Represent block prevHash and merkleRoot in expected order

Author: Braydon Fuller

lib/block/block.js

@@ -232,7 +232,7 @@ Block.prototype.getMerkleRoot = function getMerkleRoot() {
  */
 Block.prototype.validMerkleRoot = function validMerkleRoot() {
 
-  var h = new BN(this.header.merkleRoot.toString('hex'), 'hex');
+  var h = new BN(BufferUtil.reverse(this.header.merkleRoot).toString('hex'), 'hex');
   var c = new BN(this.getMerkleRoot().toString('hex'), 'hex');
 
   if (h.cmp(c) !== 0) {

lib/block/blockheader.js

@@ -6,7 +6,6 @@ var BufferUtil = require('../util/buffer');
 var BufferReader = require('../encoding/bufferreader');
 var BufferWriter = require('../encoding/bufferwriter');
 var Hash = require('../crypto/hash');
-var JSUtil = require('../util/js');
 var $ = require('../util/preconditions');
 
 var GENESIS_BITS = 0x1d00ffff;
@@ -70,10 +69,10 @@ BlockHeader._fromObject = function _fromObject(data) {
   var prevHash = data.prevHash;
   var merkleRoot = data.merkleRoot;
   if (_.isString(data.prevHash)) {
-    prevHash = BufferUtil.reverse(new Buffer(data.prevHash, 'hex'));
+    prevHash = new Buffer(data.prevHash, 'hex');
   }
   if (_.isString(data.merkleRoot)) {
-    merkleRoot = BufferUtil.reverse(new Buffer(data.merkleRoot, 'hex'));
+    merkleRoot = new Buffer(data.merkleRoot, 'hex');
   }
   var info = {
     hash: data.hash,
@@ -137,8 +136,8 @@ BlockHeader.fromString = function fromString(str) {
 BlockHeader._fromBufferReader = function _fromBufferReader(br) {
   var info = {};
   info.version = br.readUInt32LE();
-  info.prevHash = br.read(32);
-  info.merkleRoot = br.read(32);
+  info.prevHash = BufferUtil.reverse(br.read(32));
+  info.merkleRoot = BufferUtil.reverse(br.read(32));
   info.time = br.readUInt32LE();
   info.bits = br.readUInt32LE();
   info.nonce = br.readUInt32LE();
@@ -161,8 +160,8 @@ BlockHeader.prototype.toObject = BlockHeader.prototype.toJSON = function toObjec
   return {
     hash: this.hash,
     version: this.version,
-    prevHash: BufferUtil.reverse(this.prevHash).toString('hex'),
-    merkleRoot: BufferUtil.reverse(this.merkleRoot).toString('hex'),
+    prevHash: this.prevHash.toString('hex'),
+    merkleRoot: this.merkleRoot.toString('hex'),
     time: this.time,
     bits: this.bits,
     nonce: this.nonce
@@ -192,8 +191,8 @@ BlockHeader.prototype.toBufferWriter = function toBufferWriter(bw) {
     bw = new BufferWriter();
   }
   bw.writeUInt32LE(this.version);
-  bw.write(this.prevHash);
-  bw.write(this.merkleRoot);
+  bw.write(BufferUtil.reverse(this.prevHash));
+  bw.write(BufferUtil.reverse(this.merkleRoot));
   bw.writeUInt32LE(this.time);
   bw.writeUInt32LE(this.bits);
   bw.writeUInt32LE(this.nonce);

lib/block/merkleblock.js

@@ -146,7 +146,7 @@ MerkleBlock.prototype.validMerkleTree = function validMerkleTree() {
   if(opts.hashesUsed !== this.hashes.length) {
     return false;
   }
-  return BufferUtil.equals(root, this.header.merkleRoot);
+  return BufferUtil.equals(root, BufferUtil.reverse(this.header.merkleRoot));
 };
 
 /**

test/block/blockheader.js

@@ -96,6 +96,13 @@ describe('BlockHeader', function() {
       should.exist(bh.time);
       should.exist(bh.bits);
       should.exist(bh.nonce);
+      var expectedPrevHash = '000000003c35b5e70b13d5b938fef4e998a977c17bea978390273b7c50a9aa4b';
+      bh.prevHash.toString('hex').should.equal(expectedPrevHash);
+      var expectedMerkleRoot = '58e6d52d1eb00470ae1ab4d5a3375c0f51382c6f249fff84e9888286974cfc97';
+      bh.merkleRoot.toString('hex').should.equal(expectedMerkleRoot);
+      bh.timestamp.should.equal(1371410638);
+      bh.bits.should.equal(473956288);
+      bh.version.should.equal(2);
     });
 
   });
@@ -110,6 +117,15 @@ describe('BlockHeader', function() {
       should.exist(json.time);
       should.exist(json.bits);
       should.exist(json.nonce);
+      json.should.deep.equal({
+        hash: '000000000b99b16390660d79fcc138d2ad0c89a0d044c4201a02bdf1f61ffa11',
+        version: 2,
+        prevHash: '000000003c35b5e70b13d5b938fef4e998a977c17bea978390273b7c50a9aa4b',
+        merkleRoot: '58e6d52d1eb00470ae1ab4d5a3375c0f51382c6f249fff84e9888286974cfc97',
+        time: 1371410638,
+        bits: 473956288,
+        nonce: 3594009557
+      });
     });
 
   });
@@ -150,7 +166,15 @@ describe('BlockHeader', function() {
   describe('#fromBuffer', function() {
 
     it('should parse this known buffer', function() {
-      BlockHeader.fromBuffer(bhbuf).toBuffer().toString('hex').should.equal(bhhex);
+      var blockHeader = BlockHeader.fromBuffer(bhbuf);
+      var expectedPrevHash = '000000003c35b5e70b13d5b938fef4e998a977c17bea978390273b7c50a9aa4b';
+      blockHeader.prevHash.toString('hex').should.equal(expectedPrevHash);
+      var expectedMerkleRoot = '58e6d52d1eb00470ae1ab4d5a3375c0f51382c6f249fff84e9888286974cfc97';
+      blockHeader.merkleRoot.toString('hex').should.equal(expectedMerkleRoot);
+      blockHeader.timestamp.should.equal(1371410638);
+      blockHeader.bits.should.equal(473956288);
+      blockHeader.version.should.equal(2);
+      blockHeader.toBuffer().toString('hex').should.equal(bhhex);
     });
 
   });