Convert Buffers, not Byte Arrays

src/convert.js

@@ -2,42 +2,31 @@ var assert = require('assert')
 var Crypto = require('crypto-js')
 var WordArray = Crypto.lib.WordArray
 
-function bytesToWords(bytes) {
-  assert(Array.isArray(bytes) || Buffer.isBuffer(bytes), 'Input must be a byte array')
+function bufferToWordArray(buffer) {
+  assert(Buffer.isBuffer(buffer), 'Expected Buffer, got', buffer)
+
   var words = []
-  for (var i = 0, b = 0; i < bytes.length; i++, b += 8) {
-    words[b >>> 5] |= bytes[i] << (24 - b % 32)
+  for (var i = 0, b = 0; i < buffer.length; i++, b += 8) {
+    words[b >>> 5] |= buffer[i] << (24 - b % 32)
   }
-  return words
-}
 
-function wordsToBytes(words) {
-  var bytes = []
-  for (var b = 0; b < words.length * 32; b += 8) {
-    bytes.push((words[b >>> 5] >>> (24 - b % 32)) & 0xFF)
-  }
-  return bytes
+  return new WordArray.init(words, buffer.length)
 }
 
-function bytesToWordArray(bytes) {
-  return new WordArray.init(bytesToWords(bytes), bytes.length)
-}
+function wordArrayToBuffer(wordArray) {
+  assert(Array.isArray(wordArray.words), 'Expected WordArray, got' + wordArray)
 
-function wordArrayToBytes(wordArray) {
-  return wordsToBytes(wordArray.words)
-}
+  var words = wordArray.words
+  var buffer = new Buffer(words.length * 4)
 
-function reverseEndian(hex) {
-  var buffer = new Buffer(hex, 'hex')
-  Array.prototype.reverse.call(buffer)
+  words.forEach(function(value, i) {
+    buffer.writeInt32BE(value & -1, i * 4)
+  })
 
-  return buffer.toString('hex')
+  return buffer
 }
 
 module.exports = {
-  bytesToWords: bytesToWords,
-  wordsToBytes: wordsToBytes,
-  bytesToWordArray: bytesToWordArray,
-  wordArrayToBytes: wordArrayToBytes,
-  reverseEndian: reverseEndian
+  bufferToWordArray: bufferToWordArray,
+  wordArrayToBuffer: wordArrayToBuffer
 }

src/crypto.js

@@ -5,13 +5,12 @@ var crypto = require('crypto')
 var convert = require('./convert')
 
 function hash160(buffer) {
-
   var step1 = sha256(buffer)
 
-  var step2a = convert.bytesToWordArray(step1)
+  var step2a = convert.bufferToWordArray(step1)
   var step2b = CryptoJS.RIPEMD160(step2a)
 
-  return new Buffer(convert.wordArrayToBytes(step2b))
+  return convert.wordArrayToBuffer(step2b)
 }
 
 function hash256(buffer) {
@@ -35,12 +34,12 @@ function HmacSHA512(data, secret) {
   assert(Buffer.isBuffer(data), 'Expected Buffer for data, got ' + data)
   assert(Buffer.isBuffer(secret), 'Expected Buffer for secret, got ' + secret)
 
-  var dataWords = convert.bytesToWordArray(data)
-  var secretWords = convert.bytesToWordArray(secret)
+  var dataWords = convert.bufferToWordArray(data)
+  var secretWords = convert.bufferToWordArray(secret)
 
   var hash = CryptoJS.HmacSHA512(dataWords, secretWords)
 
-  return new Buffer(convert.wordArrayToBytes(hash))
+  return convert.wordArrayToBuffer(hash)
 }
 
 module.exports = {

test/address.js

@@ -29,7 +29,7 @@ describe('Address', function() {
     })
 
     fixtures.invalid.fromBase58Check.forEach(function(f) {
-      it('throws on ' + f.descpription, function() {
+      it('throws on ' + f.description, function() {
         assert.throws(function() {
           Address.fromBase58Check(f.base58check)
         }, new RegExp(f.exception))

test/convert.js

@@ -1,40 +1,27 @@
 var assert = require('assert')
 var convert = require('../src/convert')
 
-describe('convert', function() {
-  describe('byte array and word array conversions', function(){
-    var bytes, wordArray
-
-    beforeEach(function(){
-      bytes = [
-        98, 233, 7, 177, 92, 191, 39, 213, 66, 83,
-        153, 235, 246, 240, 251, 80, 235, 184, 143, 24
-      ]
-      wordArray = {
-        words: [1659439025, 1556031445, 1112775147, -151979184, -340226280],
-        sigBytes: 20
-      }
-    })
+var fixtures = require('./fixtures/convert')
 
-    describe('bytesToWords', function() {
-      it('works', function() {
-        assert.deepEqual(convert.bytesToWordArray(bytes), wordArray)
-      })
-    })
+describe('convert', function() {
+  describe('bufferToWordArray', function() {
+    fixtures.valid.forEach(function(f) {
+      it('converts ' + f.hex + ' correctly', function() {
+        var buffer = new Buffer(f.hex, 'hex')
+        var result = convert.bufferToWordArray(buffer)
 
-    describe('bytesToWords', function() {
-      it('works', function() {
-        assert.deepEqual(convert.wordArrayToBytes(wordArray), bytes)
+        assert.deepEqual(result, f.wordArray)
       })
     })
   })
 
-  describe('reverseEndian', function() {
-    it('works', function() {
-      var bigEndian = "6a4062273ac4f9ea4ffca52d9fd102b08f6c32faa0a4d1318e3a7b2e437bb9c7"
-      var littleEdian = "c7b97b432e7b3a8e31d1a4a0fa326c8fb002d19f2da5fc4feaf9c43a2762406a"
-      assert.deepEqual(convert.reverseEndian(bigEndian), littleEdian)
-      assert.deepEqual(convert.reverseEndian(littleEdian), bigEndian)
+  describe('wordArrayToBuffer', function() {
+    fixtures.valid.forEach(function(f) {
+      it('converts to ' + f.hex + ' correctly', function() {
+        var resultHex = convert.wordArrayToBuffer(f.wordArray).toString('hex')
+
+        assert.deepEqual(resultHex, f.hex)
+      })
     })
   })
 })

test/fixtures/convert.json

@@ -0,0 +1,25 @@
+{
+  "valid": [
+    {
+      "hex": "0000000000000000000000000000000000000000",
+      "wordArray": {
+        "words": [0, 0, 0, 0, 0],
+        "sigBytes": 20
+      }
+    },
+    {
+      "hex": "62e907b15cbf27d5425399ebf6f0fb50ebb88f18",
+      "wordArray": {
+        "words": [1659439025, 1556031445, 1112775147, -151979184, -340226280],
+        "sigBytes": 20
+      }
+    },
+    {
+      "hex": "ffffffffffffffffffffffffffffffffffffffff",
+      "wordArray": {
+        "words": [-1, -1, -1, -1, -1],
+        "sigBytes": 20
+      }
+    }
+  ]
+}

test/hdnode.js

@@ -136,7 +136,7 @@ describe('HDNode', function() {
     })
 
     fixtures.invalid.fromBuffer.forEach(function(f) {
-      it('throws on ' + f.string, function() {
+      it('throws on ' + f.hex, function() {
         assert.throws(function() {
           HDNode.fromHex(f.hex)
         }, new RegExp(f.exception))