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chore: contracts on a diet (#10389)
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@LHerskind
LHerskind authored Dec 4, 2024
1 parent a1e5966 commit dddb008
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Showing 34 changed files with 1,414 additions and 985 deletions.
2 changes: 1 addition & 1 deletion l1-contracts/.solhint.json
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Original file line number Diff line number Diff line change
Expand Up @@ -27,7 +27,7 @@
"no-unused-vars": "error",
"state-visibility": "error",
"var-name-mixedcase": "error",
"private-func-leading-underscore": "error",
"private-func-leading-underscore": "warn",
"private-vars-no-leading-underscore": "error",
"func-param-name-leading-underscore": "error",
"func-param-name-mixedcase": "error",
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233 changes: 22 additions & 211 deletions l1-contracts/src/core/Leonidas.sol
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Original file line number Diff line number Diff line change
Expand Up @@ -2,16 +2,14 @@
// Copyright 2024 Aztec Labs.
pragma solidity >=0.8.27;

import {ILeonidas} from "@aztec/core/interfaces/ILeonidas.sol";
import {SampleLib} from "@aztec/core/libraries/crypto/SampleLib.sol";
import {SignatureLib} from "@aztec/core/libraries/crypto/SignatureLib.sol";
import {ILeonidas, EpochData, LeonidasStorage} from "@aztec/core/interfaces/ILeonidas.sol";
import {Signature} from "@aztec/core/libraries/crypto/SignatureLib.sol";
import {DataStructures} from "@aztec/core/libraries/DataStructures.sol";
import {Errors} from "@aztec/core/libraries/Errors.sol";
import {LeonidasLib} from "@aztec/core/libraries/LeonidasLib/LeonidasLib.sol";
import {
Timestamp, Slot, Epoch, SlotLib, EpochLib, TimeFns
} from "@aztec/core/libraries/TimeMath.sol";
import {Ownable} from "@oz/access/Ownable.sol";
import {MessageHashUtils} from "@oz/utils/cryptography/MessageHashUtils.sol";
import {EnumerableSet} from "@oz/utils/structs/EnumerableSet.sol";

/**
Expand All @@ -30,39 +28,19 @@ import {EnumerableSet} from "@oz/utils/structs/EnumerableSet.sol";
*/
contract Leonidas is Ownable, TimeFns, ILeonidas {
using EnumerableSet for EnumerableSet.AddressSet;
using SignatureLib for SignatureLib.Signature;
using MessageHashUtils for bytes32;
using LeonidasLib for LeonidasStorage;

using SlotLib for Slot;
using EpochLib for Epoch;

/**
* @notice The data structure for an epoch
* @param committee - The validator set for the epoch
* @param sampleSeed - The seed used to sample the validator set of the epoch
* @param nextSeed - The seed used to influence the NEXT epoch
*/
struct EpochData {
address[] committee;
uint256 sampleSeed;
uint256 nextSeed;
}

// The target number of validators in a committee
// @todo #8021
uint256 public immutable TARGET_COMMITTEE_SIZE;

// The time that the contract was deployed
Timestamp public immutable GENESIS_TIME;

// An enumerable set of validators that are up to date
EnumerableSet.AddressSet private validatorSet;

// A mapping to snapshots of the validator set
mapping(Epoch => EpochData) public epochs;

// The last stored randao value, same value as `seed` in the last inserted epoch
uint256 private lastSeed;
LeonidasStorage private store;

constructor(
address _ares,
Expand Down Expand Up @@ -103,7 +81,7 @@ contract Leonidas is Ownable, TimeFns, ILeonidas {
*/
function removeValidator(address _validator) external override(ILeonidas) onlyOwner {
setupEpoch();
validatorSet.remove(_validator);
store.validatorSet.remove(_validator);
}

/**
Expand All @@ -121,15 +99,15 @@ contract Leonidas is Ownable, TimeFns, ILeonidas {
override(ILeonidas)
returns (address[] memory)
{
return epochs[_epoch].committee;
return store.epochs[_epoch].committee;
}

/**
* @notice Get the validator set for the current epoch
* @return The validator set for the current epoch
*/
function getCurrentEpochCommittee() external view override(ILeonidas) returns (address[] memory) {
return _getCommitteeAt(Timestamp.wrap(block.timestamp));
return store.getCommitteeAt(getCurrentEpoch(), TARGET_COMMITTEE_SIZE);
}

/**
Expand All @@ -140,7 +118,7 @@ contract Leonidas is Ownable, TimeFns, ILeonidas {
* @return The validator set
*/
function getValidators() external view override(ILeonidas) returns (address[] memory) {
return validatorSet.values();
return store.validatorSet.values();
}

/**
Expand All @@ -155,13 +133,13 @@ contract Leonidas is Ownable, TimeFns, ILeonidas {
*/
function setupEpoch() public override(ILeonidas) {
Epoch epochNumber = getCurrentEpoch();
EpochData storage epoch = epochs[epochNumber];
EpochData storage epoch = store.epochs[epochNumber];

if (epoch.sampleSeed == 0) {
epoch.sampleSeed = _getSampleSeed(epochNumber);
epoch.nextSeed = lastSeed = _computeNextSeed(epochNumber);
epoch.sampleSeed = store.getSampleSeed(epochNumber);
epoch.nextSeed = store.lastSeed = _computeNextSeed(epochNumber);

epoch.committee = _sampleValidators(epoch.sampleSeed);
epoch.committee = store.sampleValidators(epoch.sampleSeed, TARGET_COMMITTEE_SIZE);
}
}

Expand All @@ -171,7 +149,7 @@ contract Leonidas is Ownable, TimeFns, ILeonidas {
* @return The number of validators in the validator set
*/
function getValidatorCount() public view override(ILeonidas) returns (uint256) {
return validatorSet.length();
return store.validatorSet.length();
}

/**
Expand All @@ -180,7 +158,7 @@ contract Leonidas is Ownable, TimeFns, ILeonidas {
* @return The number of validators in the validator set
*/
function getValidatorAt(uint256 _index) public view override(ILeonidas) returns (address) {
return validatorSet.at(_index);
return store.validatorSet.at(_index);
}

/**
Expand All @@ -191,7 +169,7 @@ contract Leonidas is Ownable, TimeFns, ILeonidas {
* @return True if the address is in the validator set, false otherwise
*/
function isValidator(address _validator) public view override(ILeonidas) returns (bool) {
return validatorSet.contains(_validator);
return store.validatorSet.contains(_validator);
}

/**
Expand Down Expand Up @@ -261,31 +239,9 @@ contract Leonidas is Ownable, TimeFns, ILeonidas {
* @return The address of the proposer
*/
function getProposerAt(Timestamp _ts) public view override(ILeonidas) returns (address) {
Epoch epochNumber = getEpochAt(_ts);
Slot slot = getSlotAt(_ts);

EpochData storage epoch = epochs[epochNumber];

// If the epoch is setup, we can just return the proposer. Otherwise we have to emulate sampling
if (epoch.sampleSeed != 0) {
uint256 committeeSize = epoch.committee.length;
if (committeeSize == 0) {
return address(0);
}

return
epoch.committee[_computeProposerIndex(epochNumber, slot, epoch.sampleSeed, committeeSize)];
}

// Allow anyone if there is no validator set
if (validatorSet.length() == 0) {
return address(0);
}

// Emulate a sampling of the validators
uint256 sampleSeed = _getSampleSeed(epochNumber);
address[] memory committee = _sampleValidators(sampleSeed);
return committee[_computeProposerIndex(epochNumber, slot, sampleSeed, committee.length)];
Epoch epochNumber = getEpochAtSlot(slot);
return store.getProposerAt(slot, epochNumber, TARGET_COMMITTEE_SIZE);
}

/**
Expand Down Expand Up @@ -326,29 +282,7 @@ contract Leonidas is Ownable, TimeFns, ILeonidas {
* @param _validator - The validator to add
*/
function _addValidator(address _validator) internal {
validatorSet.add(_validator);
}

function _getCommitteeAt(Timestamp _ts) internal view returns (address[] memory) {
Epoch epochNumber = getEpochAt(_ts);
EpochData storage epoch = epochs[epochNumber];

if (epoch.sampleSeed != 0) {
uint256 committeeSize = epoch.committee.length;
if (committeeSize == 0) {
return new address[](0);
}
return epoch.committee;
}

// Allow anyone if there is no validator set
if (validatorSet.length() == 0) {
return new address[](0);
}

// Emulate a sampling of the validators
uint256 sampleSeed = _getSampleSeed(epochNumber);
return _sampleValidators(sampleSeed);
store.validatorSet.add(_validator);
}

/**
Expand All @@ -369,57 +303,12 @@ contract Leonidas is Ownable, TimeFns, ILeonidas {
*/
function _validateLeonidas(
Slot _slot,
SignatureLib.Signature[] memory _signatures,
Signature[] memory _signatures,
bytes32 _digest,
DataStructures.ExecutionFlags memory _flags
) internal view {
Timestamp ts = getTimestampForSlot(_slot);
address proposer = getProposerAt(ts);

// @todo Consider getting rid of this option.
// If the proposer is open, we allow anyone to propose without needing any signatures
if (proposer == address(0)) {
return;
}

// @todo We should allow to provide a signature instead of needing the proposer to broadcast.
require(proposer == msg.sender, Errors.Leonidas__InvalidProposer(proposer, msg.sender));

// @note This is NOT the efficient way to do it, but it is a very convenient way for us to do it
// that allows us to reduce the number of code paths. Also when changed with optimistic for
// pleistarchus, this will be changed, so we can live with it.

if (_flags.ignoreSignatures) {
return;
}

address[] memory committee = _getCommitteeAt(ts);

uint256 needed = committee.length * 2 / 3 + 1;
require(
_signatures.length >= needed,
Errors.Leonidas__InsufficientAttestationsProvided(needed, _signatures.length)
);

// Validate the attestations
uint256 validAttestations = 0;

bytes32 digest = _digest.toEthSignedMessageHash();
for (uint256 i = 0; i < _signatures.length; i++) {
SignatureLib.Signature memory signature = _signatures[i];
if (signature.isEmpty) {
continue;
}

// The verification will throw if invalid
signature.verify(committee[i], digest);
validAttestations++;
}

require(
validAttestations >= needed,
Errors.Leonidas__InsufficientAttestations(needed, validAttestations)
);
Epoch epochNumber = getEpochAtSlot(_slot);
store.validateLeonidas(_slot, epochNumber, _signatures, _digest, _flags, TARGET_COMMITTEE_SIZE);
}

/**
Expand All @@ -435,82 +324,4 @@ contract Leonidas is Ownable, TimeFns, ILeonidas {
function _computeNextSeed(Epoch _epoch) private view returns (uint256) {
return uint256(keccak256(abi.encode(_epoch, block.prevrandao)));
}

/**
* @notice Samples a validator set for a specific epoch
*
* @dev Only used internally, should never be called for anything but the "next" epoch
* Allowing us to always use `lastSeed`.
*
* @return The validators for the given epoch
*/
function _sampleValidators(uint256 _seed) private view returns (address[] memory) {
uint256 validatorSetSize = validatorSet.length();
if (validatorSetSize == 0) {
return new address[](0);
}

// If we have less validators than the target committee size, we just return the full set
if (validatorSetSize <= TARGET_COMMITTEE_SIZE) {
return validatorSet.values();
}

uint256[] memory indicies =
SampleLib.computeCommitteeClever(TARGET_COMMITTEE_SIZE, validatorSetSize, _seed);

address[] memory committee = new address[](TARGET_COMMITTEE_SIZE);
for (uint256 i = 0; i < TARGET_COMMITTEE_SIZE; i++) {
committee[i] = validatorSet.at(indicies[i]);
}
return committee;
}

/**
* @notice Get the sample seed for an epoch
*
* @dev This should behave as walking past the line, but it does not currently do that.
* If there are entire skips, e.g., 1, 2, 5 and we then go back and try executing
* for 4 we will get an invalid value because we will read lastSeed which is from 5.
*
* @dev The `_epoch` will never be 0 nor in the future
*
* @dev The return value will be equal to keccak256(n, block.prevrandao) for n being the last epoch
* setup.
*
* @return The sample seed for the epoch
*/
function _getSampleSeed(Epoch _epoch) private view returns (uint256) {
if (Epoch.unwrap(_epoch) == 0) {
return type(uint256).max;
}
uint256 sampleSeed = epochs[_epoch].sampleSeed;
if (sampleSeed != 0) {
return sampleSeed;
}

sampleSeed = epochs[_epoch - Epoch.wrap(1)].nextSeed;
if (sampleSeed != 0) {
return sampleSeed;
}

return lastSeed;
}

/**
* @notice Computes the index of the committee member that acts as proposer for a given slot
*
* @param _epoch - The epoch to compute the proposer index for
* @param _slot - The slot to compute the proposer index for
* @param _seed - The seed to use for the computation
* @param _size - The size of the committee
*
* @return The index of the proposer
*/
function _computeProposerIndex(Epoch _epoch, Slot _slot, uint256 _seed, uint256 _size)
private
pure
returns (uint256)
{
return uint256(keccak256(abi.encode(_epoch, _slot, _seed))) % _size;
}
}
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