From 28d3a40704e942c7c880748a69319f2b13bc7541 Mon Sep 17 00:00:00 2001
From: "Ryan X. Charles" <ryan@bitpay.com>
Date: Thu, 28 Aug 2014 16:18:36 -0700
Subject: [PATCH] Key.prototype.set

---
 lib/expmt/stealth.js |  6 +++---
 lib/kdf.js           |  2 +-
 lib/key.js           | 14 ++++++++++----
 test/test.key.js     | 10 +++++++++-
 4 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/lib/expmt/stealth.js b/lib/expmt/stealth.js
index 20fe407..c5fdaea 100644
--- a/lib/expmt/stealth.js
+++ b/lib/expmt/stealth.js
@@ -22,9 +22,9 @@ Stealth.prototype.fromAddressBuffer = function(buf) {
   var sPubBuf = buf.slice(33, 66);
   
   var payloadPubkey = Pubkey().fromDER(pPubBuf);
-  this.payloadKey = Key(undefined, payloadPubkey);
+  this.payloadKey = Key({pubkey: payloadPubkey});
   var scanPubkey = Pubkey().fromDER(sPubBuf);
-  this.scanKey = Key(undefined, scanPubkey);
+  this.scanKey = Key({pubkey: scanPubkey});
 
   return this;
 };
@@ -78,7 +78,7 @@ Stealth.prototype.getReceivePubkeyAsSender = function(senderKey) {
 Stealth.prototype.getReceiveKey = function(senderPubkey) {
   var sharedKey = this.getSharedKeyAsReceiver(senderPubkey);
   var privkey = Privkey(this.payloadKey.privkey.bn.add(sharedKey.privkey.bn).mod(Point.getN()));
-  var key = Key(privkey);
+  var key = Key({privkey: privkey});
   key.privkey2pubkey();
 
   return key;
diff --git a/lib/kdf.js b/lib/kdf.js
index 91d0752..4cba312 100644
--- a/lib/kdf.js
+++ b/lib/kdf.js
@@ -14,7 +14,7 @@ KDF.buf2key = function(buf) {
 
 KDF.sha256hmac2key = function(buf) {
   var privkey = KDF.sha256hmac2privkey(buf);
-  var key = new Key(privkey);
+  var key = new Key({privkey: privkey});
   key.privkey2pubkey();
   return key;
 };
diff --git a/lib/key.js b/lib/key.js
index a7a3aa5..0515072 100644
--- a/lib/key.js
+++ b/lib/key.js
@@ -5,11 +5,17 @@ var Random = require('./random');
 var Bn = require('./bn');
 var point = require('./point');
 
-var Key = function Key(privkey, pubkey) {
+var Key = function Key(obj) {
   if (!(this instanceof Key))
-    return new Key(privkey, pubkey);
-  this.privkey = privkey;
-  this.pubkey = pubkey;
+    return new Key(obj);
+  if (obj)
+    this.set(obj);
+};
+
+Key.prototype.set = function(obj) {
+  this.privkey = obj.privkey || this.privkey || undefined;
+  this.pubkey = obj.pubkey || this.pubkey || undefined;
+  return this;
 };
 
 Key.prototype.fromRandom = function() {
diff --git a/test/test.key.js b/test/test.key.js
index b7e76c3..05ae214 100644
--- a/test/test.key.js
+++ b/test/test.key.js
@@ -16,12 +16,20 @@ describe('Key', function() {
   it('should make a key with a priv and pub', function() {
     var priv = new Privkey();
     var pub = new Pubkey();
-    var key = new Key(priv, pub);
+    var key = new Key({privkey: priv, pubkey: pub});
     should.exist(key);
     should.exist(key.privkey);
     should.exist(key.pubkey);
   });
 
+  describe("#set", function() {
+    
+    it('should make a new priv and pub', function() {
+      should.exist(Key().set({privkey: Privkey()}).privkey);
+    });
+
+  });
+
   describe("#fromRandom", function() {
     
     it('should make a new priv and pub', function() {