1 files changed, 244 insertions, 0 deletions

diff --git a/libs/bitcoinjs-bip38/index.js b/libs/bitcoinjs-bip38/index.js
new file mode 100644
index 0000000..51c20e4
--- /dev/null
+++ b/libs/bitcoinjs-bip38/index.js
@@ -0,0 +1,244 @@
+var aes = require('browserify-aes')
+var assert = require('assert')
+var Buffer = require('safe-buffer').Buffer
+var bs58check = require('bs58check')
+var createHash = require('create-hash')
+var scrypt = require('scryptsy')
+var xor = require('buffer-xor/inplace')
+
+var ecurve = require('ecurve')
+var curve = ecurve.getCurveByName('secp256k1')
+
+var BigInteger = require('bigi')
+
+// constants
+var SCRYPT_PARAMS = {
+  N: 16384, // specified by BIP38
+  r: 8,
+  p: 8
+}
+var NULL = Buffer.alloc(0)
+
+function hash160 (buffer) {
+  var hash
+  try {
+    hash = createHash('rmd160')
+  } catch (e) {
+    hash = createHash('ripemd160')
+  }
+  return hash.update(
+    createHash('sha256').update(buffer).digest()
+  ).digest()
+}
+
+function hash256 (buffer) {
+  return createHash('sha256').update(
+    createHash('sha256').update(buffer).digest()
+  ).digest()
+}
+
+function getAddress (d, compressed) {
+  var Q = curve.G.multiply(d).getEncoded(compressed)
+  var hash = hash160(Q)
+  var payload = Buffer.allocUnsafe(21)
+  payload.writeUInt8(0x00, 0) // XXX TODO FIXME bitcoin only??? damn you BIP38
+  hash.copy(payload, 1)
+
+  return bs58check.encode(payload)
+}
+
+function encryptRaw (buffer, compressed, passphrase, progressCallback, scryptParams) {
+  if (buffer.length !== 32) throw new Error('Invalid private key length')
+  scryptParams = scryptParams || SCRYPT_PARAMS
+
+  var d = BigInteger.fromBuffer(buffer)
+  var address = getAddress(d, compressed)
+  var secret = Buffer.from(passphrase, 'utf8')
+  var salt = hash256(address).slice(0, 4)
+
+  var N = scryptParams.N
+  var r = scryptParams.r
+  var p = scryptParams.p
+
+  var scryptBuf = scrypt(secret, salt, N, r, p, 64, progressCallback)
+  var derivedHalf1 = scryptBuf.slice(0, 32)
+  var derivedHalf2 = scryptBuf.slice(32, 64)
+
+  var xorBuf = xor(derivedHalf1, buffer)
+  var cipher = aes.createCipheriv('aes-256-ecb', derivedHalf2, NULL)
+  cipher.setAutoPadding(false)
+  cipher.end(xorBuf)
+
+  var cipherText = cipher.read()
+
+  // 0x01 | 0x42 | flagByte | salt (4) | cipherText (32)
+  var result = Buffer.allocUnsafe(7 + 32)
+  result.writeUInt8(0x01, 0)
+  result.writeUInt8(0x42, 1)
+  result.writeUInt8(compressed ? 0xe0 : 0xc0, 2)
+  salt.copy(result, 3)
+  cipherText.copy(result, 7)
+
+  return result
+}
+
+function encrypt (buffer, compressed, passphrase, progressCallback, scryptParams) {
+  return bs58check.encode(encryptRaw(buffer, compressed, passphrase, progressCallback, scryptParams))
+}
+
+// some of the techniques borrowed from: https://github.com/pointbiz/bitaddress.org
+function decryptRaw (buffer, passphrase, progressCallback, scryptParams) {
+  // 39 bytes: 2 bytes prefix, 37 bytes payload
+  if (buffer.length !== 39) throw new Error('Invalid BIP38 data length')
+  if (buffer.readUInt8(0) !== 0x01) throw new Error('Invalid BIP38 prefix')
+  scryptParams = scryptParams || SCRYPT_PARAMS
+
+  // check if BIP38 EC multiply
+  var type = buffer.readUInt8(1)
+  if (type === 0x43) return decryptECMult(buffer, passphrase, progressCallback, scryptParams)
+  if (type !== 0x42) throw new Error('Invalid BIP38 type')
+
+  passphrase = Buffer.from(passphrase, 'utf8')
+
+  var flagByte = buffer.readUInt8(2)
+  var compressed = flagByte === 0xe0
+  if (!compressed && flagByte !== 0xc0) throw new Error('Invalid BIP38 compression flag')
+
+  var N = scryptParams.N
+  var r = scryptParams.r
+  var p = scryptParams.p
+
+  var salt = buffer.slice(3, 7)
+  var scryptBuf = scrypt(passphrase, salt, N, r, p, 64, progressCallback)
+  var derivedHalf1 = scryptBuf.slice(0, 32)
+  var derivedHalf2 = scryptBuf.slice(32, 64)
+
+  var privKeyBuf = buffer.slice(7, 7 + 32)
+  var decipher = aes.createDecipheriv('aes-256-ecb', derivedHalf2, NULL)
+  decipher.setAutoPadding(false)
+  decipher.end(privKeyBuf)
+
+  var plainText = decipher.read()
+  var privateKey = xor(derivedHalf1, plainText)
+
+  // verify salt matches address
+  var d = BigInteger.fromBuffer(privateKey)
+  var address = getAddress(d, compressed)
+  var checksum = hash256(address).slice(0, 4)
+  assert.deepStrictEqual(salt, checksum)
+
+  return {
+    privateKey: privateKey,
+    compressed: compressed
+  }
+}
+
+function decrypt (string, passphrase, progressCallback, scryptParams) {
+  return decryptRaw(bs58check.decode(string), passphrase, progressCallback, scryptParams)
+}
+
+function decryptECMult (buffer, passphrase, progressCallback, scryptParams) {
+  passphrase = Buffer.from(passphrase, 'utf8')
+  buffer = buffer.slice(1) // FIXME: we can avoid this
+  scryptParams = scryptParams || SCRYPT_PARAMS
+
+  var flag = buffer.readUInt8(1)
+  var compressed = (flag & 0x20) !== 0
+  var hasLotSeq = (flag & 0x04) !== 0
+
+  assert.strictEqual((flag & 0x24), flag, 'Invalid private key.')
+
+  var addressHash = buffer.slice(2, 6)
+  var ownerEntropy = buffer.slice(6, 14)
+  var ownerSalt
+
+  // 4 bytes ownerSalt if 4 bytes lot/sequence
+  if (hasLotSeq) {
+    ownerSalt = ownerEntropy.slice(0, 4)
+
+  // else, 8 bytes ownerSalt
+  } else {
+    ownerSalt = ownerEntropy
+  }
+
+  var encryptedPart1 = buffer.slice(14, 22) // First 8 bytes
+  var encryptedPart2 = buffer.slice(22, 38) // 16 bytes
+
+  var N = scryptParams.N
+  var r = scryptParams.r
+  var p = scryptParams.p
+  var preFactor = scrypt(passphrase, ownerSalt, N, r, p, 32, progressCallback)
+
+  var passFactor
+  if (hasLotSeq) {
+    var hashTarget = Buffer.concat([preFactor, ownerEntropy])
+    passFactor = hash256(hashTarget)
+  } else {
+    passFactor = preFactor
+  }
+
+  var passInt = BigInteger.fromBuffer(passFactor)
+  var passPoint = curve.G.multiply(passInt).getEncoded(true)
+
+  var seedBPass = scrypt(passPoint, Buffer.concat([addressHash, ownerEntropy]), 1024, 1, 1, 64)
+  var derivedHalf1 = seedBPass.slice(0, 32)
+  var derivedHalf2 = seedBPass.slice(32, 64)
+
+  var decipher = aes.createDecipheriv('aes-256-ecb', derivedHalf2, Buffer.alloc(0))
+  decipher.setAutoPadding(false)
+  decipher.end(encryptedPart2)
+
+  var decryptedPart2 = decipher.read()
+  var tmp = xor(decryptedPart2, derivedHalf1.slice(16, 32))
+  var seedBPart2 = tmp.slice(8, 16)
+
+  var decipher2 = aes.createDecipheriv('aes-256-ecb', derivedHalf2, Buffer.alloc(0))
+  decipher2.setAutoPadding(false)
+  decipher2.write(encryptedPart1) // first 8 bytes
+  decipher2.end(tmp.slice(0, 8)) // last 8 bytes
+
+  var seedBPart1 = xor(decipher2.read(), derivedHalf1.slice(0, 16))
+  var seedB = Buffer.concat([seedBPart1, seedBPart2], 24)
+  var factorB = BigInteger.fromBuffer(hash256(seedB))
+
+  // d = passFactor * factorB (mod n)
+  var d = passInt.multiply(factorB).mod(curve.n)
+
+  return {
+    privateKey: d.toBuffer(32),
+    compressed: compressed
+  }
+}
+
+function verify (string) {
+  var decoded = bs58check.decodeUnsafe(string)
+  if (!decoded) return false
+
+  if (decoded.length !== 39) return false
+  if (decoded.readUInt8(0) !== 0x01) return false
+
+  var type = decoded.readUInt8(1)
+  var flag = decoded.readUInt8(2)
+
+  // encrypted WIF
+  if (type === 0x42) {
+    if (flag !== 0xc0 && flag !== 0xe0) return false
+
+  // EC mult
+  } else if (type === 0x43) {
+    if ((flag & ~0x24)) return false
+  } else {
+    return false
+  }
+
+  return true
+}
+
+module.exports = {
+  decrypt: decrypt,
+  decryptECMult: decryptECMult,
+  decryptRaw: decryptRaw,
+  encrypt: encrypt,
+  encryptRaw: encryptRaw,
+  verify: verify
+}