From a9b7db1d43c13c79062e657e7520a2ad7263561e Mon Sep 17 00:00:00 2001
From: garyghayrat <gary.ghayrat@pm.me>
Date: Tue, 30 Jan 2024 12:43:21 -0500
Subject: [PATCH] Add standalone type hash definition and remove `regitrant`
 from it

---
 src/ERC6538Registry.sol    | 12 +++++-------
 test/ERC6538Registry.t.sol | 20 ++++++++------------
 2 files changed, 13 insertions(+), 19 deletions(-)

diff --git a/src/ERC6538Registry.sol b/src/ERC6538Registry.sol
index e72d1ef..b42926f 100644
--- a/src/ERC6538Registry.sol
+++ b/src/ERC6538Registry.sol
@@ -17,6 +17,10 @@ contract ERC6538Registry {
   /// @dev `nonce` will be incremented after each valid `registerKeysOnBehalf` call.
   mapping(address user => uint256) public nonceOf;
 
+  /// @notice The EIP-712 type hash used in `registerKeysOnBehalf`.
+  bytes32 public constant ERC6538REGISTRY_ENTRY_TYPE_HASH =
+    keccak256("Erc6538RegistryEntry(uint256 schemeId,bytes stealthMetaAddress,uint256 nonce)");
+
   /// @dev The chain ID where this contract is initially deployed.
   uint256 internal immutable INITIAL_CHAIN_ID;
 
@@ -76,13 +80,7 @@ contract ERC6538Registry {
           DOMAIN_SEPARATOR(),
           keccak256(
             abi.encode(
-              keccak256(
-                "RegisterKeysOnBehalf(address registrant,uint256 schemeId,bytes stealthMetaAddress,uint256 nonce)"
-              ),
-              registrant,
-              schemeId,
-              stealthMetaAddress,
-              nonceOf[registrant]++
+              ERC6538REGISTRY_ENTRY_TYPE_HASH, schemeId, stealthMetaAddress, nonceOf[registrant]++
             )
           )
         )
diff --git a/test/ERC6538Registry.t.sol b/test/ERC6538Registry.t.sol
index ccbc76d..b3591a1 100644
--- a/test/ERC6538Registry.t.sol
+++ b/test/ERC6538Registry.t.sol
@@ -66,7 +66,7 @@ contract RegisterKeysOnBehalf_Address is ERC6538RegistryTest {
   ) external {
     (address alice, uint256 alicePk) = makeAddrAndKey(name);
     SigUtils.RegistrantInfo memory registrantInfo =
-      SigUtils.RegistrantInfo(alice, schemeId, stealthMetaAddress, 0 /* nonce */ );
+      SigUtils.RegistrantInfo(schemeId, stealthMetaAddress, 0 /* nonce */ );
     bytes32 hash = sigUtils.getTypedDataHash(registrantInfo);
     (uint8 v, bytes32 r, bytes32 s) = vm.sign(alicePk, hash);
     bytes memory signature = abi.encodePacked(r, s, v);
@@ -88,7 +88,7 @@ contract RegisterKeysOnBehalf_Address is ERC6538RegistryTest {
     address registrant = address(erc1271MockContract);
 
     SigUtils.RegistrantInfo memory registrantInfo =
-      SigUtils.RegistrantInfo(registrant, schemeId, stealthMetaAddress, 0 /* nonce */ );
+      SigUtils.RegistrantInfo(schemeId, stealthMetaAddress, 0 /* nonce */ );
     bytes32 hash = sigUtils.getTypedDataHash(registrantInfo);
     (uint8 v, bytes32 r, bytes32 s) = vm.sign(alicePk, hash);
     bytes memory signature = abi.encodePacked(r, s, v);
@@ -109,7 +109,7 @@ contract RegisterKeysOnBehalf_Address is ERC6538RegistryTest {
 
     for (uint256 nonce = 0; nonce < numOfUpdates; nonce++) {
       SigUtils.RegistrantInfo memory registrantInfo =
-        SigUtils.RegistrantInfo(alice, schemeId, stealthMetaAddress, nonce);
+        SigUtils.RegistrantInfo(schemeId, stealthMetaAddress, nonce);
       bytes32 hash = sigUtils.getTypedDataHash(registrantInfo);
       (uint8 v, bytes32 r, bytes32 s) = vm.sign(alicePk, hash);
       bytes memory signature = abi.encodePacked(r, s, v);
@@ -126,9 +126,9 @@ contract RegisterKeysOnBehalf_Address is ERC6538RegistryTest {
     uint256 schemeId,
     bytes memory stealthMetaAddress
   ) external {
-    (address alice, uint256 alicePk) = makeAddrAndKey(name);
+    ( /*address alice */ , uint256 alicePk) = makeAddrAndKey(name);
     SigUtils.RegistrantInfo memory registrantInfo =
-      SigUtils.RegistrantInfo(alice, schemeId, stealthMetaAddress, 0 /* nonce */ );
+      SigUtils.RegistrantInfo(schemeId, stealthMetaAddress, 0 /* nonce */ );
     bytes32 hash = sigUtils.getTypedDataHash(registrantInfo);
     (uint8 v, bytes32 r, bytes32 s) = vm.sign(alicePk, hash);
     bytes memory signature = abi.encodePacked(r, s, v);
@@ -150,7 +150,7 @@ contract RegisterKeysOnBehalf_Address is ERC6538RegistryTest {
     address registrant = address(erc1271MockContract);
 
     SigUtils.RegistrantInfo memory registrantInfo =
-      SigUtils.RegistrantInfo(registrant, schemeId, stealthMetaAddress, 0 /* nonce */ );
+      SigUtils.RegistrantInfo(schemeId, stealthMetaAddress, 0 /* nonce */ );
     bytes32 hash = sigUtils.getTypedDataHash(registrantInfo);
     (uint8 v, bytes32 r, bytes32 s) = vm.sign(alicePk, hash);
     bytes memory signature = abi.encodePacked(r, s, v);
@@ -168,7 +168,7 @@ contract RegisterKeysOnBehalf_Address is ERC6538RegistryTest {
     vm.assume(nonce != 0);
     (address alice, uint256 alicePk) = makeAddrAndKey(name);
     SigUtils.RegistrantInfo memory registrantInfo =
-      SigUtils.RegistrantInfo(alice, schemeId, stealthMetaAddress, nonce);
+      SigUtils.RegistrantInfo(schemeId, stealthMetaAddress, nonce);
     bytes32 hash = sigUtils.getTypedDataHash(registrantInfo);
     (uint8 v, bytes32 r, bytes32 s) = vm.sign(alicePk, hash);
     bytes memory signature = abi.encodePacked(r, s, v);
@@ -302,7 +302,6 @@ contract SigUtils {
   }
 
   struct RegistrantInfo {
-    address registrant;
     uint256 schemeId;
     bytes stealthMetaAddress;
     uint256 nonce;
@@ -312,10 +311,7 @@ contract SigUtils {
   function getStructHash(RegistrantInfo memory _info) internal pure returns (bytes32) {
     return keccak256(
       abi.encode(
-        keccak256(
-          "RegisterKeysOnBehalf(address registrant,uint256 schemeId,bytes stealthMetaAddress,uint256 nonce)"
-        ),
-        _info.registrant,
+        keccak256("Erc6538RegistryEntry(uint256 schemeId,bytes stealthMetaAddress,uint256 nonce)"),
         _info.schemeId,
         _info.stealthMetaAddress,
         _info.nonce