Move isValidSignature implementation into signatureUtils

2 files changed, 17 insertions, 13 deletions

diff --git a/src/0x.ts b/src/0x.ts
index cb0090469..59688e948 100644
--- a/src/0x.ts
+++ b/src/0x.ts
@@ -88,19 +88,8 @@ export class ZeroEx {
         assert.doesConformToSchema('signature', signature, schemas.ecSignatureSchema);
         assert.isETHAddressHex('signerAddress', signerAddress);
 
-        const dataBuff = ethUtil.toBuffer(data);
-        const msgHashBuff = ethUtil.hashPersonalMessage(dataBuff);
-        try {
-            const pubKey = ethUtil.ecrecover(
-                msgHashBuff,
-                signature.v,
-                ethUtil.toBuffer(signature.r),
-                ethUtil.toBuffer(signature.s));
-            const retrievedAddress = ethUtil.bufferToHex(ethUtil.pubToAddress(pubKey));
-            return retrievedAddress === signerAddress;
-        } catch (err) {
-            return false;
-        }
+        const isValidSignature = signatureUtils.isValidSignature(data, signature, signerAddress);
+        return isValidSignature;
     }
     /**
      * Generates a pseudo-random 256-bit salt.
diff --git a/src/utils/signature_utils.ts b/src/utils/signature_utils.ts
index b312b5554..d066f8bf0 100644
--- a/src/utils/signature_utils.ts
+++ b/src/utils/signature_utils.ts
@@ -2,6 +2,21 @@ import * as ethUtil from 'ethereumjs-util';
 import {ECSignature} from '../types';
 
 export const signatureUtils = {
+    isValidSignature(data: string, signature: ECSignature, signerAddress: string): boolean {
+        const dataBuff = ethUtil.toBuffer(data);
+        const msgHashBuff = ethUtil.hashPersonalMessage(dataBuff);
+        try {
+            const pubKey = ethUtil.ecrecover(
+                msgHashBuff,
+                signature.v,
+                ethUtil.toBuffer(signature.r),
+                ethUtil.toBuffer(signature.s));
+            const retrievedAddress = ethUtil.bufferToHex(ethUtil.pubToAddress(pubKey));
+            return retrievedAddress === signerAddress;
+        } catch (err) {
+            return false;
+        }
+    },
     parseSignatureHexAsVRS(signatureHex: string): ECSignature {
         const signatureBuffer = ethUtil.toBuffer(signatureHex);
         let v = signatureBuffer[0];