Hello World

utils/rm/node_modules/ip-address/lib/ipv6.js

@@ -0,0 +1,966 @@
+'use strict';
+
+var BigInteger = require('jsbn').BigInteger;
+var sprintf = require('sprintf-js').sprintf;
+var _ = require('lodash');
+
+var constants4 = require('./v4/constants.js');
+var constants6 = require('./v6/constants.js');
+
+var Address4 = require('./ipv4.js');
+
+function addCommas(number) {
+  var r = /(\d+)(\d{3})/;
+
+  while (r.test(number)) {
+    number = number.replace(r, '$1,$2');
+  }
+
+  return number;
+}
+
+function spanLeadingZeroes4(n) {
+  n = n.replace(/^(0{1,})([1-9]+)$/, '<span class="parse-error">$1</span>$2');
+  n = n.replace(/^(0{1,})(0)$/, '<span class="parse-error">$1</span>$2');
+
+  return n;
+}
+
+/**
+ * Represents an IPv6 address
+ * @class Address6
+ * @param {string} address - An IPv6 address string
+ * @param {number} [groups=8] - How many octets to parse
+ * @example
+ * var address = new Address6('2001::/32');
+ */
+function Address6(address, optionalGroups) {
+  if (optionalGroups === undefined) {
+    this.groups = constants6.GROUPS;
+  } else {
+    this.groups = optionalGroups;
+  }
+
+  this.v4 = false;
+
+  this.subnet = '/128';
+  this.subnetMask = 128;
+
+  this.zone = '';
+
+  this.address = address;
+
+  var subnet = constants6.RE_SUBNET_STRING.exec(address);
+
+  if (subnet) {
+    this.parsedSubnet = subnet[0].replace('/', '');
+    this.subnetMask = parseInt(this.parsedSubnet, 10);
+    this.subnet = '/' + this.subnetMask;
+
+    if (isNaN(this.subnetMask) ||
+      this.subnetMask < 0 ||
+      this.subnetMask > constants6.BITS) {
+      this.valid = false;
+      this.error = 'Invalid subnet mask.';
+
+      return;
+    }
+
+    address = address.replace(constants6.RE_SUBNET_STRING, '');
+  } else if (/\//.test(address)) {
+    this.valid = false;
+    this.error = 'Invalid subnet mask.';
+
+    return;
+  }
+
+  var zone = constants6.RE_ZONE_STRING.exec(address);
+
+  if (zone) {
+    this.zone = zone[0];
+
+    address = address.replace(constants6.RE_ZONE_STRING, '');
+  }
+
+  this.addressMinusSuffix = address;
+
+  this.parsedAddress = this.parse(this.addressMinusSuffix);
+}
+
+_.merge(Address6.prototype, require('./v6/attributes.js'));
+_.merge(Address6.prototype, require('./v6/html.js'));
+_.merge(Address6.prototype, require('./v6/regular-expressions.js'));
+
+/**
+ * Convert a BigInteger to a v6 address object
+ * @memberof Address6
+ * @static
+ * @param {BigInteger} bigInteger - a BigInteger to convert
+ * @returns {Address6}
+ * @example
+ * var bigInteger = new BigInteger('1000000000000');
+ * var address = Address6.fromBigInteger(bigInteger);
+ * address.correctForm(); // '::e8:d4a5:1000'
+ */
+Address6.fromBigInteger = function (bigInteger) {
+  var hex = _.padStart(bigInteger.toString(16), 32, '0');
+  var groups = [];
+  var i;
+
+  for (i = 0; i < constants6.GROUPS; i++) {
+    groups.push(hex.slice(i * 4, (i + 1) * 4));
+  }
+
+  return new Address6(groups.join(':'));
+};
+
+/**
+ * Convert a URL (with optional port number) to an address object
+ * @memberof Address6
+ * @static
+ * @param {string} url - a URL with optional port number
+ * @returns {Address6}
+ * @example
+ * var addressAndPort = Address6.fromURL('http://[ffff::]:8080/foo/');
+ * addressAndPort.address.correctForm(); // 'ffff::'
+ * addressAndPort.port; // 8080
+ */
+Address6.fromURL = function (url) {
+  var host;
+  var port;
+  var result;
+
+  // If we have brackets parse them and find a port
+  if (url.indexOf('[') !== -1 && url.indexOf(']:') !== -1) {
+    result = constants6.RE_URL_WITH_PORT.exec(url);
+
+    if (result === null) {
+      return {
+        error: 'failed to parse address with port',
+        address: null,
+        port: null
+      };
+    }
+
+    host = result[1];
+    port = result[2];
+  // If there's a URL extract the address
+  } else if (url.indexOf('/') !== -1) {
+    // Remove the protocol prefix
+    url = url.replace(/^[a-z0-9]+:\/\//, '');
+
+    // Parse the address
+    result = constants6.RE_URL.exec(url);
+
+    if (result === null) {
+      return {
+        error: 'failed to parse address from URL',
+        address: null,
+        port: null
+      };
+    }
+
+    host = result[1];
+  // Otherwise just assign the URL to the host and let the library parse it
+  } else {
+    host = url;
+  }
+
+  // If there's a port convert it to an integer
+  if (port) {
+    port = parseInt(port, 10);
+
+    //squelch out of range ports
+    if (port < 0 || port > 65536) {
+      port = null;
+    }
+  } else {
+    // Standardize `undefined` to `null`
+    port = null;
+  }
+
+  return {
+    address: new Address6(host),
+    port: port
+  };
+};
+
+/**
+ * Create an IPv6-mapped address given an IPv4 address
+ * @memberof Address6
+ * @static
+ * @param {string} address - An IPv4 address string
+ * @returns {Address6}
+ * @example
+ * var address = Address6.fromAddress4('192.168.0.1');
+ * address.correctForm(); // '::ffff:c0a8:1'
+ * address.to4in6(); // '::ffff:192.168.0.1'
+ */
+Address6.fromAddress4 = function (address4) {
+  var address4 = new Address4(address4);
+
+  var mask6 = constants6.BITS - (constants4.BITS - address4.subnetMask);
+
+  return new Address6('::ffff:' + address4.correctForm() + '/' + mask6);
+};
+
+/**
+ * Return an address from ip6.arpa form
+ * @memberof Address6
+ * @static
+ * @param {string} arpaFormAddress - an 'ip6.arpa' form address 
+ * @returns {Adress6}
+ * @example
+ * var address = Address6.fromArpa(e.f.f.f.3.c.2.6.f.f.f.e.6.6.8.e.1.0.6.7.9.4.e.c.0.0.0.0.1.0.0.2.ip6.arpa.)
+ * address.correctForm(); // '2001:0:ce49:7601:e866:efff:62c3:fffe'
+ */
+Address6.fromArpa = function (arpaFormAddress) {
+  //remove ending ".ip6.arpa." or just "."
+  var address = arpaFormAddress.replace(/(\.ip6\.arpa)?\.$/, '');
+  var semicolonAmount = 7;
+
+  //correct ip6.arpa form with ending removed will be 63 characters
+  if (address.length !== 63) {
+    address = {
+      error: "Not Valid 'ip6.arpa' form",
+      address: null
+    };
+    return address;
+  }
+
+  address = address.split('.').reverse();
+
+  for (var i = semicolonAmount; i > 0; i--) {
+    var insertIndex = i * 4;
+    address.splice(insertIndex, 0, ':');
+  }
+
+  address = address.join('');
+  return new Address6(address);
+};
+
+/*
+ * A helper function to compact an array
+ */
+function compact (address, slice) {
+  var s1 = [];
+  var s2 = [];
+  var i;
+
+  for (i = 0; i < address.length; i++) {
+    if (i < slice[0]) {
+      s1.push(address[i]);
+    } else if (i > slice[1]) {
+      s2.push(address[i]);
+    }
+  }
+
+  return s1.concat(['compact']).concat(s2);
+}
+
+/**
+ * Return the Microsoft UNC transcription of the address
+ * @memberof Address6
+ * @instance
+ * @returns {String} the Microsoft UNC transcription of the address
+ */
+Address6.prototype.microsoftTranscription = function () {
+  return sprintf('%s.ipv6-literal.net',
+    this.correctForm().replace(/:/g, '-'));
+};
+
+/**
+ * Return the first n bits of the address, defaulting to the subnet mask
+ * @memberof Address6
+ * @instance
+ * @param {number} [mask=subnet] - the number of bits to mask
+ * @returns {String} the first n bits of the address as a string
+ */
+Address6.prototype.mask = function (optionalMask) {
+  if (optionalMask === undefined) {
+    optionalMask = this.subnetMask;
+  }
+
+  return this.getBitsBase2(0, optionalMask);
+};
+
+/**
+ * Return the number of possible subnets of a given size in the address
+ * @memberof Address6
+ * @instance
+ * @param {number} [size=128] - the subnet size
+ * @returns {String}
+ */
+// TODO: probably useful to have a numeric version of this too
+Address6.prototype.possibleSubnets = function (optionalSubnetSize) {
+  if (optionalSubnetSize === undefined) {
+    optionalSubnetSize = 128;
+  }
+
+  var availableBits = constants6.BITS - this.subnetMask;
+  var subnetBits = Math.abs(optionalSubnetSize - constants6.BITS);
+  var subnetPowers = availableBits - subnetBits;
+
+  if (subnetPowers < 0) {
+    return '0';
+  }
+
+  return addCommas(new BigInteger('2', 10).pow(subnetPowers).toString(10));
+};
+
+/**
+ * Helper function getting start address.
+ * @memberof Address6
+ * @instance
+ * @returns {BigInteger}
+ */
+Address6.prototype._startAddress = function () {
+  return new BigInteger(
+    this.mask() + _.repeat('0', constants6.BITS - this.subnetMask), 2
+  );
+};
+
+/**
+ * The first address in the range given by this address' subnet
+ * Often referred to as the Network Address.
+ * @memberof Address6
+ * @instance
+ * @returns {Address6}
+ */
+Address6.prototype.startAddress = function () {
+  return Address6.fromBigInteger(this._startAddress());
+};
+
+/**
+ * The first host address in the range given by this address's subnet ie
+ * the first address after the Network Address
+ * @memberof Address6
+ * @instance
+ * @returns {Address6}
+ */
+Address6.prototype.startAddressExclusive = function () {
+  var adjust = new BigInteger('1');
+  return Address6.fromBigInteger(this._startAddress().add(adjust));
+};
+
+/**
+ * Helper function getting end address.
+ * @memberof Address6
+ * @instance
+ * @returns {BigInteger}
+ */
+Address6.prototype._endAddress = function () {
+  return new BigInteger(
+    this.mask() + _.repeat('1', constants6.BITS - this.subnetMask), 2
+  );
+};
+
+/**
+ * The last address in the range given by this address' subnet
+ * Often referred to as the Broadcast
+ * @memberof Address6
+ * @instance
+ * @returns {Address6}
+ */
+Address6.prototype.endAddress = function () {
+  return Address6.fromBigInteger(this._endAddress());
+};
+
+/**
+ * The last host address in the range given by this address's subnet ie
+ * the last address prior to the Broadcast Address
+ * @memberof Address6
+ * @instance
+ * @returns {Address6}
+ */
+Address6.prototype.endAddressExclusive = function () {
+  var adjust = new BigInteger('1');
+  return Address6.fromBigInteger(this._endAddress().subtract(adjust));
+};
+
+/**
+ * Return the scope of the address
+ * @memberof Address6
+ * @instance
+ * @returns {String}
+ */
+Address6.prototype.getScope = function () {
+  var scope = constants6.SCOPES[this.getBits(12, 16)];
+
+  if (this.getType() === 'Global unicast' &&
+      scope !== 'Link local') {
+    scope = 'Global';
+  }
+
+  return scope;
+};
+
+/**
+ * Return the type of the address
+ * @memberof Address6
+ * @instance
+ * @returns {String}
+ */
+Address6.prototype.getType = function () {
+  var self = this;
+
+  function isType(name, type) {
+    return self.isInSubnet(new Address6(type));
+  }
+
+  return _.find(constants6.TYPES, isType) || 'Global unicast';
+};
+
+/**
+ * Return the bits in the given range as a BigInteger
+ * @memberof Address6
+ * @instance
+ * @returns {BigInteger}
+ */
+Address6.prototype.getBits = function (start, end) {
+  return new BigInteger(this.getBitsBase2(start, end), 2);
+};
+
+/**
+ * Return the bits in the given range as a base-2 string
+ * @memberof Address6
+ * @instance
+ * @returns {String}
+ */
+Address6.prototype.getBitsBase2 = function (start, end) {
+  return this.binaryZeroPad().slice(start, end);
+};
+
+/**
+ * Return the bits in the given range as a base-16 string
+ * @memberof Address6
+ * @instance
+ * @returns {String}
+ */
+Address6.prototype.getBitsBase16 = function (start, end) {
+  var length = end - start;
+
+  if (length % 4 !== 0) {
+    return null;
+  }
+
+  return _.padStart(this.getBits(start, end).toString(16), length / 4, '0');
+};
+
+/**
+ * Return the bits that are set past the subnet mask length
+ * @memberof Address6
+ * @instance
+ * @returns {String}
+ */
+Address6.prototype.getBitsPastSubnet = function () {
+  return this.getBitsBase2(this.subnetMask, constants6.BITS);
+};
+
+/**
+ * Return the reversed ip6.arpa form of the address
+ * @memberof Address6
+ * @param {Object} options
+ * @param {boolean} options.omitSuffix - omit the "ip6.arpa" suffix
+ * @instance
+ * @returns {String}
+ */
+Address6.prototype.reverseForm = function (options) {
+  if (!options) {
+    options = {};
+  }
+
+  var characters = Math.floor(this.subnetMask / 4);
+
+  var reversed = this.canonicalForm()
+    .replace(/:/g, '')
+    .split('')
+    .slice(0, characters)
+    .reverse()
+    .join('.');
+
+  if (characters > 0) {
+    if (options.omitSuffix) {
+      return reversed;
+    }
+
+    return sprintf('%s.ip6.arpa.', reversed);
+  }
+
+  if (options.omitSuffix) {
+    return '';
+  }
+
+  return 'ip6.arpa.';
+};
+
+/**
+ * Return the correct form of the address
+ * @memberof Address6
+ * @instance
+ * @returns {String}
+ */
+Address6.prototype.correctForm = function () {
+  if (!this.parsedAddress) {
+    return null;
+  }
+
+  var i;
+  var groups = [];
+
+  var zeroCounter = 0;
+  var zeroes = [];
+
+  for (i = 0; i < this.parsedAddress.length; i++) {
+    var value = parseInt(this.parsedAddress[i], 16);
+
+    if (value === 0) {
+      zeroCounter++;
+    }
+
+    if (value !== 0 && zeroCounter > 0) {
+      if (zeroCounter > 1) {
+        zeroes.push([i - zeroCounter, i - 1]);
+      }
+
+      zeroCounter = 0;
+    }
+  }
+
+  // Do we end with a string of zeroes?
+  if (zeroCounter > 1) {
+    zeroes.push([this.parsedAddress.length - zeroCounter,
+      this.parsedAddress.length - 1]);
+  }
+
+  var zeroLengths = zeroes.map(function (n) {
+    return (n[1] - n[0]) + 1;
+  });
+
+  if (zeroes.length > 0) {
+    var index = zeroLengths.indexOf(_.max(zeroLengths));
+
+    groups = compact(this.parsedAddress, zeroes[index]);
+  } else {
+    groups = this.parsedAddress;
+  }
+
+  for (i = 0; i < groups.length; i++) {
+    if (groups[i] !== 'compact') {
+      groups[i] = parseInt(groups[i], 16).toString(16);
+    }
+  }
+
+  var correct = groups.join(':');
+
+  correct = correct.replace(/^compact$/, '::');
+  correct = correct.replace(/^compact|compact$/, ':');
+  correct = correct.replace(/compact/, '');
+
+  return correct;
+};
+
+/**
+ * Return a zero-padded base-2 string representation of the address
+ * @memberof Address6
+ * @instance
+ * @returns {String}
+ * @example
+ * var address = new Address6('2001:4860:4001:803::1011');
+ * address.binaryZeroPad();
+ * // '0010000000000001010010000110000001000000000000010000100000000011
+ * //  0000000000000000000000000000000000000000000000000001000000010001'
+ */
+Address6.prototype.binaryZeroPad = function () {
+  return _.padStart(this.bigInteger().toString(2), constants6.BITS, '0');
+};
+
+// TODO: Improve the semantics of this helper function
+Address6.prototype.parse4in6 = function (address) {
+  var groups = address.split(':');
+  var lastGroup = groups.slice(-1)[0];
+
+  var address4 = lastGroup.match(constants4.RE_ADDRESS);
+
+  if (address4) {
+    var temp4 = new Address4(address4[0]);
+
+    for (var i = 0; i < temp4.groups; i++) {
+      if (/^0[0-9]+/.test(temp4.parsedAddress[i])) {
+        this.valid = false;
+        this.error = 'IPv4 addresses can not have leading zeroes.';
+
+        this.parseError = address.replace(constants4.RE_ADDRESS,
+          temp4.parsedAddress.map(spanLeadingZeroes4).join('.'));
+
+        return null;
+      }
+    }
+
+    this.v4 = true;
+
+    groups[groups.length - 1] = temp4.toGroup6();
+
+    address = groups.join(':');
+  }
+
+  return address;
+};
+
+// TODO: Make private?
+Address6.prototype.parse = function (address) {
+  address = this.parse4in6(address);
+
+  if (this.error) {
+    return null;
+  }
+
+  var badCharacters = address.match(constants6.RE_BAD_CHARACTERS);
+
+  if (badCharacters) {
+    this.valid = false;
+    this.error = sprintf('Bad character%s detected in address: %s',
+      badCharacters.length > 1 ? 's' : '', badCharacters.join(''));
+
+    this.parseError = address.replace(constants6.RE_BAD_CHARACTERS,
+      '<span class="parse-error">$1</span>');
+
+    return null;
+  }
+
+  var badAddress = address.match(constants6.RE_BAD_ADDRESS);
+
+  if (badAddress) {
+    this.valid = false;
+    this.error = sprintf('Address failed regex: %s', badAddress.join(''));
+
+    this.parseError = address.replace(constants6.RE_BAD_ADDRESS,
+      '<span class="parse-error">$1</span>');
+
+    return null;
+  }
+
+  var groups = [];
+
+  var halves = address.split('::');
+
+  if (halves.length === 2) {
+    var first = halves[0].split(':');
+    var last = halves[1].split(':');
+
+    if (first.length === 1 &&
+      first[0] === '') {
+      first = [];
+    }
+
+    if (last.length === 1 &&
+      last[0] === '') {
+      last = [];
+    }
+
+    var remaining = this.groups - (first.length + last.length);
+
+    if (!remaining) {
+      this.valid = false;
+      this.error = 'Error parsing groups';
+
+      return null;
+    }
+
+    this.elidedGroups = remaining;
+
+    this.elisionBegin = first.length;
+    this.elisionEnd = first.length + this.elidedGroups;
+
+    first.forEach(function (group) {
+      groups.push(group);
+    });
+
+    for (var i = 0; i < remaining; i++) {
+      groups.push(0);
+    }
+
+    last.forEach(function (group) {
+      groups.push(group);
+    });
+  } else if (halves.length === 1) {
+    groups = address.split(':');
+
+    this.elidedGroups = 0;
+  } else {
+    this.valid = false;
+    this.error = 'Too many :: groups found';
+
+    return null;
+  }
+
+  groups = groups.map(function (g) {
+    return sprintf('%x', parseInt(g, 16));
+  });
+
+  if (groups.length !== this.groups) {
+    this.valid = false;
+    this.error = 'Incorrect number of groups found';
+
+    return null;
+  }
+
+  this.valid = true;
+
+  return groups;
+};
+
+function paddedHex(octet) {
+  return sprintf('%04x', parseInt(octet, 16));
+}
+
+/**
+ * Return the canonical form of the address
+ * @memberof Address6
+ * @instance
+ * @returns {String}
+ */
+Address6.prototype.canonicalForm = function () {
+  if (!this.valid) {
+    return null;
+  }
+
+  return this.parsedAddress.map(paddedHex).join(':');
+};
+
+/**
+ * Return the decimal form of the address
+ * @memberof Address6
+ * @instance
+ * @returns {String}
+ */
+Address6.prototype.decimal = function () {
+  if (!this.valid) {
+    return null;
+  }
+
+  return this.parsedAddress.map(function (n) {
+    return sprintf('%05d', parseInt(n, 16));
+  }).join(':');
+};
+
+/**
+ * Return the address as a BigInteger
+ * @memberof Address6
+ * @instance
+ * @returns {BigInteger}
+ */
+Address6.prototype.bigInteger = function () {
+  if (!this.valid) {
+    return null;
+  }
+
+  return new BigInteger(this.parsedAddress.map(paddedHex).join(''), 16);
+};
+
+/**
+ * Return the last two groups of this address as an IPv4 address string
+ * @memberof Address6
+ * @instance
+ * @returns {String}
+ * @example
+ * var address = new Address6('2001:4860:4001::1825:bf11');
+ * address.to4(); // '24.37.191.17'
+ */
+Address6.prototype.to4 = function () {
+  var binary = this.binaryZeroPad().split('');
+
+  return Address4.fromHex(new BigInteger(binary.slice(96, 128)
+    .join(''), 2).toString(16));
+};
+
+/**
+ * Return the v4-in-v6 form of the address
+ * @memberof Address6
+ * @instance
+ * @returns {String}
+ */
+Address6.prototype.to4in6 = function () {
+  var address4 = this.to4();
+  var address6 = new Address6(this.parsedAddress.slice(0, 6).join(':'), 6);
+
+  var correct = address6.correctForm();
+
+  var infix = '';
+
+  if (!/:$/.test(correct)) {
+    infix = ':';
+  }
+
+  return address6.correctForm() + infix + address4.address;
+};
+
+/**
+ * Return an object containing the Teredo properties of the address
+ * @memberof Address6
+ * @instance
+ * @returns {Object}
+ */
+Address6.prototype.inspectTeredo = function () {
+  /*
+  - Bits 0 to 31 are set to the Teredo prefix (normally 2001:0000::/32).
+  - Bits 32 to 63 embed the primary IPv4 address of the Teredo server that
+    is used.
+  - Bits 64 to 79 can be used to define some flags. Currently only the
+    higher order bit is used; it is set to 1 if the Teredo client is
+    located behind a cone NAT, 0 otherwise. For Microsoft's Windows Vista
+    and Windows Server 2008 implementations, more bits are used. In those
+    implementations, the format for these 16 bits is "CRAAAAUG AAAAAAAA",
+    where "C" remains the "Cone" flag. The "R" bit is reserved for future
+    use. The "U" bit is for the Universal/Local flag (set to 0). The "G" bit
+    is Individual/Group flag (set to 0). The A bits are set to a 12-bit
+    randomly generated number chosen by the Teredo client to introduce
+    additional protection for the Teredo node against IPv6-based scanning
+    attacks.
+  - Bits 80 to 95 contains the obfuscated UDP port number. This is the
+    port number that is mapped by the NAT to the Teredo client with all
+    bits inverted.
+  - Bits 96 to 127 contains the obfuscated IPv4 address. This is the
+    public IPv4 address of the NAT with all bits inverted.
+  */
+  var prefix = this.getBitsBase16(0, 32);
+
+  var udpPort = this.getBits(80, 96).xor(new BigInteger('ffff', 16)).toString();
+
+  var server4 = Address4.fromHex(this.getBitsBase16(32, 64));
+  var client4 = Address4.fromHex(this.getBits(96, 128)
+    .xor(new BigInteger('ffffffff', 16)).toString(16));
+
+  var flags = this.getBits(64, 80);
+  var flagsBase2 = this.getBitsBase2(64, 80);
+
+  var coneNat = flags.testBit(15);
+  var reserved = flags.testBit(14);
+  var groupIndividual = flags.testBit(8);
+  var universalLocal = flags.testBit(9);
+  var nonce = new BigInteger(flagsBase2.slice(2, 6) +
+    flagsBase2.slice(8, 16), 2).toString(10);
+
+  return {
+    prefix: sprintf('%s:%s', prefix.slice(0, 4), prefix.slice(4, 8)),
+    server4: server4.address,
+    client4: client4.address,
+    flags: flagsBase2,
+    coneNat: coneNat,
+    microsoft: {
+      reserved: reserved,
+      universalLocal: universalLocal,
+      groupIndividual: groupIndividual,
+      nonce: nonce
+    },
+    udpPort: udpPort
+  };
+};
+
+/**
+ * Return an object containing the 6to4 properties of the address
+ * @memberof Address6
+ * @instance
+ * @returns {Object}
+ */
+Address6.prototype.inspect6to4 = function () {
+  /*
+  - Bits 0 to 15 are set to the 6to4 prefix (2002::/16).
+  - Bits 16 to 48 embed the IPv4 address of the 6to4 gateway that is used.
+  */
+
+  var prefix = this.getBitsBase16(0, 16);
+
+  var gateway = Address4.fromHex(this.getBitsBase16(16, 48));
+
+  return {
+    prefix: sprintf('%s', prefix.slice(0, 4)),
+    gateway: gateway.address
+  };
+};
+
+/**
+ * Return a v6 6to4 address from a v6 v4inv6 address
+ * @memberof Address6
+ * @instance
+ * @returns {Address6}
+ */
+Address6.prototype.to6to4 = function () {
+  if (!this.is4()) {
+    return null;
+  }
+
+  var addr6to4 = [
+    '2002',
+    this.getBitsBase16(96, 112),
+    this.getBitsBase16(112, 128),
+    '',
+    '/16'
+  ].join(':');
+
+  return new Address6(addr6to4);
+};
+
+/**
+ * Return a byte array
+ * @memberof Address6
+ * @instance
+ * @returns {Array}
+ */
+Address6.prototype.toByteArray = function () {
+  var byteArray = this.bigInteger().toByteArray();
+
+  // work around issue where `toByteArray` returns a leading 0 element
+  if (byteArray.length === 17 && byteArray[0] === 0) {
+    return byteArray.slice(1);
+  }
+
+  return byteArray;
+};
+
+function unsignByte(b) {
+  return b & 0xFF;
+}
+
+/**
+ * Return an unsigned byte array
+ * @memberof Address6
+ * @instance
+ * @returns {Array}
+ */
+Address6.prototype.toUnsignedByteArray = function () {
+  return this.toByteArray().map(unsignByte);
+};
+
+/**
+ * Convert a byte array to an Address6 object
+ * @memberof Address6
+ * @static
+ * @returns {Address6}
+ */
+Address6.fromByteArray = function (bytes) {
+  return this.fromUnsignedByteArray(bytes.map(unsignByte));
+};
+
+/**
+ * Convert an unsigned byte array to an Address6 object
+ * @memberof Address6
+ * @static
+ * @returns {Address6}
+ */
+Address6.fromUnsignedByteArray = function (bytes) {
+  var BYTE_MAX = new BigInteger('256', 10);
+  var result = new BigInteger('0', 10);
+  var multiplier = new BigInteger('1', 10);
+
+  for (var i = bytes.length - 1; i >= 0; i--) {
+    result = result.add(
+      multiplier.multiply(new BigInteger(bytes[i].toString(10), 10)));
+
+    multiplier = multiplier.multiply(BYTE_MAX);
+  }
+
+  return Address6.fromBigInteger(result);
+};
+
+module.exports = Address6;