text: // Copyright 2014 The Chromium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  var utils = require('utils');
  
  /**
   * Enum of possible key types (subset of WebCrypto.KeyType).
   * @enum {string}
   */
  var KeyType = {
    public: 'public',
    private: 'private'
  };
  
  /**
   * Enum of possible key usages (subset of WebCrypto.KeyUsage).
   * @enum {string}
   */
  var KeyUsage = {
    sign: 'sign',
    verify: 'verify'
  };
  
  /**
   * Implementation of WebCrypto.Key used in enterprise.platformKeys.
   * @param {KeyType} type The type of the new key.
   * @param {ArrayBuffer} publicKeySpki The Subject Public Key Info in DER
   *   encoding.
   * @param {KeyAlgorithm} algorithm The algorithm identifier.
   * @param {KeyUsage[]} usages The allowed key usages.
   * @param {boolean} extractable Whether the key is extractable.
   * @constructor
   */
  var KeyImpl = function(type, publicKeySpki, algorithm, usages, extractable) {
    this.type = type;
    this.spki = publicKeySpki;
    this.algorithm = algorithm;
    this.usages = usages;
    this.extractable = extractable;
  };
  
  var KeyBase = function() {};
  
  Object.defineProperty(KeyBase.prototype, 'algorithm', {
    enumerable: true,
    get: function() {
      return utils.deepCopy(privates(this).impl.algorithm);
    }
  });
  
  var Key = utils.expose(
      'Key',
      KeyImpl,
      {superclass: KeyBase, readonly: ['extractable', 'type', 'usages']});
  
  /**
   * Returns |key|'s Subject Public Key Info. Throws an exception if |key| is not
   * a valid Key object.
   * @param {Key} key
   * @return {ArrayBuffer} The Subject Public Key Info in DER encoding of |key|.
   */
  function getSpki(key) {
    if (!privates(key))
      throw new Error('Invalid key object.');
    var keyImpl = privates(key).impl;
    if (!keyImpl || !keyImpl.spki)
      throw new Error('Invalid key object.');
    return keyImpl.spki;
  }
  
  exports.Key = Key;
  exports.KeyType = KeyType;
  exports.KeyUsage = KeyUsage;
  exports.getSpki = getSpki;
  