From 51a1b9069ddd04a0c5eca3f596531e2416bcf122 Mon Sep 17 00:00:00 2001
From: Sahil Vasava <sahilvasava@gmail.com>
Date: Mon, 5 Aug 2024 22:15:46 +0530
Subject: [PATCH] feat: added counterfactual delegator account support in
 multiTenantAccount and onInstall in DM

---
 src/DelegationManagerBatch.sol |  5 +++
 src/MultiTenantAccount.sol     | 69 ++++++++++++++++++++++++++++++++++
 2 files changed, 74 insertions(+)
 create mode 100644 src/MultiTenantAccount.sol

diff --git a/src/DelegationManagerBatch.sol b/src/DelegationManagerBatch.sol
index 636e77c..ccaa255 100644
--- a/src/DelegationManagerBatch.sol
+++ b/src/DelegationManagerBatch.sol
@@ -82,6 +82,11 @@ contract DelegationManagerBatch is IDelegationManagerBatch, Ownable2Step, Pausab
         _unpause();
     }
 
+    /**
+     * @notice Allows the Kernel v3 to install DM as an executor
+     */
+    function onInstall(bytes calldata) external {}
+
     /**
      * @notice This method is used to cache a delegation's hash onchain for future use
      * @dev This method MUST be called by the delegator
diff --git a/src/MultiTenantAccount.sol b/src/MultiTenantAccount.sol
new file mode 100644
index 0000000..614d7d7
--- /dev/null
+++ b/src/MultiTenantAccount.sol
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.23;
+
+import {PackedUserOperation} from "account-abstraction/interfaces/PackedUserOperation.sol";
+import {IEntryPoint} from "account-abstraction/interfaces/IEntryPoint.sol";
+import {Action, Delegation} from "delegation-framework/src/utils/Types.sol";
+import {IDelegationManagerBatch} from "./interfaces/IDelegationManagerBatch.sol";
+import "./SenderCreator.sol";
+
+import {ECDSA} from "solady/utils/ECDSA.sol";
+
+contract MultiTenantAccount {
+    error ActionFailed(uint256 i, bytes reason);
+    error WrongDelegator();
+    error WrongDelegate();
+
+    IEntryPoint public immutable ep;
+    IDelegationManagerBatch public immutable dm;
+    SenderCreator public immutable deployer;
+
+    constructor(IEntryPoint _ep, IDelegationManagerBatch _dm) {
+        ep = _ep;
+        dm = _dm;
+        deployer = new SenderCreator();
+    }
+
+    function validateUserOp(PackedUserOperation calldata userOp, bytes32 userOpHash, uint256 missingAccountFunds)
+        external
+        returns (uint256)
+    {
+        require(msg.sender == address(ep), "!ep");
+        address caller = address(bytes20(bytes32(userOp.nonce)));
+        address signer = ecrecover(
+            userOpHash,
+            uint8(bytes1(userOp.signature[64])),
+            bytes32(userOp.signature[0:32]),
+            bytes32(userOp.signature[32:64])
+        );
+        // NOTE : since auth is not allowed on validation phase, you should be have paymaster here, we don't send missingAccountFunds
+        // But invoker can still pay for gas when someone staked for the invoker
+        if (caller == signer) {
+            return 0;
+        }
+        signer = ecrecover(
+            ECDSA.toEthSignedMessageHash(userOpHash),
+            uint8(bytes1(userOp.signature[64])),
+            bytes32(userOp.signature[0:32]),
+            bytes32(userOp.signature[32:64])
+        );
+        return caller == signer ? 0 : 1; // return true when caller == signer
+    }
+
+    function executeUserOp(PackedUserOperation calldata userOp, bytes32 userOpHash) external {
+        require(msg.sender == address(ep), "!ep");
+        bytes calldata execData = userOp.callData[4:];
+        (Delegation[] memory delegations, bytes32 executionMode, bytes memory executionData, bytes memory deleGatorInitCode) = abi.decode(execData, (Delegation[], bytes32, bytes, bytes));
+        address signer = address(bytes20(bytes32(userOp.nonce)));
+        if (delegations[0].delegator != signer) {
+            revert WrongDelegator();
+        }
+        if (delegations[0].delegate != address(this)) {
+            revert WrongDelegate();
+        }
+        if (deleGatorInitCode.length > 0) {
+            deployer.createSender(deleGatorInitCode);
+        }
+        dm.redeemDelegation(abi.encode(delegations), executionMode, executionData);
+    }
+}