Add missing EIP191 prefix for EIP712

1 files changed, 28 insertions, 2 deletions

diff --git a/packages/contracts/src/utils/transaction_factory.ts b/packages/contracts/src/utils/transaction_factory.ts
index 434611908..1c1029d62 100644
--- a/packages/contracts/src/utils/transaction_factory.ts
+++ b/packages/contracts/src/utils/transaction_factory.ts
@@ -2,9 +2,22 @@ import { crypto, generatePseudoRandomSalt } from '@0xproject/order-utils';
 import { SignatureType } from '@0xproject/types';
 import { BigNumber } from '@0xproject/utils';
 import * as ethUtil from 'ethereumjs-util';
+import * as _ from 'lodash';
 
+import { crypto } from './crypto';
+import { EIP712Utils } from './eip712_utils';
+import { orderUtils } from './order_utils';
 import { signingUtils } from './signing_utils';
-import { SignedTransaction } from './types';
+import { EIP712Schema, SignatureType, SignedTransaction } from './types';
+
+const EIP712_EXECUTE_TRANSACTION_SCHEMA: EIP712Schema = {
+    name: 'ExecuteTransaction',
+    parameters: [
+        { name: 'salt', type: 'uint256' },
+        { name: 'signer', type: 'address' },
+        { name: 'data', type: 'bytes' },
+    ],
+};
 
 export class TransactionFactory {
     private _signerBuff: Buffer;
@@ -16,8 +29,21 @@ export class TransactionFactory {
         this._signerBuff = ethUtil.privateToAddress(this._privateKey);
     }
     public newSignedTransaction(data: string, signatureType: SignatureType = SignatureType.EthSign): SignedTransaction {
+        const executeTransactionSchemaHashBuff = EIP712Utils.compileSchema(EIP712_EXECUTE_TRANSACTION_SCHEMA);
+
         const salt = generatePseudoRandomSalt();
-        const txHash = crypto.solSHA3([this._exchangeAddress, this._signerBuff, salt, ethUtil.toBuffer(data)]);
+        const dataHash = crypto.solSHA3([ethUtil.toBuffer(data)]);
+
+        const executeTransactionDataHash = crypto.solSHA3([
+            executeTransactionSchemaHashBuff,
+            salt,
+            EIP712Utils.pad32Buffer(this._signerBuff),
+            dataHash,
+        ]);
+
+        const executeTransactionMessageHex = `0x${executeTransactionDataHash.toString('hex')}`;
+
+        const txHash = EIP712Utils.createEIP712Message(executeTransactionMessageHex, this._exchangeAddress);
         const signature = signingUtils.signMessage(txHash, this._privateKey, signatureType);
         const signedTx = {
             exchangeAddress: this._exchangeAddress,