1 files changed, 22 insertions, 0 deletions
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MTransactions.sol b/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MTransactions.sol
index f2b5e4b16..4f61a4945 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MTransactions.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MTransactions.sol
@@ -23,6 +23,28 @@ import "../interfaces/ITransactions.sol";
 contract MTransactions is
     ITransactions
 {
+    // Hash for the EIP712 ZeroEx Transaction Schema
+    bytes32 constant internal EIP712_ZEROEX_TRANSACTION_SCHEMA_HASH = keccak256(abi.encodePacked(
+        "ZeroExTransaction(",
+        "uint256 salt,",
+        "address signerAddress,",
+        "bytes data",
+        ")"
+    ));
+
+    /// @dev Calculates EIP712 hash of the Transaction.
+    /// @param salt Arbitrary number to ensure uniqueness of transaction hash.
+    /// @param signerAddress Address of transaction signer.
+    /// @param data AbiV2 encoded calldata.
+    /// @return EIP712 hash of the Transaction.
+    function hashZeroExTransaction(
+        uint256 salt,
+        address signerAddress,
+        bytes memory data
+    )
+        internal
+        pure
+        returns (bytes32 result);
 
     /// @dev The current function will be called in the context of this address (either 0x transaction signer or `msg.sender`).
     ///      If calling a fill function, this address will represent the taker.