4 files changed, 82 insertions, 3 deletions
diff --git a/src/0x.js.ts b/src/0x.js.ts
index de082146f..aed7513a8 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 elliptic curve signature
+     * 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 0062a05cb..0f2fe0f2f 100644
--- a/src/globals.d.ts
+++ b/src/globals.d.ts
@@ -36,6 +36,7 @@ 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
@@ -53,6 +54,18 @@ declare module 'truffle-contract' {
     export = contract;
 }
 
+// find-version declarations
+declare function findVersions(version: string): string[];
+declare module 'find-versions' {
+    export = findVersions;
+}
+
+// compare-version declarations
+declare function compareVersions(firstVersion: string, secondVersion: string): number;
+declare module 'compare-versions' {
+    export = compareVersions;
+}
+
 // es6-promisify declarations
 declare function promisify(original: any, settings?: any): ((...arg: any[]) => Promise<any>);
 declare module 'es6-promisify' {
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..336eaf7bb 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 = {
@@ -11,8 +12,10 @@ export const utils = {
         return new BN(value.toString(), 10);
     },
     consoleLog(message: string): void {
-        /* tslint:disable */
+        // tslint:disable-next-line: no-console
         console.log(message);
-        /* tslint:enable */
+    },
+    isParityNode(nodeVersion: string): boolean {
+        return _.includes(nodeVersion, 'Parity');
     },
 };