Use Node crypto AES

lib/bip38.js

@@ -1,4 +1,3 @@
-var AES = require('aes')
 var assert = require('assert')
 var crypto = require('crypto')
 var cs = require('coinstring')
@@ -9,6 +8,23 @@ var curve = ecurve.getCurveByName('secp256k1')
 
 var BigInteger = require('bigi')
 
+function bufferXOR(buf1, buf2) {
+  assert.equal(buf1.length, buf2.length)
+
+  var out = new Buffer(buf1.length)
+  for (var i = 0; i < buf1.length; i++) {
+    out[i] = buf1[i] ^ buf2[i]
+  }
+
+  return out
+}
+
+// SHA256(SHA256(buffer))
+function sha256x2(buffer) {
+  buffer = crypto.createHash('sha256').update(buffer).digest()
+  return crypto.createHash('sha256').update(buffer).digest()
+}
+
 function Bip38(versions) {
   if (!(this instanceof Bip38)) return new Bip38()
 
@@ -40,21 +56,21 @@ Bip38.prototype.encryptRaw = function(buffer, compressed, passphrase, saltAddres
   var derivedHalf1 = scryptBuf.slice(0, 32)
   var derivedHalf2 = scryptBuf.slice(32, 64)
 
-  var aes = createAES(derivedHalf2)
-  var encryptFn = aes.encrypt.bind(aes)
+  var xorBuf = bufferXOR(buffer, derivedHalf1)
+  var cipher = crypto.createCipheriv('aes-256-ecb', derivedHalf2, new Buffer(0))
+  cipher.setAutoPadding(false)
+  cipher.end(xorBuf)
 
-  var xorBuf = BufferXOR(buffer, derivedHalf1)
-  var encryptedHalf1 = callAES(xorBuf.slice(0, 16), encryptFn)
-  var encryptedHalf2 = callAES(xorBuf.slice(16, 32), encryptFn)
+  var cipherText = cipher.read()
 
-  // 0x01 + 0x42 + flagByte + salt + encryptedHalf1 + encryptedHalf2
+  // 0x01 + 0x42 + flagByte + salt + cipherText
   var flagByte = compressed ? 0xe0 : 0xc0
   var prefix = new Buffer(3)
   prefix.writeUInt8(0x01, 0)
   prefix.writeUInt8(0x42, 1)
   prefix.writeUInt8(flagByte, 2)
 
-  return Buffer.concat([prefix, salt, encryptedHalf1, encryptedHalf2])
+  return Buffer.concat([prefix, salt, cipherText])
 }
 
 Bip38.prototype.encrypt = function(wif, passphrase, saltAddress) {
@@ -103,20 +119,16 @@ Bip38.prototype.decryptRaw = function(encData, passphrase) {
   var derivedHalf1 = scryptBuf.slice(0, 32)
   var derivedHalf2 = scryptBuf.slice(32, 64)
 
-  var aes = createAES(derivedHalf2)
-  var decryptFn = aes.decrypt.bind(aes)
-
   var privKeyBuf = encData.slice(7, 7 + 32)
-  var decryptedHalf1 = callAES(privKeyBuf.slice(0, 16), decryptFn)
-  var decryptedHalf2 = callAES(privKeyBuf.slice(16, 32), decryptFn)
-  var dec = Buffer.concat([decryptedHalf1, decryptedHalf2])
+  var decipher = crypto.createDecipheriv('aes-256-ecb', derivedHalf2, new Buffer(0))
+  decipher.setAutoPadding(false)
+  decipher.end(privKeyBuf)
 
-  for (var x = 0; x < 32; x++) {
-    dec[x] ^= derivedHalf1[x]
-  }
+  var plainText = decipher.read()
+  var privateKey = bufferXOR(plainText, derivedHalf1)
 
   return {
-    privateKey: dec,
+    privateKey: privateKey,
     compressed: compressed
   }
 }
@@ -185,15 +197,20 @@ Bip38.prototype.decryptECMult = function(encData, passphrase) {
   var derivedHalf1 = seedBPass.slice(0,32)
   var derivedHalf2 = seedBPass.slice(32,64)
 
-  var aes = createAES(derivedHalf2)
-  var decryptFn = aes.decrypt.bind(aes)
-
-  var tmp = BufferXOR(callAES(encryptedPart2, decryptFn), derivedHalf1.slice(16,32))
-  encryptedPart1 = Buffer.concat([encryptedPart1, tmp.slice(0, 8)], 16); // Append last 8 bytes
+  var decipher = crypto.createDecipheriv('aes-256-ecb', derivedHalf2, new Buffer(0))
+  decipher.setAutoPadding(false)
+  decipher.end(encryptedPart2)
 
+  var decryptedPart2 = decipher.read()
+  var tmp = bufferXOR(decryptedPart2, derivedHalf1.slice(16, 32))
   var seedBPart2 = tmp.slice(8, 16)
-  var tmp2 = callAES(encryptedPart1, decryptFn)
-  var seedBPart1 = BufferXOR(tmp2, derivedHalf1.slice(0,16))
+
+  var decipher2 = crypto.createDecipheriv('aes-256-ecb', derivedHalf2, new Buffer(0))
+  decipher2.setAutoPadding(false)
+  decipher2.write(encryptedPart1) // first 8 bytes
+  decipher2.end(tmp.slice(0, 8)) // last 8 bytes
+
+  var seedBPart1 = bufferXOR(decipher2.read(), derivedHalf1.slice(0, 16))
   var seedB = Buffer.concat([seedBPart1, seedBPart2], 24)
   var factorB = sha256x2(seedB)
 
@@ -206,50 +223,4 @@ Bip38.prototype.decryptECMult = function(encData, passphrase) {
   }
 }
 
-function BufferXOR(buf1, buf2) {
-  assert.equal(buf1.length, buf2.length)
-
-  var out = new Buffer(buf1.length)
-  for (var i = 0; i < buf1.length; i++) {
-    out[i] = buf1[i] ^ buf2[i]
-  }
-
-  return out
-}
-
-//convert 256 bit buffer to SJCL AES (requires big endian)
-function createAES(keyBuffer) {
-  assert.equal(keyBuffer.length, 32, 'AES key must be 256 bits')
-
-  var aesKey = []
-
-  for (var i = 0; i < 8; ++i) {
-    aesKey.push(keyBuffer.readUInt32BE(i*4))
-  }
-
-  return new AES(aesKey)
-}
-
-function callAES(dataBuffer, fn) {
-  var part = []
-  for (var i = 0; i < 4; ++i) {
-    part.push(dataBuffer.readUInt32BE(i * 4))
-  }
-
-  var encryptedData = fn(part)
-  var encryptedDataBuf = new Buffer(16)
-
-  for (var i = 0; i < encryptedData.length; ++i) {
-    encryptedDataBuf.writeUInt32BE(encryptedData[i], i * 4)
-  }
-
-  return encryptedDataBuf
-}
-
-// SHA256(SHA256(buffer))
-function sha256x2(buffer) {
-  buffer = crypto.createHash('sha256').update(buffer).digest()
-  return crypto.createHash('sha256').update(buffer).digest()
-}
-
 module.exports = Bip38

test/bip38.test.js

@@ -4,6 +4,8 @@ var Bip38 = require('../')
 var fixtures = require('./fixtures')
 
 describe('bip38', function() {
+  this.timeout(70000)
+
   var bip38
   beforeEach(function() {
     bip38 = new Bip38()