From eb90367fc4fc666786398ab9803b77bfb900c661 Mon Sep 17 00:00:00 2001
From: Fabio Berger <me@fabioberger.com>
Date: Mon, 29 May 2017 13:37:08 +0200
Subject: Port over signOrderHashAsync

---
 package.json       |  2 ++
 src/0x.js.ts       | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
 src/globals.d.ts   |  3 +++
 src/types.ts       |  1 +
 src/utils/utils.ts |  4 ++++
 5 files changed, 73 insertions(+), 1 deletion(-)

diff --git a/package.json b/package.json
index 5c352bc88..a191d4b73 100644
--- a/package.json
+++ b/package.json
@@ -68,9 +68,11 @@
   },
   "dependencies": {
     "bignumber.js": "^4.0.2",
+    "compare-versions": "^3.0.1",
     "es6-promisify": "^5.0.0",
     "ethereumjs-abi": "^0.6.4",
     "ethereumjs-util": "^5.1.1",
+    "find-versions": "^2.0.0",
     "jsonschema": "^1.1.1",
     "lodash": "^4.17.4",
     "truffle-contract": "^2.0.0",
diff --git a/src/0x.js.ts b/src/0x.js.ts
index de082146f..eff371c3b 100644
--- a/src/0x.js.ts
+++ b/src/0x.js.ts
@@ -8,9 +8,11 @@ import {Web3Wrapper} from './web3_wrapper';
 import {constants} from './utils/constants';
 import {utils} from './utils/utils';
 import {assert} from './utils/assert';
+import findVersions = require('find-versions');
+import compareVersions = require('compare-versions');
 import {ExchangeWrapper} from './contract_wrappers/exchange_wrapper';
 import {ECSignatureSchema} from './schemas/ec_signature_schema';
-import {SolidityTypes, ECSignature} from './types';
+import {SolidityTypes, ECSignature, ZeroExError} from './types';
 
 const MAX_DIGITS_IN_UNSIGNED_256_INT = 78;
 
@@ -131,4 +133,64 @@ export class ZeroEx {
         this.web3Wrapper = new Web3Wrapper(web3);
         this.exchange = new ExchangeWrapper(this.web3Wrapper);
     }
+    /**
+     * Signs an orderHash and returns it's ECSignature
+     * This method currently supports TestRPC, Geth and Parity above and below V1.6.6
+     */
+    public async signOrderHashAsync(orderHashHex: string): Promise<ECSignature> {
+        assert.isHexString('orderHashHex', orderHashHex);
+
+        let msgHashHex;
+        const nodeVersion = await this.web3Wrapper.getNodeVersionAsync();
+        const isParityNode = utils.isParityNode(nodeVersion);
+        if (isParityNode) {
+            // Parity node adds the personalMessage prefix itself
+            msgHashHex = orderHashHex;
+        } else {
+            const orderHashBuff = ethUtil.toBuffer(orderHashHex);
+            const msgHashBuff = ethUtil.hashPersonalMessage(orderHashBuff);
+            msgHashHex = ethUtil.bufferToHex(msgHashBuff);
+        }
+
+        const makerAddressIfExists = await this.web3Wrapper.getSenderAddressIfExistsAsync();
+        if (_.isUndefined(makerAddressIfExists)) {
+            throw new Error(ZeroExError.USER_HAS_NO_ASSOCIATED_ADDRESSES);
+        }
+
+        const signature = await this.web3Wrapper.signTransactionAsync(makerAddressIfExists, msgHashHex);
+
+        let signatureData;
+        const [nodeVersionNumber] = findVersions(nodeVersion);
+        // Parity v1.6.6 and earlier returns the signatureData as vrs instead of rsv as Geth does
+        // Later versions return rsv but for the time being we still want to support version < 1.6.6
+        // Date: May 23rd 2017
+        const latestParityVersionWithVRS = '1.6.6';
+        const isVersionBeforeParityFix = compareVersions(nodeVersionNumber, latestParityVersionWithVRS) <= 0;
+        if (isParityNode && isVersionBeforeParityFix) {
+            const signatureBuffer = ethUtil.toBuffer(signature);
+            let v = signatureBuffer[0];
+            if (v < 27) {
+                v += 27;
+            }
+            signatureData = {
+                v,
+                r: signatureBuffer.slice(1, 33),
+                s: signatureBuffer.slice(33, 65),
+            };
+        } else {
+            signatureData = ethUtil.fromRpcSig(signature);
+        }
+
+        const {v, r, s} = signatureData;
+        const ecSignature: ECSignature = {
+            v,
+            r: ethUtil.bufferToHex(r),
+            s: ethUtil.bufferToHex(s),
+        };
+        const isValidSignature = ZeroEx.isValidSignature(orderHashHex, ecSignature, makerAddressIfExists);
+        if (!isValidSignature) {
+            throw new Error(ZeroExError.INVALID_SIGNATURE);
+        }
+        return ecSignature;
+    }
 }
diff --git a/src/globals.d.ts b/src/globals.d.ts
index dee957f2f..78b768dd1 100644
--- a/src/globals.d.ts
+++ b/src/globals.d.ts
@@ -3,6 +3,8 @@ declare module 'bn.js';
 declare module 'request-promise-native';
 declare module 'web3-provider-engine';
 declare module 'web3-provider-engine/subproviders/rpc';
+declare module 'find-versions';
+declare module 'compare-versions';
 
 declare interface Schema {
     id: string;
@@ -35,6 +37,7 @@ declare module 'ethereumjs-util' {
     const pubToAddress: (pubKey: string) => Buffer;
     const isValidAddress: (address: string) => boolean;
     const bufferToInt: (buffer: Buffer) => number;
+    const fromRpcSig: (signature: string) => {v: number, r: Buffer, s: Buffer};
 }
 
 // truffle-contract declarations
diff --git a/src/types.ts b/src/types.ts
index 4da03a4d3..3bed01547 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -13,6 +13,7 @@ export const ZeroExError = strEnum([
   'CONTRACT_DOES_NOT_EXIST',
   'UNHANDLED_ERROR',
   'USER_HAS_NO_ASSOCIATED_ADDRESSES',
+  'INVALID_SIGNATURE',
 ]);
 export type ZeroExError = keyof typeof ZeroExError;
 
diff --git a/src/utils/utils.ts b/src/utils/utils.ts
index b514b702d..2098a67b3 100644
--- a/src/utils/utils.ts
+++ b/src/utils/utils.ts
@@ -1,3 +1,4 @@
+import * as _ from 'lodash';
 import * as BN from 'bn.js';
 
 export const utils = {
@@ -15,4 +16,7 @@ export const utils = {
         console.log(message);
         /* tslint:enable */
     },
+    isParityNode(nodeVersion: string): boolean {
+        return _.includes(nodeVersion, 'Parity');
+    },
 };
-- 
cgit v1.2.3