Support cast vote by signature in ZrxTreasury (#297)

* Support cast vote by signature in ZrxTreasury

* Address comments and fix existing tests

* test that doesnt work

* test file format

* updates

* address some of the comments

* Remove unused const

* get rid of vote_factory

* unit test for castVoteBySignature p1

* unit test for castVoteBySignature p2

* Add version to domain, and one more test

* unit test for castVoteBySignature p3

* unit test for castVoteBySignature p4

* bump utils version

* remove debug code

* address some comments

* address more pr comments

* move Vote class to protocol-utils

* Address pr comments and update changelogs

.gitignore

@@ -75,8 +75,9 @@ generated_docs/
 
 TODO.md
 
-# VSCode file
+# IDE file
 .vscode
+.idea
 
 # generated contract artifacts/
 contracts/broker/generated-artifacts/

contracts/treasury/CHANGELOG.json

@@ -1,4 +1,12 @@
 [
+    {
+        "version": "1.4.0",
+        "changes": [
+            {
+                "note": "Support cast vote by signature in Treasury"
+            }
+        ]
+    },
     {
         "timestamp": 1631120757,
         "version": "1.3.5",

contracts/treasury/contracts/src/IZrxTreasury.sol

@@ -136,8 +136,9 @@ interface IZrxTreasury {
         returns (uint256 proposalId);
 
     /// @dev Casts a vote for the given proposal. Only callable
-    ///      during the voting period for that proposal. See
+    ///      during the voting period for that proposal.
-    ///      `getVotingPower` for how voting power is computed.
+    ///      One address can only vote once.
+    ///      See `getVotingPower` for how voting power is computed.
     /// @param proposalId The ID of the proposal to vote on.
     /// @param support Whether to support the proposal or not.
     /// @param operatedPoolIds The pools operated by `msg.sender`. The
@@ -150,6 +151,28 @@ interface IZrxTreasury {
     )
         external;
 
+    /// @dev Casts a vote for the given proposal, by signature.
+    ///      Only callable during the voting period for that proposal.
+    ///      One address/voter can only vote once.
+    ///      See `getVotingPower` for how voting power is computed.
+    /// @param proposalId The ID of the proposal to vote on.
+    /// @param support Whether to support the proposal or not.
+    /// @param operatedPoolIds The pools operated by the signer. The
+    ///        ZRX currently delegated to those pools will be accounted
+    ///        for in the voting power.
+    /// @param v the v field of the signature
+    /// @param r the r field of the signature
+    /// @param s the s field of the signature
+    function castVoteBySignature(
+        uint256 proposalId,
+        bool support,
+        bytes32[] memory operatedPoolIds,
+        uint8 v,
+        bytes32 r,
+        bytes32 s
+    )
+        external;
+
     /// @dev Executes a proposal that has passed and is
     ///      currently executable.
     /// @param proposalId The ID of the proposal to execute.

contracts/treasury/contracts/src/ZrxTreasury.sol

@@ -34,11 +34,25 @@ contract ZrxTreasury is
     using LibRichErrorsV06 for bytes;
     using LibBytesV06 for bytes;
 
+    /// Contract name
+    string private constant CONTRACT_NAME = "Zrx Treasury";
+
+    /// Contract version
+    string private constant CONTRACT_VERSION = "1.0.0";
+
+    /// The EIP-712 typehash for the contract's domain
+    bytes32 private constant DOMAIN_TYPEHASH = keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)");
+
+    /// The EIP-712 typehash for the vote struct
+    bytes32 private constant VOTE_TYPEHASH = keccak256("TreasuryVote(uint256 proposalId,bool support,bytes32[] operatedPoolIds)");
+
     // Immutables
     IStaking public immutable override stakingProxy;
     DefaultPoolOperator public immutable override defaultPoolOperator;
     bytes32 public immutable override defaultPoolId;
     uint256 public immutable override votingPeriod;
+    bytes32 immutable domainSeparator;
+
     uint256 public override proposalThreshold;
     uint256 public override quorumThreshold;
 
@@ -67,6 +81,15 @@ contract ZrxTreasury is
         defaultPoolId = params.defaultPoolId;
         IStaking.Pool memory defaultPool = stakingProxy_.getStakingPool(params.defaultPoolId);
         defaultPoolOperator = DefaultPoolOperator(defaultPool.operator);
+        domainSeparator = keccak256(
+            abi.encode(
+                DOMAIN_TYPEHASH,
+                keccak256(bytes(CONTRACT_NAME)),
+                _getChainId(),
+                keccak256(bytes(CONTRACT_VERSION)),
+                address(this)
+            )
+        );
     }
 
     // solhint-disable
@@ -105,7 +128,7 @@ contract ZrxTreasury is
     ///        be executed if it passes. Must be at least two epochs
     ///        from the current epoch.
     /// @param description A text description for the proposal.
-    /// @param operatedPoolIds The pools operated by `msg.sender`. The
+    /// @param operatedPoolIds The pools operated by the signer. The
     ///        ZRX currently delegated to those pools will be accounted
     ///        for in the voting power.
     /// @return proposalId The ID of the newly created proposal.
@@ -150,8 +173,9 @@ contract ZrxTreasury is
     }
 
     /// @dev Casts a vote for the given proposal. Only callable
-    ///      during the voting period for that proposal. See
+    ///      during the voting period for that proposal.
-    ///      `getVotingPower` for how voting power is computed.
+    ///      One address can only vote once.
+    ///      See `getVotingPower` for how voting power is computed.
     /// @param proposalId The ID of the proposal to vote on.
     /// @param support Whether to support the proposal or not.
     /// @param operatedPoolIds The pools operated by `msg.sender`. The
@@ -165,43 +189,39 @@ contract ZrxTreasury is
         public
         override
     {
-        if (proposalId >= proposalCount()) {
+        return _castVote(msg.sender, proposalId, support, operatedPoolIds);
-            revert("castVote/INVALID_PROPOSAL_ID");
-        }
-        if (hasVoted[proposalId][msg.sender]) {
-            revert("castVote/ALREADY_VOTED");
     }
 
-        Proposal memory proposal = proposals[proposalId];
+    /// @dev Casts a vote for the given proposal, by signature.
-        if (
+    ///      Only callable during the voting period for that proposal.
-            proposal.voteEpoch != stakingProxy.currentEpoch() ||
+    ///      One address/voter can only vote once.
-            _hasVoteEnded(proposal.voteEpoch)
+    ///      See `getVotingPower` for how voting power is computed.
-        ) {
+    /// @param proposalId The ID of the proposal to vote on.
-            revert("castVote/VOTING_IS_CLOSED");
+    /// @param support Whether to support the proposal or not.
-        }
+    /// @param operatedPoolIds The pools operated by voter. The
-
+    ///        ZRX currently delegated to those pools will be accounted
-        uint256 votingPower = getVotingPower(msg.sender, operatedPoolIds);
+    ///        for in the voting power.
-        if (votingPower == 0) {
+    /// @param v the v field of the signature
-            revert("castVote/NO_VOTING_POWER");
+    /// @param r the r field of the signature
-        }
+    /// @param s the s field of the signature
-
+    function castVoteBySignature(
-        if (support) {
+        uint256 proposalId,
-            proposals[proposalId].votesFor = proposals[proposalId].votesFor
+        bool support,
-                .safeAdd(votingPower);
+        bytes32[] memory operatedPoolIds,
-            hasVoted[proposalId][msg.sender] = true;
+        uint8 v,
-        } else {
+        bytes32 r,
-            proposals[proposalId].votesAgainst = proposals[proposalId].votesAgainst
+        bytes32 s
-                .safeAdd(votingPower);
+    )
-            hasVoted[proposalId][msg.sender] = true;
+        public
-        }
+        override
-
+    {
-        emit VoteCast(
+        bytes32 structHash = keccak256(
-            msg.sender,
+            abi.encode(VOTE_TYPEHASH, proposalId, support, keccak256(abi.encodePacked(operatedPoolIds)))
-            operatedPoolIds,
-            proposalId,
-            support,
-            votingPower
         );
+        bytes32 digest = keccak256(abi.encodePacked("\x19\x01", domainSeparator, structHash));
+        address signatory = ecrecover(digest, v, r, s);
+
+        return _castVote(signatory, proposalId, support, operatedPoolIds);
     }
 
     /// @dev Executes a proposal that has passed and is
@@ -373,4 +393,60 @@ contract ZrxTreasury is
             .safeAdd(votingPeriod);
         return block.timestamp > voteEndTime;
     }
+
+    /// @dev Casts a vote for the given proposal. Only callable
+    ///      during the voting period for that proposal. See
+    ///      `getVotingPower` for how voting power is computed.
+    function _castVote(
+        address voter,
+        uint256 proposalId,
+        bool support,
+        bytes32[] memory operatedPoolIds
+    )
+        private
+    {
+        if (proposalId >= proposalCount()) {
+            revert("_castVote/INVALID_PROPOSAL_ID");
+        }
+        if (hasVoted[proposalId][voter]) {
+            revert("_castVote/ALREADY_VOTED");
+        }
+
+        Proposal memory proposal = proposals[proposalId];
+        if (
+            proposal.voteEpoch != stakingProxy.currentEpoch() ||
+            _hasVoteEnded(proposal.voteEpoch)
+        ) {
+            revert("_castVote/VOTING_IS_CLOSED");
+        }
+
+        uint256 votingPower = getVotingPower(voter, operatedPoolIds);
+        if (votingPower == 0) {
+            revert("_castVote/NO_VOTING_POWER");
+        }
+
+        if (support) {
+            proposals[proposalId].votesFor = proposals[proposalId].votesFor
+                .safeAdd(votingPower);
+        } else {
+            proposals[proposalId].votesAgainst = proposals[proposalId].votesAgainst
+                .safeAdd(votingPower);
+        }
+        hasVoted[proposalId][voter] = true;
+
+        emit VoteCast(
+            voter,
+            operatedPoolIds,
+            proposalId,
+            support,
+            votingPower
+        );
+    }
+
+    /// @dev Gets the Ethereum chain id
+    function _getChainId() private pure returns (uint256) {
+        uint256 chainId;
+        assembly { chainId := chainid() }
+        return chainId;
+    }
 }

contracts/treasury/test/treasury_test.ts

@@ -17,8 +17,9 @@ import {
     randomAddress,
     verifyEventsFromLogs,
 } from '@0x/contracts-test-utils';
-import { BigNumber } from '@0x/utils';
+import { TreasuryVote } from '@0x/protocol-utils';
-import * as _ from 'lodash';
+import { BigNumber, hexUtils } from '@0x/utils';
+import * as ethUtil from 'ethereumjs-util';
 
 import { artifacts } from './artifacts';
 import { DefaultPoolOperatorContract, ZrxTreasuryContract, ZrxTreasuryEvents } from './wrappers';
@@ -55,6 +56,8 @@ blockchainTests.resets('Treasury governance', env => {
     let nonDefaultPoolId: string;
     let poolOperator: string;
     let delegator: string;
+    let relayer: string;
+    let delegatorPrivateKey: string;
     let actions: ProposedAction[];
 
     async function deployStakingAsync(): Promise<void> {
@@ -105,7 +108,10 @@ blockchainTests.resets('Treasury governance', env => {
     }
 
     before(async () => {
-        [admin, poolOperator, delegator] = await env.getAccountAddressesAsync();
+        const accounts = await env.getAccountAddressesAsync();
+        [admin, poolOperator, delegator, relayer] = accounts;
+        delegatorPrivateKey = hexUtils.toHex(constants.TESTRPC_PRIVATE_KEYS[accounts.indexOf(delegator)]);
+
         zrx = await DummyERC20TokenContract.deployFrom0xArtifactAsync(
             erc20Artifacts.DummyERC20Token,
             env.provider,
@@ -399,7 +405,7 @@ blockchainTests.resets('Treasury governance', env => {
             expect(await treasury.proposalCount().callAsync()).to.bignumber.equal(1);
         });
     });
-    describe('castVote()', () => {
+    describe('castVote() and castVoteBySignature()', () => {
         const VOTE_PROPOSAL_ID = new BigNumber(0);
         const DELEGATOR_VOTING_POWER = new BigNumber(420);
 
@@ -418,17 +424,18 @@ blockchainTests.resets('Treasury governance', env => {
                 .propose(actions, currentEpoch.plus(2), PROPOSAL_DESCRIPTION, [])
                 .awaitTransactionSuccessAsync({ from: delegator });
         });
+        // castVote()
         it('Cannot vote on invalid proposalId', async () => {
             await fastForwardToNextEpochAsync();
             await fastForwardToNextEpochAsync();
             const tx = treasury
                 .castVote(INVALID_PROPOSAL_ID, true, [])
                 .awaitTransactionSuccessAsync({ from: delegator });
-            return expect(tx).to.revertWith('castVote/INVALID_PROPOSAL_ID');
+            return expect(tx).to.revertWith('_castVote/INVALID_PROPOSAL_ID');
         });
         it('Cannot vote before voting period starts', async () => {
             const tx = treasury.castVote(VOTE_PROPOSAL_ID, true, []).awaitTransactionSuccessAsync({ from: delegator });
-            return expect(tx).to.revertWith('castVote/VOTING_IS_CLOSED');
+            return expect(tx).to.revertWith('_castVote/VOTING_IS_CLOSED');
         });
         it('Cannot vote after voting period ends', async () => {
             await fastForwardToNextEpochAsync();
@@ -436,14 +443,14 @@ blockchainTests.resets('Treasury governance', env => {
             await env.web3Wrapper.increaseTimeAsync(TREASURY_PARAMS.votingPeriod.plus(1).toNumber());
             await env.web3Wrapper.mineBlockAsync();
             const tx = treasury.castVote(VOTE_PROPOSAL_ID, true, []).awaitTransactionSuccessAsync({ from: delegator });
-            return expect(tx).to.revertWith('castVote/VOTING_IS_CLOSED');
+            return expect(tx).to.revertWith('_castVote/VOTING_IS_CLOSED');
         });
         it('Cannot vote twice on same proposal', async () => {
             await fastForwardToNextEpochAsync();
             await fastForwardToNextEpochAsync();
             await treasury.castVote(VOTE_PROPOSAL_ID, true, []).awaitTransactionSuccessAsync({ from: delegator });
             const tx = treasury.castVote(VOTE_PROPOSAL_ID, false, []).awaitTransactionSuccessAsync({ from: delegator });
-            return expect(tx).to.revertWith('castVote/ALREADY_VOTED');
+            return expect(tx).to.revertWith('_castVote/ALREADY_VOTED');
         });
         it('Can cast a valid vote', async () => {
             await fastForwardToNextEpochAsync();
@@ -465,6 +472,110 @@ blockchainTests.resets('Treasury governance', env => {
                 ZrxTreasuryEvents.VoteCast,
             );
         });
+        // castVoteBySignature()
+        it('Cannot vote by signature on invalid proposalId', async () => {
+            await fastForwardToNextEpochAsync();
+            await fastForwardToNextEpochAsync();
+            const vote = new TreasuryVote({
+                proposalId: INVALID_PROPOSAL_ID,
+                verifyingContract: admin,
+            });
+            const signature = vote.getSignatureWithKey(delegatorPrivateKey);
+            const tx = treasury
+                .castVoteBySignature(INVALID_PROPOSAL_ID, true, [], signature.v,  signature.r,  signature.s)
+                .awaitTransactionSuccessAsync({ from: relayer });
+            return expect(tx).to.revertWith('_castVote/INVALID_PROPOSAL_ID');
+        });
+        it('Cannot vote by signature before voting period starts', async () => {
+            const vote = new TreasuryVote({
+                proposalId: VOTE_PROPOSAL_ID,
+                verifyingContract: admin,
+            });
+            const signature = vote.getSignatureWithKey(delegatorPrivateKey);
+            const tx = treasury
+                .castVoteBySignature(VOTE_PROPOSAL_ID, true, [], signature.v,  signature.r,  signature.s)
+                .awaitTransactionSuccessAsync({ from: relayer });
+            return expect(tx).to.revertWith('_castVote/VOTING_IS_CLOSED');
+        });
+        it('Cannot vote by signature after voting period ends', async () => {
+            await fastForwardToNextEpochAsync();
+            await fastForwardToNextEpochAsync();
+            await env.web3Wrapper.increaseTimeAsync(TREASURY_PARAMS.votingPeriod.plus(1).toNumber());
+            await env.web3Wrapper.mineBlockAsync();
+
+            const vote = new TreasuryVote({
+                proposalId: VOTE_PROPOSAL_ID,
+                verifyingContract: admin,
+            });
+            const signature = vote.getSignatureWithKey(delegatorPrivateKey);
+            const tx = treasury
+                .castVoteBySignature(VOTE_PROPOSAL_ID, true, [], signature.v,  signature.r,  signature.s)
+                .awaitTransactionSuccessAsync({ from: relayer });
+            return expect(tx).to.revertWith('_castVote/VOTING_IS_CLOSED');
+        });
+        it('Can recover the address from signature correctly', async () => {
+            const vote = new TreasuryVote({
+                proposalId: VOTE_PROPOSAL_ID,
+                verifyingContract: admin,
+            });
+            const signature = vote.getSignatureWithKey(delegatorPrivateKey);
+            const publicKey = ethUtil.ecrecover(
+                ethUtil.toBuffer(vote.getEIP712Hash()),
+                signature.v,
+                ethUtil.toBuffer(signature.r),
+                ethUtil.toBuffer(signature.s),
+            );
+            const address = ethUtil.publicToAddress(publicKey);
+
+            expect(ethUtil.bufferToHex(address)).to.be.equal(delegator);
+        });
+        it('Can cast a valid vote by signature', async () => {
+            await fastForwardToNextEpochAsync();
+            await fastForwardToNextEpochAsync();
+
+            const vote = new TreasuryVote({
+                proposalId: VOTE_PROPOSAL_ID,
+                verifyingContract: treasury.address,
+                chainId: 1337,
+                support: false,
+            });
+            const signature = vote.getSignatureWithKey(delegatorPrivateKey);
+            const tx = await treasury
+                .castVoteBySignature(VOTE_PROPOSAL_ID, false, [], signature.v,  signature.r,  signature.s)
+                .awaitTransactionSuccessAsync({ from: relayer });
+
+            verifyEventsFromLogs(
+                tx.logs,
+                [
+                    {
+                        voter: delegator,
+                        operatedPoolIds: [],
+                        proposalId: VOTE_PROPOSAL_ID,
+                        support: vote.support,
+                        votingPower: DELEGATOR_VOTING_POWER,
+                    },
+                ],
+                ZrxTreasuryEvents.VoteCast,
+            );
+        });
+        it('Cannot vote by signature twice on same proposal', async () => {
+            await fastForwardToNextEpochAsync();
+            await fastForwardToNextEpochAsync();
+            await treasury.castVote(VOTE_PROPOSAL_ID, true, [])
+                .awaitTransactionSuccessAsync({ from: delegator });
+
+            const secondVote = new TreasuryVote({
+                proposalId: VOTE_PROPOSAL_ID,
+                verifyingContract: treasury.address,
+                chainId: 1337,
+                support: false,
+            });
+            const signature = secondVote.getSignatureWithKey(delegatorPrivateKey);
+            const secondVoteTx = treasury
+                .castVoteBySignature(VOTE_PROPOSAL_ID, false, [], signature.v,  signature.r,  signature.s)
+                .awaitTransactionSuccessAsync({ from: relayer });
+            return expect(secondVoteTx).to.revertWith('_castVote/ALREADY_VOTED');
+        });
     });
     describe('execute()', () => {
         let passedProposalId: BigNumber;
@@ -473,7 +584,7 @@ blockchainTests.resets('Treasury governance', env => {
         let ongoingVoteProposalId: BigNumber;
 
         before(async () => {
-            // OPerator has enough ZRX to create and pass a proposal
+            // Operator has enough ZRX to create and pass a proposal
             await staking.stake(TREASURY_PARAMS.quorumThreshold).awaitTransactionSuccessAsync({ from: poolOperator });
             await staking
                 .moveStake(
@@ -549,7 +660,7 @@ blockchainTests.resets('Treasury governance', env => {
         });
         it('Cannot execute before or after the execution epoch', async () => {
             const tooEarly = treasury.execute(passedProposalId, actions).awaitTransactionSuccessAsync();
-            expect(tooEarly).to.revertWith('_assertProposalExecutable/CANNOT_EXECUTE_THIS_EPOCH');
+            await expect(tooEarly).to.revertWith('_assertProposalExecutable/CANNOT_EXECUTE_THIS_EPOCH');
             await fastForwardToNextEpochAsync();
             // Proposal 0 is executable here
             await fastForwardToNextEpochAsync();

packages/protocol-utils/CHANGELOG.json

@@ -1,4 +1,12 @@
 [
+    {
+        "version": "1.9.0",
+        "changes": [
+            {
+                "note": "Add 'TreasuryVote' class"
+            }
+        ]
+    },
     {
         "timestamp": 1630459879,
         "version": "1.8.4",

packages/protocol-utils/package.json

@@ -67,7 +67,7 @@
         "@0x/contract-wrappers": "^13.17.6",
         "@0x/json-schemas": "^6.1.3",
         "@0x/subproviders": "^6.5.3",
-        "@0x/utils": "^6.4.3",
+        "@0x/utils": "^6.4.4",
         "@0x/web3-wrapper": "^7.5.3",
         "chai": "^4.0.1",
         "ethereumjs-util": "^7.0.10",

packages/protocol-utils/src/index.ts

@@ -9,3 +9,4 @@ export * from './signature_utils';
 export * from './transformer_utils';
 export * from './constants';
 export * from './vip_utils';
+export * from './treasury_votes';

packages/protocol-utils/src/treasury_votes.ts

@@ -0,0 +1,97 @@
+import { BigNumber, hexUtils, NULL_ADDRESS } from '@0x/utils';
+import * as ethUtil from 'ethereumjs-util';
+
+import { ZERO } from './constants';
+import { EIP712_DOMAIN_PARAMETERS, getTypeHash } from './eip712_utils';
+import { eip712SignHashWithKey, Signature } from './signature_utils';
+
+const VOTE_DEFAULT_VALUES = {
+    proposalId: ZERO,
+    support: false,
+    operatedPoolIds: [] as string[],
+    chainId: 1,
+    version: '1.0.0',
+    verifyingContract: NULL_ADDRESS,
+};
+
+export type TreasuryVoteFields = typeof VOTE_DEFAULT_VALUES;
+
+export class TreasuryVote {
+    public static readonly CONTRACT_NAME = 'Zrx Treasury';
+
+    public static readonly MESSAGE_STRUCT_NAME = 'TreasuryVote';
+    public static readonly MESSAGE_STRUCT_ABI = [
+        { type: 'uint256', name: 'proposalId' },
+        { type: 'bool', name: 'support' },
+        { type: 'bytes32[]', name: 'operatedPoolIds' },
+    ];
+    public static readonly MESSAGE_TYPE_HASH = getTypeHash(
+        TreasuryVote.MESSAGE_STRUCT_NAME, TreasuryVote.MESSAGE_STRUCT_ABI,
+    );
+
+    public static readonly DOMAIN_STRUCT_NAME = 'EIP712Domain';
+    public static readonly DOMAIN_TYPE_HASH = getTypeHash(
+        TreasuryVote.DOMAIN_STRUCT_NAME, EIP712_DOMAIN_PARAMETERS,
+    );
+
+    public proposalId: BigNumber;
+    public support: boolean;
+    public operatedPoolIds: string[];
+    public chainId: number;
+    public version: string;
+    public verifyingContract: string;
+
+    constructor(fields: Partial<TreasuryVoteFields> = {}) {
+        const _fields = { ...VOTE_DEFAULT_VALUES, ...fields };
+        this.proposalId = _fields.proposalId;
+        this.support = _fields.support;
+        this.operatedPoolIds = _fields.operatedPoolIds;
+        this.chainId = _fields.chainId;
+        this.version = _fields.version;
+        this.verifyingContract = _fields.verifyingContract;
+    }
+
+    public getDomainHash(): string {
+        return hexUtils.hash(
+            hexUtils.concat(
+                hexUtils.leftPad(TreasuryVote.DOMAIN_TYPE_HASH),
+                hexUtils.hash(
+                    hexUtils.toHex(Buffer.from(TreasuryVote.CONTRACT_NAME)),
+                ),
+                hexUtils.leftPad(this.chainId),
+                hexUtils.hash(
+                    hexUtils.toHex(Buffer.from(this.version)),
+                ),
+                hexUtils.leftPad(this.verifyingContract),
+            ),
+        );
+    }
+
+    public getStructHash(): string {
+        return hexUtils.hash(
+            hexUtils.concat(
+                hexUtils.leftPad(TreasuryVote.MESSAGE_TYPE_HASH),
+                hexUtils.leftPad(this.proposalId),
+                hexUtils.leftPad(this.support ? 1 : 0),
+                hexUtils.hash(
+                    ethUtil.toBuffer(hexUtils.concat(...this.operatedPoolIds.map(id => hexUtils.leftPad(id)))),
+                ),
+            ),
+        );
+    }
+
+    public getEIP712Hash(): string {
+        return hexUtils.hash(
+            hexUtils.toHex(
+                hexUtils.concat(
+                    '0x1901',
+                    this.getDomainHash(),
+                    this.getStructHash()),
+            ),
+        );
+    }
+
+    public getSignatureWithKey(privateKey: string): Signature {
+        return eip712SignHashWithKey(this.getEIP712Hash(), privateKey);
+    }
+}