bitcoinjs-lib/src/wallet.js

var assert = require('assert')
var bufferutils = require('./bufferutils')
var crypto = require('crypto')
var networks = require('./networks')

var Address = require('./address')
var HDNode = require('./hdnode')
var TransactionBuilder = require('./transaction_builder')
var Script = require('./script')

function Wallet(seed, network) {
  seed = seed || crypto.randomBytes(32)
  network = network || networks.bitcoin

  // Stored in a closure to make accidental serialization less likely
  var masterKey = HDNode.fromSeedBuffer(seed, network)

  // HD first-level child derivation method should be hardened
  // See https://bitcointalk.org/index.php?topic=405179.msg4415254#msg4415254
  var accountZero = masterKey.deriveHardened(0)
  var externalAccount = accountZero.derive(0)
  var internalAccount = accountZero.derive(1)

  this.addresses = []
  this.changeAddresses = []
  this.network = network
  this.unspentMap = {}

  // FIXME: remove in 2.x.y
  var me = this
  this.newMasterKey = function(seed) {
    console.warn('newMasterKey is deprecated, please make a new Wallet instance instead')

    seed = seed || crypto.randomBytes(32)
    masterKey = HDNode.fromSeedBuffer(seed, network)

    accountZero = masterKey.deriveHardened(0)
    externalAccount = accountZero.derive(0)
    internalAccount = accountZero.derive(1)

    me.addresses = []
    me.changeAddresses = []

    me.unspentMap = {}
  }

  this.getMasterKey = function() { return masterKey }
  this.getAccountZero = function() { return accountZero }
  this.getExternalAccount = function() { return externalAccount }
  this.getInternalAccount = function() { return internalAccount }
}

Wallet.prototype.createTx = function(to, value, fixedFee, changeAddress) {
  assert(value > this.network.dustThreshold, value + ' must be above dust threshold (' + this.network.dustThreshold + ' Satoshis)')

  var utxos = getCandidateOutputs(this.unspentMap, value)
  var accum = 0
  var subTotal = value
  var addresses = []

  var txb = new TransactionBuilder()
  txb.addOutput(to, value)

  for (var i = 0; i < utxos.length; ++i) {
    var utxo = utxos[i]
    addresses.push(utxo.address)

    txb.addInput(utxo.hash, utxo.index)

    var fee = fixedFee === undefined ? estimatePaddedFee(txb.buildIncomplete(), this.network) : fixedFee

    accum += utxo.value
    subTotal = value + fee
    if (accum >= subTotal) {
      var change = accum - subTotal

      if (change > this.network.dustThreshold) {
        txb.addOutput(changeAddress || this.getChangeAddress(), change)
      }

      break
    }
  }

  assert(accum >= subTotal, 'Not enough funds (incl. fee): ' + accum + ' < ' + subTotal)

  return this.signWith(txb, addresses).build()
}

Wallet.prototype.processPendingTx = function(tx){
  this.__processTx(tx, true)
}

Wallet.prototype.processConfirmedTx = function(tx){
  this.__processTx(tx, false)
}

Wallet.prototype.__processTx = function(tx, isPending) {
  var txId = tx.getId()
  var txHash = tx.getHash()

  tx.outs.forEach(function(txOut, i) {
    var address

    try {
      address = Address.fromOutputScript(txOut.script, this.network).toString()
    } catch(e) {
      if (!(e.message.match(/has no matching Address/))) throw e
    }

    var myAddresses = this.addresses.concat(this.changeAddresses)
    if (myAddresses.indexOf(address) > -1) {
      var output = txId + ':' + i

      this.unspentMap[output] = {
        hash: txHash,
        index: i,
        value: txOut.value,
        address: address,
        pending: isPending
      }
    }
  }, this)

  tx.ins.forEach(function(txIn, i) {
    // copy and convert to big-endian hex
    var txinId = bufferutils.reverse(txIn.hash).toString('hex')
    var output = txinId + ':' + txIn.index

    if (!(output in this.unspentMap)) return

    if (isPending) {
      this.unspentMap[output].pending = true
      this.unspentMap[output].spent = true

    } else {
      delete this.unspentMap[output]
    }
  }, this)
}

Wallet.prototype.generateAddress = function() {
  var k = this.addresses.length
  var address = this.getExternalAccount().derive(k).getAddress()

  this.addresses.push(address.toString())

  return this.getReceiveAddress()
}

Wallet.prototype.generateChangeAddress = function() {
  var k = this.changeAddresses.length
  var address = this.getInternalAccount().derive(k).getAddress()

  this.changeAddresses.push(address.toString())

  return this.getChangeAddress()
}

Wallet.prototype.getBalance = function() {
  return this.getUnspentOutputs().reduce(function(accum, output) {
    return accum + output.value
  }, 0)
}

Wallet.prototype.getChangeAddress = function() {
  if (this.changeAddresses.length === 0) {
    this.generateChangeAddress()
  }

  return this.changeAddresses[this.changeAddresses.length - 1]
}

Wallet.prototype.getInternalPrivateKey = function(index) {
  return this.getInternalAccount().derive(index).privKey
}

Wallet.prototype.getPrivateKey = function(index) {
  return this.getExternalAccount().derive(index).privKey
}

Wallet.prototype.getPrivateKeyForAddress = function(address) {
  var index

  if ((index = this.addresses.indexOf(address)) > -1) {
    return this.getPrivateKey(index)
  }

  if ((index = this.changeAddresses.indexOf(address)) > -1) {
    return this.getInternalPrivateKey(index)
  }

  assert(false, 'Unknown address. Make sure the address is from the keychain and has been generated')
}

Wallet.prototype.getReceiveAddress = function() {
  if (this.addresses.length === 0) {
    this.generateAddress()
  }

  return this.addresses[this.addresses.length - 1]
}

Wallet.prototype.getUnspentOutputs = function() {
  var utxos = []

  for (var key in this.unspentMap) {
    var output = this.unspentMap[key]

    // Don't include pending spent outputs
    if (!output.spent) {
      // hash is little-endian, we want big-endian
      var txId = bufferutils.reverse(output.hash)

      utxos.push({
        hash: txId.toString('hex'),
        index: output.index,
        address: output.address,
        value: output.value,
        pending: output.pending
      })
    }
  }

  return utxos
}

Wallet.prototype.setUnspentOutputs = function(utxos) {
  utxos.forEach(function(utxo) {
    var txId = utxo.hash
    assert.equal(typeof txId, 'string', 'Expected txId, got ' +  txId)

    var hash = bufferutils.reverse(new Buffer(txId, 'hex'))
    var index = utxo.index
    var address = utxo.address
    var value = utxo.value

    // FIXME: remove alternative in 2.x.y
    if (index === undefined) index = utxo.outputIndex

    assert.equal(hash.length, 32, 'Expected hash length of 32, got ' + hash.length)
    assert.equal(typeof index, 'number', 'Expected number index, got ' + index)
    assert.doesNotThrow(function() { Address.fromBase58Check(address) }, 'Expected Base58 Address, got ' + address)
    assert.equal(typeof value, 'number', 'Expected number value, got ' + value)

    var output = txId + ':' + index

    this.unspentMap[output] = {
      address: address,
      hash: hash,
      index: index,
      pending: utxo.pending,
      value: value
    }
  }, this)
}

Wallet.prototype.signWith = function(tx, addresses) {
  addresses.forEach(function(address, i) {
    var privKey = this.getPrivateKeyForAddress(address)

    tx.sign(i, privKey)
  }, this)

  return tx
}

function estimatePaddedFee(tx, network) {
  var tmpTx = tx.clone()
  tmpTx.addOutput(Script.EMPTY, network.dustSoftThreshold || 0)

  return network.estimateFee(tmpTx)
}

function getCandidateOutputs(outputs/*, value*/) {
  var unspents = []

  for (var key in outputs) {
    var output = outputs[key]

    if (!output.pending) {
      unspents.push(output)
    }
  }

  // sorted by descending value
  return unspents.sort(function(o1, o2) {
    return o2.value - o1.value
  })
}

module.exports = Wallet