git.r.bdr.sh - rbdr/dasein/blob - lib/handlers/auth.js

   1 'use strict';
   2
   3 const Co = require('co');
   4 const JsonWebToken = require('jsonwebtoken');
   5 const Pify = require('pify');
   6 const TwitterHelper = require('../twitter_helper');
   7
   8 const internals = {};
   9
  10 internals.kRedirectUrl = 'https://api.twitter.com/oauth/authenticate?oauth_token=';
  11 internals.kLoginRedirect = '/login';
  12
  13 internals.signJsonWebToken = Pify(JsonWebToken.sign);
  14
  15 /**
  16  * Handles the HTTP requests for auth related operations.
  17  *
  18  * @class AuthHandler
  19  * @param {Dasein.tConfiguration} config The configuration to
  20  * initialize.
  21  */
  22 module.exports = internals.AuthHandler = class AuthHandler {
  23
  24   constructor(config) {
  25
  26     this._twitterHelper = new TwitterHelper(config.twitter);
  27     this._jwtConfig = config.jwt;
  28   }
  29
  30   /**
  31    * Triggers the twitter login flow. Redirects to twitter's oauth
  32    * request page
  33    *
  34    * @function login
  35    * @memberof AuthHandler
  36    * @instance
  37    * @return {generator} a koa compatible handler generator function
  38    */
  39   login() {
  40
  41     const twitterHelper = this._twitterHelper;
  42
  43     return function *handleLogin() {
  44
  45       const requestToken = yield twitterHelper.getRequestToken();
  46       const loginUrl = `${internals.kRedirectUrl}${requestToken.oAuthToken}`;
  47
  48       this.body = { loginUrl };
  49     };
  50   }
  51
  52   /**
  53    * Handles twitter's callback. Fetches the oAuth Verifier, attempts to
  54    * obtain a user object and responds with the JWT
  55    *
  56    * @function callback
  57    * @memberof AuthHandler
  58    * @instance
  59    * @return {generator} a koa compatible handler generator function
  60    */
  61   callback() {
  62
  63     const self = this;
  64
  65     return function *handleCallback() {
  66
  67       if (this.request.query.denied) {
  68         return this.throw(401);
  69       }
  70
  71       const oAuthToken = this.request.body.oAuthToken;
  72       const oAuthVerifier = this.request.body.oAuthVerifier;
  73       let user;
  74
  75       try {
  76         const accessToken = yield self._twitterHelper.getAccessToken(oAuthToken, oAuthVerifier);
  77         user = yield self._twitterHelper.getUser(accessToken.oAuthAccessToken, accessToken.oAuthAccessTokenSecret);
  78       }
  79       catch (err) {
  80         console.error(err.stack || err.message || err);
  81         return this.throw(401);
  82       }
  83
  84       const expiresAt = Date.now() + self._jwtConfig.duration * 1000;
  85
  86       const token = yield self._getToken(user);
  87
  88       const response = {
  89         expiresAt,
  90         user,
  91         token
  92       };
  93
  94       this.body = response;
  95     };
  96   }
  97
  98   // Generates a JSON Web Token
  99
 100   _getToken(payload) {
 101
 102     const self = this;
 103
 104     return Co(function * () {
 105
 106       const token = yield internals.signJsonWebToken(payload, self._jwtConfig.secret, {
 107         expiresIn: self._jwtConfig.duration
 108       });
 109
 110       return token;
 111     });
 112   }
 113 };