bitcoinjs-lib/src/address.js

var base58 = require('./base58');
var Crypto = require('./crypto-js/crypto');
var conv = require('./convert');

var address_types = {
    prod: 0,
    testnet: 111
};

var p2sh_types = {
    prod: 5,
    testnet: 196
};

var Address = function (bytes) {
  if (typeof bytes === 'string') {
    bytes = Address.decodeString(bytes);
  }
  this.hash = bytes;

  this.version = 0x00;
};

/**
 * Serialize this object as a standard Bitcoin address.
 *
 * Returns the address as a base58-encoded string in the standardized format.
 */
Address.prototype.toString = function () {
  // Get a copy of the hash
  var hash = this.hash.slice(0);

  // Version
  hash.unshift(this.version);

  var checksum = Crypto.SHA256(Crypto.SHA256(hash, {asBytes: true}), {asBytes: true});

  var bytes = hash.concat(checksum.slice(0,4));

  return base58.encode(bytes);
};

Address.prototype.getHashBase64 = function () {
  return conv.bytesToBase64(this.hash);
};

// TODO(shtylman) isValid?
Address.validate = function(string, type) {
  try {
    var bytes = base58.decode(string);
  } catch (e) {
    return false;
  }

  var hash = bytes.slice(0, 21);

  var checksum = Crypto.SHA256(Crypto.SHA256(hash, {asBytes: true}), {asBytes: true});

  if (checksum[0] != bytes[21] ||
      checksum[1] != bytes[22] ||
      checksum[2] != bytes[23] ||
      checksum[3] != bytes[24]) {
    return false;
  }

  var version = hash[0];

  if (type && version !== address_types[type] && version !== p2sh_types[type]) {
    return false;
  }

  return true;
};

/**
 * Parse a Bitcoin address contained in a string.
 */
Address.decodeString = function (string) {
  var bytes = base58.decode(string);

  var hash = bytes.slice(0, 21);

  var checksum = Crypto.SHA256(Crypto.SHA256(hash, {asBytes: true}), {asBytes: true});

  if (checksum[0] != bytes[21] ||
      checksum[1] != bytes[22] ||
      checksum[2] != bytes[23] ||
      checksum[3] != bytes[24]) {
    throw new Error('Address Checksum validation failed: ' + string);
  }

  var version = hash.shift();
  // TODO(shtylman) allow for specific version decoding same as validate above
  if (version != 0) {
    throw new Error('Address version not supported: ' + string);
  }

  return hash;
};

module.exports = Address;