Custom Authentication for Google Cloud Endpoints (instead of OAuth2) - python

We are super excited about App Engine's support for Google Cloud Endpoints.
That said we don't use OAuth2 yet and usually authenticate users with username/password
so we can support customers that don't have Google accounts.
We want to migrate our API over to Google Cloud Endpoints because of all the benefits we then get for free (API Console, Client Libraries, robustness, …) but our main question is …
How to add custom authentication to cloud endpoints where we previously check for a valid user session + CSRF token in our existing API.
Is there an elegant way to do this without adding stuff like session information and CSRF tokens to the protoRPC messages?

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)

I wrote a custom python authentication library called Authtopus that may be of interest to anyone looking for a solution to this problem: https://github.com/rggibson/Authtopus
Authtopus supports basic username and password registrations and logins, as well as social logins via Facebook or Google (more social providers could probably be added without too much hassle too). User accounts are merged according to verified email addresses, so if a user first registers by username and password, then later uses a social login, and the verified email addresses of the accounts match up, then no separate User account is created.

From my understanding Google Cloud Endpoints provides a way to implement a (RESTful?) API and to generate a mobile client library. Authentication in this case would be OAuth2. OAuth2 provides different 'flows', some of which support mobile clients.
In the case of authentication using a principal and credentials (username and password) this doesn't seem like a good fit. I honestly think you would be better off by using OAuth2.
Implementing a custom OAuth2 flow to support your case is an approach that could work but is very error prone.
I haven't worked with OAuth2 yet but maybe an 'API key' can be created for a user so they can both use the front-end and the back-end through the use of mobile clients.

you can used jwt for authentication. Solutions here

I did not coded it yet, but it imagined next way:
When server receives login request it look up username/password in datastore. In case user not found server responds with some error object that contains appropriate message like "User doesn't exist" or like. In case found it stored in FIFO kind of collection (cache) with limited size like 100 (or 1000 or 10000).
On successful login request server returns to client sessionid like ";LKJLK345345LKJLKJSDF53KL". Can be Base64 encoded username:password.
Client stores it in Cookie named "authString" or "sessionid" (or something less eloquent) with 30 min (any) expiration.
With each request after login client sends Autorization header that it takes from cookie. Each time cookie taken, it renewed -- so it never expires while user active.
On server side we will have AuthFilter that will check presence of Authorization header in each request (exclude login, signup, reset_password). If no such header found, filter returns response to client with status code 401 (client shows login screen to user). If header found filter first checks presence of user in the cache, after in datastore and if user found -- does nothing (request handled by appropriate method), not found -- 401.
Above architecture allows to keep server stateless but still have auto disconnecting sessions.

Related

FastAPI fetch User and token from Azure

Im building an API using FastAPI and fastapi-azure-auth
I followed the tutorials, and my openAPI/docs endpoints are protected. If I try to access any protected endpoint I am redirected to the Microsoft login page, and then I am able to use those endpoints.
What I am trying to do next is an endpoint which fetches an User object (which includes a token) which is called from the frontend. Then the front will use this User to call the authenticated endpoints.
I have been trying for days using the mentioned package, making calls to Azure, but all I manage is to get a "default" token.
I just want to simply click a link, let Azure authenticate the person, and return the User object with the information
you can use MSAL to get the azure tokens for auth.
To this you will need the client Id, tenant Id from you registered azure ad app and username, password of your account.
Now we can use PublicClientApplication to create a client and then use acquire_token_by_username_password to get the tokens.
from msal import PublicClientApplication
clientid = ''
tenantid = ''
USERNAME = ''
PASSWORD = ''
scope = [ '2ff814a6-3304-4ab8-85cb-cd0e6f879c1d/.default' ]
app = PublicClientApplication(
client_id = clientid,
authority = "https://login.microsoftonline.com/" + tenantid
)
acquire_tokens_result = app.acquire_token_by_username_password(
username = USERNAME,
password = ,
scopes = scope
)
print(acquire_tokens_result['access_token'])
Also, you need to configure Allow public client flows under authentication tab in the azure ad registered app.

Django REST Custom (token) authentication

Because I'm mixing things up and just making myself more confused, maybe someone can actually guide me through it.
I need to make a Django REST API that requires login. However the User table already exists in a Postgres database. I think token-based authentication is most suitable, however, those tokens don't exist yet.
(Login once to retrieve/create a token, check the token on each request)
How can I use a POST request to submit login details purely for verifying the user?
How would I generate a token upon successful login, and should I store it in a new Token table?
After this, how can I use the token to provide authentication/authorization on API data requests?
All examples I can find use the default Django User model or don't go into enough detail, which I can't use in this case.
I've made a custom authenticator that checks the username and password, however I can't get through the next steps.
from api.models import LogonAccount
from rest_framework import authentication
from rest_framework import exceptions
import bcrypt
class ExampleAuthentication(authentication.BaseAuthentication):
def authenticate(self, request):
username = request.data.get('username') # get the username request header
password = request.data.get('password') # get the password request header
if not username or not password: # no username or password passed in request headers
return None # authentication did not succeed
try:
user = LogonAccount.objects.get(username=username)
if bcrypt.hashpw(password.encode(), user.password.encode()):
print("succes")
return (user, None) # authentication successful
except LogonAccount.DoesNotExist:
raise exceptions.AuthenticationFailed('No such user')
Don't get confused, you are simply trying to achieve token-based authentication with DRF. DRF already comes with this feature. This article will guide you through that https://simpleisbetterthancomplex.com/tutorial/2018/11/22/how-to-implement-token-authentication-using-django-rest-framework.html

Using JWT between two Flask applications

I have two separate Flask applications, one is an API with the domain "admin.company.com" and the second one is a dashboard under the domain "dashboard.company.com".
My main goal is to secure the api and enable authentication.
I set up authentication on the api and when I'm testing it via the swagger-ui it works good with no issues. I manage to authenticate myself and submit requests. On top of that, in the token_required() below I coded a section that expects to receive JWT and decode it:
def token_required(f):
#wraps(f)
def decorator(*args, **kwargs):
token = None
if 'jwt-token' in request.headers:
token = request.headers['jwt-token']
if not token:
return jsonify({'message': 'a valid token is missing'})
try:
current_user = False
# for authentication via the swagger-ui
if token == 'my_awesome_password':
current_user = 'admin'
else:
data = jwt.decode(token, app.secret_key)
current_user = 'admin' if data['public_id'] == 'admin' else False
if not current_user:
return jsonify({'message': 'token is invalid'})
except:
return jsonify({'message': 'token is invalid'})
return f(*args, **kwargs)
return decorator
The problem is with the dashboard application:
On the dashboard app, I configured the /login route to generate JWT (which needs to be sent to the api app in every HTTP request I made), then do a set_cookie() with httpOnly=True flag (for security purposes), but then how can the JavaScript access it when it has to make XHR requests? Having the httpOnly flag on makes it unreachable.
If using httpOnly=True is not the ideal way in this case, how can I tackle it and make sure the JWT will always be sent to the api app in the request headers?
I'm using PyJWT package.
Thanks for any help.
If you use JWTs for XHR requests, then you don't necessarily need to use cookies – the browser/consumer could store the token and attach it to every request. If you do want to use cookies (this is also a viable option) then you don't need to worry about attaching the JWT as the browser will do that automatically for the domains you specified in the set_cookie command.

Alexa skill acount linking

I have a REST API defined using Python Flask, and I would like to make http requests to that API through the use of an Alexa Skill.
#app.route('/auth', methods=["POST"])
def auth_user():
data = request.get_json()
users = db.users
logged_user = users.find_one({'username' : data["username"]})
if logged_user is not None and bcrypt.check_password_hash(logged_user['password'], data['password']):
access_token = create_access_token(identity=data["username"])
return jsonify({'logged_user':logged_user,'access_token':access_token})
else:
return "Invalid password or username"
As you can see above I check if the credentials are correct and then I send the acess_token in the response. The remaning endpoints then require the jwt the execute the requests.
How can I do this with an Alexa skill? How can I first autenticate the user in the API?
You need to do account linking between Amazon's registered user and your system. It's quite a big subject. You can read more here: https://developer.amazon.com/en-US/docs/alexa/account-linking/understand-account-linking.html

Searching for users in Foursquare API- Missing credentials error 401

Please help. I am trying to search for a specific user in Foursquare but for some reason I got Missing credentials error 401.
user_id = '484542633' # user ID with most agree counts and complete profile
url = 'https://api.foursquare.com/v2/users/{}?client_id={}&client_secret={}&v={}'.format(user_id, CLIENT_ID, CLIENT_SECRET, VERSION) # define URL
# send GET request
results = requests.get(url).json()
user_data = results['response']['user']
# display features associated with user
user_data.keys()
As documentation states, this endpoint is meant to be accessed on behalf of the user:
This endpoint requires user authentication.
User calls require a valid OAuth access token in the query string of each request instead of the Client ID and Secret (&oauth_token=XXXX).
For more information about this authentication method and how to obtain an access token, see the Authentication docs.
This means v2/users can only be accessed by your app, after a user (which can be you, using your own Foursquare account) goes through the OAuth login flow and grants necessary permissions. OAuth doesn't mean your app "logs in" as the user, rather that the user has given you permission to do something on their behalf.
To learn more about OAuth you can watch this talk: https://www.youtube.com/watch?v=996OiexHze0
To read more about Foursquare's API visit their documentation site: https://developer.foursquare.com/docs/api/

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