Merge pull request #100 from 0xProject/improveSignOrder

Improve signOrderHashAsync

2 files changed, 48 insertions, 29 deletions

diff --git a/src/0x.ts b/src/0x.ts
index 95935c258..92a892336 100644
--- a/src/0x.ts
+++ b/src/0x.ts
@@ -9,6 +9,7 @@ import compareVersions = require('compare-versions');
 import {Web3Wrapper} from './web3_wrapper';
 import {constants} from './utils/constants';
 import {utils} from './utils/utils';
+import {signatureUtils} from './utils/signature_utils';
 import {assert} from './utils/assert';
 import {ExchangeWrapper} from './contract_wrappers/exchange_wrapper';
 import {TokenRegistryWrapper} from './contract_wrappers/token_registry_wrapper';
@@ -221,39 +222,28 @@ export class ZeroEx {
 
         const signature = await this._web3Wrapper.signTransactionAsync(signerAddress, 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;
+        // HACK: There is no consensus on whether the signatureHex string should be formatted as
+        // 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.
+        const validVParamValues = [27, 28];
+        const ecSignatureVRS = signatureUtils.parseSignatureHexAsVRS(signature);
+        if (_.includes(validVParamValues, ecSignatureVRS.v)) {
+            const isValidVRSSignature = ZeroEx.isValidSignature(orderHash, ecSignatureVRS, signerAddress);
+            if (isValidVRSSignature) {
+                return ecSignatureVRS;
             }
-            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(orderHash, ecSignature, signerAddress);
-        if (!isValidSignature) {
-            throw new Error(ZeroExError.INVALID_SIGNATURE);
+        const ecSignatureRSV = signatureUtils.parseSignatureHexAsRSV(signature);
+        if (_.includes(validVParamValues, ecSignatureRSV.v)) {
+            const isValidRSVSignature = ZeroEx.isValidSignature(orderHash, ecSignatureRSV, signerAddress);
+            if (isValidRSVSignature) {
+                return ecSignatureRSV;
+            }
         }
-        return ecSignature;
+
+        throw new Error(ZeroExError.INVALID_SIGNATURE);
     }
     /**
      * Returns the ethereum addresses of all available exchange contracts
diff --git a/src/utils/signature_utils.ts b/src/utils/signature_utils.ts
new file mode 100644
index 000000000..b312b5554
--- /dev/null
+++ b/src/utils/signature_utils.ts
@@ -0,0 +1,29 @@
+import * as ethUtil from 'ethereumjs-util';
+import {ECSignature} from '../types';
+
+export const signatureUtils = {
+    parseSignatureHexAsVRS(signatureHex: string): ECSignature {
+        const signatureBuffer = ethUtil.toBuffer(signatureHex);
+        let v = signatureBuffer[0];
+        if (v < 27) {
+            v += 27;
+        }
+        const r = signatureBuffer.slice(1, 33);
+        const s = signatureBuffer.slice(33, 65);
+        const ecSignature: ECSignature = {
+            v,
+            r: ethUtil.bufferToHex(r),
+            s: ethUtil.bufferToHex(s),
+        };
+        return ecSignature;
+    },
+    parseSignatureHexAsRSV(signatureHex: string): ECSignature {
+        const {v, r, s} = ethUtil.fromRpcSig(signatureHex);
+        const ecSignature: ECSignature = {
+            v,
+            r: ethUtil.bufferToHex(r),
+            s: ethUtil.bufferToHex(s),
+        };
+        return ecSignature;
+    },
+};