HORIZON PROJECT

/*!

 * cookie-parser

 * Copyright(c) 2014 TJ Holowaychuk

 * Copyright(c) 2015 Douglas Christopher Wilson

 * MIT Licensed

 */

'use strict';

/**

 * Module dependencies.

 * @private

 */

var cookie = require('cookie');

var signature = require('cookie-signature');

/**

 * Module exports.

 * @public

 */

module.exports = cookieParser;

module.exports.JSONCookie = JSONCookie;

module.exports.JSONCookies = JSONCookies;

module.exports.signedCookie = signedCookie;

module.exports.signedCookies = signedCookies;

/**

 * Parse Cookie header and populate `req.cookies`

 * with an object keyed by the cookie names.

 *

 * @param {string|array} [secret] A string (or array of strings) representing cookie signing secret(s).

 * @param {Object} [options]

 * @return {Function}

 * @public

 */

function cookieParser(secret, options) {

  return function cookieParser(req, res, next) {

    if (req.cookies) {

      return next();

    }

    var cookies = req.headers.cookie;

    var secrets = !secret || Array.isArray(secret)

      ? (secret || [])

      : [secret];

    req.secret = secrets[0];

    req.cookies = Object.create(null);

    req.signedCookies = Object.create(null);

    // no cookies

    if (!cookies) {

      return next();

    }

    req.cookies = cookie.parse(cookies, options);

    // parse signed cookies

    if (secrets.length !== 0) {

      req.signedCookies = signedCookies(req.cookies, secrets);

      req.signedCookies = JSONCookies(req.signedCookies);

    }

    // parse JSON cookies

    req.cookies = JSONCookies(req.cookies);

    next();

  };

}

/**

 * Parse JSON cookie string.

 *

 * @param {String} str

 * @return {Object} Parsed object or undefined if not json cookie

 * @public

 */

function JSONCookie(str) {

  if (typeof str !== 'string' || str.substr(0, 2) !== 'j:') {

    return undefined;

  }

  try {

    return JSON.parse(str.slice(2));

  } catch (err) {

    return undefined;

  }

}

/**

 * Parse JSON cookies.

 *

 * @param {Object} obj

 * @return {Object}

 * @public

 */

function JSONCookies(obj) {

  var cookies = Object.keys(obj);

  var key;

  var val;

  for (var i = 0; i < cookies.length; i++) {

    key = cookies[i];

    val = JSONCookie(obj[key]);

    if (val) {

      obj[key] = val;

    }

  }

  return obj;

}

/**

 * Parse a signed cookie string, return the decoded value.

 *

 * @param {String} str signed cookie string

 * @param {string|array} secret

 * @return {String} decoded value

 * @public

 */

function signedCookie(str, secret) {

  if (typeof str !== 'string') {

    return undefined;

  }

  if (str.substr(0, 2) !== 's:') {

    return str;

  }

  var secrets = !secret || Array.isArray(secret)

    ? (secret || [])

    : [secret];

  for (var i = 0; i < secrets.length; i++) {

    var val = signature.unsign(str.slice(2), secrets[i]);

    if (val !== false) {

      return val;

    }

  }

  return false;

}

/**

 * Parse signed cookies, returning an object containing the decoded key/value

 * pairs, while removing the signed key from obj.

 *

 * @param {Object} obj

 * @param {string|array} secret

 * @return {Object}

 * @public

 */

function signedCookies(obj, secret) {

  var cookies = Object.keys(obj);

  var dec;

  var key;

  var ret = Object.create(null);

  var val;

  for (var i = 0; i < cookies.length; i++) {

    key = cookies[i];

    val = obj[key];

    dec = signedCookie(val, secret);

    if (val !== dec) {

      ret[key] = dec;

      delete obj[key];

    }

  }

  return ret;

}