Optimize and remove redundant encodePacked

4 files changed, 23 insertions, 13 deletions

diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/MixinTransactions.sol b/packages/contracts/src/contracts/current/protocol/Exchange/MixinTransactions.sol
index 9bdaa0f8f..f1332363c 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/MixinTransactions.sol
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/MixinTransactions.sol
@@ -53,14 +53,14 @@ contract MixinTransactions is
     /// @return EIP712 hash of the Transaction.
     function hashZeroExTransaction(uint256 salt, address signer, bytes data)
         internal
-        view
+        pure
         returns (bytes32)
     {
-        return keccak256(abi.encodePacked(
+        return keccak256(abi.encode(
             EIP712_ZEROEX_TRANSACTION_SCHEMA_HASH,
             salt,
-            bytes32(signer),
-            keccak256(abi.encodePacked(data))
+            signer,
+            keccak256(data)
         ));
     }
 
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibEIP712.sol b/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibEIP712.sol
index 991137f32..b983347a4 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibEIP712.sol
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibEIP712.sol
@@ -22,6 +22,12 @@ contract LibEIP712 {
     // EIP191 header for EIP712 prefix
     string constant EIP191_HEADER = "\x19\x01";
 
+    // EIP712 Domain Name value
+    string constant EIP712_DOMAIN_NAME = "0x Protocol";
+
+    // EIP712 Domain Version value
+    string constant EIP712_DOMAIN_VERSION = "2";
+
     // Hash of the EIP712 Domain Separator Schema
     bytes32 public constant EIP712_DOMAIN_SEPARATOR_SCHEMA_HASH = keccak256(abi.encodePacked(
         "EIP712Domain(",
@@ -35,16 +41,19 @@ contract LibEIP712 {
     bytes32 public EIP712_DOMAIN_HASH;
 
     constructor ()
-    public
+        public
     {
-        EIP712_DOMAIN_HASH = keccak256(abi.encodePacked(
+        EIP712_DOMAIN_HASH = keccak256(abi.encode(
             EIP712_DOMAIN_SEPARATOR_SCHEMA_HASH,
-            keccak256(abi.encodePacked("0x Protocol")),
-            keccak256(abi.encodePacked("2")),
-            bytes32(address(this))
+            keccak256(bytes(EIP712_DOMAIN_NAME)),
+            keccak256(bytes(EIP712_DOMAIN_VERSION)),
+            address(this)
         ));
     }
 
+    /// @dev Calculates EIP712 encoding for a hash struct in this EIP712 Domain.
+    /// @param hashStruct The EIP712 hash struct.
+    /// @return EIP712 hash applied to this EIP712 Domain.
     function hashEIP712Message(bytes32 hashStruct)
         internal
         view
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibOrder.sol b/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibOrder.sol
index 04374f1d0..b21de6927 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibOrder.sol
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibOrder.sol
@@ -99,6 +99,8 @@ contract LibOrder is
         pure
         returns (bytes32)
     {
+        // Note: changing this to abi.encode results in an error on 0.4.24
+        // UnimplementedFeatureError: Variable inaccessible, too deep inside stack (17)
         return keccak256(abi.encodePacked(
             EIP712_ORDER_SCHEMA_HASH,
             bytes32(order.makerAddress),
@@ -111,8 +113,8 @@ contract LibOrder is
             order.takerFee,
             order.expirationTimeSeconds,
             order.salt,
-            keccak256(abi.encodePacked(order.makerAssetData)),
-            keccak256(abi.encodePacked(order.takerAssetData))
+            keccak256(order.makerAssetData),
+            keccak256(order.takerAssetData)
         ));
     }
 }
diff --git a/packages/contracts/src/utils/transaction_factory.ts b/packages/contracts/src/utils/transaction_factory.ts
index c0a32b83a..19ef4e1bf 100644
--- a/packages/contracts/src/utils/transaction_factory.ts
+++ b/packages/contracts/src/utils/transaction_factory.ts
@@ -1,4 +1,4 @@
-import { crypto, EIP712Schema, EIP712Types, EIP712Utils, generatePseudoRandomSalt } from '@0xproject/order-utils';
+import { EIP712Schema, EIP712Types, EIP712Utils, generatePseudoRandomSalt } from '@0xproject/order-utils';
 import { SignatureType } from '@0xproject/types';
 import * as ethUtil from 'ethereumjs-util';
 
@@ -24,7 +24,6 @@ export class TransactionFactory {
         this._signerBuff = ethUtil.privateToAddress(this._privateKey);
     }
     public newSignedTransaction(data: string, signatureType: SignatureType = SignatureType.EthSign): SignedTransaction {
-        const executeTransactionSchemaHashBuff = EIP712Utils.compileSchema(EIP712_ZEROEX_TRANSACTION_SCHEMA);
         const salt = generatePseudoRandomSalt();
         const signer = `0x${this._signerBuff.toString('hex')}`;
         const executeTransactionData = {