I'm using webapp2 Authentication system for my entire application. So I tried to reuse this for Google Cloud Authentication and I get it!
webapp2_extras.auth uses webapp2_extras.sessions to store auth information. And it this session could be stored in 3 different formats: securecookie, datastore or memcache.
Securecookie is the default format and which I'm using. I consider it secure enough as webapp2 auth system is used for a lot of GAE application running in production enviroment.
So I decode this securecookie and reuse it from GAE Endpoints. I don't know if this could generate some secure problem (I hope not) but maybe @bossylobster could say if it is ok looking at security side.
My Api:
import Cookie
import logging
import endpoints
import os
from google.appengine.ext import ndb
from protorpc import remote
import time
from webapp2_extras.sessions import SessionDict
from web.frankcrm_api_messages import IdContactMsg, FullContactMsg, ContactList, SimpleResponseMsg
from web.models import Contact, User
from webapp2_extras import sessions, securecookie, auth
import config
__author__ = 'Douglas S. Correa'
TOKEN_CONFIG = {
'token_max_age': 86400 * 7 * 3,
'token_new_age': 86400,
'token_cache_age': 3600,
}
SESSION_ATTRIBUTES = ['user_id', 'remember',
'token', 'token_ts', 'cache_ts']
SESSION_SECRET_KEY = '9C3155EFEEB9D9A66A22EDC16AEDA'
@endpoints.api(name='frank', version='v1',
description='FrankCRM API')
class FrankApi(remote.Service):
user = None
token = None
@classmethod
def get_user_from_cookie(cls):
serializer = securecookie.SecureCookieSerializer(SESSION_SECRET_KEY)
cookie_string = os.environ.get('HTTP_COOKIE')
cookie = Cookie.SimpleCookie()
cookie.load(cookie_string)
session = cookie['session'].value
session_name = cookie['session_name'].value
session_name_data = serializer.deserialize('session_name', session_name)
session_dict = SessionDict(cls, data=session_name_data, new=False)
if session_dict:
session_final = dict(zip(SESSION_ATTRIBUTES, session_dict.get('_user')))
_user, _token = cls.validate_token(session_final.get('user_id'), session_final.get('token'),
token_ts=session_final.get('token_ts'))
cls.user = _user
cls.token = _token
@classmethod
def user_to_dict(cls, user):
"""Returns a dictionary based on a user object.
Extra attributes to be retrieved must be set in this module's
configuration.
:param user:
User object: an instance the custom user model.
:returns:
A dictionary with user data.
"""
if not user:
return None
user_dict = dict((a, getattr(user, a)) for a in [])
user_dict['user_id'] = user.get_id()
return user_dict
@classmethod
def get_user_by_auth_token(cls, user_id, token):
"""Returns a user dict based on user_id and auth token.
:param user_id:
User id.
:param token:
Authentication token.
:returns:
A tuple ``(user_dict, token_timestamp)``. Both values can be None.
The token timestamp will be None if the user is invalid or it
is valid but the token requires renewal.
"""
user, ts = User.get_by_auth_token(user_id, token)
return cls.user_to_dict(user), ts
@classmethod
def validate_token(cls, user_id, token, token_ts=None):
"""Validates a token.
Tokens are random strings used to authenticate temporarily. They are
used to validate sessions or service requests.
:param user_id:
User id.
:param token:
Token to be checked.
:param token_ts:
Optional token timestamp used to pre-validate the token age.
:returns:
A tuple ``(user_dict, token)``.
"""
now = int(time.time())
delete = token_ts and ((now - token_ts) > TOKEN_CONFIG['token_max_age'])
create = False
if not delete:
# Try to fetch the user.
user, ts = cls.get_user_by_auth_token(user_id, token)
if user:
# Now validate the real timestamp.
delete = (now - ts) > TOKEN_CONFIG['token_max_age']
create = (now - ts) > TOKEN_CONFIG['token_new_age']
if delete or create or not user:
if delete or create:
# Delete token from db.
User.delete_auth_token(user_id, token)
if delete:
user = None
token = None
return user, token
@endpoints.method(IdContactMsg, ContactList,
path='contact/list', http_method='GET',
name='contact.list')
def list_contacts(self, request):
self.get_user_from_cookie()
if not self.user:
raise endpoints.UnauthorizedException('Invalid token.')
model_list = Contact.query().fetch(20)
contact_list = []
for contact in model_list:
contact_list.append(contact.to_full_contact_message())
return ContactList(contact_list=contact_list)
@endpoints.method(FullContactMsg, IdContactMsg,
path='contact/add', http_method='POST',
name='contact.add')
def add_contact(self, request):
self.get_user_from_cookie()
if not self.user:
raise endpoints.UnauthorizedException('Invalid token.')
new_contact = Contact.put_from_message(request)
logging.info(new_contact.key.id())
return IdContactMsg(id=new_contact.key.id())
@endpoints.method(FullContactMsg, IdContactMsg,
path='contact/update', http_method='POST',
name='contact.update')
def update_contact(self, request):
self.get_user_from_cookie()
if not self.user:
raise endpoints.UnauthorizedException('Invalid token.')
new_contact = Contact.put_from_message(request)
logging.info(new_contact.key.id())
return IdContactMsg(id=new_contact.key.id())
@endpoints.method(IdContactMsg, SimpleResponseMsg,
path='contact/delete', http_method='POST',
name='contact.delete')
def delete_contact(self, request):
self.get_user_from_cookie()
if not self.user:
raise endpoints.UnauthorizedException('Invalid token.')
if request.id:
contact_to_delete_key = ndb.Key(Contact, request.id)
if contact_to_delete_key.get():
contact_to_delete_key.delete()
return SimpleResponseMsg(success=True)
return SimpleResponseMsg(success=False)
APPLICATION = endpoints.api_server([FrankApi],
restricted=False)
