Merge pull request #914 from 0xProject/feature/0x.js/ec-signature-string

0x.js Return signature as a hex encoded string

13 files changed, 225 insertions, 140 deletions

diff --git a/packages/0x.js/CHANGELOG.json b/packages/0x.js/CHANGELOG.json
index 913b7a76e..a1bdcc506 100644
--- a/packages/0x.js/CHANGELOG.json
+++ b/packages/0x.js/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "1.0.1-rc.4",
+        "changes": [
+            {
+                "pr": 914,
+                "note": "Update ecSignOrderHashAsync to return the signature as a string for immediate use in contracts"
+            }
+        ]
+    },
+    {
         "version": "1.0.1-rc.3",
         "changes": [
             {
diff --git a/packages/0x.js/src/0x.ts b/packages/0x.js/src/0x.ts
index 2a2b82f63..48d00c1ac 100644
--- a/packages/0x.js/src/0x.ts
+++ b/packages/0x.js/src/0x.ts
@@ -14,13 +14,12 @@ 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, SignerType } from '@0xproject/types';
 import { BigNumber } from '@0xproject/utils';
 import { Web3Wrapper } from '@0xproject/web3-wrapper';
 import { Provider, TransactionReceiptWithDecodedLogs } from 'ethereum-types';
@@ -238,19 +237,21 @@ 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   signerType the signer type that will perform the `eth_sign` operation. E.g Default, Metamask, Ledger or Trezor.
+     *          Some implementations exhibit different behaviour. Default will assume a spec compliant eth_sign implementation.
+     *          This parameter is defaulted to `SignerType.Default`.
+     * @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> {
+        signerType: SignerType = SignerType.Default,
+    ): Promise<string> {
         const signature = await ecSignOrderHashAsync(
             this._contractWrappers.getProvider(),
             orderHash,
             signerAddress,
-            messagePrefixOpts,
+            signerType,
         );
         return signature;
     }
diff --git a/packages/0x.js/src/index.ts b/packages/0x.js/src/index.ts
index 95ca07eea..2ba60e730 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,
+    SignerType,
     ECSignature,
     OrderStateValid,
     OrderStateInvalid,
diff --git a/packages/contracts/test/exchange/signature_validator.ts b/packages/contracts/test/exchange/signature_validator.ts
index bef0547bd..56a06c247 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, SignerType } 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, SignerType.Default);
             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, SignerType.Default);
             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, SignerType.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, SignerType.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..6f59580b3 100644
--- a/packages/order-utils/CHANGELOG.json
+++ b/packages/order-utils/CHANGELOG.json
@@ -1,5 +1,15 @@
 [
     {
+        "version": "1.0.1-rc.4",
+        "changes": [
+            {
+                "pr": 914,
+                "note":
+                    "Update ecSignOrderHashAsync to return signature string with signature type byte. Removes messagePrefixOpts."
+            }
+        ]
+    },
+    {
         "version": "1.0.1-rc.3",
         "changes": [
             {
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..4a6f3924b 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, SignerType } 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(
@@ -59,12 +58,7 @@ 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, SignerType.Default);
         const signedOrder: SignedOrder = _.assign(order, { signature });
         return signedOrder;
     },
@@ -89,16 +83,3 @@ function generateDefaultCreateOrderOpts(): {
         expirationTimeSeconds: constants.INFINITE_TIMESTAMP_SEC,
     };
 }
-
-function getVRSHexString(ecSignature: ECSignature): string {
-    const ETH_SIGN_SIGNATURE_TYPE = '03';
-    const vrs = `${intToHex(ecSignature.v)}${ethUtil.stripHexPrefix(ecSignature.r)}${ethUtil.stripHexPrefix(
-        ecSignature.s,
-    )}${ETH_SIGN_SIGNATURE_TYPE}`;
-    return vrs;
-}
-
-function intToHex(i: number): string {
-    const hex = ethUtil.bufferToHex(ethUtil.toBuffer(i));
-    return hex;
-}
diff --git a/packages/order-utils/src/signature_utils.ts b/packages/order-utils/src/signature_utils.ts
index 26fb24705..870aef2ed 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, SignerType, 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, SignerType.Default);
             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, SignerType.Trezor);
             const ecSignature = parseECSignature(signature);
             return isValidECSignature(prefixedMessageHex, ecSignature, signerAddress);
         }
@@ -191,22 +191,21 @@ 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.
- *          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.
+ * @param   signerType Different signers add/require different prefixes to be prepended to the message being signed.
+ *          Since we cannot know ahead of time which signer you are using, you must supply a SignerType.
+ * @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> {
+    signerType: SignerType,
+): Promise<string> {
     assert.isWeb3Provider('provider', provider);
     assert.isHexString('orderHash', orderHash);
     assert.isETHAddressHex('signerAddress', signerAddress);
@@ -215,8 +214,10 @@ export async function ecSignOrderHashAsync(
     const normalizedSignerAddress = signerAddress.toLowerCase();
 
     let msgHashHex = orderHash;
-    const prefixedMsgHashHex = addSignedMessagePrefix(orderHash, messagePrefixOpts.prefixType);
-    if (messagePrefixOpts.shouldAddPrefixBeforeCallingEthSign) {
+    const prefixedMsgHashHex = addSignedMessagePrefix(orderHash, signerType);
+    // Metamask incorrectly implements eth_sign and does not prefix the message as per the spec
+    // Source: https://github.com/MetaMask/metamask-extension/commit/a9d36860bec424dcee8db043d3e7da6a5ff5672e
+    if (signerType === SignerType.Metamask) {
         msgHashHex = prefixedMsgHashHex;
     }
     const signature = await web3Wrapper.signMessageAsync(normalizedSignerAddress, msgHashHex);
@@ -225,57 +226,97 @@ export async function ecSignOrderHashAsync(
     // v + r + s OR r + s + v, and different clients (even different versions of the same client)
     // return the signature params in different orders. In order to support all client implementations,
     // we parse the signature in both ways, and evaluate if either one is a valid signature.
+    // r + s + v is the most prevalent format from eth_sign, so we attempt this first.
     // tslint:disable-next-line:custom-no-magic-numbers
     const validVParamValues = [27, 28];
+    const ecSignatureRSV = parseSignatureHexAsRSV(signature);
+    if (_.includes(validVParamValues, ecSignatureRSV.v)) {
+        const isValidRSVSignature = isValidECSignature(prefixedMsgHashHex, ecSignatureRSV, normalizedSignerAddress);
+        if (isValidRSVSignature) {
+            const convertedSignatureHex = convertECSignatureToSignatureHex(ecSignatureRSV, signerType);
+            return convertedSignatureHex;
+        }
+    }
     const ecSignatureVRS = parseSignatureHexAsVRS(signature);
     if (_.includes(validVParamValues, ecSignatureVRS.v)) {
         const isValidVRSSignature = isValidECSignature(prefixedMsgHashHex, ecSignatureVRS, normalizedSignerAddress);
         if (isValidVRSSignature) {
-            return ecSignatureVRS;
+            const convertedSignatureHex = convertECSignatureToSignatureHex(ecSignatureVRS, signerType);
+            return convertedSignatureHex;
         }
     }
 
-    const ecSignatureRSV = parseSignatureHexAsRSV(signature);
-    if (_.includes(validVParamValues, ecSignatureRSV.v)) {
-        const isValidRSVSignature = isValidECSignature(prefixedMsgHashHex, ecSignatureRSV, normalizedSignerAddress);
-        if (isValidRSVSignature) {
-            return ecSignatureRSV;
+    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 signerType The SignerType of the signed data
+ * @return Hex encoded string of signature (v,r,s) with Signature Type
+ */
+export function convertECSignatureToSignatureHex(ecSignature: ECSignature, signerType: SignerType): string {
+    const signatureBuffer = Buffer.concat([
+        ethUtil.toBuffer(ecSignature.v),
+        ethUtil.toBuffer(ecSignature.r),
+        ethUtil.toBuffer(ecSignature.s),
+    ]);
+    const signatureHex = `0x${signatureBuffer.toString('hex')}`;
+    let signatureType;
+    switch (signerType) {
+        case SignerType.Metamask:
+        case SignerType.Ledger:
+        case SignerType.Default: {
+            signatureType = SignatureType.EthSign;
+            break;
+        }
+        case SignerType.Trezor: {
+            signatureType = SignatureType.Trezor;
+            break;
         }
+        default:
+            throw new Error(`Unrecognized SignerType: ${signerType}`);
     }
-
-    throw new Error(OrderError.InvalidSignature);
+    const signatureWithType = convertToSignatureWithType(signatureHex, signatureType);
+    return signatureWithType;
+}
+/**
+ * Combines the signature proof and the Signature Type.
+ * @param signature The hex encoded signature proof
+ * @param signatureType The signature type, i.e EthSign, Trezor, Wallet etc.
+ * @return Hex encoded string of signature proof with Signature Type
+ */
+export function convertToSignatureWithType(signature: string, signatureType: SignatureType): string {
+    const signatureBuffer = Buffer.concat([ethUtil.toBuffer(signature), ethUtil.toBuffer(signatureType)]);
+    const signatureHex = `0x${signatureBuffer.toString('hex')}`;
+    return signatureHex;
 }
-
 /**
  * Adds the relevant prefix to the message being signed.
  * @param message Message to sign
- * @param messagePrefixType The type of message prefix to add. Different signers expect
+ * @param signerType The type of message prefix to add for a given SignerType. Different signers expect
  *                          specific message prefixes.
  * @return Prefixed message
  */
-export function addSignedMessagePrefix(message: string, messagePrefixType: MessagePrefixType): string {
+export function addSignedMessagePrefix(message: string, signerType: SignerType = SignerType.Default): string {
     assert.isString('message', message);
-    assert.doesBelongToStringEnum('messagePrefixType', messagePrefixType, MessagePrefixType);
-    switch (messagePrefixType) {
-        case MessagePrefixType.None:
-            return message;
-
-        case MessagePrefixType.EthSign: {
+    assert.doesBelongToStringEnum('signerType', signerType, SignerType);
+    switch (signerType) {
+        case SignerType.Metamask:
+        case SignerType.Ledger:
+        case SignerType.Default: {
             const msgBuff = ethUtil.toBuffer(message);
             const prefixedMsgBuff = ethUtil.hashPersonalMessage(msgBuff);
             const prefixedMsgHex = ethUtil.bufferToHex(prefixedMsgBuff);
             return prefixedMsgHex;
         }
-
-        case MessagePrefixType.Trezor: {
+        case SignerType.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 SignerType: ${signerType}`);
     }
 }
 
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..a25d2afd6 100644
--- a/packages/order-utils/test/signature_utils_test.ts
+++ b/packages/order-utils/test/signature_utils_test.ts
@@ -1,3 +1,4 @@
+import { SignerType } from '@0xproject/types';
 import { BigNumber } from '@0xproject/utils';
 import * as chai from 'chai';
 import { JSONRPCErrorCallback, JSONRPCRequestPayload } from 'ethereum-types';
@@ -5,8 +6,8 @@ import * as _ from 'lodash';
 import 'mocha';
 import * as Sinon from 'sinon';
 
-import { ecSignOrderHashAsync, generatePseudoRandomSalt, MessagePrefixType } from '../src';
-import { isValidECSignature, isValidSignatureAsync } from '../src/signature_utils';
+import { ecSignOrderHashAsync, generatePseudoRandomSalt } from '../src';
+import { convertECSignatureToSignatureHex, isValidECSignature, isValidSignatureAsync } from '../src/signature_utils';
 
 import { chaiSetup } from './utils/chai_setup';
 import { provider, web3Wrapper } from './utils/web3_wrapper';
@@ -119,32 +120,23 @@ 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);
+            const expectedSignature =
+                '0x1b61a3ed31b43c8780e905a260a35faefcc527be7516aa11c0256729b5b351bc3340349190569279751135161d22529dc25add4f6069af05be04cacbda2ace225403';
+            const ecSignature = await ecSignOrderHashAsync(provider, orderHash, makerAddress, SignerType.Default);
+            expect(ecSignature).to.equal(expectedSignature);
         });
-        it('should return the correct ECSignature for signatureHex concatenated as R + S + V', async () => {
+        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 +150,13 @@ describe('Signature utils', () => {
                     }
                 },
             };
-
-            const messagePrefixOpts = {
-                prefixType: MessagePrefixType.EthSign,
-                shouldAddPrefixBeforeCallingEthSign: false,
-            };
-            const ecSignature = await ecSignOrderHashAsync(fakeProvider, orderHash, makerAddress, messagePrefixOpts);
-            expect(ecSignature).to.deep.equal(expectedECSignature);
+            const ecSignature = await ecSignOrderHashAsync(fakeProvider, orderHash, makerAddress, SignerType.Default);
+            expect(ecSignature).to.equal(expectedSignature);
         });
-        it('should return the correct ECSignature for signatureHex concatenated as V + R + S', async () => {
+        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 +173,81 @@ describe('Signature utils', () => {
                 },
             };
 
-            const messagePrefixOpts = {
-                prefixType: MessagePrefixType.EthSign,
-                shouldAddPrefixBeforeCallingEthSign: false,
+            const ecSignature = await ecSignOrderHashAsync(fakeProvider, orderHash, makerAddress, SignerType.Default);
+            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
+        // Source: https://github.com/MetaMask/metamask-extension/commit/a9d36860bec424dcee8db043d3e7da6a5ff5672e
+        it('should receive a payload modified with a prefix when Metamask is SignerType', async () => {
+            const orderHash = '0x34decbedc118904df65f379a175bb39ca18209d6ce41d5ed549d54e6e0a95004';
+            const orderHashPrefixed = '0xae70f31d26096291aa681b26cb7574563956221d0b4213631e1ef9df675d4cba';
+            const expectedSignature =
+                '0x1b117902c86dfb95fe0d1badd983ee166ad259b27acb220174cbb4460d872871137feabdfe76e05924b484789f79af4ee7fa29ec006cedce1bbf369320d034e10b03';
+            // Generated from a MM eth_sign request from 0x5409ed021d9299bf6814279a6a1411a7e866a631 signing 0xae70f31d26096291aa681b26cb7574563956221d0b4213631e1ef9df675d4cba
+            const metamaskSignature =
+                '0x117902c86dfb95fe0d1badd983ee166ad259b27acb220174cbb4460d872871137feabdfe76e05924b484789f79af4ee7fa29ec006cedce1bbf369320d034e10b1b';
+            const fakeProvider = {
+                async sendAsync(payload: JSONRPCRequestPayload, callback: JSONRPCErrorCallback): Promise<void> {
+                    if (payload.method === 'eth_sign') {
+                        const [, message] = payload.params;
+                        expect(message).to.equal(orderHashPrefixed);
+                        callback(null, {
+                            id: 42,
+                            jsonrpc: '2.0',
+                            result: metamaskSignature,
+                        });
+                    } 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, SignerType.Metamask);
+            expect(ecSignature).to.equal(expectedSignature);
+        });
+        it('should return a valid signature', async () => {
+            const orderHash = '0x34decbedc118904df65f379a175bb39ca18209d6ce41d5ed549d54e6e0a95004';
+            const ecSignature = await ecSignOrderHashAsync(provider, orderHash, makerAddress, SignerType.Default);
+
+            const isValidSignature = await isValidSignatureAsync(provider, orderHash, ecSignature, makerAddress);
+            expect(isValidSignature).to.be.true();
+        });
+    });
+    describe('#convertECSignatureToSignatureHex', () => {
+        const ecSignature: ECSignature = {
+            v: 27,
+            r: '0xaca7da997ad177f040240cdccf6905b71ab16b74434388c3a72f34fd25d64393',
+            s: '0x46b2bac274ff29b48b3ea6e2d04c1336eaceafda3c53ab483fc3ff12fac3ebf2',
+        };
+        it('should concatenate v,r,s and append the Trezor signature type', async () => {
+            const expectedSignatureWithSignatureType =
+                '0x1baca7da997ad177f040240cdccf6905b71ab16b74434388c3a72f34fd25d6439346b2bac274ff29b48b3ea6e2d04c1336eaceafda3c53ab483fc3ff12fac3ebf208';
+            const signatureWithSignatureType = convertECSignatureToSignatureHex(ecSignature, SignerType.Trezor);
+            expect(signatureWithSignatureType).to.equal(expectedSignatureWithSignatureType);
+        });
+        it('should concatenate v,r,s and append the EthSign signature type when SignerType is Default', async () => {
+            const expectedSignatureWithSignatureType =
+                '0x1baca7da997ad177f040240cdccf6905b71ab16b74434388c3a72f34fd25d6439346b2bac274ff29b48b3ea6e2d04c1336eaceafda3c53ab483fc3ff12fac3ebf203';
+            const signatureWithSignatureType = convertECSignatureToSignatureHex(ecSignature, SignerType.Default);
+            expect(signatureWithSignatureType).to.equal(expectedSignatureWithSignatureType);
+        });
+        it('should concatenate v,r,s and append the EthSign signature type when SignerType is Ledger', async () => {
+            const expectedSignatureWithSignatureType =
+                '0x1baca7da997ad177f040240cdccf6905b71ab16b74434388c3a72f34fd25d6439346b2bac274ff29b48b3ea6e2d04c1336eaceafda3c53ab483fc3ff12fac3ebf203';
+            const signatureWithSignatureType = convertECSignatureToSignatureHex(ecSignature, SignerType.Ledger);
+            expect(signatureWithSignatureType).to.equal(expectedSignatureWithSignatureType);
+        });
+        it('should concatenate v,r,s and append the EthSign signature type when SignerType is Metamask', async () => {
+            const expectedSignatureWithSignatureType =
+                '0x1baca7da997ad177f040240cdccf6905b71ab16b74434388c3a72f34fd25d6439346b2bac274ff29b48b3ea6e2d04c1336eaceafda3c53ab483fc3ff12fac3ebf203';
+            const signatureWithSignatureType = convertECSignatureToSignatureHex(ecSignature, SignerType.Metamask);
+            expect(signatureWithSignatureType).to.equal(expectedSignatureWithSignatureType);
+        });
+        it('should throw if the SignerType is invalid', async () => {
+            const expectedMessage = 'Unrecognized SignerType: INVALID_SIGNER';
+            expect(() => convertECSignatureToSignatureHex(ecSignature, 'INVALID_SIGNER' as SignerType)).to.throw(
+                expectedMessage,
+            );
         });
     });
 });
diff --git a/packages/subproviders/test/utils/fixture_data.ts b/packages/subproviders/test/utils/fixture_data.ts
index 3137e08b0..7cf502c97 100644
--- a/packages/subproviders/test/utils/fixture_data.ts
+++ b/packages/subproviders/test/utils/fixture_data.ts
@@ -25,7 +25,7 @@ export const fixtureData = {
         chainId: networkId,
         from: TEST_RPC_ACCOUNT_0,
     },
-    // This is the signed result of the abouve Transaction Data
+    // This is the signed result of the above Transaction Data
     TX_DATA_SIGNED_RESULT:
         '0xf85f8080822710940000000000000000000000000000000000000000808078a0712854c73c69445cc1b22a7c3d7312ff9a97fe4ffba35fd636e8236b211b6e7ca0647cee031615e52d916c7c707025bc64ad525d8f1b9876c3435a863b42743178',
     TX_DATA_ACCOUNT_1_SIGNED_RESULT:
diff --git a/packages/types/CHANGELOG.json b/packages/types/CHANGELOG.json
index 8520c5146..9d78d3dc0 100644
--- a/packages/types/CHANGELOG.json
+++ b/packages/types/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "1.0.1-rc.4",
+        "changes": [
+            {
+                "pr": 914,
+                "note": "Added SignerType to handle different signing prefix scenarios"
+            }
+        ]
+    },
+    {
         "version": "1.0.1-rc.3",
         "changes": [
             {
diff --git a/packages/types/src/index.ts b/packages/types/src/index.ts
index 7774b61b0..fa634420d 100644
--- a/packages/types/src/index.ts
+++ b/packages/types/src/index.ts
@@ -143,6 +143,17 @@ export enum SignatureType {
 }
 
 /**
+ * The type of the Signer implementation. Some signer implementations use different message prefixes (e.g Trezor) or implement different
+ * eth_sign behaviour (e.g Metamask). Default assumes a spec compliant `eth_sign`.
+ */
+export enum SignerType {
+    Default = 'DEFAULT',
+    Ledger = 'LEDGER',
+    Metamask = 'METAMASK',
+    Trezor = 'TREZOR',
+}
+
+/**
  * Elliptic Curve signature
  */
 export interface ECSignature {