Merge branch 'main' into ierc165-validation

src/handlers/ERC1271Handler.sol

@@ -2,6 +2,7 @@
 pragma solidity ^0.8.24;
 
 import { IERC1271Upgradeable } from "@openzeppelin/contracts-upgradeable/interfaces/IERC1271Upgradeable.sol";
+import { ECDSA } from "@openzeppelin/contracts/utils/cryptography/ECDSA.sol";
 import { Transaction } from "@matterlabs/zksync-contracts/l2/system-contracts/libraries/TransactionHelper.sol";
 
 import { SignatureDecoder } from "../libraries/SignatureDecoder.sol";
@@ -23,12 +24,18 @@ abstract contract ERC1271Handler is IERC1271Upgradeable, EIP712("Sso1271", "1.0.
   bytes4 private constant _ERC1271_MAGIC = 0x1626ba7e;
 
   /**
-   * @dev Should return whether the signature provided is valid for the provided data
+   * @dev Should return whether the signature provided is valid for the provided data. Does not run validation hooks.
    * @param hash bytes32 - Hash of the data that is signed
-   * @param signature bytes calldata - Validator address concatenated to signature
+   * @param signature bytes calldata - K1 owner signature OR validator address concatenated to signature
    * @return magicValue bytes4 - Magic value if the signature is valid, 0 otherwise
    */
   function isValidSignature(bytes32 hash, bytes memory signature) external view override returns (bytes4 magicValue) {
+    if (signature.length == 65) {
+      (address signer, ECDSA.RecoverError error) = ECDSA.tryRecover(hash, signature);
+      return
+        signer == address(0) || error != ECDSA.RecoverError.NoError || !_k1IsOwner(signer) ? bytes4(0) : _ERC1271_MAGIC;
+    }
+
     (bytes memory decodedSignature, address validator) = SignatureDecoder.decodeSignatureNoHookData(signature);
 
     bytes32 eip712Hash = _hashTypedDataV4(_ssoMessageHash(SsoMessage(hash)));

src/libraries/SessionLib.sol

@@ -179,8 +179,8 @@ library SessionLib {
     // most of the computation needed to validate the session.
 
     // TODO: update fee allowance with the gasleft/refund at the end of execution
-    if (transaction.paymaster != 0) {
-      // If a paymaster is paying the fee, we don't need to check the fee limit
+    // If a paymaster is paying the fee, we don't need to check the fee limit
+    if (transaction.paymaster == 0) {
       uint256 fee = transaction.maxFeePerGas * transaction.gasLimit;
       spec.feeLimit.checkAndUpdate(state.fee, fee, periodId);
     }