From 2d7599d2d3bd043dd71de0d5551cda648908047f Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Sat, 24 May 2014 01:19:32 -0500
Subject: [PATCH] block: use utils.dsha256 instead of hash.js for merkle tree
 building.

---
 lib/bcoin/block.js | 18 ++----------------
 1 file changed, 2 insertions(+), 16 deletions(-)

diff --git a/lib/bcoin/block.js b/lib/bcoin/block.js
index c21d16cb..451cb66a 100644
--- a/lib/bcoin/block.js
+++ b/lib/bcoin/block.js
@@ -1,5 +1,4 @@
 var bcoin = require('../bcoin');
-var hash = require('hash.js');
 var utils = bcoin.utils;
 
 function Block(data, subtype) {
@@ -160,18 +159,6 @@ Block.fromJSON = function fromJSON(json) {
   return block;
 };
 
-Block.prototype._phash = function phash(p1begin, p1end, p2begin, p2end) {
-  var pblank = '';
-  var hash1 = hash.sha256();
-  hash1.update(p1begin === p1end ? pblank : p1begin, 'hex');
-  hash1.update(p2begin === p2end ? pblank : p2begin, 'hex');
-  hash1 = hash1.digest('hex');
-  var hash2 = hash.sha256();
-  hash2.update(hash1, 'hex');
-  hash2 = hash2.digest('hex');
-  return hash2;
-};
-
 Block.prototype._buildMerkle = function buildMerkle() {
   var merkleTree = [];
   for (var i = 0; i < this.txs.length; i++) {
@@ -181,9 +168,8 @@ Block.prototype._buildMerkle = function buildMerkle() {
   for (var size = this.txs.length; size > 1; size = ((size + 1) / 2) | 0) {
     for (var i = 0; i < size; i += 2) {
       var i2 = Math.min(i + 1, size - 1);
-      merkleTree.push(
-        this._phash(merkleTree[j+i],  merkleTree[j+i+1],
-                    merkleTree[j+i2], merkleTree[j+i2+1]));
+      var hash = utils.dsha256(merkleTree[j+i] + merkleTree[j+i2], 'hex');
+      merkleTree.push(utils.toHex(hash));
     }
     j += size;
   }