Implement Janrain Capture and Janrain Engage auth provider (#2436)

* Janrain engage auth provider
* Modeled after the existing providers in /src/authDataManager/ and also after https://github.com/janrain/Janrain-Sample-Code/blob/master/widget-examples/server.js
* See also: http://developers.janrain.com/overview/social-login/identity-providers/user-profile-data/#normalized-user-profile-data

* Janrain capture auth provider
* Modeled after the existing providers in /src/authDataManager/
* See also: https://docs.janrain.com/api/registration/entity/#entity

* Janrain engage auth provider
* Modeled after the existing providers in /src/authDataManager/ and also after https://github.com/janrain/Janrain-Sample-Code/blob/master/widget-examples/server.js
* See also: http://developers.janrain.com/overview/social-login/identity-providers/user-profile-data/#normalized-user-profile-data

* Janrain capture auth provider
* Modeled after the existing providers in /src/authDataManager/
* See also: https://docs.janrain.com/api/registration/entity/#entity

* Adding missing newlines at EOF

src/authDataManager/janrainengage.js

@@ -0,0 +1,67 @@
+// Helper functions for accessing the Janrain Engage API.
+var https = require('https');
+var Parse = require('parse/node').Parse;
+var querystring = require('querystring');
+
+// Returns a promise that fulfills iff this user id is valid.
+function validateAuthData(authData, options) {
+  return request(options.api_key, authData.auth_token)
+    .then((data) => {
+      //successful response will have a "stat" (status) of 'ok' and a profile node with an identifier
+      //see: http://developers.janrain.com/overview/social-login/identity-providers/user-profile-data/#normalized-user-profile-data
+      if (data && data.stat == 'ok' && data.profile.identifier == authData.id) {
+        return;
+      }
+      throw new Parse.Error(Parse.Error.OBJECT_NOT_FOUND, 'Janrain engage auth is invalid for this user.');
+    });
+}
+
+// Returns a promise that fulfills iff this app id is valid.
+function validateAppId() {
+  //no-op
+  return Promise.resolve();
+}
+
+// A promisey wrapper for api requests
+function request(api_key, auth_token) {
+
+  var post_data = querystring.stringify({
+    'token': auth_token,
+    'apiKey': api_key,
+    'format': 'json'
+  });
+
+  var post_options = {
+    host: 'rpxnow.com',
+    path: '/api/v2/auth_info',
+    method: 'POST',
+    headers: {
+      'Content-Type': 'application/x-www-form-urlencoded',
+      'Content-Length': post_data.length
+    }
+  };
+
+  return new Promise(function (resolve, reject) {
+    // Create the post request.
+    var post_req = https.request(post_options, function (res) {
+      var data = '';
+      res.setEncoding('utf8');
+      // Append data as we receive it from the Janrain engage server.
+      res.on('data', function (d) {
+        data += d;
+      });
+      // Once we have all the data, we can parse it and return the data we want.
+      res.on('end', function () {
+        resolve(JSON.parse(data));
+      });
+    });
+
+    post_req.write(post_data);
+    post_req.end();
+  });
+}
+
+module.exports = {
+  validateAppId: validateAppId,
+  validateAuthData: validateAuthData
+};