Update Order utils to use eip712

12 files changed, 121 insertions, 183 deletions

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 d28ef876f..7704e3db4 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibEIP712.sol
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibEIP712.sol
@@ -20,16 +20,19 @@ pragma solidity ^0.4.24;
 
 contract LibEIP712 {
     string public constant EIP191_HEADER = "\x19\x01";
+
     bytes32 public constant EIP712_DOMAIN_SEPARATOR_NAME_HASH = keccak256("0x Protocol");
 
-    bytes32 public constant EIP712_DOMAIN_SEPARATOR_VERSION_HASH = keccak256("1");
+    bytes32 public constant EIP712_DOMAIN_SEPARATOR_VERSION_HASH = keccak256("2");
 
     bytes32 public constant EIP712_DOMAIN_SEPARATOR_SCHEMA_HASH = keccak256(
-        "DomainSeparator(",
-        "string name,",
-        "string version,",
-        "address contract",
-        ")"
+        abi.encodePacked(
+            "DomainSeparator(",
+            "string name,",
+            "string version,",
+            "address contract",
+            ")"
+        )
     );
 
     function createEIP712Message(bytes32 hashStruct)
@@ -41,14 +44,18 @@ contract LibEIP712 {
         // Source: https://github.com/ethereum/EIPs/pull/712
         // TODO: Cache the Domain Separator
         message = keccak256(
-            EIP191_HEADER,
-            keccak256(
-                EIP712_DOMAIN_SEPARATOR_SCHEMA_HASH,
-                EIP712_DOMAIN_SEPARATOR_NAME_HASH,
-                EIP712_DOMAIN_SEPARATOR_VERSION_HASH,
-                bytes32(address(this))
-            ),
-            hashStruct
+            abi.encodePacked(
+                EIP191_HEADER,
+                keccak256(
+                    abi.encodePacked(
+                        EIP712_DOMAIN_SEPARATOR_SCHEMA_HASH,
+                        EIP712_DOMAIN_SEPARATOR_NAME_HASH,
+                        EIP712_DOMAIN_SEPARATOR_VERSION_HASH,
+                        bytes32(address(this))
+                    )
+                ),
+                hashStruct
+            )
         );
         return message;
     }
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 6888918e2..ed532fd59 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibOrder.sol
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibOrder.sol
@@ -89,20 +89,22 @@ contract LibOrder is
         orderHash = createEIP712Message(
             keccak256(
                 abi.encodePacked(
-                EIP712_ORDER_SCHEMA_HASH,
-                bytes32(order.makerAddress),
-                bytes32(order.takerAddress),
-                bytes32(order.feeRecipientAddress),
-                bytes32(order.senderAddress),
-                order.makerAssetAmount,
-                order.takerAssetAmount,
-                order.makerFee,
-                order.takerFee,
-                order.expirationTimeSeconds,
-                order.salt,
-                keccak256(abi.encodePacked(order.makerAssetData)),
-                keccak256(abi.encodePacked(order.takerAssetData))
-        )));
+                    EIP712_ORDER_SCHEMA_HASH,
+                    bytes32(order.makerAddress),
+                    bytes32(order.takerAddress),
+                    bytes32(order.feeRecipientAddress),
+                    bytes32(order.senderAddress),
+                    order.makerAssetAmount,
+                    order.takerAssetAmount,
+                    order.makerFee,
+                    order.takerFee,
+                    order.expirationTimeSeconds,
+                    order.salt,
+                    keccak256(abi.encodePacked(order.makerAssetData)),
+                    keccak256(abi.encodePacked(order.takerAssetData))
+                )
+            )
+        );
         return orderHash;
     }
 }
diff --git a/packages/contracts/src/utils/order_factory.ts b/packages/contracts/src/utils/order_factory.ts
index bfe5013e8..dd02e1f5c 100644
--- a/packages/contracts/src/utils/order_factory.ts
+++ b/packages/contracts/src/utils/order_factory.ts
@@ -1,5 +1,5 @@
 import { generatePseudoRandomSalt, orderHashUtils } from '@0xproject/order-utils';
-import { Order, SignatureType, SignedOrder, UnsignedOrder } from '@0xproject/types';
+import { Order, SignatureType, SignedOrder } from '@0xproject/types';
 import { BigNumber } from '@0xproject/utils';
 import * as _ from 'lodash';
 
@@ -26,7 +26,7 @@ export class OrderFactory {
             takerAddress: constants.NULL_ADDRESS,
             ...this._defaultOrderParams,
             ...customOrderParams,
-        } as any) as UnsignedOrder;
+        } as any) as Order;
         const orderHashBuff = orderHashUtils.getOrderHashBuffer(order);
         const signature = signingUtils.signMessage(orderHashBuff, this._privateKey, signatureType);
         const signedOrder = {
diff --git a/packages/contracts/src/utils/order_utils.ts b/packages/contracts/src/utils/order_utils.ts
index 316350ffb..180761f2c 100644
--- a/packages/contracts/src/utils/order_utils.ts
+++ b/packages/contracts/src/utils/order_utils.ts
@@ -1,29 +1,8 @@
-import { Order, OrderWithoutExchangeAddress, SignedOrder, UnsignedOrder } from '@0xproject/types';
+import { OrderWithoutExchangeAddress, SignedOrder } from '@0xproject/types';
 import { BigNumber } from '@0xproject/utils';
 import ethUtil = require('ethereumjs-util');
-import * as _ from 'lodash';
 
-import { crypto } from './crypto';
-import { EIP712Utils } from './eip712_utils';
-import { CancelOrder, EIP712Schema, MatchOrder } from './types';
-
-const EIP712_ORDER_SCHEMA: EIP712Schema = {
-    name: 'Order',
-    parameters: [
-        { name: 'makerAddress', type: 'address' },
-        { name: 'takerAddress', type: 'address' },
-        { name: 'feeRecipientAddress', type: 'address' },
-        { name: 'senderAddress', type: 'address' },
-        { name: 'makerAssetAmount', type: 'uint256' },
-        { name: 'takerAssetAmount', type: 'uint256' },
-        { name: 'makerFee', type: 'uint256' },
-        { name: 'takerFee', type: 'uint256' },
-        { name: 'expirationTimeSeconds', type: 'uint256' },
-        { name: 'salt', type: 'uint256' },
-        { name: 'makerAssetData', type: 'bytes' },
-        { name: 'takerAssetData', type: 'bytes' },
-    ],
-};
+import { CancelOrder, MatchOrder } from './types';
 
 export const orderUtils = {
     createFill: (signedOrder: SignedOrder, takerAssetFillAmount?: BigNumber) => {
@@ -58,37 +37,6 @@ export const orderUtils = {
         };
         return orderStruct;
     },
-    getOrderSchemaBuffer(): Buffer {
-        return EIP712Utils.compileSchema(EIP712_ORDER_SCHEMA);
-    },
-    getOrderHashBuffer(order: SignedOrder | UnsignedOrder): Buffer {
-        const makerAssetDataHash = crypto.solSHA3([ethUtil.toBuffer(order.makerAssetData)]);
-        const takerAssetDataHash = crypto.solSHA3([ethUtil.toBuffer(order.takerAssetData)]);
-
-        const orderParamsHashBuff = crypto.solSHA3([
-            orderUtils.getOrderSchemaBuffer(),
-            EIP712Utils.pad32Address(order.makerAddress),
-            EIP712Utils.pad32Address(order.takerAddress),
-            EIP712Utils.pad32Address(order.feeRecipientAddress),
-            EIP712Utils.pad32Address(order.senderAddress),
-            order.makerAssetAmount,
-            order.takerAssetAmount,
-            order.makerFee,
-            order.takerFee,
-            order.expirationTimeSeconds,
-            order.salt,
-            makerAssetDataHash,
-            takerAssetDataHash,
-        ]);
-        const orderParamsHashHex = `0x${orderParamsHashBuff.toString('hex')}`;
-        const orderHashBuff = EIP712Utils.createEIP712Message(orderParamsHashHex, order.exchangeAddress);
-        return orderHashBuff;
-    },
-    getOrderHashHex(order: SignedOrder | UnsignedOrder): string {
-        const orderHashBuff = orderUtils.getOrderHashBuffer(order);
-        const orderHashHex = `0x${orderHashBuff.toString('hex')}`;
-        return orderHashHex;
-    },
     createMatchOrders(signedOrderLeft: SignedOrder, signedOrderRight: SignedOrder): MatchOrder {
         const fill = {
             left: orderUtils.getOrderWithoutExchangeAddress(signedOrderLeft),
diff --git a/packages/contracts/src/utils/transaction_factory.ts b/packages/contracts/src/utils/transaction_factory.ts
index 1c1029d62..7aaf3691c 100644
--- a/packages/contracts/src/utils/transaction_factory.ts
+++ b/packages/contracts/src/utils/transaction_factory.ts
@@ -1,14 +1,9 @@
-import { crypto, generatePseudoRandomSalt } from '@0xproject/order-utils';
+import { crypto, EIP712Schema, EIP712Utils, 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 { EIP712Schema, SignatureType, SignedTransaction } from './types';
+import { SignedTransaction } from './types';
 
 const EIP712_EXECUTE_TRANSACTION_SCHEMA: EIP712Schema = {
     name: 'ExecuteTransaction',
@@ -30,20 +25,15 @@ export class TransactionFactory {
     }
     public newSignedTransaction(data: string, signatureType: SignatureType = SignatureType.EthSign): SignedTransaction {
         const executeTransactionSchemaHashBuff = EIP712Utils.compileSchema(EIP712_EXECUTE_TRANSACTION_SCHEMA);
-
         const salt = generatePseudoRandomSalt();
         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 txHash = EIP712Utils.createEIP712Message(executeTransactionDataHash, this._exchangeAddress);
         const signature = signingUtils.signMessage(txHash, this._privateKey, signatureType);
         const signedTx = {
             exchangeAddress: this._exchangeAddress,
diff --git a/packages/contracts/src/utils/types.ts b/packages/contracts/src/utils/types.ts
index 5b7f1bcee..360e1fdbc 100644
--- a/packages/contracts/src/utils/types.ts
+++ b/packages/contracts/src/utils/types.ts
@@ -147,13 +147,3 @@ export interface MatchOrder {
     leftSignature: string;
     rightSignature: string;
 }
-
-export interface EIP712Parameter {
-    name: string;
-    type: string;
-}
-
-export interface EIP712Schema {
-    name: string;
-    parameters: EIP712Parameter[];
-}
diff --git a/packages/contracts/test/exchange/core.ts b/packages/contracts/test/exchange/core.ts
index 91ead93f0..6d62c2b86 100644
--- a/packages/contracts/test/exchange/core.ts
+++ b/packages/contracts/test/exchange/core.ts
@@ -1,5 +1,5 @@
 import { BlockchainLifecycle } from '@0xproject/dev-utils';
-import { assetProxyUtils, crypto, orderHashUtils } from '@0xproject/order-utils';
+import { assetProxyUtils, orderHashUtils } from '@0xproject/order-utils';
 import { AssetProxyId, SignedOrder } from '@0xproject/types';
 import { BigNumber } from '@0xproject/utils';
 import { Web3Wrapper } from '@0xproject/web3-wrapper';
@@ -24,8 +24,7 @@ import { ERC20Wrapper } from '../../src/utils/erc20_wrapper';
 import { ERC721Wrapper } from '../../src/utils/erc721_wrapper';
 import { ExchangeWrapper } from '../../src/utils/exchange_wrapper';
 import { OrderFactory } from '../../src/utils/order_factory';
-import { orderUtils } from '../../src/utils/order_utils';
-import { ContractName, ERC20BalancesByOwner, OrderStatus } from '../../src/utils/types';
+import { ERC20BalancesByOwner } from '../../src/utils/types';
 import { provider, txDefaults, web3Wrapper } from '../../src/utils/web3_wrapper';
 
 chaiSetup.configure();
diff --git a/packages/contracts/test/exchange/libs.ts b/packages/contracts/test/exchange/libs.ts
index b6de4d3b0..ac9020bce 100644
--- a/packages/contracts/test/exchange/libs.ts
+++ b/packages/contracts/test/exchange/libs.ts
@@ -1,5 +1,5 @@
 import { BlockchainLifecycle } from '@0xproject/dev-utils';
-import { assetProxyUtils, orderHashUtils } from '@0xproject/order-utils';
+import { assetProxyUtils, EIP712Utils, orderHashUtils } from '@0xproject/order-utils';
 import { SignedOrder } from '@0xproject/types';
 import { BigNumber } from '@0xproject/utils';
 import * as chai from 'chai';
@@ -10,7 +10,6 @@ import { addressUtils } from '../../src/utils/address_utils';
 import { artifacts } from '../../src/utils/artifacts';
 import { chaiSetup } from '../../src/utils/chai_setup';
 import { constants } from '../../src/utils/constants';
-import { EIP712Utils } from '../../src/utils/eip712_utils';
 import { OrderFactory } from '../../src/utils/order_factory';
 import { provider, txDefaults, web3Wrapper } from '../../src/utils/web3_wrapper';
 
@@ -58,15 +57,15 @@ describe('Exchange libs', () => {
         describe('getOrderSchema', () => {
             it('should output the correct order schema hash', async () => {
                 const orderSchema = await libs.getOrderSchemaHash.callAsync();
-                const orderSchemaBuffer = orderHashUtils._getOrderSchemaHex();
-                const schemaHashHex = `0x${orderSchemaBuffer.toString('hex')}`;
+                const schemaHashBuffer = orderHashUtils._getOrderSchemaBuffer();
+                const schemaHashHex = `0x${schemaHashBuffer.toString('hex')}`;
                 expect(schemaHashHex).to.be.equal(orderSchema);
             });
         });
         describe('getDomainSeparatorSchema', () => {
             it('should output the correct domain separator schema hash', async () => {
                 const domainSeparatorSchema = await libs.getDomainSeparatorSchemaHash.callAsync();
-                const domainSchemaBuffer = EIP712Utils.getDomainSeparatorSchemaBuffer();
+                const domainSchemaBuffer = EIP712Utils._getDomainSeparatorSchemaBuffer();
                 const schemaHashHex = `0x${domainSchemaBuffer.toString('hex')}`;
                 expect(schemaHashHex).to.be.equal(domainSeparatorSchema);
             });
diff --git a/packages/contracts/src/utils/eip712_utils.ts b/packages/order-utils/src/eip712_utils.ts
index 07b45c8af..f7583f8d5 100644
--- a/packages/contracts/src/utils/eip712_utils.ts
+++ b/packages/order-utils/src/eip712_utils.ts
@@ -7,7 +7,8 @@ import { EIP712Schema } from './types';
 
 const EIP191_PREFIX = '\x19\x01';
 const EIP712_DOMAIN_NAME = '0x Protocol';
-const EIP712_DOMAIN_VERSION = '1';
+const EIP712_DOMAIN_VERSION = '2';
+const EIP712_VALUE_LENGTH = 32;
 
 const EIP712_DOMAIN_SCHEMA: EIP712Schema = {
     name: 'DomainSeparator',
@@ -19,6 +20,11 @@ const EIP712_DOMAIN_SCHEMA: EIP712Schema = {
 };
 
 export const EIP712Utils = {
+    /**
+     * Compiles the EIP712Schema and returns the hash of the schema.
+     * @param   schema The EIP712 schema.
+     * @return  The hash of the compiled schema
+     */
     compileSchema(schema: EIP712Schema): Buffer {
         const namedTypes = _.map(schema.parameters, parameter => `${parameter.type} ${parameter.name}`);
         const namedTypesJoined = namedTypes.join(',');
@@ -26,20 +32,31 @@ export const EIP712Utils = {
         const eip712SchemaHashBuffer = crypto.solSHA3([eip712Schema]);
         return eip712SchemaHashBuffer;
     },
-    createEIP712Message(hashStruct: string, contractAddress: string): Buffer {
-        const domainSeparatorHashHex = EIP712Utils.getDomainSeparatorHashHex(contractAddress);
-        const messageBuff = crypto.solSHA3([
-            EIP191_PREFIX,
-            new BigNumber(domainSeparatorHashHex),
-            new BigNumber(hashStruct),
-        ]);
+    /**
+     * Merges the EIP712 hash of a struct with the DomainSeparator for 0x v2.
+     * @param   hashStruct the EIP712 hash of a struct
+     * @param   contractAddress the exchange contract address
+     * @return  The hash of an EIP712 message with domain separator prefixed
+     */
+    createEIP712Message(hashStruct: Buffer, contractAddress: string): Buffer {
+        const domainSeparatorHashBuffer = EIP712Utils._getDomainSeparatorHashBuffer(contractAddress);
+        const messageBuff = crypto.solSHA3([EIP191_PREFIX, domainSeparatorHashBuffer, hashStruct]);
         return messageBuff;
     },
-    getDomainSeparatorSchemaBuffer(): Buffer {
+    pad32Address(address: string): Buffer {
+        const addressBuffer = ethUtil.toBuffer(address);
+        const addressPadded = EIP712Utils.pad32Buffer(addressBuffer);
+        return addressPadded;
+    },
+    pad32Buffer(buffer: Buffer): Buffer {
+        const bufferPadded = ethUtil.setLengthLeft(buffer, EIP712_VALUE_LENGTH);
+        return bufferPadded;
+    },
+    _getDomainSeparatorSchemaBuffer(): Buffer {
         return EIP712Utils.compileSchema(EIP712_DOMAIN_SCHEMA);
     },
-    getDomainSeparatorHashHex(exchangeAddress: string): string {
-        const domainSeparatorSchemaBuffer = EIP712Utils.getDomainSeparatorSchemaBuffer();
+    _getDomainSeparatorHashBuffer(exchangeAddress: string): Buffer {
+        const domainSeparatorSchemaBuffer = EIP712Utils._getDomainSeparatorSchemaBuffer();
         const nameHash = crypto.solSHA3([EIP712_DOMAIN_NAME]);
         const versionHash = crypto.solSHA3([EIP712_DOMAIN_VERSION]);
         const domainSeparatorHashBuff = crypto.solSHA3([
@@ -48,16 +65,6 @@ export const EIP712Utils = {
             versionHash,
             EIP712Utils.pad32Address(exchangeAddress),
         ]);
-        const domainSeparatorHashHex = `0x${domainSeparatorHashBuff.toString('hex')}`;
-        return domainSeparatorHashHex;
-    },
-    pad32Address(address: string): Buffer {
-        const addressBuffer = ethUtil.toBuffer(address);
-        const addressPadded = EIP712Utils.pad32Buffer(addressBuffer);
-        return addressPadded;
-    },
-    pad32Buffer(buffer: Buffer): Buffer {
-        const bufferPadded = ethUtil.setLengthLeft(buffer, 32);
-        return bufferPadded;
+        return domainSeparatorHashBuff;
     },
 };
diff --git a/packages/order-utils/src/index.ts b/packages/order-utils/src/index.ts
index b844fbfcb..caa996621 100644
--- a/packages/order-utils/src/index.ts
+++ b/packages/order-utils/src/index.ts
@@ -4,9 +4,10 @@ export { orderFactory } from './order_factory';
 export { constants } from './constants';
 export { crypto } from './crypto';
 export { generatePseudoRandomSalt } from './salt';
-export { OrderError, MessagePrefixType, MessagePrefixOpts } from './types';
+export { OrderError, MessagePrefixType, MessagePrefixOpts, EIP712Parameter, EIP712Schema } from './types';
 export { AbstractBalanceAndProxyAllowanceFetcher } from './abstract/abstract_balance_and_proxy_allowance_fetcher';
 export { AbstractOrderFilledCancelledFetcher } from './abstract/abstract_order_filled_cancelled_fetcher';
 export { RemainingFillableCalculator } from './remaining_fillable_calculator';
 export { OrderStateUtils } from './order_state_utils';
 export { assetProxyUtils } from './asset_proxy_utils';
+export { EIP712Utils } from './eip712_utils';
diff --git a/packages/order-utils/src/order_hash.ts b/packages/order-utils/src/order_hash.ts
index 2ef746ef8..b2414febc 100644
--- a/packages/order-utils/src/order_hash.ts
+++ b/packages/order-utils/src/order_hash.ts
@@ -9,9 +9,29 @@ import * as _ from 'lodash';
 
 import { assert } from './assert';
 import { crypto } from './crypto';
+import { EIP712Utils } from './eip712_utils';
+import { EIP712Schema } from './types';
 
 const INVALID_TAKER_FORMAT = 'instance.takerAddress is not of a type(s) string';
 
+const EIP712_ORDER_SCHEMA: EIP712Schema = {
+    name: 'Order',
+    parameters: [
+        { name: 'makerAddress', type: 'address' },
+        { name: 'takerAddress', type: 'address' },
+        { name: 'feeRecipientAddress', type: 'address' },
+        { name: 'senderAddress', type: 'address' },
+        { name: 'makerAssetAmount', type: 'uint256' },
+        { name: 'takerAssetAmount', type: 'uint256' },
+        { name: 'makerFee', type: 'uint256' },
+        { name: 'takerFee', type: 'uint256' },
+        { name: 'expirationTimeSeconds', type: 'uint256' },
+        { name: 'salt', type: 'uint256' },
+        { name: 'makerAssetData', type: 'bytes' },
+        { name: 'takerAssetData', type: 'bytes' },
+    ],
+};
+
 export const orderHashUtils = {
     /**
      * Checks if the supplied hex encoded order hash is valid.
@@ -45,7 +65,7 @@ export const orderHashUtils = {
             throw error;
         }
 
-        const orderHashBuff = this.getOrderHashBuff(order);
+        const orderHashBuff = orderHashUtils.getOrderHashBuffer(order);
         const orderHashHex = `0x${orderHashBuff.toString('hex')}`;
         return orderHashHex;
     },
@@ -54,15 +74,16 @@ export const orderHashUtils = {
      * @param   order   An object that conforms to the Order or SignedOrder interface definitions.
      * @return  The resulting orderHash from hashing the supplied order as a Buffer
      */
-    getOrderHashBuff(order: SignedOrder | Order): Buffer {
+    getOrderHashBuffer(order: SignedOrder | Order): Buffer {
         const makerAssetDataHash = crypto.solSHA3([ethUtil.toBuffer(order.makerAssetData)]);
         const takerAssetDataHash = crypto.solSHA3([ethUtil.toBuffer(order.takerAssetData)]);
 
         const orderParamsHashBuff = crypto.solSHA3([
-            order.makerAddress,
-            order.takerAddress,
-            order.feeRecipientAddress,
-            order.senderAddress,
+            orderHashUtils._getOrderSchemaBuffer(),
+            EIP712Utils.pad32Address(order.makerAddress),
+            EIP712Utils.pad32Address(order.takerAddress),
+            EIP712Utils.pad32Address(order.feeRecipientAddress),
+            EIP712Utils.pad32Address(order.senderAddress),
             order.makerAssetAmount,
             order.takerAssetAmount,
             order.makerFee,
@@ -72,46 +93,10 @@ export const orderHashUtils = {
             makerAssetDataHash,
             takerAssetDataHash,
         ]);
-        const orderParamsHashHex = `0x${orderParamsHashBuff.toString('hex')}`;
-        const orderSchemaHashHex = this._getOrderSchemaHex();
-        const domainSeparatorHashHex = this._getDomainSeparatorHashHex(order.exchangeAddress);
-        const domainSeparatorSchemaHex = this._getDomainSeparatorSchemaHex();
-        const orderHashBuff = crypto.solSHA3([
-            new BigNumber(domainSeparatorSchemaHex),
-            new BigNumber(domainSeparatorHashHex),
-            new BigNumber(orderSchemaHashHex),
-            new BigNumber(orderParamsHashHex),
-        ]);
+        const orderHashBuff = EIP712Utils.createEIP712Message(orderParamsHashBuff, order.exchangeAddress);
         return orderHashBuff;
     },
-    _getOrderSchemaHex(): string {
-        const orderSchemaHashBuff = crypto.solSHA3([
-            'Order(',
-            'address makerAddress,',
-            'address takerAddress,',
-            'address feeRecipientAddress,',
-            'address senderAddress,',
-            'uint256 makerAssetAmount,',
-            'uint256 takerAssetAmount,',
-            'uint256 makerFee,',
-            'uint256 takerFee,',
-            'uint256 expirationTimeSeconds,',
-            'uint256 salt,',
-            'bytes makerAssetData,',
-            'bytes takerAssetData,',
-            ')',
-        ]);
-        const schemaHashHex = `0x${orderSchemaHashBuff.toString('hex')}`;
-        return schemaHashHex;
-    },
-    _getDomainSeparatorSchemaHex(): string {
-        const domainSeparatorSchemaHashBuff = crypto.solSHA3(['DomainSeparator(address contract)']);
-        const schemaHashHex = `0x${domainSeparatorSchemaHashBuff.toString('hex')}`;
-        return schemaHashHex;
-    },
-    _getDomainSeparatorHashHex(exchangeAddress: string): string {
-        const domainSeparatorHashBuff = crypto.solSHA3([exchangeAddress]);
-        const domainSeparatorHashHex = `0x${domainSeparatorHashBuff.toString('hex')}`;
-        return domainSeparatorHashHex;
+    _getOrderSchemaBuffer(): Buffer {
+        return EIP712Utils.compileSchema(EIP712_ORDER_SCHEMA);
     },
 };
diff --git a/packages/order-utils/src/types.ts b/packages/order-utils/src/types.ts
index db0bfb249..858c0e18b 100644
--- a/packages/order-utils/src/types.ts
+++ b/packages/order-utils/src/types.ts
@@ -23,3 +23,13 @@ export interface MessagePrefixOpts {
     prefixType: MessagePrefixType;
     shouldAddPrefixBeforeCallingEthSign: boolean;
 }
+
+export interface EIP712Parameter {
+    name: string;
+    type: string;
+}
+
+export interface EIP712Schema {
+    name: string;
+    parameters: EIP712Parameter[];
+}