value))));
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
*/
function toHexString(uint256 value) internal pure returns (string memory) {
unchecked {
return toHexString(value, Math.log256(value) + 1);
}
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
*/
function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
bytes memory buffer = new bytes(2 * length + 2);
buffer[0] = "0";
buffer[1] = "x";
for (uint256 i = 2 * length + 1; i > 1; --i) {
buffer[i] = _SYMBOLS[value & 0xf];
value >>= 4;
}
require(value == 0, "Strings: hex length insufficient");
return string(buffer);
}
/**
* @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
*/
function toHexString(address addr) internal pure returns (string memory) {
return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
}
/**
* @dev Returns true if the two strings are equal.
*/
function equal(string memory a, string memory b) internal pure returns (bool) {
return keccak256(bytes(a)) == keccak256(bytes(b));
}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;
import { Predeploys } from "../libraries/Predeploys.sol";
import { Semver } from "../universal/Semver.sol";
import { StandardBridge } from "../universal/StandardBridge.sol";
/**
* @custom:proxied
* @custom:predeploy 0x4200000000000000000000000000000000000009
* @title L2StandardBridge
* @notice The L2StandardBridge is responsible for transfering ETH and ERC20 tokens between L1 and
* L2. In the case that an ERC20 token is native to L2, it will be escrowed within this
* contract. If the ERC20 token is native to L1, it will be burnt.
* NOTE: this contract is not intended to support all variations of ERC20 tokens. Examples
* of some token types that may not be properly supported by this contract include, but are
* not limited to: tokens with transfer fees, rebasing tokens, and tokens with blocklists.
*/
contract L2StandardBridge is StandardBridge, Semver {
/**
* @custom:semver 1.0.0
*
* @param _otherBridge Address of the L1StandardBridge.
*/
constructor(address payable _otherBridge)
Semver(1, 0, 0)
StandardBridge(payable(Predeploys.L2_CROSS_DOMAIN_MESSENGER), _otherBridge)
{}
/**
* @notice Allows EOAs to bridge ETH by sending directly to the bridge.
*/
receive() external payable override onlyEOA {
_initiateBridgeETH(
msg.sender,
msg.sender,
msg.value,
RECEIVE_DEFAULT_GAS_LIMIT,
bytes("")
);
}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;
import { Predeploys } from "../libraries/Predeploys.sol";
import { L2StandardBridge } from "../L2/L2StandardBridge.sol";
/**
* @title FeeVault
* @notice The FeeVault contract contains the basic logic for the various different vault contracts
* used to hold fee revenue generated by the L2 system.
*/
abstract contract FeeVault {
/**
* @notice Emits each time that a withdrawal occurs.
*
* @param value Amount that was withdrawn (in wei).
* @param to Address that the funds were sent to.
* @param from Address that triggered the withdrawal.
*/
event Withdrawal(uint256 value, address to, address from);
/**
* @notice Minimum balance before a withdrawal can be triggered.
*/
uint256 public immutable MIN_WITHDRAWAL_AMOUNT;
/**
* @notice Wallet that will receive the fees on L1.
*/
address public immutable RECIPIENT;
/**
* @notice The minimum gas limit for the FeeVault withdrawal transaction.
*/
uint32 internal constant WITHDRAWAL_MIN_GAS = 35_000;
/**
* @notice Total amount of wei processed by the contract.
*/
uint256 public totalProcessed;
/**
* @param _recipient Wallet that will receive the fees on L1.
* @param _minWithdrawalAmount Minimum balance before a withdrawal can be triggered.
*/
constructor(address _recipient, uint256 _minWithdrawalAmount) {
MIN_WITHDRAWAL_AMOUNT = _minWithdrawalAmount;
RECIPIENT = _recipient;
}
/**
* @notice Allow the contract to receive ETH.
*/
receive() external payable {}
/**
* @notice Triggers a withdrawal of funds to the L1 fee wallet.
*/
function withdraw() external virtual {
require(
address(this).balance >= MIN_WITHDRAWAL_AMOUNT,
"FeeVault: withdrawal amount must be greater than minimum withdrawal amount"
);
uint256 value = address(this).balance;
totalProcessed += value;
emit Withdrawal(value, RECIPIENT, msg.sender);
L2StandardBridge(payable(Predeploys.L2_STANDARD_BRIDGE)).bridgeETHTo{ value: value }(
RECIPIENT,
WITHDRAWAL_MIN_GAS,
bytes("")
);
}
}
// SPDX-License-Identifier: Apache-2.0
/*
* Copyright 2019-2021, Offchain Labs, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
pragma solidity ^0.8.0;
library AddressAliasHelper {
uint160 constant offset = uint160(0x1111000000000000000000000000000000001111);
/// @notice Utility function that converts the address in the L1 that submitted a tx to
/// the inbox to the msg.sender viewed in the L2
/// @param l1Address the address in the L1 that triggered the tx to L2
/// @return l2Address L2 address as viewed in msg.sender
function applyL1ToL2Alias(address l1Address) internal pure returns (address l2Address) {
unchecked {
l2Address = address(uint160(l1Address) + offset);
}
}
/// @notice Utility function that converts the msg.sender viewed in the L2 to the
/// address in the L1 that submitted a tx to the inbox
/// @param l2Address L2 address as viewed in msg.sender
/// @return l1Address the address in the L1 that triggered the tx to L2
function undoL1ToL2Alias(address l2Address) internal pure returns (address l1Address) {
unchecked {
l1Address = address(uint160(l2Address) - offset);
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (proxy/utils/Initializable.sol)
pragma solidity ^0.8.2;
import "../../utils/Address.sol";
/**
* @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
* behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an
* external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
* function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
*
* The initialization functions use a version number. Once a version number is used, it is consumed and cannot be
* reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in
* case an upgrade adds a module that needs to be initialized.
*
* For example:
*
* [.hljs-theme-light.nopadding]
* ```solidity
* contract MyToken is ERC20Upgradeable {
* function initialize() initializer public {
* __ERC20_init("MyToken", "MTK");
* }
* }
*
* contract MyTokenV2 is MyToken, ERC20PermitUpgradeable {
* function initializeV2() reinitializer(2) public {
* __ERC20Permit_init("MyToken");
* }
* }
* ```
*
* TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
* possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
*
* CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
* that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
*
* [CAUTION]
* ====
* Avoid leaving a contract uninitialized.
*
* An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
* contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke
* the {_disableInitializers} function in the constructor to automatically lock it when it is deployed:
*
* [.hljs-theme-light.nopadding]
* ```
* /// @custom:oz-upgrades-unsafe-allow constructor
* constructor() {
* _disableInitializers();
* }
* ```
* ====
*/
abstract contract Initializable {
/**
* @dev Indicates that the contract has been initialized.
* @custom:oz-retyped-from bool
*/
uint8 private _initialized;
/**
* @dev Indicates that the contract is in the process of being initialized.
*/
bool private _initializing;
/**
* @dev Triggered when the contract has been initialized or reinitialized.
*/
event Initialized(uint8 version);
/**
* @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,
* `onlyInitializing` functions can be used to initialize parent contracts.
*
* Similar to `reinitializer(1)`, except that functions marked with `initializer` can be nested in the context of a
* constructor.
*
* Emits an {Initialized} event.
*/
modifier initializer() {
bool isTopLevelCall = !_initializing;
require(
(isTopLevelCall && _initialized < 1) || (!Address.isContract(address(this)) && _initialized == 1),
"Initializable: contract is already initialized"
);
_initialized = 1;
if (isTopLevelCall) {
_initializing = true;
}
_;
if (isTopLevelCall) {
_initializing = false;
emit Initialized(1);
}
}
/**
* @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
* contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
* used to initialize parent contracts.
*
* A reinitializer may be used after the original initialization step. This is essential to configure modules that
* are added through upgrades and that require initialization.
*
* When `version` is 1, this modifier is similar to `initializer`, except that functions marked with `reinitializer`
* cannot be nested. If one is invoked in the context of another, execution will revert.
*
* Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in
* a contract, executing them in the right order is up to the developer or operator.
*
* WARNING: setting the version to 255 will prevent any future reinitialization.
*
* Emits an {Initialized} event.
*/
modifier reinitializer(uint8 version) {
require(!_initializing && _initialized < version, "Initializable: contract is already initialized");
_initialized = version;
_initializing = true;
_;
_initializing = false;
emit Initialized(version);
}
/**
* @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
* {initializer} and {reinitializer} modifiers, directly or indirectly.
*/
modifier onlyInitializing() {
require(_initializing, "Initializable: contract is not initializing");
_;
}
/**
* @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call.
* Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized
* to any version. It is recommended to use this to lock implementation contracts that are designed to be called
* through proxies.
*
* Emits an {Initialized} event the first time it is successfully executed.
*/
function _disableInitializers() internal virtual {
require(!_initializing, "Initializable: contract is initializing");
if (_initialized != type(uint8).max) {
_initialized = type(uint8).max;
emit Initialized(type(uint8).max);
}
}
/**
* @dev Returns the highest version that has been initialized. See {reinitializer}.
*/
function _getInitializedVersion() internal view returns (uint8) {
return _initialized;
}
/**
* @dev Returns `true` if the contract is currently initializing. See {onlyInitializing}.
*/
function _isInitializing() internal view returns (bool) {
return _initializing;
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import { Encoding } from "./Encoding.sol";
import { RLPWriter } from "./rlp/RLPWriter.sol";
import { Types } from "./Types.sol";
/**
* @title Hashing
* @notice Hashing handles Kroma's various different hashing schemes.
*/
library Hashing {
/**
* @notice Computes the hash of the RLP encoded L2 transaction that would be generated when a
* given deposit is sent to the L2 system. Useful for searching for a deposit in the L2
* system.
*
* @param _tx User deposit transaction to hash.
*
* @return Hash of the RLP encoded L2 deposit transaction.
*/
function hashDepositTransaction(Types.UserDepositTransaction memory _tx)
internal
pure
returns (bytes32)
{
return keccak256(Encoding.encodeDepositTransaction(_tx));
}
/**
* @notice Computes the deposit transaction's "source hash", a value that guarantees the hash
* of the L2 transaction that corresponds to a deposit is unique and is
* deterministically generated from L1 transaction data.
*
* @param _l1BlockHash Hash of the L1 block where the deposit was included.
* @param _logIndex The index of the log that created the deposit transaction.
*
* @return Hash of the deposit transaction's "source hash".
*/
function hashDepositSource(bytes32 _l1BlockHash, uint64 _logIndex)
internal
pure
returns (bytes32)
{
bytes32 depositId = keccak256(abi.encode(_l1BlockHash, _logIndex));
return keccak256(abi.encode(bytes32(0), depositId));
}
/**
* @notice Hashes the cross domain message based on the version that is encoded into the
* message nonce.
*
* @param _nonce Message nonce with version encoded into the first two bytes.
* @param _sender Address of the sender of the message.
* @param _target Address of the target of the message.
* @param _value ETH value to send to the target.
* @param _gasLimit Gas limit to use for the message.
* @param _data Data to send with the message.
*
* @return Hashed cross domain message.
*/
function hashCrossDomainMessage(
uint256 _nonce,
address _sender,
address _target,
uint256 _value,
uint256 _gasLimit,
bytes memory _data
) internal pure returns (bytes32) {
(, uint16 version) = Encoding.decodeVersionedNonce(_nonce);
if (version == 0) {
return hashCrossDomainMessageV0(_nonce, _sender, _target, _value, _gasLimit, _data);
} else {
revert("Hashing: unknown cross domain message version");
}
}
/**
* @notice Hashes a cross domain message based on the V0 (current) encoding.
*
* @param _nonce Message nonce.
* @param _sender Address of the sender of the message.
* @param _target Address of the target of the message.
* @param _value ETH value to send to the target.
* @param _gasLimit Gas limit to use for the message.
* @param _data Data to send with the message.
*
* @return Hashed cross domain message.
*/
function hashCrossDomainMessageV0(
uint256 _nonce,
address _sender,
address _target,
uint256 _value,
uint256 _gasLimit,
bytes memory _data
) internal pure returns (bytes32) {
return
keccak256(
Encoding.encodeCrossDomainMessageV0(
_nonce,
_sender,
_target,
_value,
_gasLimit,
_data
)
);
}
/**
* @notice Derives the withdrawal hash according to the encoding in the L2 Withdrawer contract
*
* @param _tx Withdrawal transaction to hash.
*
* @return Hashed withdrawal transaction.
*/
function hashWithdrawal(Types.WithdrawalTransaction memory _tx)
internal
pure
returns (bytes32)
{
return
keccak256(
abi.encode(_tx.nonce, _tx.sender, _tx.target, _tx.value, _tx.gasLimit, _tx.data)
);
}
/**
* @notice Hashes the various elements of an output root proof into an output root hash which
* can be used to check if the proof is valid.
*
* @param _outputRootProof Output root proof which should be hashed to an output root.
*
* @return Hashed output root proof.
*/
function hashOutputRootProof(Types.OutputRootProof memory _outputRootProof)
internal
pure
returns (bytes32)
{
if (_outputRootProof.version == bytes32(uint256(0))) {
return hashOutputRootProofV0(_outputRootProof);
} else {
revert("Hashing: unknown output root proof version");
}
}
/**
* @notice Hashes the various elements of an output root proof into an output root hash which
* can be used to check if the proof is valid. (version 0)
*
* @param _outputRootProof Output root proof which should be hashed to an output root.
*
* @return Hashed output root proof.
*/
function hashOutputRootProofV0(Types.OutputRootProof memory _outputRootProof)
internal
pure
returns (bytes32)
{
return
keccak256(
abi.encode(
_outputRootProof.version,
_outputRootProof.stateRoot,
_outputRootProof.messagePasserStorageRoot,
_outputRootProof.blockHash,
_outputRootProof.nextBlockHash
)
);
}
/**
* @notice Fills the values of the block hash fields to a given bytes.
*
* @param _publicInput Public input which should be hashed to a block hash.
* @param _rlps Pre-RLP encoded data which should be hashed to a block hash.
* @param _raw An array of bytes to be populated.
*/
function _fillBlockHashFieldsToBytes(
Types.PublicInput memory _publicInput,
Types.BlockHeaderRLP memory _rlps,
bytes[] memory _raw
) private pure {
_raw[0] = RLPWriter.writeBytes(abi.encodePacked(_publicInput.parentHash));
_raw[1] = _rlps.uncleHash;
_raw[2] = _rlps.coinbase;
_raw[3] = RLPWriter.writeBytes(abi.encodePacked(_publicInput.stateRoot));
_raw[4] = RLPWriter.writeBytes(abi.encodePacked(_publicInput.transactionsRoot));
_raw[5] = _rlps.receiptsRoot;
_raw[6] = _rlps.logsBloom;
_raw[7] = _rlps.difficulty;
_raw[8] = RLPWriter.writeUint(_publicInput.number);
_raw[9] = RLPWriter.writeUint(_publicInput.gasLimit);
_raw[10] = _rlps.gasUsed;
_raw[11] = RLPWriter.writeUint(_publicInput.timestamp);
_raw[12] = _rlps.extraData;
_raw[13] = _rlps.mixHash;
_raw[14] = _rlps.nonce;
_raw[15] = RLPWriter.writeUint(_publicInput.baseFee);
}
/**
* @notice Hashes the various elements of a block header into a block hash(before shanghai).
*
* @param _publicInput Public input which should be hashed to a block hash.
* @param _rlps Pre-RLP encoded data which should be hashed to a block hash.
*
* @return Hashed block header.
*/
function hashBlockHeader(
Types.PublicInput memory _publicInput,
Types.BlockHeaderRLP memory _rlps
) internal pure returns (bytes32) {
bytes[] memory raw = new bytes[](16);
_fillBlockHashFieldsToBytes(_publicInput, _rlps, raw);
return keccak256(RLPWriter.writeList(raw));
}
/**
* @notice Hashes the various elements of a block header into a block hash(after shanghai).
*
* @param _publicInput Public input which should be hashed to a block hash.
* @param _rlps Pre-RLP encoded data which should be hashed to a block hash.
*
* @return Hashed block header.
*/
function hashBlockHeaderShanghai(
Types.PublicInput memory _publicInput,
Types.BlockHeaderRLP memory _rlps
) internal pure returns (bytes32) {
bytes[] memory raw = new bytes[](17);
_fillBlockHashFieldsToBytes(_publicInput, _rlps, raw);
raw[16] = RLPWriter.writeBytes(abi.encodePacked(_publicInput.withdrawalsRoot));
return keccak256(RLPWriter.writeList(raw));
}
/**
* @notice Hashes the various elements of a public input into a public input hash.
*
* @param _prevStateRoot Previous state root.
* @param _publicInput Public input which should be hashed to a public input hash.
* @param _dummyHashes Dummy hashes returned from generateDummyHashes().
*
* @return Hashed block header.
*/
function hashPublicInput(
bytes32 _prevStateRoot,
Types.PublicInput memory _publicInput,
bytes32[] memory _dummyHashes
) internal pure returns (bytes32) {
return
keccak256(
abi.encodePacked(
_prevStateRoot,
_publicInput.stateRoot,
_publicInput.withdrawalsRoot,
_publicInput.blockHash,
_publicInput.parentHash,
_publicInput.number,
_publicInput.timestamp,
_publicInput.baseFee,
_publicInput.gasLimit,
uint16(_publicInput.txHashes.length),
_publicInput.txHashes,
_dummyHashes
)
);
}
/**
* @notice Generates a bytes32 array filled with a dummy hash for the given length.
*
* @param _dummyHashes Dummy hash.
* @param _length A length of the array.
*
* @return Bytes32 array filled with dummy hash.
*/
function generateDummyHashes(bytes32 _dummyHashes, uint256 _length)
internal
pure
returns (bytes32[] memory)
{
bytes32[] memory hashes = new bytes32[](_length);
for (uint256 i = 0; i < _length; i++) {
hashes[i] = _dummyHashes;
}
return hashes;
}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;
import {
OwnableUpgradeable
} from "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
import { Constants } from "../libraries/Constants.sol";
import { Semver } from "../universal/Semver.sol";
import { ResourceMetering } from "./ResourceMetering.sol";
/**
* @title SystemConfig
* @notice The SystemConfig contract is used to manage configuration of a Kroma network. All
* configuration is stored on L1 and picked up by L2 as part of the derivation of the L2
* chain.
*/
contract SystemConfig is OwnableUpgradeable, Semver {
/**
* @notice Enum representing different types of updates.
*
* @custom:value BATCHER Represents an update to the batcher hash.
* @custom:value GAS_CONFIG Represents an update to txn fee config on L2.
* @custom:value GAS_LIMIT Represents an update to gas limit on L2.
* @custom:value UNSAFE_BLOCK_SIGNER Represents an update to the signer key for unsafe
* block distribution.
* @custom:value VALIDATOR_REWARD_SCALAR Represents an update to validator reward scalar.
*/
enum UpdateType {
BATCHER,
GAS_CONFIG,
GAS_LIMIT,
UNSAFE_BLOCK_SIGNER,
VALIDATOR_REWARD_SCALAR
}
/**
* @notice Version identifier, used for upgrades.
*/
uint256 public constant VERSION = 0;
/**
* @notice Storage slot that the unsafe block signer is stored at. Storing it at this
* deterministic storage slot allows for decoupling the storage layout from the way
* that `solc` lays out storage. The `kroma-node` uses a storage proof to fetch this value.
*/
bytes32 public constant UNSAFE_BLOCK_SIGNER_SLOT = keccak256("systemconfig.unsafeblocksigner");
/**
* @notice Fixed L2 gas overhead. Used as part of the L2 fee calculation.
*/
uint256 public overhead;
/**
* @notice Dynamic L2 gas overhead. Used as part of the L2 fee calculation.
*/
uint256 public scalar;
/**
* @notice Identifier for the batcher. For version 1 of this configuration, this is represented
* as an address left-padded with zeros to 32 bytes.
*/
bytes32 public batcherHash;
/**
* @notice L2 block gas limit.
*/
uint64 public gasLimit;
/**
* @notice The configuration for the deposit fee market. Used by the KromaPortal
* to meter the cost of buying L2 gas on L1. Set as internal and wrapped with a getter
* so that the struct is returned instead of a tuple.
*/
ResourceMetering.ResourceConfig internal _resourceConfig;
/**
* @notice The scalar value to distribute transaction fees as validator reward.
* The denominator is 10000, so the ratio is expressed in 4 decimal places.
*/
uint256 public validatorRewardScalar;
/**
* @notice Emitted when configuration is updated
*
* @param version SystemConfig version.
* @param updateType Type of update.
* @param data Encoded update data.
*/
event ConfigUpdate(uint256 indexed version, UpdateType indexed updateType, bytes data);
/**
* @custom:semver 1.0.0
*
* @param _owner Initial owner of the contract.
* @param _overhead Initial overhead value.
* @param _scalar Initial scalar value.
* @param _batcherHash Initial batcher hash.
* @param _gasLimit Initial gas limit.
* @param _unsafeBlockSigner Initial unsafe block signer address.
* @param _config Initial resource config.
* @param _validatorRewardScalar Initial validator reward scalar.
*/
constructor(
address _owner,
uint256 _overhead,
uint256 _scalar,
bytes32 _batcherHash,
uint64 _gasLimit,
address _unsafeBlockSigner,
ResourceMetering.ResourceConfig memory _config,
uint256 _validatorRewardScalar
) Semver(1, 0, 0) {
initialize(
_owner,
_overhead,
_scalar,
_batcherHash,
_gasLimit,
_unsafeBlockSigner,
_config,
_validatorRewardScalar
);
}
/**
* @notice Initializer. The resource config must be set before the
* require check.
*
* @param _owner Initial owner of the contract.
* @param _overhead Initial overhead value.
* @param _scalar Initial scalar value.
* @param _batcherHash Initial batcher hash.
* @param _gasLimit Initial gas limit.
* @param _unsafeBlockSigner Initial unsafe block signer address.
* @param _config Initial ResourceConfig.
* @param _validatorRewardScalar Initial validator reward scalar.
*/
function initialize(
address _owner,
uint256 _overhead,
uint256 _scalar,
bytes32 _batcherHash,
uint64 _gasLimit,
address _unsafeBlockSigner,
ResourceMetering.ResourceConfig memory _config,
uint256 _validatorRewardScalar
) public initializer {
__Ownable_init();
transferOwnership(_owner);
overhead = _overhead;
scalar = _scalar;
batcherHash = _batcherHash;
gasLimit = _gasLimit;
_setUnsafeBlockSigner(_unsafeBlockSigner);
_setResourceConfig(_config);
require(_gasLimit >= minimumGasLimit(), "SystemConfig: gas limit too low");
validatorRewardScalar = _validatorRewardScalar;
}
/**
* @notice Returns the minimum L2 gas limit that can be safely set for the system to
* operate. The L2 gas limit must be larger than or equal to the amount of
* gas that is allocated for deposits per block plus the amount of gas that
* is allocated for the system transaction.
* This function is used to determine if changes to parameters are safe.
*
* @return uint64
*/
function minimumGasLimit() public view returns (uint64) {
return uint64(_resourceConfig.maxResourceLimit) + uint64(_resourceConfig.systemTxMaxGas);
}
/**
* @notice High level getter for the unsafe block signer address. Unsafe blocks can be
* propagated across the p2p network if they are signed by the key corresponding to
* this address.
*
* @return Address of the unsafe block signer.
*/
// solhint-disable-next-line ordering
function unsafeBlockSigner() external view returns (address) {
address addr;
bytes32 slot = UNSAFE_BLOCK_SIGNER_SLOT;
assembly {
addr := sload(slot)
}
return addr;
}
/**
* @notice Updates the unsafe block signer address.
*
* @param _unsafeBlockSigner New unsafe block signer address.
*/
function setUnsafeBlockSigner(address _unsafeBlockSigner) external onlyOwner {
_setUnsafeBlockSigner(_unsafeBlockSigner);
bytes memory data = abi.encode(_unsafeBlockSigner);
emit ConfigUpdate(VERSION, UpdateType.UNSAFE_BLOCK_SIGNER, data);
}
/**
* @notice Updates the batcher hash.
*
* @param _batcherHash New batcher hash.
*/
function setBatcherHash(bytes32 _batcherHash) external onlyOwner {
batcherHash = _batcherHash;
bytes memory data = abi.encode(_batcherHash);
emit ConfigUpdate(VERSION, UpdateType.BATCHER, data);
}
/**
* @notice Updates gas config.
*
* @param _overhead New overhead value.
* @param _scalar New scalar value.
*/
function setGasConfig(uint256 _overhead, uint256 _scalar) external onlyOwner {
overhead = _overhead;
scalar = _scalar;
bytes memory data = abi.encode(_overhead, _scalar);
emit ConfigUpdate(VERSION, UpdateType.GAS_CONFIG, data);
}
/**
* @notice Updates the L2 gas limit.
*
* @param _gasLimit New gas limit.
*/
function setGasLimit(uint64 _gasLimit) external onlyOwner {
require(_gasLimit >= minimumGasLimit(), "SystemConfig: gas limit too low");
gasLimit = _gasLimit;
bytes memory data = abi.encode(_gasLimit);
emit ConfigUpdate(VERSION, UpdateType.GAS_LIMIT, data);
}
/**
* @notice Low level setter for the unsafe block signer address. This function exists to
* deduplicate code around storing the unsafeBlockSigner address in storage.
*
* @param _unsafeBlockSigner New unsafeBlockSigner value.
*/
function _setUnsafeBlockSigner(address _unsafeBlockSigner) internal {
bytes32 slot = UNSAFE_BLOCK_SIGNER_SLOT;
assembly {
sstore(slot, _unsafeBlockSigner)
}
}
/**
* @notice A getter for the resource config. Ensures that the struct is
* returned instead of a tuple.
*
* @return ResourceConfig
*/
function resourceConfig() external view returns (ResourceMetering.ResourceConfig memory) {
return _resourceConfig;
}
/**
* @notice An external setter for the resource config. In the future, this
* method may emit an event that the `kroma-node` picks up for when the
* resource config is changed.
*
* @param _config The new resource config values.
*/
function setResourceConfig(ResourceMetering.ResourceConfig memory _config) external onlyOwner {
_setResourceConfig(_config);
}
/**
* @notice An internal setter for the resource config. Ensures that the
* config is sane before storing it by checking for invariants.
*
* @param _config The new resource config.
*/
function _setResourceConfig(ResourceMetering.ResourceConfig memory _config) internal {
// Min base fee must be less than or equal to max base fee.
require(
_config.minimumBaseFee <= _config.maximumBaseFee,
"SystemConfig: min base fee must be less than max base"
);
// Base fee change denominator must be greater than 1.
require(
_config.baseFeeMaxChangeDenominator > 1,
"SystemConfig: denominator must be larger than 1"
);
// Max resource limit plus system tx gas must be less than or equal to the L2 gas limit.
// The gas limit must be increased before these values can be increased.
require(
_config.maxResourceLimit + _config.systemTxMaxGas <= gasLimit,
"SystemConfig: gas limit too low"
);
// Elasticity multiplier must be greater than 0.
require(
_config.elasticityMultiplier > 0,
"SystemConfig: elasticity multiplier cannot be 0"
);
// No precision loss when computing target resource limit.
require(
((_config.maxResourceLimit / _config.elasticityMultiplier) *
_config.elasticityMultiplier) == _config.maxResourceLimit,
"SystemConfig: precision loss with target resource limit"
);
_resourceConfig = _config;
}
/**
* @notice Updates the validator reward scalar.
*
* @param _validatorRewardScalar New validator reward scalar.
*/
function setValidatorRewardScalar(uint256 _validatorRewardScalar) external onlyOwner {
require(
_validatorRewardScalar <= Constants.VALIDATOR_REWARD_DENOMINATOR,
"SystemConfig: the max value of validator reward scalar has been exceeded"
);
validatorRewardScalar = _validatorRewardScalar;
bytes memory data = abi.encode(_validatorRewardScalar);
emit ConfigUpdate(VERSION, UpdateType.VALIDATOR_REWARD_SCALAR, data);
}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;
import { Bytes } from "../libraries/Bytes.sol";
import { NodeReader } from "../libraries/NodeReader.sol";
import { IZKMerkleTrie } from "./IZKMerkleTrie.sol";
import { ZKTrieHasher } from "./ZKTrieHasher.sol";
/**
* @custom:proxied
* @title ZKMerkleTrie
* @notice The ZKMerkleTrie is contract which can produce a hash according to ZKTrie.
* This owns an interface of Poseidon2 that is required to compute hash used by ZKTrie.
*/
contract ZKMerkleTrie is IZKMerkleTrie, ZKTrieHasher {
/**
* @notice Struct representing a node in the trie.
*/
struct TrieNode {
bytes encoded;
NodeReader.Node decoded;
}
/**
* @notice Magic hash which indicates
* See https://github.com/kroma-network/zktrie/blob/main/trie/zk_trie_proof.go.
*/
bytes32 private constant MAGIC_SMT_BYTES_HASH =
keccak256(
hex"5448495320495320534f4d45204d4147494320425954455320464f5220534d54206d3172525867503278704449"
);
/**
* @param _poseidon2 The address of poseidon2 contract.
*/
constructor(address _poseidon2) ZKTrieHasher(_poseidon2) {}
/**
* @notice Checks if a given bytes is MAGIC_SMT_BYTES_HASH.
*
* @param _value Bytes to be compared.
*/
function isMagicSmtBytesHash(bytes memory _value) private pure returns (bool) {
return keccak256(_value) == MAGIC_SMT_BYTES_HASH;
}
/**
* @inheritdoc IZKMerkleTrie
*/
function verifyInclusionProof(
bytes32 _key,
bytes memory _value,
bytes[] memory _proofs,
bytes32 _root
) external view returns (bool) {
(bool exists, bytes memory value) = this.get(_key, _proofs, _root);
return (exists && Bytes.equal(_value, value));
}
/**
* @notice Retrieves the value associated with a given key.
*
* @param _key Key to search for, as hex bytes.
* @param _proofs Merkle trie inclusion proof for the key.
* @param _root Known root of the Merkle trie.
*
* @return Whether or not the key exists.
* @return Value of the key if it exists.
*/
function get(
bytes32 _key,
bytes[] memory _proofs,
bytes32 _root
) external view returns (bool, bytes memory) {
require(_proofs.length >= 2, "ZKMerkleTrie: provided proof is too short");
require(
isMagicSmtBytesHash(_proofs[_proofs.length - 1]),
"ZKMerkleTrie: the last item is not magic hash"
);
bytes32 key = _hashElem(_key);
TrieNode[] memory nodes = _parseProofs(_proofs);
NodeReader.Node memory currentNode;
bytes32 computedKey = bytes32(0);
bool exists = false;
bool empty = false;
bytes memory value = bytes("");
for (uint256 i = nodes.length - 2; i >= 0; ) {
currentNode = nodes[i].decoded;
if (currentNode.nodeType == NodeReader.NodeType.MIDDLE) {
bool isLeft = _isLeft(key, i);
if (isLeft) {
require(computedKey == currentNode.childL, "ZKMerkleTrie: invalid key L");
} else {
require(computedKey == currentNode.childR, "ZKMerkleTrie: invalid key R");
}
computedKey = _hashFixed2Elems(
currentNode.childL,
currentNode.childR
);
} else if (currentNode.nodeType == NodeReader.NodeType.LEAF) {
require(!exists && !empty, "ZKMerkleTrie: duplicated terminal node");
exists = currentNode.nodeKey == key;
if (!exists) {
break;
}
computedKey = _hashFixed3Elems(
bytes32(uint256(1)),
currentNode.nodeKey,
_valueHash(currentNode.compressedFlags, currentNode.valuePreimage)
);
bytes32[] memory valuePreimage = currentNode.valuePreimage;
uint256 len = valuePreimage.length;
assembly {
value := valuePreimage
mstore(value, mul(len, 32))
}
if (currentNode.keyPreimage != bytes32(0)) {
// NOTE(chokobole): The comparison order is important, because in this setting,
// first condition is mostly evaluted to be true. When we're sure about
// database preimage, then we need to enable just one of check below!
require(
currentNode.keyPreimage == _key || currentNode.keyPreimage == key,
"ZKMerkleTrie: invalid key preimage"
);
}
} else if (currentNode.nodeType == NodeReader.NodeType.EMPTY) {
require(!exists && !empty, "ZKMerkleTrie: duplicated terminal node");
empty = true;
}
if (i == 0) {
require(computedKey == _root, "ZKMerkeTrie: invalid root");
break;
}
unchecked {
--i;
}
}
return (exists, value);
}
/**
* @notice Parses an array of proof elements into a new array that contains both the original
* encoded element and the decoded element.
*
* @param _proofs Array of proof elements to parse.
*
* @return TrieNode parsed into easily accessible structs.
*/
function _parseProofs(bytes[] memory _proofs) private pure returns (TrieNode[] memory) {
uint256 length = _proofs.length;
TrieNode[] memory nodes = new TrieNode[](length);
// NOTE(chokobole): Last proof is MAGIC_SMT_BYTES_HASH!
for (uint256 i = 0; i < length - 1; ) {
NodeReader.Node memory node = NodeReader.readNode(_proofs[i]);
nodes[i] = TrieNode({ encoded: _proofs[i], decoded: node });
unchecked {
++i;
}
}
return nodes;
}
/**
* @notice Computes merkle path at index n based on a given keyPreimage.
*
* @param _keyPreimage Keypreimage.
* @param _n Bit to mask.
*
* @return Whether merkle path is left or not.
*/
function _isLeft(bytes32 _keyPreimage, uint256 _n) private pure returns (bool) {
require(_n < 256, "ZKMerkleTrie: too long depth");
return _keyPreimage & bytes32(1 << _n) == 0;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/Address.sol)
pragma solidity ^0.8.1;
/**
* @dev Collection of functions related to the address type
*/
library AddressUpgradeable {
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
*
* Furthermore, `isContract` will also return true if the target contract within
* the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
* which only has an effect at the end of a transaction.
* ====
*
* [IMPORTANT]
* ====
* You shouldn't rely on `isContract` to protect against flash loan attacks!
*
* Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
* like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
* constructor.
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize/address.code.length, which returns 0
// for contracts in construction, since the code is only stored at the end
// of the constructor execution.
return account.code.length > 0;
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://consensys.net/diligence/blog/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.8.0/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient balance");
(bool success, ) = recipient.call{value: amount}("");
require(success, "Address: unable to send value, recipient may have reverted");
}
/**
* @dev Performs a Solidity function call using a low level `call`. A
* plain `call` is an unsafe replacement for a function call: use this
* function instead.
*
* If `target` reverts with a revert reason, it is bubbled up by this
* function (like regular Solidity function calls).
*
* Returns the raw returned data. To convert to the expected return value,
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
*
* Requirements:
*
* - `target` must be a contract.
* - calling `target` with `data` must not revert.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0, "Address: low-level call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
* `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but also transferring `value` wei to `target`.
*
* Requirements:
*
* - the calling contract must have an ETH balance of at least `value`.
* - the called Solidity function must be `payable`.
*
* _Available since v3.1._
*/
function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
}
/**
* @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
* with `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCallWithValue(
address target,
bytes memory data,
uint256 value,
string memory errorMessage
) internal returns (bytes memory) {
require(address(this).balance >= value, "Address: insufficient balance for call");
(bool success, bytes memory returndata) = target.call{value: value}(data);
return verifyCallResultFromTarget(target, success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
return functionStaticCall(target, data, "Address: low-level static call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(
address target,
bytes memory data,
string memory errorMessage
) internal view returns (bytes memory) {
(bool success, bytes memory returndata) = target.staticcall(data);
return verifyCallResultFromTarget(target, success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
return functionDelegateCall(target, data, "Address: low-level delegate call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
(bool success, bytes memory returndata) = target.delegatecall(data);
return verifyCallResultFromTarget(target, success, returndata, errorMessage);
}
/**
* @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
* the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
*
* _Available since v4.8._
*/
function verifyCallResultFromTarget(
address target,
bool success,
bytes memory returndata,
string memory errorMessage
) internal view returns (bytes memory) {
if (success) {
if (returndata.length == 0) {
// only check isContract if the call was successful and the return data is empty
// otherwise we already know that it was a contract
require(isContract(target), "Address: call to non-contract");
}
return returndata;
} else {
_revert(returndata, errorMessage);
}
}
/**
* @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
* revert reason or using the provided one.
*
* _Available since v4.3._
*/
function verifyCallResult(
bool success,
bytes memory returndata,
string memory errorMessage
) internal pure returns (bytes memory) {
if (success) {
return returndata;
} else {
_revert(returndata, errorMessage);
}
}
function _revert(bytes memory returndata, string memory errorMessage) private pure {
// Look for revert reason and bubble it up if present
if (returndata.length > 0) {
// The easiest way to bubble the revert reason is using memory via assembly
/// @solidity memory-safe-assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;
import { Math } from "@openzeppelin/contracts/utils/math/Math.sol";
import { SignedMath } from "@openzeppelin/contracts/utils/math/SignedMath.sol";
import { FixedPointMathLib } from "@rari-capital/solmate/src/utils/FixedPointMathLib.sol";
/**
* @title Arithmetic
* @notice Even more math than before.
*/
library Arithmetic {
/**
* @notice Clamps a value between a minimum and maximum.
*
* @param _value The value to clamp.
* @param _min The minimum value.
* @param _max The maximum value.
*
* @return The clamped value.
*/
function clamp(
int256 _value,
int256 _min,
int256 _max
) internal pure returns (int256) {
return SignedMath.min(SignedMath.max(_value, _min), _max);
}
/**
* @notice Clamps a value between a minimum and maximum.
*
* @param _value The value to clamp.
* @param _min The minimum value.
* @param _max The maximum value.
*
* @return The clamped value.
*/
function clamp(
uint256 _value,
uint256 _min,
uint256 _max
) internal pure returns (uint256) {
return Math.min(Math.max(_value, _min), _max);
}
/**
* @notice (c)oefficient (d)enominator (exp)onentiation function.
* Returns the result of: c * (1 - 1/d)^exp.
*
* @param _coefficient Coefficient of the function.
* @param _denominator Fractional denominator.
* @param _exponent Power function exponent.
*
* @return Result of c * (1 - 1/d)^exp.
*/
function cdexp(
int256 _coefficient,
int256 _denominator,
int256 _exponent
) internal pure returns (int256) {
return
(_coefficient *
(FixedPointMathLib.powWad(1e18 - (1e18 / _denominator), _exponent * 1e18))) / 1e18;
}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;
import { SafeCall } from "./SafeCall.sol";
/**
* @title Burn
* @notice Utilities for burning stuff.
*/
library Burn {
/**
* Burns a given amount of ETH.
* Note that execution engine of Kroma does not support SELFDESTRUCT opcode, so it sends ETH to zero address.
*
* @param _amount Amount of ETH to burn.
*/
function eth(uint256 _amount) internal {
SafeCall.call(address(0), gasleft(), _amount, "");
}
/**
* Burns a given amount of gas.
*
* @param _amount Amount of gas to burn.
*/
function gas(uint256 _amount) internal view {
uint256 i = 0;
uint256 initialGas = gasleft();
while (initialGas - gasleft() < _amount) {
++i;
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/math/SignedMath.sol)
pragma solidity ^0.8.0;
/**
* @dev Standard signed math utilities missing in the Solidity language.
*/
library SignedMath {
/**
* @dev Returns the largest of two signed numbers.
*/
function max(int256 a, int256 b) internal pure returns (int256) {
return a > b ? a : b;
}
/**
* @dev Returns the smallest of two signed numbers.
*/
function min(int256 a, int256 b) internal pure returns (int256) {
return a < b ? a : b;
}
/**
* @dev Returns the average of two signed numbers without overflow.
* The result is rounded towards zero.
*/
function average(int256 a, int256 b) internal pure returns (int256) {
// Formula from the book "Hacker's Delight"
int256 x = (a & b) + ((a ^ b) >> 1);
return x + (int256(uint256(x) >> 255) & (a ^ b));
}
/**
* @dev Returns the absolute unsigned value of a signed value.
*/
function abs(int256 n) internal pure returns (uint256) {
unchecked {
// must be unchecked in order to support `n = type(int256).min`
return uint256(n >= 0 ? n : -n);
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;
import { Address } from "@openzeppelin/contracts/utils/Address.sol";
import { ERC165Checker } from "@openzeppelin/contracts/utils/introspection/ERC165Checker.sol";
import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import { SafeCall } from "../libraries/SafeCall.sol";
import { CrossDomainMessenger } from "./CrossDomainMessenger.sol";
import { IKromaMintableERC20 } from "./IKromaMintableERC20.sol";
import { KromaMintableERC20 } from "./KromaMintableERC20.sol";
/**
* @custom:upgradeable
* @title StandardBridge
* @notice StandardBridge is a base contract for the L1 and L2 standard ERC20 bridges. It handles
* the core bridging logic, including escrowing tokens that are native to the local chain
* and minting/burning tokens that are native to the remote chain.
*/
abstract contract StandardBridge {
using SafeERC20 for IERC20;
/**
* @notice The L2 gas limit set when eth is depoisited using the receive() function.
*/
uint32 internal constant RECEIVE_DEFAULT_GAS_LIMIT = 200_000;
/**
* @notice Messenger contract on this domain.
*/
CrossDomainMessenger public immutable MESSENGER;
/**
* @notice Corresponding bridge on the other domain.
*/
StandardBridge public immutable OTHER_BRIDGE;
/**
* @notice Mapping that stores deposits for a given pair of local and remote tokens.
*/
mapping(address => mapping(address => uint256)) public deposits;
/**
* @notice Reserve extra slots (to a total of 50) in the storage layout for future upgrades.
* A gap size of 49 was chosen here, so that the first slot used in a child contract
* would be a multiple of 50.
*/
uint256[49] private __gap;
/**
* @notice Emitted when an ETH bridge is initiated to the other chain.
*
* @param from Address of the sender.
* @param to Address of the receiver.
* @param amount Amount of ETH sent.
* @param extraData Extra data sent with the transaction.
*/
event ETHBridgeInitiated(
address indexed from,
address indexed to,
uint256 amount,
bytes extraData
);
/**
* @notice Emitted when an ETH bridge is finalized on this chain.
*
* @param from Address of the sender.
* @param to Address of the receiver.
* @param amount Amount of ETH sent.
* @param extraData Extra data sent with the transaction.
*/
event ETHBridgeFinalized(
address indexed from,
address indexed to,
uint256 amount,
bytes extraData
);
/**
* @notice Emitted when an ERC20 bridge is initiated to the other chain.
*
* @param localToken Address of the ERC20 on this chain.
* @param remoteToken Address of the ERC20 on the remote chain.
* @param from Address of the sender.
* @param to Address of the receiver.
* @param amount Amount of the ERC20 sent.
* @param extraData Extra data sent with the transaction.
*/
event ERC20BridgeInitiated(
address indexed localToken,
address indexed remoteToken,
address indexed from,
address to,
uint256 amount,
bytes extraData
);
/**
* @notice Emitted when an ERC20 bridge is finalized on this chain.
*
* @param localToken Address of the ERC20 on this chain.
* @param remoteToken Address of the ERC20 on the remote chain.
* @param from Address of the sender.
* @param to Address of the receiver.
* @param amount Amount of the ERC20 sent.
* @param extraData Extra data sent with the transaction.
*/
event ERC20BridgeFinalized(
address indexed localToken,
address indexed remoteToken,
address indexed from,
address to,
uint256 amount,
bytes extraData
);
/**
* @notice Only allow EOAs to call the functions. Note that this is not safe against contracts
* calling code within their constructors, but also doesn't really matter since we're
* just trying to prevent users accidentally depositing with smart contract wallets.
*/
modifier onlyEOA() {
require(
!Address.isContract(msg.sender),
"StandardBridge: function can only be called from an EOA"
);
_;
}
/**
* @notice Ensures that the caller is a cross-chain message from the other bridge.
*/
modifier onlyOtherBridge() {
require(
msg.sender == address(MESSENGER) &&
MESSENGER.xDomainMessageSender() == address(OTHER_BRIDGE),
"StandardBridge: function can only be called from the other bridge"
);
_;
}
/**
* @param _messenger Address of CrossDomainMessenger on this network.
* @param _otherBridge Address of the other StandardBridge contract.
*/
constructor(address payable _messenger, address payable _otherBridge) {
MESSENGER = CrossDomainMessenger(_messenger);
OTHER_BRIDGE = StandardBridge(_otherBridge);
}
/**
* @notice Allows EOAs to bridge ETH by sending directly to the bridge.
* Must be implemented by contracts that inherit.
*/
receive() external payable virtual;
/**
* @notice Sends ETH to the sender's address on the other chain.
*
* @param _minGasLimit Minimum amount of gas that the bridge can be relayed with.
* @param _extraData Extra data to be sent with the transaction. Note that the recipient will
* not be triggered with this data, but it will be emitted and can be used
* to identify the transaction.
*/
function bridgeETH(uint32 _minGasLimit, bytes calldata _extraData) public payable onlyEOA {
_initiateBridgeETH(msg.sender, msg.sender, msg.value, _minGasLimit, _extraData);
}
/**
* @notice Sends ETH to a receiver's address on the other chain. Note that if ETH is sent to a
* smart contract and the call fails, the ETH will be temporarily locked in the
* StandardBridge on the other chain until the call is replayed. If the call cannot be
* replayed with any amount of gas (call always reverts), then the ETH will be
* permanently locked in the StandardBridge on the other chain. ETH will also
* be locked if the receiver is the other bridge, because finalizeBridgeETH will revert
* in that case.
*
* @param _to Address of the receiver.
* @param _minGasLimit Minimum amount of gas that the bridge can be relayed with.
* @param _extraData Extra data to be sent with the transaction. Note that the recipient will
* not be triggered with this data, but it will be emitted and can be used
* to identify the transaction.
*/
function bridgeETHTo(
address _to,
uint32 _minGasLimit,
bytes calldata _extraData
) public payable {
_initiateBridgeETH(msg.sender, _to, msg.value, _minGasLimit, _extraData);
}
/**
* @notice Sends ERC20 tokens to the sender's address on the other chain. Note that if the
* ERC20 token on the other chain does not recognize the local token as the correct
* pair token, the ERC20 bridge will fail and the tokens will be returned to sender on
* this chain.
*
* @param _localToken Address of the ERC20 on this chain.
* @param _remoteToken Address of the corresponding token on the remote chain.
* @param _amount Amount of local tokens to deposit.
* @param _minGasLimit Minimum amount of gas that the bridge can be relayed with.
* @param _extraData Extra data to be sent with the transaction. Note that the recipient will
* not be triggered with this data, but it will be emitted and can be used
* to identify the transaction.
*/
function bridgeERC20(
address _localToken,
address _remoteToken,
uint256 _amount,
uint32 _minGasLimit,
bytes calldata _extraData
) public onlyEOA {
_initiateBridgeERC20(
_localToken,
_remoteToken,
msg.sender,
msg.sender,
_amount,
_minGasLimit,
_extraData
);
}
/**
* @notice Sends ERC20 tokens to a receiver's address on the other chain. Note that if the
* ERC20 token on the other chain does not recognize the local token as the correct
* pair token, the ERC20 bridge will fail and the tokens will be returned to sender on
* this chain.
*
* @param _localToken Address of the ERC20 on this chain.
* @param _remoteToken Address of the corresponding token on the remote chain.
* @param _to Address of the receiver.
* @param _amount Amount of local tokens to deposit.
* @param _minGasLimit Minimum amount of gas that the bridge can be relayed with.
* @param _extraData Extra data to be sent with the transaction. Note that the recipient will
* not be triggered with this data, but it will be emitted and can be used
* to identify the transaction.
*/
function bridgeERC20To(
address _localToken,
address _remoteToken,
address _to,
uint256 _amount,
uint32 _minGasLimit,
bytes calldata _extraData
) public {
_initiateBridgeERC20(
_localToken,
_remoteToken,
msg.sender,
_to,
_amount,
_minGasLimit,
_extraData
);
}
/**
* @notice Finalizes an ETH bridge on this chain. Can only be triggered by the other
* StandardBridge contract on the remote chain.
*
* @param _from Address of the sender.
* @param _to Address of the receiver.
* @param _amount Amount of ETH being bridged.
* @param _extraData Extra data to be sent with the transaction. Note that the recipient will
* not be triggered with this data, but it will be emitted and can be used
* to identify the transaction.
*/
function finalizeBridgeETH(
address _from,
address _to,
uint256 _amount,
bytes calldata _extraData
) public payable onlyOtherBridge {
require(msg.value == _amount, "StandardBridge: amount sent does not match amount required");
require(_to != address(this), "StandardBridge: cannot send to self");
require(_to != address(MESSENGER), "StandardBridge: cannot send to messenger");
emit ETHBridgeFinalized(_from, _to, _amount, _extraData);
bool success = SafeCall.call(_to, gasleft(), _amount, hex"");
require(success, "StandardBridge: ETH transfer failed");
}
/**
* @notice Finalizes an ERC20 bridge on this chain. Can only be triggered by the other
* StandardBridge contract on the remote chain.
*
* @param _localToken Address of the ERC20 on this chain.
* @param _remoteToken Address of the corresponding token on the remote chain.
* @param _from Address of the sender.
* @param _to Address of the receiver.
* @param _amount Amount of the ERC20 being bridged.
* @param _extraData Extra data to be sent with the transaction. Note that the recipient will
* not be triggered with this data, but it will be emitted and can be used
* to identify the transaction.
*/
function finalizeBridgeERC20(
address _localToken,
address _remoteToken,
address _from,
address _to,
uint256 _amount,
bytes calldata _extraData
) public onlyOtherBridge {
if (_isKromaMintableERC20(_localToken)) {
require(
_isCorrectTokenPair(_localToken, _remoteToken),
"StandardBridge: wrong remote token for Kroma Mintable ERC20 local token"
);
KromaMintableERC20(_localToken).mint(_to, _amount);
} else {
deposits[_localToken][_remoteToken] = deposits[_localToken][_remoteToken] - _amount;
IERC20(_localToken).safeTransfer(_to, _amount);
}
emit ERC20BridgeFinalized(_localToken, _remoteToken, _from, _to, _amount, _extraData);
}
/**
* @notice Initiates a bridge of ETH through the CrossDomainMessenger.
*
* @param _from Address of the sender.
* @param _to Address of the receiver.
* @param _amount Amount of ETH being bridged.
* @param _minGasLimit Minimum amount of gas that the bridge can be relayed with.
* @param _extraData Extra data to be sent with the transaction. Note that the recipient will
* not be triggered with this data, but it will be emitted and can be used
* to identify the transaction.
*/
function _initiateBridgeETH(
address _from,
address _to,
uint256 _amount,
uint32 _minGasLimit,
bytes memory _extraData
) internal {
require(
msg.value == _amount,
"StandardBridge: bridging ETH must include sufficient ETH value"
);
emit ETHBridgeInitiated(_from, _to, _amount, _extraData);
MESSENGER.sendMessage{ value: _amount }(
address(OTHER_BRIDGE),
abi.encodeWithSelector(
this.finalizeBridgeETH.selector,
_from,
_to,
_amount,
_extraData
),
_minGasLimit
);
}
/**
* @notice Sends ERC20 tokens to a receiver's address on the other chain.
*
* @param _localToken Address of the ERC20 on this chain.
* @param _remoteToken Address of the corresponding token on the remote chain.
* @param _to Address of the receiver.
* @param _amount Amount of local tokens to deposit.
* @param _minGasLimit Minimum amount of gas that the bridge can be relayed with.
* @param _extraData Extra data to be sent with the transaction. Note that the recipient will
* not be triggered with this data, but it will be emitted and can be used
* to identify the transaction.
*/
function _initiateBridgeERC20(
address _localToken,
address _remoteToken,
address _from,
address _to,
uint256 _amount,
uint32 _minGasLimit,
bytes memory _extraData
) internal {
if (_isKromaMintableERC20(_localToken)) {
require(
_isCorrectTokenPair(_localToken, _remoteToken),
"StandardBridge: wrong remote token for Kroma Mintable ERC20 local token"
);
KromaMintableERC20(_localToken).burn(_from, _amount);
} else {
IERC20(_localToken).safeTransferFrom(_from, address(this), _amount);
deposits[_localToken][_remoteToken] = deposits[_localToken][_remoteToken] + _amount;
}
emit ERC20BridgeInitiated(_localToken, _remoteToken, _from, _to, _amount, _extraData);
MESSENGER.sendMessage(
address(OTHER_BRIDGE),
abi.encodeWithSelector(
this.finalizeBridgeERC20.selector,
// Because this call will be executed on the remote chain, we reverse the order of
// the remote and local token addresses relative to their order in the
// finalizeBridgeERC20 function.
_remoteToken,
_localToken,
_from,
_to,
_amount,
_extraData
),
_minGasLimit
);
}
/**
* @notice Checks if a given address is a KromaMintableERC20. Not perfect, but good enough.
* Just the way we like it.
*
* @param _token Address of the token to check.
*
* @return True if the token is a KromaMintableERC20.
*/
function _isKromaMintableERC20(address _token) internal view returns (bool) {
return ERC165Checker.supportsInterface(_token, type(IKromaMintableERC20).interfaceId);
}
/**
* @notice Checks if the "other token" is the correct pair token for the KromaMintableERC20.
*
* @param _mintableToken KromaMintableERC20 to check against.
* @param _otherToken Pair token to check.
*
* @return True if the other token is the correct pair token for the KromaMintableERC20.
*/
function _isCorrectTokenPair(address _mintableToken, address _otherToken)
internal
view
returns (bool)
{
return _otherToken == KromaMintableERC20(_mintableToken).REMOTE_TOKEN();
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/Address.sol)
pragma solidity ^0.8.1;
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
*
* Furthermore, `isContract` will also return true if the target contract within
* the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
* which only has an effect at the end of a transaction.
* ====
*
* [IMPORTANT]
* ====
* You shouldn't rely on `isContract` to protect against flash loan attacks!
*
* Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
* like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
* constructor.
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize/address.code.length, which returns 0
// for contracts in construction, since the code is only stored at the end
// of the constructor execution.
return account.code.length > 0;
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://consensys.net/diligence/blog/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.8.0/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient balance");
(bool success, ) = recipient.call{value: amount}("");
require(success, "Address: unable to send value, recipient may have reverted");
}
/**
* @dev Performs a Solidity function call using a low level `call`. A
* plain `call` is an unsafe replacement for a function call: use this
* function instead.
*
* If `target` reverts with a revert reason, it is bubbled up by this
* function (like regular Solidity function calls).
*
* Returns the raw returned data. To convert to the expected return value,
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
*
* Requirements:
*
* - `target` must be a contract.
* - calling `target` with `data` must not revert.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0, "Address: low-level call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
* `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but also transferring `value` wei to `target`.
*
* Requirements:
*
* - the calling contract must have an ETH balance of at least `value`.
* - the called Solidity function must be `payable`.
*
* _Available since v3.1._
*/
function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
}
/**
* @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
* with `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCallWithValue(
address target,
bytes memory data,
uint256 value,
string memory errorMessage
) internal returns (bytes memory) {
require(address(this).balance >= value, "Address: insufficient balance for call");
(bool success, bytes memory returndata) = target.call{value: value}(data);
return verifyCallResultFromTarget(target, success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
return functionStaticCall(target, data, "Address: low-level static call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(
address target,
bytes memory data,
string memory errorMessage
) internal view returns (bytes memory) {
(bool success, bytes memory returndata) = target.staticcall(data);
return verifyCallResultFromTarget(target, success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
return functionDelegateCall(target, data, "Address: low-level delegate call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
(bool success, bytes memory returndata) = target.delegatecall(data);
return verifyCallResultFromTarget(target, success, returndata, errorMessage);
}
/**
* @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
* the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
*
* _Available since v4.8._
*/
function verifyCallResultFromTarget(
address target,
bool success,
bytes memory returndata,
string memory errorMessage
) internal view returns (bytes memory) {
if (success) {
if (returndata.length == 0) {
// only check isContract if the call was successful and the return data is empty
// otherwise we already know that it was a contract
require(isContract(target), "Address: call to non-contract");
}
return returndata;
} else {
_revert(returndata, errorMessage);
}
}
/**
* @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
* revert reason or using the provided one.
*
* _Available since v4.3._
*/
function verifyCallResult(
bool success,
bytes memory returndata,
string memory errorMessage
) internal pure returns (bytes memory) {
if (success) {
return returndata;
} else {
_revert(returndata, errorMessage);
}
}
function _revert(bytes memory returndata, string memory errorMessage) private pure {
// Look for revert reason and bubble it up if present
if (returndata.length > 0) {
// The easiest way to bubble the revert reason is using memory via assembly
/// @solidity memory-safe-assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import { Hashing } from "./Hashing.sol";
import { Types } from "./Types.sol";
import { RLPWriter } from "./rlp/RLPWriter.sol";
/**
* @title Encoding
* @notice Encoding handles Kroma's various different encoding schemes.
*/
library Encoding {
/**
* @notice RLP encodes the L2 transaction that would be generated when a given deposit is sent
* to the L2 system. Useful for searching for a deposit in the L2 system. The
* transaction is prefixed with 0x7e to identify its EIP-2718 type.
*
* @param _tx User deposit transaction to encode.
*
* @return RLP encoded L2 deposit transaction.
*/
function encodeDepositTransaction(Types.UserDepositTransaction memory _tx)
internal
pure
returns (bytes memory)
{
bytes32 source = Hashing.hashDepositSource(_tx.l1BlockHash, _tx.logIndex);
bytes[] memory raw = new bytes[](7);
raw[0] = RLPWriter.writeBytes(abi.encodePacked(source));
raw[1] = RLPWriter.writeAddress(_tx.from);
raw[2] = _tx.isCreation ? RLPWriter.writeBytes("") : RLPWriter.writeAddress(_tx.to);
raw[3] = RLPWriter.writeUint(_tx.mint);
raw[4] = RLPWriter.writeUint(_tx.value);
raw[5] = RLPWriter.writeUint(uint256(_tx.gasLimit));
raw[6] = RLPWriter.writeBytes(_tx.data);
return abi.encodePacked(uint8(0x7e), RLPWriter.writeList(raw));
}
/**
* @notice Encodes the cross domain message based on the version that is encoded into the
* message nonce.
*
* @param _nonce Message nonce with version encoded into the first two bytes.
* @param _sender Address of the sender of the message.
* @param _target Address of the target of the message.
* @param _value ETH value to send to the target.
* @param _gasLimit Gas limit to use for the message.
* @param _data Data to send with the message.
*
* @return Encoded cross domain message.
*/
function encodeCrossDomainMessage(
uint256 _nonce,
address _sender,
address _target,
uint256 _value,
uint256 _gasLimit,
bytes memory _data
) internal pure returns (bytes memory) {
(, uint16 version) = decodeVersionedNonce(_nonce);
if (version == 0) {
return encodeCrossDomainMessageV0(_nonce, _sender, _target, _value, _gasLimit, _data);
} else {
revert("Encoding: unknown cross domain message version");
}
}
/**
* @notice Encodes a cross domain message based on the V0 (current) encoding.
*
* @param _nonce Message nonce.
* @param _sender Address of the sender of the message.
* @param _target Address of the target of the message.
* @param _value ETH value to send to the target.
* @param _gasLimit Gas limit to use for the message.
* @param _data Data to send with the message.
*
* @return Encoded cross domain message.
*/
function encodeCrossDomainMessageV0(
uint256 _nonce,
address _sender,
address _target,
uint256 _value,
uint256 _gasLimit,
bytes memory _data
) internal pure returns (bytes memory) {
return
abi.encodeWithSignature(
"relayMessage(uint256,address,address,uint256,uint256,bytes)",
_nonce,
_sender,
_target,
_value,
_gasLimit,
_data
);
}
/**
* @notice Adds a version number into the first two bytes of a message nonce.
*
* @param _nonce Message nonce to encode into.
* @param _version Version number to encode into the message nonce.
*
* @return Message nonce with version encoded into the first two bytes.
*/
function encodeVersionedNonce(uint240 _nonce, uint16 _version) internal pure returns (uint256) {
uint256 nonce;
assembly {
nonce := or(shl(240, _version), _nonce)
}
return nonce;
}
/**
* @notice Pulls the version out of a version-encoded nonce.
*
* @param _nonce Message nonce with version encoded into the first two bytes.
*
* @return Nonce without encoded version.
* @return Version of the message.
*/
function decodeVersionedNonce(uint256 _nonce) internal pure returns (uint240, uint16) {
uint240 nonce;
uint16 version;
assembly {
nonce := and(_nonce, 0x0000ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff)
version := shr(240, _nonce)
}
return (nonce, version);
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @custom:attribution https://github.com/bakaoh/solidity-rlp-encode
* @title RLPWriter
* @author RLPWriter is a library for encoding Solidity types to RLP bytes. Adapted from Bakaoh's
* RLPEncode library (https://github.com/bakaoh/solidity-rlp-encode) with minor
* modifications to improve legibility.
*/
library RLPWriter {
/**
* @notice RLP encodes a byte string.
*
* @param _in The byte string to encode.
*
* @return The RLP encoded string in bytes.
*/
function writeBytes(bytes memory _in) internal pure returns (bytes memory) {
bytes memory encoded;
if (_in.length == 1 && uint8(_in[0]) < 128) {
encoded = _in;
} else {
encoded = abi.encodePacked(_writeLength(_in.length, 128), _in);
}
return encoded;
}
/**
* @notice RLP encodes a list of RLP encoded byte byte strings.
*
* @param _in The list of RLP encoded byte strings.
*
* @return The RLP encoded list of items in bytes.
*/
function writeList(bytes[] memory _in) internal pure returns (bytes memory) {
bytes memory list = _flatten(_in);
return abi.encodePacked(_writeLength(list.length, 192), list);
}
/**
* @notice RLP encodes a string.
*
* @param _in The string to encode.
*
* @return The RLP encoded string in bytes.
*/
function writeString(string memory _in) internal pure returns (bytes memory) {
return writeBytes(bytes(_in));
}
/**
* @notice RLP encodes an address.
*
* @param _in The address to encode.
*
* @return The RLP encoded address in bytes.
*/
function writeAddress(address _in) internal pure returns (bytes memory) {
return writeBytes(abi.encodePacked(_in));
}
/**
* @notice RLP encodes a uint.
*
* @param _in The uint256 to encode.
*
* @return The RLP encoded uint256 in bytes.
*/
function writeUint(uint256 _in) internal pure returns (bytes memory) {
return writeBytes(_toBinary(_in));
}
/**
* @notice RLP encodes a bool.
*
* @param _in The bool to encode.
*
* @return The RLP encoded bool in bytes.
*/
function writeBool(bool _in) internal pure returns (bytes memory) {
bytes memory encoded = new bytes(1);
encoded[0] = (_in ? bytes1(0x01) : bytes1(0x80));
return encoded;
}
/**
* @notice Encode the first byte and then the `len` in binary form if `length` is more than 55.
*
* @param _len The length of the string or the payload.
* @param _offset 128 if item is string, 192 if item is list.
*
* @return RLP encoded bytes.
*/
function _writeLength(uint256 _len, uint256 _offset) private pure returns (bytes memory) {
bytes memory encoded;
if (_len < 56) {
encoded = new bytes(1);
encoded[0] = bytes1(uint8(_len) + uint8(_offset));
} else {
uint256 lenLen;
uint256 i = 1;
while (_len / i != 0) {
lenLen++;
i *= 256;
}
encoded = new bytes(lenLen + 1);
encoded[0] = bytes1(uint8(lenLen) + uint8(_offset) + 55);
for (i = 1; i <= lenLen; i++) {
encoded[i] = bytes1(uint8((_len / (256**(lenLen - i))) % 256));
}
}
return encoded;
}
/**
* @notice Encode integer in big endian binary form with no leading zeroes.
*
* @param _x The integer to encode.
*
* @return RLP encoded bytes.
*/
function _toBinary(uint256 _x) private pure returns (bytes memory) {
bytes memory b = abi.encodePacked(_x);
uint256 i = 0;
for (; i < 32; i++) {
if (b[i] != 0) {
break;
}
}
bytes memory res = new bytes(32 - i);
for (uint256 j = 0; j < res.length; j++) {
res[j] = b[i++];
}
return res;
}
/**
* @custom:attribution https://github.com/Arachnid/solidity-stringutils
* @notice Copies a piece of memory to another location.
*
* @param _dest Destination location.
* @param _src Source location.
* @param _len Length of memory to copy.
*/
function _memcpy(
uint256 _dest,
uint256 _src,
uint256 _len
) private pure {
uint256 dest = _dest;
uint256 src = _src;
uint256 len = _len;
for (; len >= 32; len -= 32) {
assembly {
mstore(dest, mload(src))
}
dest += 32;
src += 32;
}
uint256 mask;
unchecked {
mask = 256**(32 - len) - 1;
}
assembly {
let srcpart := and(mload(src), not(mask))
let destpart := and(mload(dest), mask)
mstore(dest, or(destpart, srcpart))
}
}
/**
* @custom:attribution https://github.com/sammayo/solidity-rlp-encoder
* @notice Flattens a list of byte strings into one byte string.
*
* @param _list List of byte strings to flatten.
*
* @return The flattened byte string.
*/
function _flatten(bytes[] memory _list) private pure returns (bytes memory) {
if (_list.length == 0) {
return new bytes(0);
}
uint256 len;
uint256 i = 0;
for (; i < _list.length; i++) {
len += _list[i].length;
}
bytes memory flattened = new bytes(len);
uint256 flattenedPtr;
assembly {
flattenedPtr := add(flattened, 0x20)
}
for (i = 0; i < _list.length; i++) {
bytes memory item = _list[i];
uint256 listPtr;
assembly {
listPtr := add(item, 0x20)
}
_memcpy(flattenedPtr, listPtr, item.length);
flattenedPtr += _list[i].length;
}
return flattened;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable.sol)
pragma solidity ^0.8.0;
import "../utils/ContextUpgradeable.sol";
import "../proxy/utils/Initializable.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
abstract contract OwnableUpgradeable is Initializable, ContextUpgradeable {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
function __Ownable_init() internal onlyInitializing {
__Ownable_init_unchained();
}
function __Ownable_init_unchained() internal onlyInitializing {
_transferOwnership(_msgSender());
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
_checkOwner();
_;
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if the sender is not the owner.
*/
function _checkOwner() internal view virtual {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby disabling any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
_transferOwnership(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Internal function without access restriction.
*/
function _transferOwnership(address newOwner) internal virtual {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
/**
* @dev This empty reserved space is put in place to allow future versions to add new
* variables without shifting down storage in the inheritance chain.
* See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
*/
uint256[49] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @title Bytes
* @notice Bytes is a library for manipulating byte arrays.
*/
library Bytes {
/**
* @notice Compares two byte arrays by comparing their keccak256 hashes.
*
* @param _bytes First byte array to compare.
* @param _other Second byte array to compare.
*
* @return True if the two byte arrays are equal, false otherwise.
*/
function equal(bytes memory _bytes, bytes memory _other) internal pure returns (bool) {
return keccak256(_bytes) == keccak256(_other);
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @title NodeReader
* @notice NodeReader is a library for reading ZKTrie Node.
*/
library NodeReader {
/**
* @notice Node types.
* See https://github.com/kroma-network/zktrie/blob/main/types/README.md.
*
* @custom:value MIDDLE Represents a middle node.
* @custom:value LEAF Represents a leaf node.
* @custom:value EMPTY Represents a empty node.
* @custom:value ROOT Represents a root node.
*/
enum NodeType {
MIDDLE,
LEAF,
EMPTY,
ROOT
}
/**
* @notice Struct representing a Node.
* See https://github.com/kroma-network/zktrie/blob/main/types/README.md.
*/
struct Node {
NodeType nodeType;
bytes32 childL;
bytes32 childR;
bytes32 nodeKey;
bytes32[] valuePreimage;
uint32 compressedFlags;
bytes32 valueHash;
bytes32 keyPreimage;
}
/**
* @notice Struct representing an Item.
*/
struct Item {
bytes ptr;
uint256 len;
}
/**
* @notice Converts bytes to Item.
*
* @param _bytes bytes to convert.
*
* @return Item referencing _bytes.
*/
function toItem(bytes memory _bytes) internal pure returns (Item memory) {
bytes memory ptr;
assembly {
ptr := add(_bytes, 32)
}
return Item({ ptr: ptr, len: _bytes.length });
}
/**
* @notice Reads an Item into an uint8.
* Internal ptr and length is updated automatically.
*
* @param _item Item to read.
*
* @return An uint8 value.
*/
function readUint8(Item memory _item) internal pure returns (uint8) {
require(_item.len >= 1, "NodeReader: too short for uint8");
bytes memory newPtr;
bytes memory ptr = _item.ptr;
uint8 ret;
assembly {
ret := shr(248, mload(ptr))
newPtr := add(ptr, 1)
}
_item.ptr = newPtr;
_item.len -= 1;
return ret;
}
/**
* @notice Reads an Item into compressed flags and length of values.
* Internal ptr and length is updated automatically.
*
* @param _item Item to read.
*
* @return Compressed flags.
* @return Length of values.
*/
function readCompressedFlags(Item memory _item) internal pure returns (uint32, uint8) {
require(_item.len >= 4, "NodeReader: too short for uint32");
bytes memory newPtr;
bytes memory ptr = _item.ptr;
uint32 temp;
uint8 flag;
uint8 len;
assembly {
temp := mload(ptr)
len := shr(248, temp)
flag := shr(240, temp)
newPtr := add(ptr, 4)
}
_item.ptr = newPtr;
_item.len -= 4;
return (flag, len);
}
/**
* @notice Reads an Item into a bytes32.
* Internal ptr and length is updated automatically.
*
* @param _item Item to read.
*
* @return A bytes32 value.
*/
function readBytes32(Item memory _item) internal pure returns (bytes32) {
require(_item.len >= 32, "NodeReader: too short for bytes32");
bytes memory newPtr;
bytes memory ptr = _item.ptr;
bytes32 ret;
assembly {
ret := mload(ptr)
newPtr := add(ptr, 32)
}
_item.ptr = newPtr;
_item.len -= 32;
return ret;
}
/**
* @notice Reads an Item by n bytes into a bytes32.
* Internal ptr and length is updated automatically.
*
* @param _item Item to read.
*
* @return A bytes32 value.
*/
function readBytesN(Item memory _item, uint256 _length) internal pure returns (bytes32) {
require(_item.len >= _length, "NodeReader: too short for n bytes");
bytes memory newPtr;
bytes memory ptr = _item.ptr;
bytes32 ret;
uint256 to = 256 - _length * 8;
assembly {
newPtr := add(ptr, _length)
ret := shr(to, mload(ptr))
}
_item.ptr = newPtr;
_item.len -= _length;
return ret;
}
/**
* @notice Reads bytes into a Node.
*
* @param _proof Bytes to read.
*
* @return A decoded Node.
*/
function readNode(bytes memory _proof) internal pure returns (Node memory) {
Node memory node;
Item memory item = toItem(_proof);
uint256 nodeType = readUint8(item);
if (nodeType == uint256(NodeType.MIDDLE)) {
// TODO(chokobole): Do the length check as much as possible at once and read the bytes.
node.childL = readBytes32(item);
node.childR = readBytes32(item);
} else if (nodeType == uint256(NodeType.LEAF)) {
// TODO(chokobole): Do the length check as much as possible at once and read the bytes.
node.nodeKey = readBytes32(item);
(uint32 compressedFlags, uint256 valuePreimageLen) = readCompressedFlags(item);
require((compressedFlags == 1 && valuePreimageLen == 1) || (compressedFlags == 4 && valuePreimageLen == 4), "NodeReader: invalid compressedFlags");
node.compressedFlags = compressedFlags;
node.valuePreimage = new bytes32[](valuePreimageLen);
for (uint256 i = 0; i < valuePreimageLen; ) {
node.valuePreimage[i] = readBytes32(item);
unchecked {
++i;
}
}
uint256 keyPreimageLen = readUint8(item);
if (keyPreimageLen > 0) {
node.keyPreimage = readBytesN(item, keyPreimageLen);
}
} else if (nodeType == uint256(NodeType.EMPTY)) {
// Do nothing.
} else if (nodeType == uint256(NodeType.ROOT)) {
revert("NodeReader: unexpected root node type");
} else {
revert("NodeReader: invalid node type");
}
node.nodeType = NodeType(nodeType);
return node;
}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;
/**
* @title IZKMerkleTrie
*/
interface IZKMerkleTrie {
/**
* @notice Verifies a proof that a given key/value pair is present in the trie.
*
* @param _key Key of the node to search for, as a hex string.
* @param _value Value of the node to search for, as a hex string.
* @param _proofs Merkle trie inclusion proof for the desired node.
* @param _root Known root of the Merkle trie. Used to verify that the included proof is
* correctly constructed.
*
* @return Whether or not the proof is valid.
*/
function verifyInclusionProof(
bytes32 _key,
bytes memory _value,
bytes[] memory _proofs,
bytes32 _root
) external view returns (bool);
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;
import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
import { Bytes32 } from "../libraries/Bytes32.sol";
/**
* @title IPoseidon2
*/
interface IPoseidon2 {
function poseidon(bytes32[2] memory inputs) external pure returns (bytes32);
}
/**
* @custom:proxied
* @title ZKTrieHasher
* @notice The ZKTrieHasher is contract which can produce a hash according to ZKTrie.
* This owns an interface of Poseidon2 that is required to compute hash used by ZKTrie.
*/
contract ZKTrieHasher {
/**
* @notice Poseidon2 contract generated by circomlibjs.
*/
IPoseidon2 public immutable POSEIDON2;
/**
* @param _poseidon2 The address of poseidon2 contract.
*/
constructor(address _poseidon2) {
POSEIDON2 = IPoseidon2(_poseidon2);
}
/**
* @notice Computes a hash of values.
*
* @param _compressedFlags Compressed flags.
* @param _values Values.
*
* @return A hash of values.
*/
function _valueHash(uint32 _compressedFlags, bytes32[] memory _values)
internal
view
returns (bytes32)
{
require(_values.length >= 1, "ZKTrieHasher: too few values for _valueHash");
bytes32[] memory ret = new bytes32[](_values.length);
for (uint256 i = 0; i < _values.length; ) {
if ((_compressedFlags & (1 << i)) != 0) {
ret[i] = _hashElem(_values[i]);
} else {
ret[i] = _values[i];
}
unchecked {
++i;
}
}
if (_values.length < 2) {
return ret[0];
}
return _hashElems(ret);
}
/**
* @notice Computes a hash of an element.
*
* @param _elem Bytes32 to be hashed.
*
* @return A hash of an element.
*/
function _hashElem(bytes32 _elem) internal view returns (bytes32) {
(bytes32 high, bytes32 low) = Bytes32.split(_elem);
return POSEIDON2.poseidon([high, low]);
}
/**
* @notice Computes a root hash of elements tree.
*
* @param _elems Bytes32 array to be hashed.
*
* @return A hash of elements tree.
*/
function _hashElems(bytes32[] memory _elems) internal view returns (bytes32) {
require(_elems.length >= 4, "ZKTrieHasher: too few values for _hashElems");
IPoseidon2 iposeidon = POSEIDON2;
uint256 idx;
uint256 adjacent_idx;
uint256 adjacent_offset = 1;
uint256 jump = 2;
uint256 length = _elems.length;
for (; adjacent_offset < length;) {
for (idx = 0; idx < length;) {
unchecked {
adjacent_idx = idx + adjacent_offset;
}
if (adjacent_idx < length) {
_elems[idx] = iposeidon.poseidon( [_elems[idx], _elems[adjacent_idx]] );
}
unchecked {
idx += jump;
}
}
adjacent_offset = jump;
jump <<= 1;
}
return _elems[0];
}
/**
* @notice Computes a root hash of 2 elements.
*
* @param left_leaf Bytes32 left leaf to be hashed.
* @param right_leaf Bytes32 right leaf to be hashed.
*
* @return A hash of 2 elements.
*/
function _hashFixed2Elems(bytes32 left_leaf, bytes32 right_leaf) internal view returns (bytes32) {
return POSEIDON2.poseidon([left_leaf, right_leaf]);
}
/**
* @notice Computes a root hash of 3 elements.
*
* @param left_leaf Bytes32 left leaf to be hashed.
* @param right_leaf Bytes32 right leaf to be hashed.
* @param up_leaf Bytes32 up leaf to be hashed with left||right hash.
*
* @return A hash of 3 elements.
*/
function _hashFixed3Elems(bytes32 left_leaf, bytes32 right_leaf, bytes32 up_leaf) internal view returns (bytes32) {
IPoseidon2 iposeidon = POSEIDON2;
left_leaf = iposeidon.poseidon([left_leaf, right_leaf]);
return iposeidon.poseidon([left_leaf, up_leaf]);
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.8.0;
/// @notice Arithmetic library with operations for fixed-point numbers.
/// @author Solmate (https://github.com/Rari-Capital/solmate/blob/main/src/utils/FixedPointMathLib.sol)
library FixedPointMathLib {
/*//////////////////////////////////////////////////////////////
SIMPLIFIED FIXED POINT OPERATIONS
//////////////////////////////////////////////////////////////*/
uint256 internal constant WAD = 1e18; // The scalar of ETH and most ERC20s.
function mulWadDown(uint256 x, uint256 y) internal pure returns (uint256) {
return mulDivDown(x, y, WAD); // Equivalent to (x * y) / WAD rounded down.
}
function mulWadUp(uint256 x, uint256 y) internal pure returns (uint256) {
return mulDivUp(x, y, WAD); // Equivalent to (x * y) / WAD rounded up.
}
function divWadDown(uint256 x, uint256 y) internal pure returns (uint256) {
return mulDivDown(x, WAD, y); // Equivalent to (x * WAD) / y rounded down.
}
function divWadUp(uint256 x, uint256 y) internal pure returns (uint256) {
return mulDivUp(x, WAD, y); // Equivalent to (x * WAD) / y rounded up.
}
function powWad(int256 x, int256 y) internal pure returns (int256) {
// Equivalent to x to the power of y because x ** y = (e ** ln(x)) ** y = e ** (ln(x) * y)
return expWad((lnWad(x) * y) / int256(WAD)); // Using ln(x) means x must be greater than 0.
}
function expWad(int256 x) internal pure returns (int256 r) {
unchecked {
// When the result is < 0.5 we return zero. This happens when
// x <= floor(log(0.5e18) * 1e18) ~ -42e18
if (x <= -42139678854452767551) return 0;
// When the result is > (2**255 - 1) / 1e18 we can not represent it as an
// int. This happens when x >= floor(log((2**255 - 1) / 1e18) * 1e18) ~ 135.
if (x >= 135305999368893231589) revert("EXP_OVERFLOW");
// x is now in the range (-42, 136) * 1e18. Convert to (-42, 136) * 2**96
// for more intermediate precision and a binary basis. This base conversion
// is a multiplication by 1e18 / 2**96 = 5**18 / 2**78.
x = (x << 78) / 5**18;
// Reduce range of x to (-½ ln 2, ½ ln 2) * 2**96 by factoring out powers
// of two such that exp(x) = exp(x') * 2**k, where k is an integer.
// Solving this gives k = round(x / log(2)) and x' = x - k * log(2).
int256 k = ((x << 96) / 54916777467707473351141471128 + 2**95) >> 96;
x = x - k * 54916777467707473351141471128;
// k is in the range [-61, 195].
// Evaluate using a (6, 7)-term rational approximation.
// p is made monic, we'll multiply by a scale factor later.
int256 y = x + 1346386616545796478920950773328;
y = ((y * x) >> 96) + 57155421227552351082224309758442;
int256 p = y + x - 94201549194550492254356042504812;
p = ((p * y) >> 96) + 28719021644029726153956944680412240;
p = p * x + (4385272521454847904659076985693276 << 96);
// We leave p in 2**192 basis so we don't need to scale it back up for the division.
int256 q = x - 2855989394907223263936484059900;
q = ((q * x) >> 96) + 50020603652535783019961831881945;
q = ((q * x) >> 96) - 533845033583426703283633433725380;
q = ((q * x) >> 96) + 3604857256930695427073651918091429;
q = ((q * x) >> 96) - 14423608567350463180887372962807573;
q = ((q * x) >> 96) + 26449188498355588339934803723976023;
assembly {
// Div in assembly because solidity adds a zero check despite the unchecked.
// The q polynomial won't have zeros in the domain as all its roots are complex.
// No scaling is necessary because p is already 2**96 too large.
r := sdiv(p, q)
}
// r should be in the range (0.09, 0.25) * 2**96.
// We now need to multiply r by:
// * the scale factor s = ~6.031367120.
// * the 2**k factor from the range reduction.
// * the 1e18 / 2**96 factor for base conversion.
// We do this all at once, with an intermediate result in 2**213
// basis, so the final right shift is always by a positive amount.
r = int256((uint256(r) * 3822833074963236453042738258902158003155416615667) >> uint256(195 - k));
}
}
function lnWad(int256 x) internal pure returns (int256 r) {
unchecked {
require(x > 0, "UNDEFINED");
// We want to convert x from 10**18 fixed point to 2**96 fixed point.
// We do this by multiplying by 2**96 / 10**18. But since
// ln(x * C) = ln(x) + ln(C), we can simply do nothing here
// and add ln(2**96 / 10**18) at the end.
// Reduce range of x to (1, 2) * 2**96
// ln(2^k * x) = k * ln(2) + ln(x)
int256 k = int256(log2(uint256(x))) - 96;
x <<= uint256(159 - k);
x = int256(uint256(x) >> 159);
// Evaluate using a (8, 8)-term rational approximation.
// p is made monic, we will multiply by a scale factor later.
int256 p = x + 3273285459638523848632254066296;
p = ((p * x) >> 96) + 24828157081833163892658089445524;
p = ((p * x) >> 96) + 43456485725739037958740375743393;
p = ((p * x) >> 96) - 11111509109440967052023855526967;
p = ((p * x) >> 96) - 45023709667254063763336534515857;
p = ((p * x) >> 96) - 14706773417378608786704636184526;
p = p * x - (795164235651350426258249787498 << 96);
// We leave p in 2**192 basis so we don't need to scale it back up for the division.
// q is monic by convention.
int256 q = x + 5573035233440673466300451813936;
q = ((q * x) >> 96) + 71694874799317883764090561454958;
q = ((q * x) >> 96) + 283447036172924575727196451306956;
q = ((q * x) >> 96) + 401686690394027663651624208769553;
q = ((q * x) >> 96) + 204048457590392012362485061816622;
q = ((q * x) >> 96) + 31853899698501571402653359427138;
q = ((q * x) >> 96) + 909429971244387300277376558375;
assembly {
// Div in assembly because solidity adds a zero check despite the unchecked.
// The q polynomial is known not to have zeros in the domain.
// No scaling required because p is already 2**96 too large.
r := sdiv(p, q)
}
// r is in the range (0, 0.125) * 2**96
// Finalization, we need to:
// * multiply by the scale factor s = 5.549…
// * add ln(2**96 / 10**18)
// * add k * ln(2)
// * multiply by 10**18 / 2**96 = 5**18 >> 78
// mul s * 5e18 * 2**96, base is now 5**18 * 2**192
r *= 1677202110996718588342820967067443963516166;
// add ln(2) * k * 5e18 * 2**192
r += 16597577552685614221487285958193947469193820559219878177908093499208371 * k;
// add ln(2**96 / 10**18) * 5e18 * 2**192
r += 600920179829731861736702779321621459595472258049074101567377883020018308;
// base conversion: mul 2**18 / 2**192
r >>= 174;
}
}
/*//////////////////////////////////////////////////////////////
LOW LEVEL FIXED POINT OPERATIONS
//////////////////////////////////////////////////////////////*/
function mulDivDown(
uint256 x,
uint256 y,
uint256 denominator
) internal pure returns (uint256 z) {
assembly {
// Store x * y in z for now.
z := mul(x, y)
// Equivalent to require(denominator != 0 && (x == 0 || (x * y) / x == y))
if iszero(and(iszero(iszero(denominator)), or(iszero(x), eq(div(z, x), y)))) {
revert(0, 0)
}
// Divide z by the denominator.
z := div(z, denominator)
}
}
function mulDivUp(
uint256 x,
uint256 y,
uint256 denominator
) internal pure returns (uint256 z) {
assembly {
// Store x * y in z for now.
z := mul(x, y)
// Equivalent to require(denominator != 0 && (x == 0 || (x * y) / x == y))
if iszero(and(iszero(iszero(denominator)), or(iszero(x), eq(div(z, x), y)))) {
revert(0, 0)
}
// First, divide z - 1 by the denominator and add 1.
// We allow z - 1 to underflow if z is 0, because we multiply the
// end result by 0 if z is zero, ensuring we return 0 if z is zero.
z := mul(iszero(iszero(z)), add(div(sub(z, 1), denominator), 1))
}
}
function rpow(
uint256 x,
uint256 n,
uint256 scalar
) internal pure returns (uint256 z) {
assembly {
switch x
case 0 {
switch n
case 0 {
// 0 ** 0 = 1
z := scalar
}
default {
// 0 ** n = 0
z := 0
}
}
default {
switch mod(n, 2)
case 0 {
// If n is even, store scalar in z for now.
z := scalar
}
default {
// If n is odd, store x in z for now.
z := x
}
// Shifting right by 1 is like dividing by 2.
let half := shr(1, scalar)
for {
// Shift n right by 1 before looping to halve it.
n := shr(1, n)
} n {
// Shift n right by 1 each iteration to halve it.
n := shr(1, n)
} {
// Revert immediately if x ** 2 would overflow.
// Equivalent to iszero(eq(div(xx, x), x)) here.
if shr(128, x) {
revert(0, 0)
}
// Store x squared.
let xx := mul(x, x)
// Round to the nearest number.
let xxRound := add(xx, half)
// Revert if xx + half overflowed.
if lt(xxRound, xx) {
revert(0, 0)
}
// Set x to scaled xxRound.
x := div(xxRound, scalar)
// If n is even:
if mod(n, 2) {
// Compute z * x.
let zx := mul(z, x)
// If z * x overflowed:
if iszero(eq(div(zx, x), z)) {
// Revert if x is non-zero.
if iszero(iszero(x)) {
revert(0, 0)
}
}
// Round to the nearest number.
let zxRound := add(zx, half)
// Revert if zx + half overflowed.
if lt(zxRound, zx) {
revert(0, 0)
}
// Return properly scaled zxRound.
z := div(zxRound, scalar)
}
}
}
}
}
/*//////////////////////////////////////////////////////////////
GENERAL NUMBER UTILITIES
//////////////////////////////////////////////////////////////*/
function sqrt(uint256 x) internal pure returns (uint256 z) {
assembly {
let y := x // We start y at x, which will help us make our initial estimate.
z := 181 // The "correct" value is 1, but this saves a multiplication later.
// This segment is to get a reasonable initial estimate for the Babylonian method. With a bad
// start, the correct # of bits increases ~linearly each iteration instead of ~quadratically.
// We check y >= 2^(k + 8) but shift right by k bits
// each branch to ensure that if x >= 256, then y >= 256.
if iszero(lt(y, 0x10000000000000000000000000000000000)) {
y := shr(128, y)
z := shl(64, z)
}
if iszero(lt(y, 0x1000000000000000000)) {
y := shr(64, y)
z := shl(32, z)
}
if iszero(lt(y, 0x10000000000)) {
y := shr(32, y)
z := shl(16, z)
}
if iszero(lt(y, 0x1000000)) {
y := shr(16, y)
z := shl(8, z)
}
// Goal was to get z*z*y within a small factor of x. More iterations could
// get y in a tighter range. Currently, we will have y in [256, 256*2^16).
// We ensured y >= 256 so that the relative difference between y and y+1 is small.
// That's not possible if x < 256 but we can just verify those cases exhaustively.
// Now, z*z*y <= x < z*z*(y+1), and y <= 2^(16+8), and either y >= 256, or x < 256.
// Correctness can be checked exhaustively for x < 256, so we assume y >= 256.
// Then z*sqrt(y) is within sqrt(257)/sqrt(256) of sqrt(x), or about 20bps.
// For s in the range [1/256, 256], the estimate f(s) = (181/1024) * (s+1) is in the range
// (1/2.84 * sqrt(s), 2.84 * sqrt(s)), with largest error when s = 1 and when s = 256 or 1/256.
// Since y is in [256, 256*2^16), let a = y/65536, so that a is in [1/256, 256). Then we can estimate
// sqrt(y) using sqrt(65536) * 181/1024 * (a + 1) = 181/4 * (y + 65536)/65536 = 181 * (y + 65536)/2^18.
// There is no overflow risk here since y < 2^136 after the first branch above.
z := shr(18, mul(z, add(y, 65536))) // A mul() is saved from starting z at 181.
// Given the worst case multiplicative error of 2.84 above, 7 iterations should be enough.
z := shr(1, add(z, div(x, z)))
z := shr(1, add(z, div(x, z)))
z := shr(1, add(z, div(x, z)))
z := shr(1, add(z, div(x, z)))
z := shr(1, add(z, div(x, z)))
z := shr(1, add(z, div(x, z)))
z := shr(1, add(z, div(x, z)))
// If x+1 is a perfect square, the Babylonian method cycles between
// floor(sqrt(x)) and ceil(sqrt(x)). This statement ensures we return floor.
// See: https://en.wikipedia.org/wiki/Integer_square_root#Using_only_integer_division
// Since the ceil is rare, we save gas on the assignment and repeat division in the rare case.
// If you don't care whether the floor or ceil square root is returned, you can remove this statement.
z := sub(z, lt(div(x, z), z))
}
}
function log2(uint256 x) internal pure returns (uint256 r) {
require(x > 0, "UNDEFINED");
assembly {
r := shl(7, lt(0xffffffffffffffffffffffffffffffff, x))
r := or(r, shl(6, lt(0xffffffffffffffff, shr(r, x))))
r := or(r, shl(5, lt(0xffffffff, shr(r, x))))
r := or(r, shl(4, lt(0xffff, shr(r, x))))
r := or(r, shl(3, lt(0xff, shr(r, x))))
r := or(r, shl(2, lt(0xf, shr(r, x))))
r := or(r, shl(1, lt(0x3, shr(r, x))))
r := or(r, lt(0x1, shr(r, x)))
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/introspection/ERC165Checker.sol)
pragma solidity ^0.8.0;
import "./IERC165.sol";
/**
* @dev Library used to query support of an interface declared via {IERC165}.
*
* Note that these functions return the actual result of the query: they do not
* `revert` if an interface is not supported. It is up to the caller to decide
* what to do in these cases.
*/
library ERC165Checker {
// As per the EIP-165 spec, no interface should ever match 0xffffffff
bytes4 private constant _INTERFACE_ID_INVALID = 0xffffffff;
/**
* @dev Returns true if `account` supports the {IERC165} interface.
*/
function supportsERC165(address account) internal view returns (bool) {
// Any contract that implements ERC165 must explicitly indicate support of
// InterfaceId_ERC165 and explicitly indicate non-support of InterfaceId_Invalid
return
supportsERC165InterfaceUnchecked(account, type(IERC165).interfaceId) &&
!supportsERC165InterfaceUnchecked(account, _INTERFACE_ID_INVALID);
}
/**
* @dev Returns true if `account` supports the interface defined by
* `interfaceId`. Support for {IERC165} itself is queried automatically.
*
* See {IERC165-supportsInterface}.
*/
function supportsInterface(address account, bytes4 interfaceId) internal view returns (bool) {
// query support of both ERC165 as per the spec and support of _interfaceId
return supportsERC165(account) && supportsERC165InterfaceUnchecked(account, interfaceId);
}
/**
* @dev Returns a boolean array where each value corresponds to the
* interfaces passed in and whether they're supported or not. This allows
* you to batch check interfaces for a contract where your expectation
* is that some interfaces may not be supported.
*
* See {IERC165-supportsInterface}.
*
* _Available since v3.4._
*/
function getSupportedInterfaces(
address account,
bytes4[] memory interfaceIds
) internal view returns (bool[] memory) {
// an array of booleans corresponding to interfaceIds and whether they're supported or not
bool[] memory interfaceIdsSupported = new bool[](interfaceIds.length);
// query support of ERC165 itself
if (supportsERC165(account)) {
// query support of each interface in interfaceIds
for (uint256 i = 0; i < interfaceIds.length; i++) {
interfaceIdsSupported[i] = supportsERC165InterfaceUnchecked(account, interfaceIds[i]);
}
}
return interfaceIdsSupported;
}
/**
* @dev Returns true if `account` supports all the interfaces defined in
* `interfaceIds`. Support for {IERC165} itself is queried automatically.
*
* Batch-querying can lead to gas savings by skipping repeated checks for
* {IERC165} support.
*
* See {IERC165-supportsInterface}.
*/
function supportsAllInterfaces(address account, bytes4[] memory interfaceIds) internal view returns (bool) {
// query support of ERC165 itself
if (!supportsERC165(account)) {
return false;
}
// query support of each interface in interfaceIds
for (uint256 i = 0; i < interfaceIds.length; i++) {
if (!supportsERC165InterfaceUnchecked(account, interfaceIds[i])) {
return false;
}
}
// all interfaces supported
return true;
}
/**
* @notice Query if a contract implements an interface, does not check ERC165 support
* @param account The address of the contract to query for support of an interface
* @param interfaceId The interface identifier, as specified in ERC-165
* @return true if the contract at account indicates support of the interface with
* identifier interfaceId, false otherwise
* @dev Assumes that account contains a contract that supports ERC165, otherwise
* the behavior of this method is undefined. This precondition can be checked
* with {supportsERC165}.
*
* Some precompiled contracts will falsely indicate support for a given interface, so caution
* should be exercised when using this function.
*
* Interface identification is specified in ERC-165.
*/
function supportsERC165InterfaceUnchecked(address account, bytes4 interfaceId) internal view returns (bool) {
// prepare call
bytes memory encodedParams = abi.encodeWithSelector(IERC165.supportsInterface.selector, interfaceId);
// perform static call
bool success;
uint256 returnSize;
uint256 returnValue;
assembly {
success := staticcall(30000, account, add(encodedParams, 0x20), mload(encodedParams), 0x00, 0x20)
returnSize := returndatasize()
returnValue := mload(0x00)
}
return success && returnSize >= 0x20 && returnValue > 0;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `to`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address to, uint256 amount) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: Beware that changing an allowance with this method brings the risk
* that someone may use both the old and the new allowance by unfortunate
* transaction ordering. One possible solution to mitigate this race
* condition is to first reduce the spender's allowance to 0 and set the
* desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* Emits an {Approval} event.
*/
function approve(address spender, uint256 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `from` to `to` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(address from, address to, uint256 amount) external returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.3) (token/ERC20/utils/SafeERC20.sol)
pragma solidity ^0.8.0;
import "../IERC20.sol";
import "../extensions/IERC20Permit.sol";
import "../../../utils/Address.sol";
/**
* @title SafeERC20
* @dev Wrappers around ERC20 operations that throw on failure (when the token
* contract returns false). Tokens that return no value (and instead revert or
* throw on failure) are also supported, non-reverting calls are assumed to be
* successful.
* To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
* which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
*/
library SafeERC20 {
using Address for address;
/**
* @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
* non-reverting calls are assumed to be successful.
*/
function safeTransfer(IERC20 token, address to, uint256 value) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
}
/**
* @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
* calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
*/
function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
}
/**
* @dev Deprecated. This function has issues similar to the ones found in
* {IERC20-approve}, and its usage is discouraged.
*
* Whenever possible, use {safeIncreaseAllowance} and
* {safeDecreaseAllowance} instead.
*/
function safeApprove(IERC20 token, address spender, uint256 value) internal {
// safeApprove should only be called when setting an initial allowance,
// or when resetting it to zero. To increase and decrease it, use
// 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
require(
(value == 0) || (token.allowance(address(this), spender) == 0),
"SafeERC20: approve from non-zero to non-zero allowance"
);
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
}
/**
* @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
* non-reverting calls are assumed to be successful.
*/
function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
uint256 oldAllowance = token.allowance(address(this), spender);
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance + value));
}
/**
* @dev Decrease the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
* non-reverting calls are assumed to be successful.
*/
function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
unchecked {
uint256 oldAllowance = token.allowance(address(this), spender);
require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance - value));
}
}
/**
* @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
* non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
* to be set to zero before setting it to a non-zero value, such as USDT.
*/
function forceApprove(IERC20 token, address spender, uint256 value) internal {
bytes memory approvalCall = abi.encodeWithSelector(token.approve.selector, spender, value);
if (!_callOptionalReturnBool(token, approvalCall)) {
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, 0));
_callOptionalReturn(token, approvalCall);
}
}
/**
* @dev Use a ERC-2612 signature to set the `owner` approval toward `spender` on `token`.
* Revert on invalid signature.
*/
function safePermit(
IERC20Permit token,
address owner,
address spender,
uint256 value,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) internal {
uint256 nonceBefore = token.nonces(owner);
token.permit(owner, spender, value, deadline, v, r, s);
uint256 nonceAfter = token.nonces(owner);
require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
}
/**
* @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
* on the return value: the return value is optional (but if data is returned, it must not be false).
* @param token The token targeted by the call.
* @param data The call data (encoded using abi.encode or one of its variants).
*/
function _callOptionalReturn(IERC20 token, bytes memory data) private {
// We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
// we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that
// the target address contains contract code and also asserts for success in the low-level call.
bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
require(returndata.length == 0 || abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
}
/**
* @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
* on the return value: the return value is optional (but if data is returned, it must not be false).
* @param token The token targeted by the call.
* @param data The call data (encoded using abi.encode or one of its variants).
*
* This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
*/
function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
// We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
// we're implementing it ourselves. We cannot use {Address-functionCall} here since this should return false
// and not revert is the subcall reverts.
(bool success, bytes memory returndata) = address(token).call(data);
return
success && (returndata.length == 0 || abi.decode(returndata, (bool))) && Address.isContract(address(token));
}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;
import {
PausableUpgradeable
} from "@openzeppelin/contracts-upgradeable/security/PausableUpgradeable.sol";
import { Constants } from "../libraries/Constants.sol";
import { Encoding } from "../libraries/Encoding.sol";
import { Hashing } from "../libraries/Hashing.sol";
import { SafeCall } from "../libraries/SafeCall.sol";
/**
* @custom:upgradeable
* @title CrossDomainMessenger
* @notice CrossDomainMessenger is a base contract that provides the core logic for the L1 and L2
* cross-chain messenger contracts. It's designed to be a universal interface that only
* needs to be extended slightly to provide low-level message passing functionality on each
* chain it's deployed on. Currently only designed for message passing between two paired
* chains and does not support one-to-many interactions.
*
* Any changes to this contract MUST result in a semver bump for contracts that inherit it.
*/
abstract contract CrossDomainMessenger is PausableUpgradeable {
/**
* @notice Current message version identifier.
*/
uint16 public constant MESSAGE_VERSION = 0;
/**
* @notice Constant overhead added to the base gas for a message.
*/
uint64 public constant RELAY_CONSTANT_OVERHEAD = 200_000;
/**
* @notice Numerator for dynamic overhead added to the base gas for a message.
*/
uint64 public constant MIN_GAS_DYNAMIC_OVERHEAD_NUMERATOR = 64;
/**
* @notice Denominator for dynamic overhead added to the base gas for a message.
*/
uint64 public constant MIN_GAS_DYNAMIC_OVERHEAD_DENOMINATOR = 63;
/**
* @notice Extra gas added to base gas for each byte of calldata in a message.
*/
uint64 public constant MIN_GAS_CALLDATA_OVERHEAD = 16;
/**
* @notice Gas reserved for performing the external call in `relayMessage`.
*/
uint64 public constant RELAY_CALL_OVERHEAD = 40_000;
/**
* @notice Gas reserved for finalizing the execution of `relayMessage` after the safe call.
*/
uint64 public constant RELAY_RESERVED_GAS = 40_000;
/**
* @notice Gas reserved for the execution between the `hasMinGas` check and the external
* call in `relayMessage`.
*/
uint64 public constant RELAY_GAS_CHECK_BUFFER = 5_000;
/**
* @notice Address of the paired CrossDomainMessenger contract on the other chain.
*/
address public immutable OTHER_MESSENGER;
/**
* @notice Mapping of message hashes to boolean receipt values. Note that a message will only
* be present in this mapping if it has successfully been relayed on this chain, and
* can therefore not be relayed again.
*/
mapping(bytes32 => bool) public successfulMessages;
/**
* @notice Address of the sender of the currently executing message on the other chain. If the
* value of this variable is the default value (0x00000000...dead) then no message is
* currently being executed. Use the xDomainMessageSender getter which will throw an
* error if this is the case.
*/
address internal xDomainMsgSender;
/**
* @notice Nonce for the next message to be sent, without the message version applied. Use the
* messageNonce getter which will insert the message version into the nonce to give you
* the actual nonce to be used for the message.
*/
uint240 internal msgNonce;
/**
* @notice Mapping of message hashes to a boolean if and only if the message has failed to be
* executed at least once. A message will not be present in this mapping if it
* successfully executed on the first attempt.
*/
mapping(bytes32 => bool) public failedMessages;
/**
* @notice Reserve extra slots in the storage layout for future upgrades.
* A gap size of 45 was chosen here, so that the first slot used in a child contract
* would be a multiple of 50.
*/
uint256[45] private __gap;
/**
* @notice Emitted whenever a message is sent to the other chain.
*
* @param target Address of the recipient of the message.
* @param sender Address of the sender of the message.
* @param value ETH value sent along with the message to the recipient.
* @param message Message to trigger the recipient address with.
* @param messageNonce Unique nonce attached to the message.
* @param gasLimit Minimum gas limit that the message can be executed with.
*/
event SentMessage(
address indexed target,
address indexed sender,
uint256 value,
bytes message,
uint256 messageNonce,
uint256 gasLimit
);
/**
* @notice Emitted whenever a message is successfully relayed on this chain.
*
* @param msgHash Hash of the message that was relayed.
*/
event RelayedMessage(bytes32 indexed msgHash);
/**
* @notice Emitted whenever a message fails to be relayed on this chain.
*
* @param msgHash Hash of the message that failed to be relayed.
*/
event FailedRelayedMessage(bytes32 indexed msgHash);
/**
* @param _otherMessenger Address of the messenger on the paired chain.
*/
constructor(address _otherMessenger) {
OTHER_MESSENGER = _otherMessenger;
}
/**
* @notice Sends a message to some target address on the other chain. Note that if the call
* always reverts, then the message will be unrelayable, and any ETH sent will be
* permanently locked. The same will occur if the target on the other chain is
* considered unsafe (see the _isUnsafeTarget() function).
*
* @param _target Target contract or wallet address.
* @param _message Message to trigger the target address with.
* @param _minGasLimit Minimum gas limit that the message can be executed with.
*/
function sendMessage(
address _target,
bytes calldata _message,
uint32 _minGasLimit
) external payable {
// Triggers a message to the other messenger. Note that the amount of gas provided to the
// message is the amount of gas requested by the user PLUS the base gas value. We want to
// guarantee the property that the call to the target contract will always have at least
// the minimum gas limit specified by the user.
_sendMessage(
OTHER_MESSENGER,
baseGas(_message, _minGasLimit),
msg.value,
abi.encodeWithSelector(
this.relayMessage.selector,
messageNonce(),
msg.sender,
_target,
msg.value,
_minGasLimit,
_message
)
);
emit SentMessage(_target, msg.sender, msg.value, _message, messageNonce(), _minGasLimit);
unchecked {
++msgNonce;
}
}
/**
* @notice Relays a message that was sent by the other CrossDomainMessenger contract. Can only
* be executed via cross-chain call from the other messenger OR if the message was
* already received once and is currently being replayed.
*
* @param _nonce Nonce of the message being relayed.
* @param _sender Address of the user who sent the message.
* @param _target Address that the message is targeted at.
* @param _value ETH value to send with the message.
* @param _minGasLimit Minimum amount of gas that the message can be executed with.
* @param _message Message to send to the target.
*/
function relayMessage(
uint256 _nonce,
address _sender,
address _target,
uint256 _value,
uint256 _minGasLimit,
bytes calldata _message
) external payable {
(, uint16 version) = Encoding.decodeVersionedNonce(_nonce);
require(
version < 1,
"CrossDomainMessenger: only version 0 messages is supported at this time"
);
// We use the v0 message hash as the unique identifier for the message because it commits
// to the value and minimum gas limit of the message.
bytes32 versionedHash = Hashing.hashCrossDomainMessageV0(
_nonce,
_sender,
_target,
_value,
_minGasLimit,
_message
);
if (_isOtherMessenger()) {
// These properties should always hold when the message is first submitted (as
// opposed to being replayed).
assert(msg.value == _value);
assert(!failedMessages[versionedHash]);
} else {
require(
msg.value == 0,
"CrossDomainMessenger: value must be zero unless message is from a system address"
);
require(
failedMessages[versionedHash],
"CrossDomainMessenger: message cannot be replayed"
);
}
require(
_isUnsafeTarget(_target) == false,
"CrossDomainMessenger: cannot send message to blocked system address"
);
require(
successfulMessages[versionedHash] == false,
"CrossDomainMessenger: message has already been relayed"
);
// If there is not enough gas left to perform the external call and finish the execution,
// return early and assign the message to the failedMessages mapping.
// We are asserting that we have enough gas to:
// 1. Call the target contract (_minGasLimit + RELAY_CALL_OVERHEAD + RELAY_GAS_CHECK_BUFFER)
// 1.a. The RELAY_CALL_OVERHEAD is included in `hasMinGas`.
// 2. Finish the execution after the external call (RELAY_RESERVED_GAS).
//
// If `xDomainMsgSender` is not the default L2 sender, this function
// is being re-entered. This marks the message as failed to allow it to be replayed.
if (
!SafeCall.hasMinGas(_minGasLimit, RELAY_RESERVED_GAS + RELAY_GAS_CHECK_BUFFER) ||
xDomainMsgSender != Constants.DEFAULT_L2_SENDER
) {
failedMessages[versionedHash] = true;
emit FailedRelayedMessage(versionedHash);
// Revert in this case if the transaction was triggered by the estimation address. This
// should only be possible during gas estimation or we have bigger problems. Reverting
// here will make the behavior of gas estimation change such that the gas limit
// computed will be the amount required to relay the message, even if that amount is
// greater than the minimum gas limit specified by the user.
if (tx.origin == Constants.ESTIMATION_ADDRESS) {
revert("CrossDomainMessenger: failed to relay message");
}
return;
}
xDomainMsgSender = _sender;
bool success = SafeCall.call(_target, gasleft() - RELAY_RESERVED_GAS, _value, _message);
xDomainMsgSender = Constants.DEFAULT_L2_SENDER;
if (success) {
successfulMessages[versionedHash] = true;
emit RelayedMessage(versionedHash);
} else {
failedMessages[versionedHash] = true;
emit FailedRelayedMessage(versionedHash);
// Revert in this case if the transaction was triggered by the estimation address. This
// should only be possible during gas estimation or we have bigger problems. Reverting
// here will make the behavior of gas estimation change such that the gas limit
// computed will be the amount required to relay the message, even if that amount is
// greater than the minimum gas limit specified by the user.
if (tx.origin == Constants.ESTIMATION_ADDRESS) {
revert("CrossDomainMessenger: failed to relay message");
}
}
}
/**
* @notice Retrieves the address of the contract or wallet that initiated the currently
* executing message on the other chain. Will throw an error if there is no message
* currently being executed. Allows the recipient of a call to see who triggered it.
*
* @return Address of the sender of the currently executing message on the other chain.
*/
function xDomainMessageSender() external view returns (address) {
require(
xDomainMsgSender != Constants.DEFAULT_L2_SENDER,
"CrossDomainMessenger: xDomainMessageSender is not set"
);
return xDomainMsgSender;
}
/**
* @notice Retrieves the next message nonce. Message version will be added to the upper two
* bytes of the message nonce. Message version allows us to treat messages as having
* different structures.
*
* @return Nonce of the next message to be sent, with added message version.
*/
function messageNonce() public view returns (uint256) {
return Encoding.encodeVersionedNonce(msgNonce, MESSAGE_VERSION);
}
/**
* @notice Computes the amount of gas required to guarantee that a given message will be
* received on the other chain without running out of gas. Guaranteeing that a message
* will not run out of gas is important because this ensures that a message can always
* be replayed on the other chain if it fails to execute completely.
*
* @param _message Message to compute the amount of required gas for.
* @param _minGasLimit Minimum desired gas limit when message goes to target.
*
* @return Amount of gas required to guarantee message receipt.
*/
function baseGas(bytes calldata _message, uint32 _minGasLimit) public pure returns (uint64) {
return
// Constant overhead
RELAY_CONSTANT_OVERHEAD +
// Calldata overhead
(uint64(_message.length) * MIN_GAS_CALLDATA_OVERHEAD) +
// Dynamic overhead (EIP-150)
((_minGasLimit * MIN_GAS_DYNAMIC_OVERHEAD_NUMERATOR) /
MIN_GAS_DYNAMIC_OVERHEAD_DENOMINATOR) +
// Gas reserved for the worst-case cost of 3/5 of the `CALL` opcode's dynamic gas
// factors. (Conservative)
RELAY_CALL_OVERHEAD +
// Relay reserved gas (to ensure execution of `relayMessage` completes after the
// subcontext finishes executing) (Conservative)
RELAY_RESERVED_GAS +
// Gas reserved for the execution between the `hasMinGas` check and the `CALL`
// opcode. (Conservative)
RELAY_GAS_CHECK_BUFFER;
}
/**
* @notice Intializer.
*/
// solhint-disable-next-line func-name-mixedcase
function __CrossDomainMessenger_init() internal onlyInitializing {
xDomainMsgSender = Constants.DEFAULT_L2_SENDER;
}
/**
* @notice Sends a low-level message to the other messenger. Needs to be implemented by child
* contracts because the logic for this depends on the network where the messenger is
* being deployed.
*
* @param _to Recipient of the message on the other chain.
* @param _gasLimit Minimum gas limit the message can be executed with.
* @param _value Amount of ETH to send with the message.
* @param _data Message data.
*/
function _sendMessage(
address _to,
uint64 _gasLimit,
uint256 _value,
bytes memory _data
) internal virtual;
/**
* @notice Checks whether the message is coming from the other messenger. Implemented by child
* contracts because the logic for this depends on the network where the messenger is
* being deployed.
*
* @return Whether the message is coming from the other messenger.
*/
function _isOtherMessenger() internal view virtual returns (bool);
/**
* @notice Checks whether a given call target is a system address that could cause the
* messenger to peform an unsafe action. This is NOT a mechanism for blocking user
* addresses. This is ONLY used to prevent the execution of messages to specific
* system addresses that could cause security issues, e.g., having the
* CrossDomainMessenger send messages to itself.
*
* @param _target Address of the contract to check.
*
* @return Whether or not the address is an unsafe system address.
*/
function _isUnsafeTarget(address _target) internal view virtual returns (bool);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import { IERC165 } from "@openzeppelin/contracts/utils/introspection/IERC165.sol";
/**
* @title IKromaMintableERC20
* @notice This interface is available on the KromaMintableERC20 contract. We declare it as a
* separate interface so that it can be used in custom implementations of
* KromaMintableERC20.
*/
interface IKromaMintableERC20 {
function REMOTE_TOKEN() external view returns (address);
function BRIDGE() external view returns (address);
function mint(address _to, uint256 _amount) external;
function burn(address _from, uint256 _amount) external;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;
import { ERC20 } from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import { IERC165 } from "@openzeppelin/contracts/utils/introspection/IERC165.sol";
import { Semver } from "../universal/Semver.sol";
import { IKromaMintableERC20 } from "./IKromaMintableERC20.sol";
/**
* @title KromaMintableERC20
* @notice KromaMintableERC20 is a standard extension of the base ERC20 token contract designed
* to allow the StandardBridge contracts to mint and burn tokens. This makes it possible to
* use a KromaMintableRC20 as the L2 representation of an L1 token, or vice-versa.
* Designed to be backwards compatible with the older StandardL2ERC20 token which was only
* meant for use on L2.
*/
contract KromaMintableERC20 is IKromaMintableERC20, ERC20, Semver {
/**
* @notice Address of the corresponding version of this token on the remote chain.
*/
address public immutable REMOTE_TOKEN;
/**
* @notice Address of the StandardBridge on this network.
*/
address public immutable BRIDGE;
/**
* @notice Emitted whenever tokens are minted for an account.
*
* @param account Address of the account tokens are being minted for.
* @param amount Amount of tokens minted.
*/
event Mint(address indexed account, uint256 amount);
/**
* @notice Emitted whenever tokens are burned from an account.
*
* @param account Address of the account tokens are being burned from.
* @param amount Amount of tokens burned.
*/
event Burn(address indexed account, uint256 amount);
/**
* @notice A modifier that only allows the bridge to call
*/
modifier onlyBridge() {
require(msg.sender == BRIDGE, "KromaMintableERC20: only bridge can mint and burn");
_;
}
/**
* @custom:semver 1.0.0
*
* @param _bridge Address of the L2 standard bridge.
* @param _remoteToken Address of the corresponding L1 token.
* @param _name ERC20 name.
* @param _symbol ERC20 symbol.
*/
constructor(
address _bridge,
address _remoteToken,
string memory _name,
string memory _symbol
) ERC20(_name, _symbol) Semver(1, 0, 0) {
REMOTE_TOKEN = _remoteToken;
BRIDGE = _bridge;
}
/**
* @notice Allows the StandardBridge on this network to mint tokens.
*
* @param _to Address to mint tokens to.
* @param _amount Amount of tokens to mint.
*/
function mint(address _to, uint256 _amount)
external
virtual
override(IKromaMintableERC20)
onlyBridge
{
_mint(_to, _amount);
emit Mint(_to, _amount);
}
/**
* @notice Allows the StandardBridge on this network to burn tokens.
*
* @param _from Address to burn tokens from.
* @param _amount Amount of tokens to burn.
*/
function burn(address _from, uint256 _amount)
external
virtual
override(IKromaMintableERC20)
onlyBridge
{
_burn(_from, _amount);
emit Burn(_from, _amount);
}
/**
* @notice ERC165 interface check function.
*
* @param _interfaceId Interface ID to check.
*
* @return Whether or not the interface is supported by this contract.
*/
function supportsInterface(bytes4 _interfaceId) external pure returns (bool) {
bytes4 iface1 = type(IERC165).interfaceId;
// Interface corresponding to the updated KromaMintableERC20 (this contract).
bytes4 iface2 = type(IKromaMintableERC20).interfaceId;
return _interfaceId == iface1 || _interfaceId == iface2;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
import "../proxy/utils/Initializable.sol";
/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract ContextUpgradeable is Initializable {
function __Context_init() internal onlyInitializing {
}
function __Context_init_unchained() internal onlyInitializing {
}
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
/**
* @dev This empty reserved space is put in place to allow future versions to add new
* variables without shifting down storage in the inheritance chain.
* See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
*/
uint256[50] private __gap;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable.sol)
pragma solidity ^0.8.0;
import "../utils/Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
abstract contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor() {
_transferOwnership(_msgSender());
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
_checkOwner();
_;
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if the sender is not the owner.
*/
function _checkOwner() internal view virtual {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby disabling any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
_transferOwnership(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Internal function without access restriction.
*/
function _transferOwnership(address newOwner) internal virtual {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @title Bytes32
* @notice Bytes32 is a library for manipulating byte32.
*/
library Bytes32 {
/**
* @notice Splits bytes32 to high and low parts.
*
* @param _bytes Bytes32 to split.
*
* @return High part of bytes32.
* @return Low part of bytes32.
*/
function split(bytes32 _bytes) internal pure returns (bytes32, bytes32) {
bytes16 high = bytes16(_bytes);
bytes16 low = bytes16(uint128(uint256(_bytes)));
return (fromBytes16(high), fromBytes16(low));
}
/**
* @notice Converts bytes16 to bytes32.
*
* @param _bytes Bytes to constrcut to bytes32.
*
* @return Bytes32 constructed from bytes16.
*/
function fromBytes16(bytes16 _bytes) internal pure returns (bytes32) {
return bytes32(uint256(uint128(_bytes)));
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC165 standard, as defined in the
* https://eips.ethereum.org/EIPS/eip-165[EIP].
*
* Implementers can declare support of contract interfaces, which can then be
* queried by others ({ERC165Checker}).
*
* For an implementation, see {ERC165}.
*/
interface IERC165 {
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
* to learn more about how these ids are created.
*
* This function call must use less than 30 000 gas.
*/
function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/extensions/IERC20Permit.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
* https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
*
* Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
* presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
* need to send a transaction, and thus is not required to hold Ether at all.
*/
interface IERC20Permit {
/**
* @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
* given ``owner``'s signed approval.
*
* IMPORTANT: The same issues {IERC20-approve} has related to transaction
* ordering also apply here.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `deadline` must be a timestamp in the future.
* - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
* over the EIP712-formatted function arguments.
* - the signature must use ``owner``'s current nonce (see {nonces}).
*
* For more information on the signature format, see the
* https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
* section].
*/
function permit(
address owner,
address spender,
uint256 value,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) external;
/**
* @dev Returns the current nonce for `owner`. This value must be
* included whenever a signature is generated for {permit}.
*
* Every successful call to {permit} increases ``owner``'s nonce by one. This
* prevents a signature from being used multiple times.
*/
function nonces(address owner) external view returns (uint256);
/**
* @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
*/
// solhint-disable-next-line func-name-mixedcase
function DOMAIN_SEPARATOR() external view returns (bytes32);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (security/Pausable.sol)
pragma solidity ^0.8.0;
import "../utils/ContextUpgradeable.sol";
import "../proxy/utils/Initializable.sol";
/**
* @dev Contract module which allows children to implement an emergency stop
* mechanism that can be triggered by an authorized account.
*
* This module is used through inheritance. It will make available the
* modifiers `whenNotPaused` and `whenPaused`, which can be applied to
* the functions of your contract. Note that they will not be pausable by
* simply including this module, only once the modifiers are put in place.
*/
abstract contract PausableUpgradeable is Initializable, ContextUpgradeable {
/**
* @dev Emitted when the pause is triggered by `account`.
*/
event Paused(address account);
/**
* @dev Emitted when the pause is lifted by `account`.
*/
event Unpaused(address account);
bool private _paused;
/**
* @dev Initializes the contract in unpaused state.
*/
function __Pausable_init() internal onlyInitializing {
__Pausable_init_unchained();
}
function __Pausable_init_unchained() internal onlyInitializing {
_paused = false;
}
/**
* @dev Modifier to make a function callable only when the contract is not paused.
*
* Requirements:
*
* - The contract must not be paused.
*/
modifier whenNotPaused() {
_requireNotPaused();
_;
}
/**
* @dev Modifier to make a function callable only when the contract is paused.
*
* Requirements:
*
* - The contract must be paused.
*/
modifier whenPaused() {
_requirePaused();
_;
}
/**
* @dev Returns true if the contract is paused, and false otherwise.
*/
function paused() public view virtual returns (bool) {
return _paused;
}
/**
* @dev Throws if the contract is paused.
*/
function _requireNotPaused() internal view virtual {
require(!paused(), "Pausable: paused");
}
/**
* @dev Throws if the contract is not paused.
*/
function _requirePaused() internal view virtual {
require(paused(), "Pausable: not paused");
}
/**
* @dev Triggers stopped state.
*
* Requirements:
*
* - The contract must not be paused.
*/
function _pause() internal virtual whenNotPaused {
_paused = true;
emit Paused(_msgSender());
}
/**
* @dev Returns to normal state.
*
* Requirements:
*
* - The contract must be paused.
*/
function _unpause() internal virtual whenPaused {
_paused = false;
emit Unpaused(_msgSender());
}
/**
* @dev This empty reserved space is put in place to allow future versions to add new
* variables without shifting down storage in the inheritance chain.
* See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
*/
uint256[49] private __gap;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/ERC20.sol)
pragma solidity ^0.8.0;
import "./IERC20.sol";
import "./extensions/IERC20Metadata.sol";
import "../../utils/Context.sol";
/**
* @dev Implementation of the {IERC20} interface.
*
* This implementation is agnostic to the way tokens are created. This means
* that a supply mechanism has to be added in a derived contract using {_mint}.
* For a generic mechanism see {ERC20PresetMinterPauser}.
*
* TIP: For a detailed writeup see our guide
* https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* The default value of {decimals} is 18. To change this, you should override
* this function so it returns a different value.
*
* We have followed general OpenZeppelin Contracts guidelines: functions revert
* instead returning `false` on failure. This behavior is nonetheless
* conventional and does not conflict with the expectations of ERC20
* applications.
*
* Additionally, an {Approval} event is emitted on calls to {transferFrom}.
* This allows applications to reconstruct the allowance for all accounts just
* by listening to said events. Other implementations of the EIP may not emit
* these events, as it isn't required by the specification.
*
* Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
* functions have been added to mitigate the well-known issues around setting
* allowances. See {IERC20-approve}.
*/
contract ERC20 is Context, IERC20, IERC20Metadata {
mapping(address => uint256) private _balances;
mapping(address => mapping(address => uint256)) private _allowances;
uint256 private _totalSupply;
string private _name;
string private _symbol;
/**
* @dev Sets the values for {name} and {symbol}.
*
* All two of these values are immutable: they can only be set once during
* construction.
*/
constructor(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
}
/**
* @dev Returns the name of the token.
*/
function name() public view virtual override returns (string memory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view virtual override returns (string memory) {
return _symbol;
}
/**
* @dev Returns the number of decimals used to get its user representation.
* For example, if `decimals` equals `2`, a balance of `505` tokens should
* be displayed to a user as `5.05` (`505 / 10 ** 2`).
*
* Tokens usually opt for a value of 18, imitating the relationship between
* Ether and Wei. This is the default value returned by this function, unless
* it's overridden.
*
* NOTE: This information is only used for _display_ purposes: it in
* no way affects any of the arithmetic of the contract, including
* {IERC20-balanceOf} and {IERC20-transfer}.
*/
function decimals() public view virtual override returns (uint8) {
return 18;
}
/**
* @dev See {IERC20-totalSupply}.
*/
function totalSupply() public view virtual override returns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/
function balanceOf(address account) public view virtual override returns (uint256) {
return _balances[account];
}
/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/
function transfer(address to, uint256 amount) public virtual override returns (bool) {
address owner = _msgSender();
_transfer(owner, to, amount);
return true;
}
/**
* @dev See {IERC20-allowance}.
*/
function allowance(address owner, address spender) public view virtual override returns (uint256) {
return _allowances[owner][spender];
}
/**
* @dev See {IERC20-approve}.
*
* NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
* `transferFrom`. This is semantically equivalent to an infinite approval.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 amount) public virtual override returns (bool) {
address owner = _msgSender();
_approve(owner, spender, amount);
return true;
}
/**
* @dev See {IERC20-transferFrom}.
*
* Emits an {Approval} event indicating the updated allowance. This is not
* required by the EIP. See the note at the beginning of {ERC20}.
*
* NOTE: Does not update the allowance if the current allowance
* is the maximum `uint256`.
*
* Requirements:
*
* - `from` and `to` cannot be the zero address.
* - `from` must have a balance of at least `amount`.
* - the caller must have allowance for ``from``'s tokens of at least
* `amount`.
*/
function transferFrom(address from, address to, uint256 amount) public virtual override returns (bool) {
address spender = _msgSender();
_spendAllowance(from, spender, amount);
_transfer(from, to, amount);
return true;
}
/**
* @dev Atomically increases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
address owner = _msgSender();
_approve(owner, spender, allowance(owner, spender) + addedValue);
return true;
}
/**
* @dev Atomically decreases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `spender` must have allowance for the caller of at least
* `subtractedValue`.
*/
function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
address owner = _msgSender();
uint256 currentAllowance = allowance(owner, spender);
require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
unchecked {
_approve(owner, spender, currentAllowance - subtractedValue);
}
return true;
}
/**
* @dev Moves `amount` of tokens from `from` to `to`.
*
* This internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a {Transfer} event.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `from` must have a balance of at least `amount`.
*/
function _transfer(address from, address to, uint256 amount) internal virtual {
require(from != address(0), "ERC20: transfer from the zero address");
require(to != address(0), "ERC20: transfer to the zero address");
_beforeTokenTransfer(from, to, amount);
uint256 fromBalance = _balances[from];
require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
unchecked {
_balances[from] = fromBalance - amount;
// Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
// decrementing then incrementing.
_balances[to] += amount;
}
emit Transfer(from, to, amount);
_afterTokenTransfer(from, to, amount);
}
/** @dev Creates `amount` tokens and assigns them to `account`, increasing
* the total supply.
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
*/
function _mint(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: mint to the zero address");
_beforeTokenTransfer(address(0), account, amount);
_totalSupply += amount;
unchecked {
// Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
_balances[account] += amount;
}
emit Transfer(address(0), account, amount);
_afterTokenTransfer(address(0), account, amount);
}
/**
* @dev Destroys `amount` tokens from `account`, reducing the
* total supply.
*
* Emits a {Transfer} event with `to` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
* - `account` must have at least `amount` tokens.
*/
function _burn(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: burn from the zero address");
_beforeTokenTransfer(account, address(0), amount);
uint256 accountBalance = _balances[account];
require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
unchecked {
_balances[account] = accountBalance - amount;
// Overflow not possible: amount <= accountBalance <= totalSupply.
_totalSupply -= amount;
}
emit Transfer(account, address(0), amount);
_afterTokenTransfer(account, address(0), amount);
}
/**
* @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
*
* This internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*/
function _approve(address owner, address spender, uint256 amount) internal virtual {
require(owner != address(0), "ERC20: approve from the zero address");
require(spender != address(0), "ERC20: approve to the zero address");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
/**
* @dev Updates `owner` s allowance for `spender` based on spent `amount`.
*
* Does not update the allowance amount in case of infinite allowance.
* Revert if not enough allowance is available.
*
* Might emit an {Approval} event.
*/
function _spendAllowance(address owner, address spender, uint256 amount) internal virtual {
uint256 currentAllowance = allowance(owner, spender);
if (currentAllowance != type(uint256).max) {
require(currentAllowance >= amount, "ERC20: insufficient allowance");
unchecked {
_approve(owner, spender, currentAllowance - amount);
}
}
}
/**
* @dev Hook that is called before any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* will be transferred to `to`.
* - when `from` is zero, `amount` tokens will be minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens will be burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual {}
/**
* @dev Hook that is called after any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* has been transferred to `to`.
* - when `from` is zero, `amount` tokens have been minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens have been burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _afterTokenTransfer(address from, address to, uint256 amount) internal virtual {}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)
pragma solidity ^0.8.0;
import "../IERC20.sol";
/**
* @dev Interface for the optional metadata functions from the ERC20 standard.
*
* _Available since v4.1._
*/
interface IERC20Metadata is IERC20 {
/**
* @dev Returns the name of the token.
*/
function name() external view returns (string memory);
/**
* @dev Returns the symbol of the token.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the decimals places of the token.
*/
function decimals() external view returns (uint8);
}