feat(contracts): Add a new 'Burn Admin' entity to control CTC's gas burn params"

ops/docker-compose-nobuild.yml

@@ -34,6 +34,8 @@ services:
         # these keys are hardhat's first 2 accounts, DO NOT use in production
         DEPLOYER_PRIVATE_KEY: "0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80"
         SEQUENCER_PRIVATE_KEY: "0x59c6995e998f97a5a0044966f0945389dc9e86dae88c7a8412f4603b6b78690d"
+        # this address is hardhat's third accounts, DO NOT use in production
+        BURN_ADMIN_ADDRESS: "0xD1D84F0e28D6fedF03c73151f98dF95139700aa7"
         # skip compilation when run in docker-compose, since the contracts
         # were already compiled in the builder step
         NO_COMPILE: 1

ops/docker-compose.yml

@@ -34,6 +34,8 @@ services:
         # these keys are hardhat's first 2 accounts, DO NOT use in production
         DEPLOYER_PRIVATE_KEY: "0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80"
         SEQUENCER_PRIVATE_KEY: "0x59c6995e998f97a5a0044966f0945389dc9e86dae88c7a8412f4603b6b78690d"
+        # this address is hardhat's third accounts, DO NOT use in production.
+        BURN_ADMIN_ADDRESS: "0xD1D84F0e28D6fedF03c73151f98dF95139700aa7"
         GAS_PRICE_ORACLE_OWNER: "0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266"
         # setting the whitelist owner to address(0) disables the whitelist
         WHITELIST_OWNER: "0x0000000000000000000000000000000000000000"

packages/contracts/bin/deploy.ts

-import { Wallet } from 'ethers'
+import { Wallet, utils } from 'ethers'
 import path from 'path'
 import dirtree from 'directory-tree'
 import fs from 'fs'
@@ -17,6 +17,7 @@ import hre from 'hardhat'
 
 const sequencer = new Wallet(process.env.SEQUENCER_PRIVATE_KEY)
 const deployer = new Wallet(process.env.DEPLOYER_PRIVATE_KEY)
+const burnAdminAddress = utils.getAddress(process.env.BURN_ADMIN_ADDRESS)
 
 const parseEnv = () => {
   const ensure = (env, type) => {
@@ -54,6 +55,7 @@ const main = async () => {
     sccSequencerPublishWindow: config.sccFraudProofWindow,
     ovmSequencerAddress: sequencer.address,
     ovmProposerAddress: sequencer.address,
+    ovmBurnAdmin: burnAdminAddress,
     ovmAddressManagerOwner: deployer.address,
     noCompile: process.env.NO_COMPILE ? true : false,
   })

packages/contracts/contracts/L1/rollup/CanonicalTransactionChain.sol

@@ -87,13 +87,13 @@ contract CanonicalTransactionChain is ICanonicalTransactionChain, Lib_AddressRes
      **********************/
 
     /**
-     * Modifier to enforce that, if configured, only the OVM_Sequencer contract may
+     * Modifier to enforce that only the OVM_BurnAdmin contract may
      * successfully call a method.
      */
-    modifier onlySequencer() {
+    modifier onlyBurnAdmin() {
         require(
-            msg.sender == resolve("OVM_Sequencer"),
-            "Only callable by the Sequencer."
+            msg.sender == resolve("OVM_BurnAdmin"),
+            "Only callable by the Burn Admin."
         );
         _;
     }
@@ -108,7 +108,7 @@ contract CanonicalTransactionChain is ICanonicalTransactionChain, Lib_AddressRes
      */
     function setEnqueueGasCost(uint256 _enqueueGasCost)
         external
-        onlySequencer
+        onlyBurnAdmin
     {
         enqueueGasCost = _enqueueGasCost;
         enqueueL2GasPrepaid = l2GasDiscountDivisor * _enqueueGasCost;
@@ -127,7 +127,7 @@ contract CanonicalTransactionChain is ICanonicalTransactionChain, Lib_AddressRes
      */
     function setGasDivisor(uint256 _l2GasDiscountDivisor)
         external
-        onlySequencer
+        onlyBurnAdmin
     {
         l2GasDiscountDivisor = _l2GasDiscountDivisor;
         enqueueL2GasPrepaid = _l2GasDiscountDivisor * enqueueGasCost;

packages/contracts/deploy/000-Lib_AddressManager.deploy.ts

@@ -39,6 +39,12 @@ const deployFn: DeployFunction = async (hre) => {
     name: 'OVM_Proposer',
     address: (hre as any).deployConfig.ovmProposerAddress,
   })
+
+  await registerAddress({
+    hre,
+    name: 'OVM_BurnAdmin',
+    address: (hre as any).deployConfig.ovmBurnAdmin,
+  })
 }
 
 deployFn.tags = ['Lib_AddressManager']

packages/contracts/tasks/deploy.ts

@@ -65,6 +65,12 @@ task('deploy')
     undefined,
     types.string
   )
+  .addOptionalParam(
+    'ovmBurnAdmin',
+    'Address that can update gas burn parameters in the CTC. Must be provided or this deployment will fail.',
+    undefined,
+    types.string
+  )
   .setAction(async (args, hre: any, runSuper) => {
     // Necessary because hardhat doesn't let us attach non-optional parameters to existing tasks.
     const validateAddressArg = (argName: string) => {

packages/contracts/test/contracts/L1/messaging/deposit.gas.spec.ts

@@ -146,7 +146,7 @@ describe('[GAS BENCHMARK] Depositing via the standard bridge', () => {
       const receipt = await res.wait()
       const gasUsed = receipt.gasUsed.toNumber()
       console.log('    - Gas used:', gasUsed)
-      expectApprox(gasUsed, 116_003, {
+      expectApprox(gasUsed, 155_089, {
         absoluteUpperDeviation: 500,
         // Assert a lower bound of 1% reduction on gas cost. If your tests are breaking because your
         // contracts are too efficient, consider updating the target value!
@@ -173,7 +173,7 @@ describe('[GAS BENCHMARK] Depositing via the standard bridge', () => {
       const receipt = await res.wait()
       const gasUsed = receipt.gasUsed.toNumber()
       console.log('    - Gas used:', gasUsed)
-      expectApprox(gasUsed, 163_844, {
+      expectApprox(gasUsed, 202_930, {
         absoluteUpperDeviation: 500,
         // Assert a lower bound of 1% reduction on gas cost. If your tests are breaking because your
         // contracts are too efficient, consider updating the target value!

packages/contracts/test/contracts/L1/rollup/CanonicalTransactionChain.gas.spec.ts

@@ -314,7 +314,7 @@ describe('[GAS BENCHMARK] CanonicalTransactionChain', () => {
 
       console.log('Benchmark complete.')
 
-      expectApprox(gasUsed, 126_700, {
+      expectApprox(gasUsed, 158_690, {
         absoluteUpperDeviation: 500,
         // Assert a lower bound of 1% reduction on gas cost. If your tests are breaking because your
         // contracts are too efficient, consider updating the target value!

packages/contracts/test/contracts/L1/rollup/CanonicalTransactionChain.spec.ts

@@ -65,8 +65,9 @@ const appendSequencerBatch = async (
 describe('CanonicalTransactionChain', () => {
   let signer: Signer
   let sequencer: Signer
+  let burnAdmin: Signer
   before(async () => {
-    ;[signer, sequencer] = await ethers.getSigners()
+    ;[signer, sequencer, burnAdmin] = await ethers.getSigners()
   })
 
   let AddressManager: Contract
@@ -78,6 +79,11 @@ describe('CanonicalTransactionChain', () => {
       await sequencer.getAddress()
     )
 
+    await AddressManager.setAddress(
+      'OVM_BurnAdmin',
+      await burnAdmin.getAddress()
+    )
+
     Mock__StateCommitmentChain = await smockit(
       await ethers.getContractFactory('StateCommitmentChain')
     )
@@ -107,7 +113,7 @@ describe('CanonicalTransactionChain', () => {
       AddressManager.address,
       MAX_GAS_LIMIT,
       L2_GAS_DISCOUNT_DIVISOR,
-      ENQUEUE_GAS_COST,
+      ENQUEUE_GAS_COST
     )
 
     const batches = await Factory__ChainStorageContainer.deploy(
@@ -137,15 +143,15 @@ describe('CanonicalTransactionChain', () => {
 
   describe('Gas param setters', () => {
     describe('setGasDivisor', async () => {
-      it('should revert when not called by the sequencer', async () => {
+      it('should revert when not called by the Burn Admin', async () => {
         await expect(
           CanonicalTransactionChain.connect(signer).setGasDivisor(32)
-        ).to.be.revertedWith('Only callable by the Sequencer.')
+        ).to.be.revertedWith('Only callable by the Burn Admin.')
       })
 
       it('should update the l2GasDiscountDivisor and enqueueL2GasPrepaid correctly', async () => {
         const newGasDivisor = 19
-        await CanonicalTransactionChain.connect(sequencer).setGasDivisor(
+        await CanonicalTransactionChain.connect(burnAdmin).setGasDivisor(
           newGasDivisor
         )
 
@@ -157,21 +163,21 @@ describe('CanonicalTransactionChain', () => {
 
       it('should emit an L2GasParamsUpdated event', async () => {
         await expect(
-          CanonicalTransactionChain.connect(sequencer).setGasDivisor(88)
+          CanonicalTransactionChain.connect(burnAdmin).setGasDivisor(88)
         ).to.emit(CanonicalTransactionChain, 'L2GasParamsUpdated')
       })
     })
 
     describe('setEnqueueGasCost', async () => {
-      it('should revert when not called by the sequencer', async () => {
+      it('should revert when not called by the Burn Admin', async () => {
         await expect(
           CanonicalTransactionChain.connect(signer).setEnqueueGasCost(60000)
-        ).to.be.revertedWith('Only callable by the Sequencer.')
+        ).to.be.revertedWith('Only callable by the Burn Admin.')
       })
 
       it('should update the enqueueGasCost and enqueueL2GasPrepaid correctly', async () => {
         const newEnqueueGasCost = 31113
-        await CanonicalTransactionChain.connect(sequencer).setEnqueueGasCost(
+        await CanonicalTransactionChain.connect(burnAdmin).setEnqueueGasCost(
           newEnqueueGasCost
         )
 
@@ -186,7 +192,7 @@ describe('CanonicalTransactionChain', () => {
 
       it('should emit an L2GasParamsUpdated event', async () => {
         await expect(
-          CanonicalTransactionChain.connect(sequencer).setEnqueueGasCost(31514)
+          CanonicalTransactionChain.connect(burnAdmin).setEnqueueGasCost(31514)
         ).to.emit(CanonicalTransactionChain, 'L2GasParamsUpdated')
       })
     })
@@ -244,7 +250,7 @@ describe('CanonicalTransactionChain', () => {
       // additional gas overhead, it will be enough trigger the gas burn, but not enough to cover
       // it.
       const l1GasLimit =
-      (l2GasLimit - _enqueueL2GasPrepaid) / l2GasDiscountDivisor
+        (l2GasLimit - _enqueueL2GasPrepaid) / l2GasDiscountDivisor
 
       await expect(
         CanonicalTransactionChain.enqueue(target, l2GasLimit, data, {