Convert string to bytes32 from subject

package.json

@@ -25,9 +25,10 @@
     "test:optimized": "pnpm run build:optimized && FOUNDRY_PROFILE=test-optimized forge test"
   },
   "dependencies": {
-    "@rhinestone/modulekit": "v0.4.2",
     "@openzeppelin/contracts-upgradeable": "v5.0.1",
-    "@zk-email/contracts": "v6.0.3"
+    "@rhinestone/modulekit": "v0.4.2",
+    "@zk-email/contracts": "v6.0.3",
+    "solidity-stringutils": "https://github.com/Arachnid/solidity-stringutils.git"
   },
   "files": [
     "src",

remappings.txt

@@ -19,4 +19,5 @@ solarray/=node_modules/solarray/src/
 @prb/math/=node_modules/@prb/math/src/
 
 ether-email-auth/=lib/ether-email-auth/
-@zk-email/contracts/=node_modules/@zk-email/contracts/
+@zk-email/contracts/=node_modules/@zk-email/contracts/
+solidity-stringutils/=node_modules/solidity-stringutils/

src/EmailRecoveryManager.sol

@@ -349,9 +349,8 @@ contract EmailRecoveryManager is EmailAccountRecoveryNew, Initializable, IEmailR
             revert InvalidTemplateIndex();
         }
 
-        (address account, string memory calldataHashString) = IEmailRecoverySubjectHandler(
-            subjectHandler
-        ).validateRecoverySubject(templateIdx, subjectParams, address(this));
+        (address account, bytes32 calldataHash) = IEmailRecoverySubjectHandler(subjectHandler)
+            .validateRecoverySubject(templateIdx, subjectParams, address(this));
 
         if (IRecoveryModule(emailRecoveryModule).getAllowedValidators(account).length == 0) {
             revert RecoveryModuleNotInstalled();
@@ -375,7 +374,7 @@ contract EmailRecoveryManager is EmailAccountRecoveryNew, Initializable, IEmailR
 
             recoveryRequest.executeAfter = executeAfter;
             recoveryRequest.executeBefore = executeBefore;
-            recoveryRequest.calldataHashString = calldataHashString;
+            recoveryRequest.calldataHash = calldataHash;
 
             emit RecoveryProcessed(account, executeAfter, executeBefore);
         }
@@ -422,11 +421,8 @@ contract EmailRecoveryManager is EmailAccountRecoveryNew, Initializable, IEmailR
 
         delete recoveryRequests[account];
 
-        // TODO: Do ZkEmail contracts have a library for converting a string to bytes32?
         bytes32 calldataHash = keccak256(recoveryCalldata);
-        string memory calldataHashString = uint256(calldataHash).toHexString(32);
-
-        if (!Strings.equal(calldataHashString, recoveryRequest.calldataHashString)) {
+        if (calldataHash != recoveryRequest.calldataHash) {
             revert InvalidCalldataHash();
         }
 

src/handlers/EmailRecoverySubjectHandler.sol

@@ -3,6 +3,7 @@ pragma solidity ^0.8.25;
 
 import { IEmailRecoverySubjectHandler } from "../interfaces/IEmailRecoverySubjectHandler.sol";
 import { EmailRecoveryManager } from "../EmailRecoveryManager.sol";
+import { StringUtils } from "../libraries/StringUtils.sol";
 import "forge-std/console2.sol";
 
 /**
@@ -90,7 +91,7 @@ contract EmailRecoverySubjectHandler is IEmailRecoverySubjectHandler {
     )
         public
         view
-        returns (address, string memory)
+        returns (address, bytes32)
     {
         if (subjectParams.length != 3) {
             revert InvalidSubjectParams();
@@ -99,6 +100,7 @@ contract EmailRecoverySubjectHandler is IEmailRecoverySubjectHandler {
         address accountInEmail = abi.decode(subjectParams[0], (address));
         address recoveryModuleInEmail = abi.decode(subjectParams[1], (address));
         string memory calldataHashInEmail = abi.decode(subjectParams[2], (string));
+        bytes32 calldataHash = StringUtils.hexToBytes32(calldataHashInEmail);
 
         if (accountInEmail == address(0)) {
             revert InvalidAccount();
@@ -114,6 +116,6 @@ contract EmailRecoverySubjectHandler is IEmailRecoverySubjectHandler {
             revert InvalidRecoveryModule();
         }
 
-        return (accountInEmail, calldataHashInEmail);
+        return (accountInEmail, calldataHash);
     }
 }

src/handlers/SafeRecoverySubjectHandler.sol

@@ -99,7 +99,7 @@ contract SafeRecoverySubjectHandler is IEmailRecoverySubjectHandler {
     )
         public
         view
-        returns (address, string memory)
+        returns (address, bytes32)
     {
         if (subjectParams.length != 4) {
             revert InvalidSubjectParams();
@@ -136,9 +136,8 @@ contract SafeRecoverySubjectHandler is IEmailRecoverySubjectHandler {
             functionSignature, previousOwnerInLinkedList, oldOwnerInEmail, newOwnerInEmail
         );
         bytes32 calldataHash = keccak256(recoveryCallData);
-        string memory calldataHashString = uint256(calldataHash).toHexString(32);
 
-        return (accountInEmail, calldataHashString);
+        return (accountInEmail, calldataHash);
     }
 
     function getPreviousOwnerInLinkedList(

src/interfaces/IEmailRecoveryManager.sol

@@ -30,7 +30,7 @@ interface IEmailRecoveryManager {
         uint256 executeAfter; // the timestamp from which the recovery request can be executed
         uint256 executeBefore; // the timestamp from which the recovery request becomes invalid
         uint256 currentWeight; // total weight of all guardian approvals for the recovery request
-        string calldataHashString; // the keccak256 hash of the calldata used to execute the
+        bytes32 calldataHash; // the keccak256 hash of the calldata used to execute the
             // recovery attempt
     }
 

src/interfaces/IEmailRecoverySubjectHandler.sol

@@ -36,5 +36,5 @@ interface IEmailRecoverySubjectHandler {
     )
         external
         view
-        returns (address, string memory);
+        returns (address, bytes32);
 }

src/libraries/StringUtils.sol

@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.13;
+
+import "solidity-stringutils/src/strings.sol";
+
+// Extracted from https://github.com/zkemail/email-wallet-sdk/blob/main/src/helpers/StringUtils.sol
+library StringUtils {
+    using strings for *;
+
+    function hexToBytes32(string calldata hexStr) public pure returns (bytes32 result) {
+        require(hexStr.toSlice().startsWith("0x".toSlice()), "invalid hex prefix");
+        hexStr = hexStr[2:];
+        require(bytes(hexStr).length == 64, "invalid hex string length");
+        uint256[] memory ints = hex2Ints(hexStr);
+        uint256 sum = 0;
+        for (uint256 i = 0; i < 32; i++) {
+            sum = (256 * sum + ints[i]);
+        }
+        return bytes32(sum);
+    }
+
+    function hex2Ints(string memory hexStr) private pure returns (uint256[] memory) {
+        uint256[] memory result = new uint256[](bytes(hexStr).length / 2);
+        for (uint256 i = 0; i < result.length; i++) {
+            result[i] =
+                16 * hexChar2Int(bytes(hexStr)[2 * i]) + hexChar2Int(bytes(hexStr)[2 * i + 1]);
+        }
+        return result;
+    }
+
+    function hexChar2Int(bytes1 char) private pure returns (uint256) {
+        uint8 charInt = uint8(char);
+        if (charInt >= 48 && charInt <= 57) {
+            return charInt - 48;
+        } else if (charInt >= 97 && charInt <= 102) {
+            return charInt - 87;
+        } else {
+            require(false, "invalid hex char");
+        }
+        return 0;
+    }
+}

test/unit/EmailRecoveryManager/cancelRecovery.t.sol

@@ -10,11 +10,8 @@ import { EmailRecoveryModule } from "src/modules/EmailRecoveryModule.sol";
 contract EmailRecoveryManager_cancelRecovery_Test is UnitBase {
     using Strings for uint256;
 
-    string calldataHashString;
-
     function setUp() public override {
         super.setUp();
-        calldataHashString = uint256(calldataHash).toHexString(32);
     }
 
     function test_CancelRecovery_CannotCancelWrongRecoveryRequest() public {
@@ -29,7 +26,7 @@ contract EmailRecoveryManager_cancelRecovery_Test is UnitBase {
         assertEq(recoveryRequest.executeAfter, 0);
         assertEq(recoveryRequest.executeBefore, 0);
         assertEq(recoveryRequest.currentWeight, 1);
-        assertEq(recoveryRequest.calldataHashString, "");
+        assertEq(recoveryRequest.calldataHash, "");
 
         vm.startPrank(otherAddress);
         emailRecoveryManager.cancelRecovery();
@@ -38,7 +35,7 @@ contract EmailRecoveryManager_cancelRecovery_Test is UnitBase {
         assertEq(recoveryRequest.executeAfter, 0);
         assertEq(recoveryRequest.executeBefore, 0);
         assertEq(recoveryRequest.currentWeight, 1);
-        assertEq(recoveryRequest.calldataHashString, "");
+        assertEq(recoveryRequest.calldataHash, "");
     }
 
     function test_CancelRecovery_PartialRequest_Succeeds() public {
@@ -51,7 +48,7 @@ contract EmailRecoveryManager_cancelRecovery_Test is UnitBase {
         assertEq(recoveryRequest.executeAfter, 0);
         assertEq(recoveryRequest.executeBefore, 0);
         assertEq(recoveryRequest.currentWeight, 1);
-        assertEq(recoveryRequest.calldataHashString, "");
+        assertEq(recoveryRequest.calldataHash, "");
 
         vm.startPrank(accountAddress);
         emailRecoveryManager.cancelRecovery();
@@ -60,7 +57,7 @@ contract EmailRecoveryManager_cancelRecovery_Test is UnitBase {
         assertEq(recoveryRequest.executeAfter, 0);
         assertEq(recoveryRequest.executeBefore, 0);
         assertEq(recoveryRequest.currentWeight, 0);
-        assertEq(recoveryRequest.calldataHashString, "");
+        assertEq(recoveryRequest.calldataHash, "");
     }
 
     function test_CancelRecovery_FullRequest_Succeeds() public {
@@ -75,7 +72,7 @@ contract EmailRecoveryManager_cancelRecovery_Test is UnitBase {
         assertEq(recoveryRequest.executeAfter, block.timestamp + delay);
         assertEq(recoveryRequest.executeBefore, block.timestamp + expiry);
         assertEq(recoveryRequest.currentWeight, 3);
-        assertEq(recoveryRequest.calldataHashString, calldataHashString);
+        assertEq(recoveryRequest.calldataHash, calldataHash);
 
         vm.startPrank(accountAddress);
         emailRecoveryManager.cancelRecovery();
@@ -84,6 +81,6 @@ contract EmailRecoveryManager_cancelRecovery_Test is UnitBase {
         assertEq(recoveryRequest.executeAfter, 0);
         assertEq(recoveryRequest.executeBefore, 0);
         assertEq(recoveryRequest.currentWeight, 0);
-        assertEq(recoveryRequest.calldataHashString, "");
+        assertEq(recoveryRequest.calldataHash, "");
     }
 }

test/unit/EmailRecoveryManager/completeRecovery.t.sol

@@ -106,7 +106,7 @@ contract EmailRecoveryManager_completeRecovery_Test is UnitBase {
         assertEq(recoveryRequest.executeAfter, 0);
         assertEq(recoveryRequest.executeBefore, 0);
         assertEq(recoveryRequest.currentWeight, 0);
-        assertEq(recoveryRequest.calldataHashString, "");
+        assertEq(recoveryRequest.calldataHash, "");
     }
 
     function test_CompleteRecovery_SucceedsAlmostExpiry() public {
@@ -127,6 +127,6 @@ contract EmailRecoveryManager_completeRecovery_Test is UnitBase {
         assertEq(recoveryRequest.executeAfter, 0);
         assertEq(recoveryRequest.executeBefore, 0);
         assertEq(recoveryRequest.currentWeight, 0);
-        assertEq(recoveryRequest.calldataHashString, "");
+        assertEq(recoveryRequest.calldataHash, "");
     }
 }

test/unit/EmailRecoveryManager/deInitRecoveryFromModule.t.sol

@@ -47,7 +47,7 @@ contract EmailRecoveryManager_deInitRecoveryFromModule_Test is UnitBase {
         assertEq(recoveryRequest.executeAfter, 0);
         assertEq(recoveryRequest.executeBefore, 0);
         assertEq(recoveryRequest.currentWeight, 0);
-        assertEq(recoveryRequest.calldataHashString, "");
+        assertEq(recoveryRequest.calldataHash, "");
 
         // assert that guardian storage has been cleared successfully for guardian 1
         GuardianStorage memory guardianStorage1 =

test/unit/EmailRecoveryManager/processRecovery.t.sol

@@ -95,7 +95,7 @@ contract EmailRecoveryManager_processRecovery_Test is UnitBase {
         assertEq(recoveryRequest.executeAfter, 0);
         assertEq(recoveryRequest.executeBefore, 0);
         assertEq(recoveryRequest.currentWeight, guardian1Weight);
-        assertEq(recoveryRequest.calldataHashString, "");
+        assertEq(recoveryRequest.calldataHash, "");
     }
 
     function test_ProcessRecovery_InitiatesRecovery() public {
@@ -118,6 +118,6 @@ contract EmailRecoveryManager_processRecovery_Test is UnitBase {
         assertEq(recoveryRequest.executeAfter, block.timestamp + delay);
         assertEq(recoveryRequest.executeBefore, block.timestamp + expiry);
         assertEq(recoveryRequest.currentWeight, guardian1Weight + guardian2Weight);
-        assertEq(recoveryRequest.calldataHashString, calldataHashString);
+        assertEq(recoveryRequest.calldataHash, calldataHash);
     }
 }

test/unit/handlers/EmailRecoverySubjectHandler/validateRecoverySubject.t.sol

@@ -75,10 +75,9 @@ contract EmailRecoverySubjectHandler_validateRecoverySubject_Test is UnitBase {
     }
 
     function test_ValidateRecoverySubject_Succeeds() public view {
-        (address account, string memory calldataHash) = emailRecoveryHandler.validateRecoverySubject(
-            templateIdx, subjectParams, emailRecoveryManagerAddress
-        );
-        assertEq(account, accountAddress);
-        assertEq(calldataHashString, calldataHash);
+        (address accountFromEmail, bytes32 calldataHashFromEmail) = emailRecoveryHandler
+            .validateRecoverySubject(templateIdx, subjectParams, emailRecoveryManagerAddress);
+        assertEq(accountFromEmail, accountAddress);
+        assertEq(calldataHashFromEmail, calldataHash);
     }
 }

test/unit/handlers/SafeRecoverySubjectHandler/validateRecoverySubject.t.sol

@@ -9,13 +9,11 @@ import { SafeUnitBase } from "../../SafeUnitBase.t.sol";
 contract SafeRecoverySubjectHandler_validateRecoverySubject_Test is SafeUnitBase {
     using Strings for uint256;
 
-    string calldataHashString;
     bytes[] subjectParams;
 
     function setUp() public override {
         super.setUp();
 
-        calldataHashString = uint256(calldataHash).toHexString(32);
         subjectParams = new bytes[](4);
         subjectParams[0] = abi.encode(accountAddress);
         subjectParams[1] = abi.encode(owner);
@@ -85,9 +83,9 @@ contract SafeRecoverySubjectHandler_validateRecoverySubject_Test is SafeUnitBase
     }
 
     function test_ValidateRecoverySubject_Succeeds() public view {
-        (address account, string memory calldataHash) = safeRecoverySubjectHandler
+        (address accountFromEmail, bytes32 calldataHashFromEmail) = safeRecoverySubjectHandler
             .validateRecoverySubject(templateIdx, subjectParams, emailRecoveryManagerAddress);
-        assertEq(account, accountAddress);
-        assertEq(calldataHash, calldataHashString);
+        assertEq(accountFromEmail, accountAddress);
+        assertEq(calldataHashFromEmail, calldataHash);
     }
 }