From 678da4671a93b9595ec0380c7cd7fc715d648893 Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Fri, 15 Jul 2016 08:36:00 -0700
Subject: [PATCH] fix hd cache.

---
 lib/bcoin/hd.js | 38 +++++++++++++++++++-------------------
 1 file changed, 19 insertions(+), 19 deletions(-)

diff --git a/lib/bcoin/hd.js b/lib/bcoin/hd.js
index 3cd0dd7f..48cee117 100644
--- a/lib/bcoin/hd.js
+++ b/lib/bcoin/hd.js
@@ -945,17 +945,11 @@ HDPrivateKey.prototype.__defineGetter__('xpubkey', function() {
  */
 
 HDPrivateKey.prototype.derive = function derive(index, hardened) {
-  var p, id, data, hash, left, right, privateKey, child;
+  var p, id, data, hash, left, right, key, child;
 
   if (typeof index === 'string')
     return this.derivePath(index);
 
-  id = this.xprivkey + '/' + index;
-  child = HD.cache.get(id);
-
-  if (child)
-    return child;
-
   hardened = index >= constants.hd.HARDENED ? true : hardened;
 
   if (index < constants.hd.HARDENED && hardened)
@@ -967,6 +961,12 @@ HDPrivateKey.prototype.derive = function derive(index, hardened) {
   if (this.depth >= 0xff)
     throw new Error('Depth too high.');
 
+  id = this.xprivkey + '/' + index;
+  child = HD.cache.get(id);
+
+  if (child)
+    return child;
+
   p = new BufferWriter();
 
   if (hardened) {
@@ -985,7 +985,7 @@ HDPrivateKey.prototype.derive = function derive(index, hardened) {
   right = hash.slice(32, 64);
 
   try {
-    privateKey = ec.privateKeyTweakAdd(this.privateKey, left);
+    key = ec.privateKeyTweakAdd(this.privateKey, left);
   } catch (e) {
     return this.derive(index + 1);
   }
@@ -999,8 +999,8 @@ HDPrivateKey.prototype.derive = function derive(index, hardened) {
   child.parentFingerPrint = this.fingerPrint;
   child.childIndex = index;
   child.chainCode = right;
-  child.privateKey = privateKey;
-  child.publicKey = ec.publicKeyCreate(privateKey, true);
+  child.privateKey = key;
+  child.publicKey = ec.publicKeyCreate(key, true);
 
   HD.cache.set(id, child);
 
@@ -1594,17 +1594,11 @@ HDPublicKey.prototype.__defineGetter__('xpubkey', function() {
  */
 
 HDPublicKey.prototype.derive = function derive(index, hardened) {
-  var p, id, data, hash, left, right, publicKey, child;
+  var p, id, data, hash, left, right, key, child;
 
   if (typeof index === 'string')
     return this.derivePath(index);
 
-  id = this.xpubkey + '/' + index;
-  child = HD.cache.get(id);
-
-  if (child)
-    return child;
-
   if (index >= constants.hd.HARDENED || hardened)
     throw new Error('Index out of range.');
 
@@ -1614,6 +1608,12 @@ HDPublicKey.prototype.derive = function derive(index, hardened) {
   if (this.depth >= 0xff)
     throw new Error('Depth too high.');
 
+  id = this.xpubkey + '/' + index;
+  child = HD.cache.get(id);
+
+  if (child)
+    return child;
+
   p = new BufferWriter();
   p.writeBytes(this.publicKey);
   p.writeU32BE(index);
@@ -1624,7 +1624,7 @@ HDPublicKey.prototype.derive = function derive(index, hardened) {
   right = hash.slice(32, 64);
 
   try {
-    publicKey = ec.publicKeyTweakAdd(this.publicKey, left, true);
+    key = ec.publicKeyTweakAdd(this.publicKey, left, true);
   } catch (e) {
     return this.derive(index + 1);
   }
@@ -1638,7 +1638,7 @@ HDPublicKey.prototype.derive = function derive(index, hardened) {
   child.parentFingerPrint = this.fingerPrint;
   child.childIndex = index;
   child.chainCode = right;
-  child.publicKey = publicKey;
+  child.publicKey = key;
 
   HD.cache.set(id, child);