Add Google SSO

This pull request adds Google SSO support. There are two main changes:

1. Add the Google auth view resource
2. Make passwords optional when creating a new user. This allows an admin
to create a user without a password so that they can only login via Google.

lemur/auth/views.py

@@ -230,5 +230,46 @@ class Ping(Resource):
         return dict(token=create_token(user))
 
 
+class Google(Resource):
+
+    def __init__(self):
+        self.reqparse = reqparse.RequestParser()
+        super(Google, self).__init__()
+
+    def post(self):
+        access_token_url = 'https://accounts.google.com/o/oauth2/token'
+        people_api_url = 'https://www.googleapis.com/plus/v1/people/me/openIdConnect'
+
+        self.reqparse.add_argument('clientId', type=str, required=True, location='json')
+        self.reqparse.add_argument('redirectUri', type=str, required=True, location='json')
+        self.reqparse.add_argument('code', type=str, required=True, location='json')
+
+        args = self.reqparse.parse_args()
+
+        # Step 1. Exchange authorization code for access token
+        payload = {
+            'client_id': args['clientId'],
+            'grant_type': 'authorization_code',
+            'redirect_uri': args['redirectUri'],
+            'code': args['code'],
+            'client_secret': current_app.config.get('GOOGLE_SECRET')
+        }
+
+        r = requests.post(access_token_url, data=payload)
+        token = r.json()
+
+        # Step 2. Retrieve information about the current user
+        headers = {'Authorization': 'Bearer {0}'.format(token['access_token'])}
+
+        r = requests.get(people_api_url, headers=headers)
+        profile = r.json()
+
+        user = user_service.get_by_email(profile['email'])
+
+        if user:
+            return dict(token=create_token(user))
+
+
 api.add_resource(Login, '/auth/login', endpoint='login')
 api.add_resource(Ping, '/auth/ping', endpoint='ping')
+api.add_resource(Google, '/auth/google', endpoint='google')

lemur/static/app/angular/users/user/user.tpl.html

@@ -30,8 +30,7 @@
                     Password
                 </label>
                 <div class="col-sm-10">
-                    <input type="password" name="password" ng-model="user.password" placeholder="hunter2" class="form-control" required/>
-                    <p ng-show="createForm.password.$invalid && !createForm.password.$pristine" class="help-block">You must enter an password</p>
+                    <input type="password" name="password" ng-model="user.password" placeholder="hunter2" class="form-control" />
                 </div>
             </div>
             <div class="form-group">

lemur/users/models.py

@@ -52,7 +52,10 @@ class User(db.Model):
         :param password:
         :return:
         """
-        return bcrypt.check_password_hash(self.password, password)
+        if self.password:
+            return bcrypt.check_password_hash(self.password, password)
+        else:
+            return False
 
     def hash_password(self):
         """
@@ -60,8 +63,11 @@ class User(db.Model):
 
         :return:
         """
-        self.password = bcrypt.generate_password_hash(self.password)
-        return self.password
+        if self.password:
+            self.password = bcrypt.generate_password_hash(self.password)
+            return self.password
+        else:
+            return None
 
     @property
     def is_admin(self):

lemur/users/views.py

@@ -157,7 +157,7 @@ class UsersList(AuthenticatedResource):
         """
         self.reqparse.add_argument('username', type=str, location='json', required=True)
         self.reqparse.add_argument('email', type=str, location='json', required=True)
-        self.reqparse.add_argument('password', type=str, location='json', required=True)
+        self.reqparse.add_argument('password', type=str, location='json', default=None)
         self.reqparse.add_argument('active', type=bool, default=True, location='json')
         self.reqparse.add_argument('roles', type=roles, default=[], location='json')