AA-176: Add ERC-165 "supportsInterface" to the EntryPoint

contracts/core/EntryPoint.sol

@@ -19,7 +19,7 @@ import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
  * Account-Abstraction (EIP-4337) singleton EntryPoint implementation.
  * Only one instance required on each chain.
  */
-contract EntryPoint is IEntryPoint, StakeManager, NonceManager, ReentrancyGuard {
+contract EntryPoint is IEntryPoint, StakeManager, NonceManager, ReentrancyGuard, OpenZeppelin.ERC165 {
 
  using UserOperationLib for UserOperation;
 
@@ -39,6 +39,15 @@ contract EntryPoint is IEntryPoint, StakeManager, NonceManager, ReentrancyGuard
  */
  uint256 public constant SIG_VALIDATION_FAILED = 1;
 
+ /// @inheritdoc OpenZeppelin.IERC165
+ function supportsInterface(bytes4 interfaceId) public view virtual override(OpenZeppelin.ERC165, OpenZeppelin.IERC165) returns (bool) {
+ return interfaceId == (type(IEntryPoint).interfaceId ^ type(IStakeManager).interfaceId ^ type(INonceManager).interfaceId) ||
+ interfaceId == type(IEntryPoint).interfaceId ||
+ interfaceId == type(IStakeManager).interfaceId ||
+ interfaceId == type(INonceManager).interfaceId ||
+ super.supportsInterface(interfaceId);
+ }
+
  /**
  * Compensate the caller's beneficiary address with the collected fees of all UserOperations.
  * @param beneficiary - The address to receive the fees.

contracts/interfaces/IEntryPoint.sol

@@ -9,12 +9,15 @@ pragma solidity ^0.8.12;
 /* solhint-disable no-inline-assembly */
 /* solhint-disable reason-string */
 
+// we also require '@gnosis.pm/safe-contracts' and both libraries have 'IERC165.sol', leading to conflicts
+import "@openzeppelin/contracts/utils/introspection/ERC165.sol" as OpenZeppelin;
+
 import "./UserOperation.sol";
 import "./IStakeManager.sol";
 import "./IAggregator.sol";
 import "./INonceManager.sol";
 
-interface IEntryPoint is IStakeManager, INonceManager {
+interface IEntryPoint is IStakeManager, INonceManager, OpenZeppelin.IERC165 {
  /***
  * An event emitted after each successful request.
  * @param userOpHash - Unique identifier for the request (hash its entire content, except signature).

reports/gas-checker.txt

@@ -4,36 +4,36 @@
 ╔══════════════════════════╤════════╗
 ║ gas estimate "simple" │ 29014 ║
 ╟──────────────────────────┼────────╢
-║ gas estimate "big tx 5k" │ 125260 ║
+║ gas estimate "big tx 5k" │ 125248 ║
 ╚══════════════════════════╧════════╝
 
 ╔════════════════════════════════╤═══════╤═══════════════╤════════════════╤═════════════════════╗
 ║ handleOps description │ count │ total gasUsed │ per UserOp gas │ per UserOp overhead ║
 ║ │ │ │ (delta for │ (compared to ║
 ║ │ │ │ one UserOp) │ account.exec()) ║
 ╟────────────────────────────────┼───────┼───────────────┼────────────────┼─────────────────────╢
-║ simple │ 1 │ 81899 │ │ ║
+║ simple │ 1 │ 81943 │ │ ║
 ╟────────────────────────────────┼───────┼───────────────┼────────────────┼─────────────────────╢
-║ simple - diff from previous │ 2 │ │ 44186 │ 15172 ║
+║ simple - diff from previous │ 2 │ │ 44208 │ 15194 ║
 ╟────────────────────────────────┼───────┼───────────────┼────────────────┼─────────────────────╢
-║ simple │ 10 │ 479702 │ │ ║
+║ simple │ 10 │ 479944 │ │ ║
 ╟────────────────────────────────┼───────┼───────────────┼────────────────┼─────────────────────╢
-║ simple - diff from previous │ 11 │ │ 44222 │ 15208 ║
+║ simple - diff from previous │ 11 │ │ 44280 │ 15266 ║
 ╟────────────────────────────────┼───────┼───────────────┼────────────────┼─────────────────────╢
-║ simple paymaster │ 1 │ 88182 │ │ ║
+║ simple paymaster │ 1 │ 88202 │ │ ║
 ╟────────────────────────────────┼───────┼───────────────┼────────────────┼─────────────────────╢
-║ simple paymaster with diff │ 2 │ │ 43175 │ 14161 ║
+║ simple paymaster with diff │ 2 │ │ 43197 │ 14183 ║
 ╟────────────────────────────────┼───────┼───────────────┼────────────────┼─────────────────────╢
-║ simple paymaster │ 10 │ 476938 │ │ ║
+║ simple paymaster │ 10 │ 477132 │ │ ║
 ╟────────────────────────────────┼───────┼───────────────┼────────────────┼─────────────────────╢
-║ simple paymaster with diff │ 11 │ │ 43234 │ 14220 ║
+║ simple paymaster with diff │ 11 │ │ 43208 │ 14194 ║
 ╟────────────────────────────────┼───────┼───────────────┼────────────────┼─────────────────────╢
-║ big tx 5k │ 1 │ 182932 │ │ ║
+║ big tx 5k │ 1 │ 182976 │ │ ║
 ╟────────────────────────────────┼───────┼───────────────┼────────────────┼─────────────────────╢
-║ big tx - diff from previous │ 2 │ │ 144721 │ 19461 ║
+║ big tx - diff from previous │ 2 │ │ 144707 │ 19459 ║
 ╟────────────────────────────────┼───────┼───────────────┼────────────────┼─────────────────────╢
-║ big tx 5k │ 10 │ 1485370 │ │ ║
+║ big tx 5k │ 10 │ 1485552 │ │ ║
 ╟────────────────────────────────┼───────┼───────────────┼────────────────┼─────────────────────╢
-║ big tx - diff from previous │ 11 │ │ 144710 │ 19450 ║
+║ big tx - diff from previous │ 11 │ │ 144744 │ 19496 ║
 ╚════════════════════════════════╧═══════╧═══════════════╧════════════════╧═════════════════════╝
 

src/Utils.ts

@@ -0,0 +1,17 @@
+import { Interface, JsonFragment } from '@ethersproject/abi'
+
+export function getERC165InterfaceID (abi: JsonFragment[]): string {
+ let interfaceId =
+ abi
+ .filter(it => it.type === 'function' && it.name != null)
+ .map(it => {
+ const iface = new Interface([it])
+ // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+ return iface.getSighash(it.name!)
+ })
+ .filter(it => it !== '0x01ffc9a7') // remove the IERC165 method itself
+ .map((x) => parseInt(x, 16))
+ .reduce((x, y) => x ^ y)
+ interfaceId = interfaceId > 0 ? interfaceId : 0xFFFFFFFF + interfaceId + 1
+ return '0x' + interfaceId.toString(16).padStart(8, '0')
+}

test/entrypoint.test.ts

@@ -21,6 +21,11 @@ import {
  TestSignatureAggregator__factory,
  MaliciousAccount__factory,
  TestWarmColdAccount__factory,
+ IEntryPoint__factory,
+ SimpleAccountFactory__factory,
+ IStakeManager__factory,
+ INonceManager__factory,
+ EntryPoint__factory,
  TestPaymasterRevertCustomError__factory
 } from '../typechain'
 import {
@@ -53,6 +58,7 @@ import { arrayify, defaultAbiCoder, hexConcat, hexZeroPad, parseEther } from 'et
 import { debugTransaction } from './debugTx'
 import { BytesLike } from '@ethersproject/bytes'
 import { toChecksumAddress } from 'ethereumjs-util'
+import { getERC165InterfaceID } from '../src/Utils'
 
 describe('EntryPoint', function () {
  let entryPoint: EntryPoint
@@ -1362,4 +1368,41 @@ describe('EntryPoint', function () {
  })
  })
  })
+
+ describe('ERC-165', function () {
+ it('should return true for IEntryPoint interface ID', async function () {
+ const iepInterface = IEntryPoint__factory.createInterface()
+ const iepInterfaceID = getERC165InterfaceID([...iepInterface.fragments])
+ expect(await entryPoint.supportsInterface(iepInterfaceID)).to.equal(true)
+ })
+
+ it('should return true for pure EntryPoint, IStakeManager and INonceManager interface IDs', async function () {
+ const epInterface = EntryPoint__factory.createInterface()
+ const smInterface = IStakeManager__factory.createInterface()
+ const nmInterface = INonceManager__factory.createInterface()
+ // note: manually generating "pure", solidity-like "type(IEntryPoint).interfaceId" without inherited methods
+ const epPureInterfaceFunctions = [
+ ...epInterface.fragments.filter(it => [
+ 'handleOps',
+ 'handleAggregatedOps',
+ 'getUserOpHash',
+ 'getSenderAddress',
+ 'simulateValidation',
+ 'simulateHandleOp'
+ ].includes(it.name))
+ ]
+ const epPureInterfaceID = getERC165InterfaceID(epPureInterfaceFunctions)
+ const smInterfaceID = getERC165InterfaceID([...smInterface.fragments])
+ const nmInterfaceID = getERC165InterfaceID([...nmInterface.fragments])
+ expect(await entryPoint.supportsInterface(smInterfaceID)).to.equal(true)
+ expect(await entryPoint.supportsInterface(nmInterfaceID)).to.equal(true)
+ expect(await entryPoint.supportsInterface(epPureInterfaceID)).to.equal(true)
+ })
+
+ it('should return false for a wrong interface', async function () {
+ const saInterface = SimpleAccountFactory__factory.createInterface()
+ const entryPointInterfaceID = getERC165InterfaceID([...saInterface.fragments])
+ expect(await entryPoint.supportsInterface(entryPointInterfaceID)).to.equal(false)
+ })
+ })
 })