Move EIP712 dependency from AccountCore to Account

CHANGELOG.md

@@ -7,7 +7,7 @@
 - `AccountCore`: Added a simple ERC-4337 account implementation with minimal logic to process user operations.
 - `Account`: Extensions of AccountCore with recommended features that most accounts should have.
 - `AbstractSigner`, `SignerECDSA`, `SignerP256`, and `SignerRSA`: Add an abstract contract, and various implementations, for contracts that deal with signature verification. Used by AccountCore and `ERC7739Utils.
-- `AccountSignerERC7702`: Implementation of `AbstractSigner` for ERC-7702 compatible accounts.
+- `SignerERC7702`: Implementation of `AbstractSigner` for Externally Owned Accounts (EOAs). Useful with ERC-7702.
 
 ## 13-12-2024
 

contracts/account/Account.sol

@@ -2,11 +2,13 @@
 
 pragma solidity ^0.8.20;
 
+import {PackedUserOperation} from "@openzeppelin/contracts/interfaces/draft-IERC4337.sol";
 import {ERC721Holder} from "@openzeppelin/contracts/token/ERC721/utils/ERC721Holder.sol";
 import {ERC1155Holder} from "@openzeppelin/contracts/token/ERC1155/utils/ERC1155Holder.sol";
 import {ERC7739Signer} from "../utils/cryptography/ERC7739Signer.sol";
 import {AccountCore} from "./AccountCore.sol";
 import {AccountERC7821} from "./extensions/AccountERC7821.sol";
+import {EIP712} from "@openzeppelin/contracts/utils/cryptography/EIP712.sol";
 
 /**
  * @dev Extension of {AccountCore} with recommended feature that most account abstraction implementation will want:
@@ -18,4 +20,36 @@ import {AccountERC7821} from "./extensions/AccountERC7821.sol";
  * NOTE: To use this contract, the {ERC7739Signer-_rawSignatureValidation} function must be
  * implemented using a specific signature verification algorithm. See {SignerECDSA}, {SignerP256} or {SignerRSA}.
  */
-abstract contract Account is AccountCore, AccountERC7821, ERC721Holder, ERC1155Holder, ERC7739Signer {}
+abstract contract Account is AccountCore, AccountERC7821, EIP712, ERC721Holder, ERC1155Holder, ERC7739Signer {
+    bytes32 internal constant _PACKED_USER_OPERATION =
+        keccak256(
+            "PackedUserOperation(address sender,uint256 nonce,bytes initCode,bytes callData,bytes32 accountGasLimits,uint256 preVerificationGas,bytes32 gasFees,bytes paymasterAndData)"
+        );
+
+    /**
+     * @dev Specialization of {AccountCore-_signableUserOpHash} that returns a typehash following EIP-712 typed data
+     * hashing for readability. This assumes the underlying signature scheme implements `signTypedData`, which will be
+     * the case when combined with {SignerECDSA} or {SignerERC7702}.
+     */
+    function _signableUserOpHash(
+        PackedUserOperation calldata userOp,
+        bytes32 /*userOpHash*/
+    ) internal view virtual override returns (bytes32) {
+        return
+            _hashTypedDataV4(
+                keccak256(
+                    abi.encode(
+                        _PACKED_USER_OPERATION,
+                        userOp.sender,
+                        userOp.nonce,
+                        keccak256(userOp.initCode),
+                        keccak256(userOp.callData),
+                        userOp.accountGasLimits,
+                        userOp.preVerificationGas,
+                        userOp.gasFees,
+                        keccak256(userOp.paymasterAndData)
+                    )
+                )
+            );
+    }
+}

contracts/account/AccountCore.sol

@@ -4,9 +4,6 @@ pragma solidity ^0.8.20;
 
 import {PackedUserOperation, IAccount, IEntryPoint} from "@openzeppelin/contracts/interfaces/draft-IERC4337.sol";
 import {ERC4337Utils} from "@openzeppelin/contracts/account/utils/draft-ERC4337Utils.sol";
-import {Address} from "@openzeppelin/contracts/utils/Address.sol";
-import {MessageHashUtils} from "@openzeppelin/contracts/utils/cryptography/MessageHashUtils.sol";
-import {EIP712} from "@openzeppelin/contracts/utils/cryptography/EIP712.sol";
 import {AbstractSigner} from "../utils/cryptography/AbstractSigner.sol";
 
 /**
@@ -23,14 +20,7 @@ import {AbstractSigner} from "../utils/cryptography/AbstractSigner.sol";
  * attacker to bypass the account's security measures. Check out {SignerECDSA}, {SignerP256}, or {SignerRSA} for
  * digital signature validation implementations.
  */
-abstract contract AccountCore is AbstractSigner, EIP712, IAccount {
-    using MessageHashUtils for bytes32;
-
-    bytes32 internal constant _PACKED_USER_OPERATION =
-        keccak256(
-            "PackedUserOperation(address sender,uint256 nonce,bytes initCode,bytes callData,bytes32 accountGasLimits,uint256 preVerificationGas,bytes32 gasFees,bytes paymasterAndData)"
-        );
-
+abstract contract AccountCore is AbstractSigner, IAccount {
     /**
      * @dev Unauthorized call to the account.
      */
@@ -89,33 +79,16 @@ abstract contract AccountCore is AbstractSigner, EIP712, IAccount {
     }
 
     /**
-     * @dev Returns the digest used by an offchain signer instead of the opaque `userOpHash`.
+     * @dev Returns the `userOpHash` by default. May be overridden for a different hashing scheme.
      *
      * Given the `userOpHash` calculation is defined by ERC-4337, offchain signers
      * may need to sign again this hash by rehashing it with other schemes (e.g. ERC-191).
-     *
-     * Returns a typehash following EIP-712 typed data hashing for readability.
      */
     function _signableUserOpHash(
-        PackedUserOperation calldata userOp,
-        bytes32 /* userOpHash */
+        PackedUserOperation calldata /*userOp*/,
+        bytes32 userOpHash
     ) internal view virtual returns (bytes32) {
-        return
-            _hashTypedDataV4(
-                keccak256(
-                    abi.encode(
-                        _PACKED_USER_OPERATION,
-                        userOp.sender,
-                        userOp.nonce,
-                        keccak256(userOp.initCode),
-                        keccak256(userOp.callData),
-                        userOp.accountGasLimits,
-                        userOp.preVerificationGas,
-                        userOp.gasFees,
-                        keccak256(userOp.paymasterAndData)
-                    )
-                )
-            );
+        return userOpHash;
     }
 
     /**

contracts/account/README.adoc

@@ -12,6 +12,6 @@ This directory includes contracts to build accounts for ERC-4337.
 
 == Extensions
 
-{{AccountSignerERC7702}}
+{{SignerERC7702}}
 
 {{AccountERC7821}}

contracts/mocks/account/AccountERC7702Mock.sol

@@ -3,6 +3,6 @@
 pragma solidity ^0.8.20;
 
 import {Account} from "../../account/Account.sol";
-import {AccountSignerERC7702} from "../../account/extensions/AccountSignerERC7702.sol";
+import {SignerERC7702} from "../../utils/cryptography/SignerERC7702.sol";
 
-abstract contract AccountERC7702Mock is Account, AccountSignerERC7702 {}
+abstract contract AccountERC7702Mock is Account, SignerERC7702 {}

contracts/account/extensions/AccountSignerERC7702.sol → contracts/utils/cryptography/SignerERC7702.sol

@@ -3,12 +3,12 @@
 pragma solidity ^0.8.20;
 
 import {ECDSA} from "@openzeppelin/contracts/utils/cryptography/ECDSA.sol";
-import {AccountCore} from "../AccountCore.sol";
+import {AbstractSigner} from "./AbstractSigner.sol";
 
 /**
- * @dev {Account} implementation whose low-level signature validation is done by an EOA.
+ * @dev Implementation of {AbstractSigner} for implementation for an EOA. Useful for ERC-7702 accounts.
  */
-abstract contract AccountSignerERC7702 is AccountCore {
+abstract contract SignerERC7702 is AbstractSigner {
     /**
      * @dev Validates the signature using the EOA's address (ie. `address(this)`).
      */