Introduce SignerProviderType

This allows the developer to indicate the nuanced signer provider. Some have different implementations (trezor, ledger) and others have different implementations (metamask). Breaking the abstraction of eth_sign. EthSign assumes a spec compliant implementation and can be used as a default

11 files changed, 176 insertions, 118 deletions

diff --git a/packages/0x.js/CHANGELOG.json b/packages/0x.js/CHANGELOG.json
index 913b7a76e..0a10e1ccf 100644
--- a/packages/0x.js/CHANGELOG.json
+++ b/packages/0x.js/CHANGELOG.json
@@ -21,6 +21,9 @@
         "changes": [
             {
                 "note": "Dependencies updated"
+            },
+            {
+                "note": "Update ecSignOrderHashAsync to return the signature as a string for immediate use in contracts"
             }
         ],
         "timestamp": 1532605697
diff --git a/packages/0x.js/src/0x.ts b/packages/0x.js/src/0x.ts
index 2a2b82f63..86859c368 100644
--- a/packages/0x.js/src/0x.ts
+++ b/packages/0x.js/src/0x.ts
@@ -14,13 +14,19 @@ import {
     ecSignOrderHashAsync,
     generatePseudoRandomSalt,
     isValidSignatureAsync,
-    MessagePrefixOpts,
     orderHashUtils,
 } from '@0xproject/order-utils';
 // HACK: Since we export assetDataUtils from ZeroEx and it has AssetProxyId, ERC20AssetData and ERC721AssetData
 // in it's public interface, we need to import these types here.
 // tslint:disable-next-line:no-unused-variable
-import { AssetProxyId, ECSignature, ERC20AssetData, ERC721AssetData, Order, SignedOrder } from '@0xproject/types';
+import {
+    AssetProxyId,
+    ERC20AssetData,
+    ERC721AssetData,
+    Order,
+    SignedOrder,
+    SignerProviderType,
+} from '@0xproject/types';
 import { BigNumber } from '@0xproject/utils';
 import { Web3Wrapper } from '@0xproject/web3-wrapper';
 import { Provider, TransactionReceiptWithDecodedLogs } from 'ethereum-types';
@@ -238,19 +244,19 @@ export class ZeroEx {
      * @param   orderHash       Hex encoded orderHash to sign.
      * @param   signerAddress   The hex encoded Ethereum address you wish to sign it with. This address
      *          must be available via the Provider supplied to 0x.js.
-     * @param   MessagePrefixOpts  Options regarding the desired prefix and whether to add it before calling `eth_sign`
-     * @return  An object containing the Elliptic curve signature parameters generated by signing the orderHash.
+     * @param   SignerProviderType  The type of Signer Provider which implements `eth_sign`. E.g Metamask, Ledger, Trezor or EthSign.
+     * @return  A hex encoded string of the Elliptic curve signature parameters generated by signing the orderHash and signature type.
      */
     public async ecSignOrderHashAsync(
         orderHash: string,
         signerAddress: string,
-        messagePrefixOpts: MessagePrefixOpts,
-    ): Promise<ECSignature> {
+        signerProviderType: SignerProviderType,
+    ): Promise<string> {
         const signature = await ecSignOrderHashAsync(
             this._contractWrappers.getProvider(),
             orderHash,
             signerAddress,
-            messagePrefixOpts,
+            signerProviderType,
         );
         return signature;
     }
diff --git a/packages/0x.js/src/index.ts b/packages/0x.js/src/index.ts
index 95ca07eea..1e5c0c270 100644
--- a/packages/0x.js/src/index.ts
+++ b/packages/0x.js/src/index.ts
@@ -1,12 +1,12 @@
 export { ZeroEx } from './0x';
 
-export { MessagePrefixType, MessagePrefixOpts } from '@0xproject/order-utils';
 export { Web3ProviderEngine, RPCSubprovider } from '@0xproject/subproviders';
 
 export {
     ExchangeContractErrs,
     Order,
     SignedOrder,
+    SignerProviderType,
     ECSignature,
     OrderStateValid,
     OrderStateInvalid,
diff --git a/packages/contracts/test/exchange/signature_validator.ts b/packages/contracts/test/exchange/signature_validator.ts
index bef0547bd..7e9f4fa59 100644
--- a/packages/contracts/test/exchange/signature_validator.ts
+++ b/packages/contracts/test/exchange/signature_validator.ts
@@ -1,6 +1,6 @@
 import { BlockchainLifecycle } from '@0xproject/dev-utils';
-import { addSignedMessagePrefix, assetDataUtils, MessagePrefixType, orderHashUtils } from '@0xproject/order-utils';
-import { RevertReason, SignatureType, SignedOrder } from '@0xproject/types';
+import { addSignedMessagePrefix, assetDataUtils, orderHashUtils } from '@0xproject/order-utils';
+import { RevertReason, SignatureType, SignedOrder, SignerProviderType } from '@0xproject/types';
 import * as chai from 'chai';
 import { LogWithDecodedArgs } from 'ethereum-types';
 import ethUtil = require('ethereumjs-util');
@@ -213,7 +213,7 @@ describe('MixinSignatureValidator', () => {
         it('should return true when SignatureType=EthSign and signature is valid', async () => {
             // Create EthSign signature
             const orderHashHex = orderHashUtils.getOrderHashHex(signedOrder);
-            const orderHashWithEthSignPrefixHex = addSignedMessagePrefix(orderHashHex, MessagePrefixType.EthSign);
+            const orderHashWithEthSignPrefixHex = addSignedMessagePrefix(orderHashHex, SignerProviderType.EthSign);
             const orderHashWithEthSignPrefixBuffer = ethUtil.toBuffer(orderHashWithEthSignPrefixHex);
             const ecSignature = ethUtil.ecsign(orderHashWithEthSignPrefixBuffer, signerPrivateKey);
             // Create 0x signature from EthSign signature
@@ -236,7 +236,7 @@ describe('MixinSignatureValidator', () => {
         it('should return false when SignatureType=EthSign and signature is invalid', async () => {
             // Create EthSign signature
             const orderHashHex = orderHashUtils.getOrderHashHex(signedOrder);
-            const orderHashWithEthSignPrefixHex = addSignedMessagePrefix(orderHashHex, MessagePrefixType.EthSign);
+            const orderHashWithEthSignPrefixHex = addSignedMessagePrefix(orderHashHex, SignerProviderType.EthSign);
             const orderHashWithEthSignPrefixBuffer = ethUtil.toBuffer(orderHashWithEthSignPrefixHex);
             const ecSignature = ethUtil.ecsign(orderHashWithEthSignPrefixBuffer, signerPrivateKey);
             // Create 0x signature from EthSign signature
@@ -385,7 +385,7 @@ describe('MixinSignatureValidator', () => {
         it('should return true when SignatureType=Trezor and signature is valid', async () => {
             // Create Trezor signature
             const orderHashHex = orderHashUtils.getOrderHashHex(signedOrder);
-            const orderHashWithTrezorPrefixHex = addSignedMessagePrefix(orderHashHex, MessagePrefixType.Trezor);
+            const orderHashWithTrezorPrefixHex = addSignedMessagePrefix(orderHashHex, SignerProviderType.Trezor);
             const orderHashWithTrezorPrefixBuffer = ethUtil.toBuffer(orderHashWithTrezorPrefixHex);
             const ecSignature = ethUtil.ecsign(orderHashWithTrezorPrefixBuffer, signerPrivateKey);
             // Create 0x signature from Trezor signature
@@ -408,7 +408,7 @@ describe('MixinSignatureValidator', () => {
         it('should return false when SignatureType=Trezor and signature is invalid', async () => {
             // Create Trezor signature
             const orderHashHex = orderHashUtils.getOrderHashHex(signedOrder);
-            const orderHashWithTrezorPrefixHex = addSignedMessagePrefix(orderHashHex, MessagePrefixType.Trezor);
+            const orderHashWithTrezorPrefixHex = addSignedMessagePrefix(orderHashHex, SignerProviderType.Trezor);
             const orderHashWithTrezorPrefixBuffer = ethUtil.toBuffer(orderHashWithTrezorPrefixHex);
             const ecSignature = ethUtil.ecsign(orderHashWithTrezorPrefixBuffer, signerPrivateKey);
             // Create 0x signature from Trezor signature
diff --git a/packages/order-utils/CHANGELOG.json b/packages/order-utils/CHANGELOG.json
index fa82976ad..60f0855c2 100644
--- a/packages/order-utils/CHANGELOG.json
+++ b/packages/order-utils/CHANGELOG.json
@@ -30,6 +30,9 @@
         "changes": [
             {
                 "note": "Dependencies updated"
+            },
+            {
+                "note": "Update ecSignOrderHashAsync to return signature string with signature type byte"
             }
         ],
         "timestamp": 1532605697
diff --git a/packages/order-utils/src/index.ts b/packages/order-utils/src/index.ts
index 858f500c6..681fbc904 100644
--- a/packages/order-utils/src/index.ts
+++ b/packages/order-utils/src/index.ts
@@ -13,15 +13,7 @@ export { orderFactory } from './order_factory';
 export { constants } from './constants';
 export { crypto } from './crypto';
 export { generatePseudoRandomSalt } from './salt';
-export {
-    CreateOrderOpts,
-    OrderError,
-    MessagePrefixType,
-    MessagePrefixOpts,
-    EIP712Parameter,
-    EIP712Schema,
-    EIP712Types,
-} from './types';
+export { CreateOrderOpts, OrderError, EIP712Parameter, EIP712Schema, EIP712Types } from './types';
 export { AbstractBalanceAndProxyAllowanceFetcher } from './abstract/abstract_balance_and_proxy_allowance_fetcher';
 export { AbstractOrderFilledCancelledFetcher } from './abstract/abstract_order_filled_cancelled_fetcher';
 export { BalanceAndProxyAllowanceLazyStore } from './store/balance_and_proxy_allowance_lazy_store';
diff --git a/packages/order-utils/src/order_factory.ts b/packages/order-utils/src/order_factory.ts
index 14727fd97..bd6bb84b8 100644
--- a/packages/order-utils/src/order_factory.ts
+++ b/packages/order-utils/src/order_factory.ts
@@ -1,14 +1,13 @@
-import { ECSignature, Order, SignedOrder } from '@0xproject/types';
+import { Order, SignedOrder, SignerProviderType } from '@0xproject/types';
 import { BigNumber } from '@0xproject/utils';
 import { Provider } from 'ethereum-types';
-import * as ethUtil from 'ethereumjs-util';
 import * as _ from 'lodash';
 
 import { constants } from './constants';
 import { orderHashUtils } from './order_hash';
 import { generatePseudoRandomSalt } from './salt';
 import { ecSignOrderHashAsync } from './signature_utils';
-import { CreateOrderOpts, MessagePrefixType } from './types';
+import { CreateOrderOpts } from './types';
 
 export const orderFactory = {
     createOrder(
@@ -59,16 +58,12 @@ export const orderFactory = {
             createOrderOpts,
         );
         const orderHash = orderHashUtils.getOrderHashHex(order);
-        const messagePrefixOpts = {
-            prefixType: MessagePrefixType.EthSign,
-            shouldAddPrefixBeforeCallingEthSign: false,
-        };
-        const ecSignature = await ecSignOrderHashAsync(provider, orderHash, makerAddress, messagePrefixOpts);
-        const signature = getVRSHexString(ecSignature);
+        const signature = await ecSignOrderHashAsync(provider, orderHash, makerAddress, SignerProviderType.EthSign);
         const signedOrder: SignedOrder = _.assign(order, { signature });
         return signedOrder;
     },
 };
+<<<<<<< HEAD
 
 function generateDefaultCreateOrderOpts(): {
     takerAddress: string;
@@ -102,3 +97,5 @@ function intToHex(i: number): string {
     const hex = ethUtil.bufferToHex(ethUtil.toBuffer(i));
     return hex;
 }
+=======
+>>>>>>> Introduce SignerProviderType
diff --git a/packages/order-utils/src/signature_utils.ts b/packages/order-utils/src/signature_utils.ts
index 26fb24705..3237259c9 100644
--- a/packages/order-utils/src/signature_utils.ts
+++ b/packages/order-utils/src/signature_utils.ts
@@ -1,5 +1,5 @@
 import { schemas } from '@0xproject/json-schemas';
-import { ECSignature, SignatureType, ValidatorSignature } from '@0xproject/types';
+import { ECSignature, SignatureType, SignerProviderType, ValidatorSignature } from '@0xproject/types';
 import { Web3Wrapper } from '@0xproject/web3-wrapper';
 import { Provider } from 'ethereum-types';
 import * as ethUtil from 'ethereumjs-util';
@@ -10,7 +10,7 @@ import { assert } from './assert';
 import { ExchangeContract } from './generated_contract_wrappers/exchange';
 import { IValidatorContract } from './generated_contract_wrappers/i_validator';
 import { IWalletContract } from './generated_contract_wrappers/i_wallet';
-import { MessagePrefixOpts, MessagePrefixType, OrderError } from './types';
+import { OrderError } from './types';
 import { utils } from './utils';
 
 /**
@@ -48,7 +48,7 @@ export async function isValidSignatureAsync(
 
         case SignatureType.EthSign: {
             const ecSignature = parseECSignature(signature);
-            const prefixedMessageHex = addSignedMessagePrefix(data, MessagePrefixType.EthSign);
+            const prefixedMessageHex = addSignedMessagePrefix(data, SignerProviderType.EthSign);
             return isValidECSignature(prefixedMessageHex, ecSignature, signerAddress);
         }
 
@@ -72,7 +72,7 @@ export async function isValidSignatureAsync(
         }
 
         case SignatureType.Trezor: {
-            const prefixedMessageHex = addSignedMessagePrefix(data, MessagePrefixType.Trezor);
+            const prefixedMessageHex = addSignedMessagePrefix(data, SignerProviderType.Trezor);
             const ecSignature = parseECSignature(signature);
             return isValidECSignature(prefixedMessageHex, ecSignature, signerAddress);
         }
@@ -191,22 +191,22 @@ export function isValidECSignature(data: string, signature: ECSignature, signerA
 }
 
 /**
- * Signs an orderHash and returns it's elliptic curve signature.
+ * Signs an orderHash and returns it's elliptic curve signature and signature type.
  * This method currently supports TestRPC, Geth and Parity above and below V1.6.6
  * @param   orderHash       Hex encoded orderHash to sign.
  * @param   signerAddress   The hex encoded Ethereum address you wish to sign it with. This address
  *          must be available via the Provider supplied to 0x.js.
- * @param   hashPrefixOpts Different signers add/require different prefixes be appended to the message being signed.
+ * @param   messagePrefixOpts Different signers add/require different prefixes be prepended to the message being signed.
  *          Since we cannot know ahead of time which signer you are using, you must supply both a prefixType and
  *          whether it must be added before calling `eth_sign` (some signers add it themselves)
- * @return  An object containing the Elliptic curve signature parameters generated by signing the orderHash.
+ * @return  A hex encoded string containing the Elliptic curve signature generated by signing the orderHash and the Signature Type.
  */
 export async function ecSignOrderHashAsync(
     provider: Provider,
     orderHash: string,
     signerAddress: string,
-    messagePrefixOpts: MessagePrefixOpts,
-): Promise<ECSignature> {
+    signerProviderType: SignerProviderType,
+): Promise<string> {
     assert.isWeb3Provider('provider', provider);
     assert.isHexString('orderHash', orderHash);
     assert.isETHAddressHex('signerAddress', signerAddress);
@@ -215,8 +215,9 @@ export async function ecSignOrderHashAsync(
     const normalizedSignerAddress = signerAddress.toLowerCase();
 
     let msgHashHex = orderHash;
-    const prefixedMsgHashHex = addSignedMessagePrefix(orderHash, messagePrefixOpts.prefixType);
-    if (messagePrefixOpts.shouldAddPrefixBeforeCallingEthSign) {
+    const prefixedMsgHashHex = addSignedMessagePrefix(orderHash, signerProviderType);
+    // Metamask incorrectly implements eth_sign and does not prefix the message as per the spec
+    if (signerProviderType === SignerProviderType.Metamask) {
         msgHashHex = prefixedMsgHashHex;
     }
     const signature = await web3Wrapper.signMessageAsync(normalizedSignerAddress, msgHashHex);
@@ -231,7 +232,8 @@ export async function ecSignOrderHashAsync(
     if (_.includes(validVParamValues, ecSignatureVRS.v)) {
         const isValidVRSSignature = isValidECSignature(prefixedMsgHashHex, ecSignatureVRS, normalizedSignerAddress);
         if (isValidVRSSignature) {
-            return ecSignatureVRS;
+            const convertedSignatureHex = convertECSignatureToSignatureHex(ecSignatureVRS, signerProviderType);
+            return convertedSignatureHex;
         }
     }
 
@@ -239,13 +241,45 @@ export async function ecSignOrderHashAsync(
     if (_.includes(validVParamValues, ecSignatureRSV.v)) {
         const isValidRSVSignature = isValidECSignature(prefixedMsgHashHex, ecSignatureRSV, normalizedSignerAddress);
         if (isValidRSVSignature) {
-            return ecSignatureRSV;
+            const convertedSignatureHex = convertECSignatureToSignatureHex(ecSignatureRSV, signerProviderType);
+            return convertedSignatureHex;
         }
     }
 
     throw new Error(OrderError.InvalidSignature);
 }
-
+/**
+ * Combines ECSignature with V,R,S and the relevant signature type for use in 0x protocol
+ * @param ecSignature The ECSignature of the signed data
+ * @param messagePrefixType The MessagePrefixType of the signed data
+ * @return Hex encoded string of signature with Signature Type
+ */
+export function convertECSignatureToSignatureHex(
+    ecSignature: ECSignature,
+    signerProviderType: SignerProviderType,
+): string {
+    const signatureBuffer = Buffer.concat([
+        ethUtil.toBuffer(ecSignature.v),
+        ethUtil.toBuffer(ecSignature.r),
+        ethUtil.toBuffer(ecSignature.s),
+    ]);
+    const signatureHex = `0x${signatureBuffer.toString('hex')}`;
+    const signatureType =
+        signerProviderType === SignerProviderType.Trezor ? SignatureType.Trezor : SignatureType.EthSign;
+    const signatureWithType = convertToSignatureWithType(signatureHex, signatureType);
+    return signatureWithType;
+}
+/**
+ * Combines the signature proof and the Signature Type.
+ * @param signature The hex encoded signature proof
+ * @param type The signature type, i.e EthSign, Trezor, Wallet etc.
+ * @return Hex encoded string of signature proof with Signature Type
+ */
+export function convertToSignatureWithType(signature: string, type: SignatureType): string {
+    const signatureBuffer = Buffer.concat([ethUtil.toBuffer(signature), ethUtil.toBuffer(type)]);
+    const signatureHex = `0x${signatureBuffer.toString('hex')}`;
+    return signatureHex;
+}
 /**
  * Adds the relevant prefix to the message being signed.
  * @param message Message to sign
@@ -253,29 +287,25 @@ export async function ecSignOrderHashAsync(
  *                          specific message prefixes.
  * @return Prefixed message
  */
-export function addSignedMessagePrefix(message: string, messagePrefixType: MessagePrefixType): string {
+export function addSignedMessagePrefix(message: string, signerProviderType: SignerProviderType): string {
     assert.isString('message', message);
-    assert.doesBelongToStringEnum('messagePrefixType', messagePrefixType, MessagePrefixType);
-    switch (messagePrefixType) {
-        case MessagePrefixType.None:
-            return message;
-
-        case MessagePrefixType.EthSign: {
+    assert.doesBelongToStringEnum('signerProviderType', signerProviderType, SignerProviderType);
+    switch (signerProviderType) {
+        case SignerProviderType.Metamask:
+        case SignerProviderType.EthSign: {
             const msgBuff = ethUtil.toBuffer(message);
             const prefixedMsgBuff = ethUtil.hashPersonalMessage(msgBuff);
             const prefixedMsgHex = ethUtil.bufferToHex(prefixedMsgBuff);
             return prefixedMsgHex;
         }
-
-        case MessagePrefixType.Trezor: {
+        case SignerProviderType.Trezor: {
             const msgBuff = ethUtil.toBuffer(message);
             const prefixedMsgBuff = hashTrezorPersonalMessage(msgBuff);
             const prefixedMsgHex = ethUtil.bufferToHex(prefixedMsgBuff);
             return prefixedMsgHex;
         }
-
         default:
-            throw new Error(`Unrecognized MessagePrefixType: ${messagePrefixType}`);
+            throw new Error(`Unrecognized SignerProviderType: ${signerProviderType}`);
     }
 }
 
diff --git a/packages/order-utils/src/types.ts b/packages/order-utils/src/types.ts
index f44e94349..1fbd8cf7b 100644
--- a/packages/order-utils/src/types.ts
+++ b/packages/order-utils/src/types.ts
@@ -4,28 +4,6 @@ export enum OrderError {
     InvalidSignature = 'INVALID_SIGNATURE',
 }
 
-/**
- * The requisite message prefix (is any) to add to an `eth_sign` request.
- */
-export enum MessagePrefixType {
-    None = 'NONE',
-    EthSign = 'ETH_SIGN',
-    Trezor = 'TREZOR',
-}
-
-/**
- * Options related to message prefixing of messages sent to `eth_sign`
- * Some signers prepend a message prefix (e.g Parity Signer, Ledger, TestRPC), while
- * others require it already be prepended (e.g Metamask). In addition, different signers
- * expect slightly different prefixes (See: https://github.com/ethereum/go-ethereum/issues/14794).
- * Depending on the signer that will receive your signing request, you must specify the
- * desired prefix and whether it should be added before making the `eth_sign` request.
- */
-export interface MessagePrefixOpts {
-    prefixType: MessagePrefixType;
-    shouldAddPrefixBeforeCallingEthSign: boolean;
-}
-
 export enum TradeSide {
     Maker = 'maker',
     Taker = 'taker',
diff --git a/packages/order-utils/test/signature_utils_test.ts b/packages/order-utils/test/signature_utils_test.ts
index baae2b414..179905b18 100644
--- a/packages/order-utils/test/signature_utils_test.ts
+++ b/packages/order-utils/test/signature_utils_test.ts
@@ -1,3 +1,4 @@
+import { SignerProviderType } from '@0xproject/types';
 import { BigNumber } from '@0xproject/utils';
 import * as chai from 'chai';
 import { JSONRPCErrorCallback, JSONRPCRequestPayload } from 'ethereum-types';
@@ -5,7 +6,7 @@ import * as _ from 'lodash';
 import 'mocha';
 import * as Sinon from 'sinon';
 
-import { ecSignOrderHashAsync, generatePseudoRandomSalt, MessagePrefixType } from '../src';
+import { ecSignOrderHashAsync, generatePseudoRandomSalt } from '../src';
 import { isValidECSignature, isValidSignatureAsync } from '../src/signature_utils';
 
 import { chaiSetup } from './utils/chai_setup';
@@ -119,32 +120,28 @@ describe('Signature utils', () => {
             _.each(stubs, s => s.restore());
             stubs = [];
         });
-        it('Should return the correct ECSignature', async () => {
+        it('Should return the correct Signature', async () => {
             const orderHash = '0x6927e990021d23b1eb7b8789f6a6feaf98fe104bb0cf8259421b79f9a34222b0';
-            const expectedECSignature = {
-                v: 27,
-                r: '0x61a3ed31b43c8780e905a260a35faefcc527be7516aa11c0256729b5b351bc33',
-                s: '0x40349190569279751135161d22529dc25add4f6069af05be04cacbda2ace2254',
-            };
-            const messagePrefixOpts = {
-                prefixType: MessagePrefixType.EthSign,
-                shouldAddPrefixBeforeCallingEthSign: false,
-            };
-            const ecSignature = await ecSignOrderHashAsync(provider, orderHash, makerAddress, messagePrefixOpts);
-            expect(ecSignature).to.deep.equal(expectedECSignature);
-        });
-        it('should return the correct ECSignature for signatureHex concatenated as R + S + V', async () => {
+            const expectedSignature =
+                '0x1b61a3ed31b43c8780e905a260a35faefcc527be7516aa11c0256729b5b351bc3340349190569279751135161d22529dc25add4f6069af05be04cacbda2ace225403';
+            const ecSignature = await ecSignOrderHashAsync(
+                provider,
+                orderHash,
+                makerAddress,
+                SignerProviderType.EthSign,
+            );
+            expect(ecSignature).to.equal(expectedSignature);
+        });
+        it('should return the correct Signature for signatureHex concatenated as R + S + V', async () => {
             const orderHash = '0x34decbedc118904df65f379a175bb39ca18209d6ce41d5ed549d54e6e0a95004';
-            const expectedECSignature = {
-                v: 27,
-                r: '0x117902c86dfb95fe0d1badd983ee166ad259b27acb220174cbb4460d87287113',
-                s: '0x7feabdfe76e05924b484789f79af4ee7fa29ec006cedce1bbf369320d034e10b',
-            };
+            const expectedSignature =
+                '0x1b117902c86dfb95fe0d1badd983ee166ad259b27acb220174cbb4460d872871137feabdfe76e05924b484789f79af4ee7fa29ec006cedce1bbf369320d034e10b03';
 
             const fakeProvider = {
                 async sendAsync(payload: JSONRPCRequestPayload, callback: JSONRPCErrorCallback): Promise<void> {
                     if (payload.method === 'eth_sign') {
                         const [address, message] = payload.params;
+                        expect(message).to.equal(orderHash);
                         const signature = await web3Wrapper.signMessageAsync(address, message);
                         // tslint:disable-next-line:custom-no-magic-numbers
                         const rsvHex = `0x${signature.substr(130)}${signature.substr(2, 128)}`;
@@ -158,21 +155,18 @@ describe('Signature utils', () => {
                     }
                 },
             };
-
-            const messagePrefixOpts = {
-                prefixType: MessagePrefixType.EthSign,
-                shouldAddPrefixBeforeCallingEthSign: false,
-            };
-            const ecSignature = await ecSignOrderHashAsync(fakeProvider, orderHash, makerAddress, messagePrefixOpts);
-            expect(ecSignature).to.deep.equal(expectedECSignature);
-        });
-        it('should return the correct ECSignature for signatureHex concatenated as V + R + S', async () => {
+            const ecSignature = await ecSignOrderHashAsync(
+                fakeProvider,
+                orderHash,
+                makerAddress,
+                SignerProviderType.EthSign,
+            );
+            expect(ecSignature).to.equal(expectedSignature);
+        });
+        it('should return the correct Signature for signatureHex concatenated as V + R + S', async () => {
             const orderHash = '0x34decbedc118904df65f379a175bb39ca18209d6ce41d5ed549d54e6e0a95004';
-            const expectedECSignature = {
-                v: 27,
-                r: '0x117902c86dfb95fe0d1badd983ee166ad259b27acb220174cbb4460d87287113',
-                s: '0x7feabdfe76e05924b484789f79af4ee7fa29ec006cedce1bbf369320d034e10b',
-            };
+            const expectedSignature =
+                '0x1b117902c86dfb95fe0d1badd983ee166ad259b27acb220174cbb4460d872871137feabdfe76e05924b484789f79af4ee7fa29ec006cedce1bbf369320d034e10b03';
             const fakeProvider = {
                 async sendAsync(payload: JSONRPCRequestPayload, callback: JSONRPCErrorCallback): Promise<void> {
                     if (payload.method === 'eth_sign') {
@@ -189,12 +183,57 @@ describe('Signature utils', () => {
                 },
             };
 
-            const messagePrefixOpts = {
-                prefixType: MessagePrefixType.EthSign,
-                shouldAddPrefixBeforeCallingEthSign: false,
+            const ecSignature = await ecSignOrderHashAsync(
+                fakeProvider,
+                orderHash,
+                makerAddress,
+                SignerProviderType.EthSign,
+            );
+            expect(ecSignature).to.equal(expectedSignature);
+        });
+        // Note this is due to a bug in Metamask where it does not prefix before signing, this is a known issue and is to be fixed in the future
+        it('should receive a payload modified with a prefix when Metamask is SignerProviderType', async () => {
+            const orderHash = '0x34decbedc118904df65f379a175bb39ca18209d6ce41d5ed549d54e6e0a95004';
+            const orderHashPrefixed = '0xae70f31d26096291aa681b26cb7574563956221d0b4213631e1ef9df675d4cba';
+            const expectedSignature =
+                '0x1b117902c86dfb95fe0d1badd983ee166ad259b27acb220174cbb4460d872871137feabdfe76e05924b484789f79af4ee7fa29ec006cedce1bbf369320d034e10b03';
+            const fakeProvider = {
+                async sendAsync(payload: JSONRPCRequestPayload, callback: JSONRPCErrorCallback): Promise<void> {
+                    if (payload.method === 'eth_sign') {
+                        const [address, message] = payload.params;
+                        expect(message).to.equal(orderHashPrefixed);
+                        const signature =
+                            '0x1b117902c86dfb95fe0d1badd983ee166ad259b27acb220174cbb4460d872871137feabdfe76e05924b484789f79af4ee7fa29ec006cedce1bbf369320d034e10b';
+                        callback(null, {
+                            id: 42,
+                            jsonrpc: '2.0',
+                            result: signature,
+                        });
+                    } else {
+                        callback(null, { id: 42, jsonrpc: '2.0', result: [makerAddress] });
+                    }
+                },
             };
-            const ecSignature = await ecSignOrderHashAsync(fakeProvider, orderHash, makerAddress, messagePrefixOpts);
-            expect(ecSignature).to.deep.equal(expectedECSignature);
+
+            const ecSignature = await ecSignOrderHashAsync(
+                fakeProvider,
+                orderHash,
+                makerAddress,
+                SignerProviderType.Metamask,
+            );
+            expect(ecSignature).to.equal(expectedSignature);
+        });
+        it('should return a valid signature', async () => {
+            const orderHash = '0x34decbedc118904df65f379a175bb39ca18209d6ce41d5ed549d54e6e0a95004';
+            const ecSignature = await ecSignOrderHashAsync(
+                provider,
+                orderHash,
+                makerAddress,
+                SignerProviderType.EthSign,
+            );
+
+            const isValidSignature = await isValidSignatureAsync(provider, orderHash, ecSignature, makerAddress);
+            expect(isValidSignature).to.be.true();
         });
     });
 });
diff --git a/packages/types/src/index.ts b/packages/types/src/index.ts
index 7774b61b0..ba384dbb8 100644
--- a/packages/types/src/index.ts
+++ b/packages/types/src/index.ts
@@ -143,6 +143,16 @@ export enum SignatureType {
 }
 
 /**
+ * The Signer Provider Type. Some Signer implementations use different message prefixes or implement different
+ * eth_sign behaviour. Note EthSign is compatible with the Ledger device.
+ */
+export enum SignerProviderType {
+    EthSign = 'ETH_SIGN',
+    Metamask = 'METAMASK',
+    Trezor = 'TREZOR',
+}
+
+/**
  * Elliptic Curve signature
  */
 export interface ECSignature {