I am working on an Ionic mobile app and have a django backend. We currently use JWT authentication in order to access the django backend (multiple applications use this backend including a react frontend). So the current auth method needs to stay in tact.
Now that we are working on an app we want the user to stay logged in after entering his credentials once on the app. I've been researching a good way to do this all day but can't seem to find a clear answer.
What is the best option to keep the user authenticated? Should I set a high expiration on the refresh token? (Not sure if that is secure..)
Should I use session auth? I found it that Django mostly supports this on services on the same domain. Seems like you have to relax quite a few security settings which doesn't seem to be the right solution.
I am not sure where to go from here. Do you guys have any suggestions?
I have not tried using ionic but generally what you want to do is to use a HTTP Client on you application which has an interceptor that will be watching for response with 401 Unauthorized response and you can check if the Authorization Header used was of the JWT if so, the HTTP client could send a request to your jwt refresh point with the refresh token and can re-update the jwt access token on the
moble application and retry the request again.
You could store the JWT refresh token on the users device.
For a quick project for a hack week me and my team implemented Google Sign-In as registration/authentication for users. The way it works:
User signs in with SDK on client (Android + iOS) and requests access_token
Client receives acces_token and uses that token for each network request to the backend as a query parameter
Our backend does not interact with google services on users behalf
The problem I'm facing is that the provided access_token returned by the google SDK is short-lived (60 minutes). That basically leads me to two questions/problems:
Is the short-living access_token even meant to be used that way?
I am used to another flow where you just use that returned token by google or any other auth provider to authenticate with your backend and then use your own authentication mechanism (probably token based as well).
If I am wrong about 1. then what is a good practise to refresh the token on the client side as it expires every 60 minutes. The way I understand it is that Google SDK starts an activity for result to sign in and I would rather want to handle all the networking in my data layer without context. Do I check the validity of that token before I request the backend every time or do I start some kind of refreshing after I get a 401 response back or something similar?
I am somewhat new in that space and I had quite some discussion about what is right and wrong with the backend guy in our team. I'm thinking number one is right, he says number two. I might be terribly wrong here. Some nice input or resources would be awesome as all the documentation online just don't answer both of those questions.
Do one thing use your google provided access token to generate a new access token in your backend and send this token on login/signup to client. Now your every request will use this token to identify users and keep track of everything.
This will not expire too. I used this in my app and it works flawlessly.
My Android app needs to send an authorization code to my server so that the server can use that to acquire an access token for the user's Google Drive account. I have been trying to figure out how to acquire the authorization code and I found this in the Google API documentation (Using OAuth 2.0 for Installed Applications):
This sequence starts by redirecting a browser (system browser or
embedded in the application as a web view) to a Google URL with a set
of query parameters that indicate the type of Google API access the
application requires. Like other scenarios, Google handles the user
authentication and consent, but the result of the sequence is an
authorization code. The authorization code is returned in the title
bar of the browser or as a query string parameter (depends on the
parameters sent in the request).
After receiving the authorization code, the application can exchange
the code for an access token and a refresh token. The application
presents its client_id and client_secret (obtained during application
registration) and the authorization code during this exchange. Upon
receipt of the refresh token, the application should store it for
future use. The access token gives your application access to a Google
API.
Now I am not sure how to get this authorization code in my Android app since the Android examples I have seen seem to get the access tokens directly. I am looking at the Android AccountManager class and it has a method getAuthToken but this seems to refer to the access token and not the authorization code.
So how does one acquire the authorization code that can be shared with a server? If it is possible I would greatly appreciate some example code. If this is not possible what are the possible workarounds?
You may want to take a look at the Cross-client Identity document. It should keep you from needing to pass user tokens back and forth.
I believe you can actually take the access token returned by the Android AccountManager, send this to your server, then have your server make a call against the Google Drive API using that same access token - it is a bearer token and not bound to the channel that created it, so please take good care of it and only send over encrypted connections.
Documentation on how to get that access token can be found here:
https://developers.google.com/drive/quickstart-android
While that access token is good for immediate use, it will expire in less than 1 hour, so if you are looking for a solution that enables your backend server to have continued access to the Drive data, without the user being present at your app at the time of request, an alternate approach will be needed.
I have android app comunicating with api on remote server. I want to make user authentication via google account. I know there's many pages/questions about this topic, but I kind of couldn't figured out which method I need to use.
What I want is, when user registers with his google account, his account will be authenticated and then I want Google to generate some auth token, which is specific for the app and users account. This token should never change, because it should be used on api server to authenticate user.
Do I need to link my app somehow to Google AppEngine or is there any simple solution which I'm not seeing? Or is this method of authenticating completly wrong?
You might be a bit wrong. Cause No one (Not even the Google apps on android) ever get a non expiring token. You Need to save the refresh token and the current token. and after every hour you need to refresh the token using refresh token. And you are good to go (If I have understood your question :P). I would suggest if you already own a server better host the back-end there else GAE works just fine. I hope it helps :)
I'm developing a website that is primarily accessed via an app, and I want to use OAuth2 for user registration and authentication. Since it is an Android app I will start using Google's OAuth2 stuff, since it provides a decent UI on Android.
Google states that "You can choose to use Google's authentication system as a way to outsource user authentication for your application. This can remove the need to create, maintain, and secure a username and password store." which is what I want to do. However when I go through all their examples and whatnot, I can only find stuff about having a website or an app authenticate a user against Google's services.
And indeed, when I go to register my app ("client") with Google's OAuth2 there are options for website clients and "installed" clients (i.e. a mobile app) but not both. I can create two separate clients but I read the OAuth2 draft and I think there will be a problem, which I will now explain.
Here's how I did envisage it working:
User asks MyApp to access his private data.
App uses Android's AccountManager class to request an access token for Google's APIs.
Android says to user "The app 'MyApp' wants access to your Basic Information on Google. Is this ok?"
User says yes.
AccountManager connects to Google's OAuth2 server using the credentials stored on the phone, and asks for an access token.
Access token (which follows the green lines) is returned.
AccountManager returns the access token to MyApp.
MyApp sends a request to MySite for the user's private data, including the access token.
MySite needs to verify the user, using the access token. It validates the token as described here, with Google - "Google, is this token valid?".
Now, what I want to happen is that Google says "Yes, whoever gave it to you is indeed that user.", but what I think will actually happen (based on the OAuth2 draft and Google's documentation) is that it will say "No way! That token is only valid for MyApp, and you're MySite. GTFO!".
So how should I do this? And PLEASE don't say "Use OpenID" or "Don't use OAuth2" or other similarly unhelpful answers. Oh and I would really like to keep using the nice AccountManager UI rather than crappy popup WebViews
Edit
Provisional answer (I will report back if it works!) from Nikolay is that it should actually work, and Google's servers won't care where the access token came from. Seems a bit insecure to me, but I will see if it works!
Update
I implemented this pattern with Facebook instead of Google and it totally works. The OAuth2 server doesn't care where the access token comes from. At least Facebook's doesn't, so I assume Google's doesn't either.
In light of that it is a very very bad idea to store access tokens! But we also don't want to have to hit Facebook/Google's servers to check authentication for every request since it will slow everything down. Probably the best thing is to add an additional authentication cookie for your site that you hand out when their access token is validated, but a simpler way is just to treat the access token like a password and store a hash of it. You don't need to salt it either since access tokens are really really long. So the steps above become something like:
9. MySite needs to verify the user, using the access token. First it checks its cache of hashed valid access tokens. If the hash of the token is found there it knows the user is authenticated. Otherwise it checks with Google as described here, with Google - "Google, is this token valid?".
10. If Google says the access token is invalid, we tell the user to GTFO. Otherwise Google says "Yes that is a valid user" and we then check our registered user database. If that Google username (or Facebook id if using Facebook) is not found we can create a new user. Then we cache the hashed value of the access token.
I just posted an answer to a similar StackOverflow question.
Google calls this Hybrid Apps and explains how an "Android app obtains offline access for Web back-end".
The gist of it is that you'll have to pass a massaged scope string into GoogleAuthUtil.getToken in order to get it to return an Authorization Code (not an OAuth2 Token). That Authorization Code can be passed from your mobile app to your server and be exchanged for an OAuth2 Token and Refresh Token, according to this schematic.
The scope parameter needs to look something like this:
oauth2:server:client_id:<your_server_client_it>:api_scope:<scope_url_1> <scope_url_2> ...
You can use the access token retrieved by the mobile application anywhere else. Drive SDK has a nice and simple intro that goes through the flow on https://developers.google.com/drive/quickstart-android
it describes exactly what you want:
https://developers.google.com/identity/protocols/CrossClientAuth
You probably need OpenID Connect, which uses OAuth tokens for authentication. As for AccountManager, the current OAuth support is a bit hacky, the new Google Play Services, set to be released 'soon' should hopefully make this better. See here for a demo.
At least with Google, the access token eventually expires. This is why the android AccountManager has the invalidateAuthToken method--the cached access token has expired, and you need to tell the AccountManager to stop giving you the old one and instead get a new one. This makes it somewhat safer to cache the token, as the token itself doesn't give you eternal access as that user. Instead, when valid, it merely says "at some point in the recent past, this token was acquired by a trusted source."
Here are a couple of things I've found helpful when working with tokens. The first is Google's tokeninfo endpoint. The token itself is just base64-encoded JSON. This means it isn't encrypted, so you need to be sure to be using HTTPS for communication. However, it also means that you can examine the token and have a better idea of what's going on.
https://www.googleapis.com/oauth2/v1/tokeninfo?id_token=
If your token was "abcdef", you would navigate to:
https://www.googleapis.com/oauth2/v1/tokeninfo?id_token=abcdef
and Google would unpack the token for you. It is a simple JSON object that includes an "expires_in" field telling you the number of seconds for which the token is still valid. At 6:03 in the video below you can see the unpacked token:
https://developers.google.com/events/io/sessions/383266187
That video includes a thorough overview of OAuth2 and is well worth watching in its entirety if you're going to be dealing with OAuth and tokens. The speaker also discusses other forms of Oauth2 tokens, that are not access tokens, that do not expire.
Another useful resource is the OAuth Playground. This lets you do basic things like request scopes, make up requests, and get back tokens. This link seems to work sporadically, and on Chrome I had to install the Oauth Playground app:
https://developers.google.com/oauthplayground/
And here is a tutorial by Tim Bray, the speaker in the video, explaining how to use access tokens to communicate to a server from an Android app. This was useful to me because I began to understand how the different things in the Google API Console work together:
http://android-developers.blogspot.in/2013/01/verifying-back-end-calls-from-android.html
With regards to the actual answer to your question, I would say you never need to cache the access token on the server. As explained in the Verifying Back End Calls from Android link above, verifying a token is almost always a fast static call, meaning there's no reason to cache the tokens:
The libraries can cache the Google certs and only refresh them when required, so the verification is (almost always) a fast static call.
Finally, you can indeed use the AccountManager to get access tokens. However, Google now instead encourages the use of the GoogleAuthUtil class in the Play Services library instead:
In a nutshell what's the difference from using OAuth2 request getAuthToken and getToken
Here note the comment by Tim Bray, the same guy yet again from the above links, saying that they are putting their efforts into the GoogleAuthUtil route. Note, however, that this means you would be limited to Google authentication. I believe that the AccountManager could be used to get, for example, a Facebook token instead--not the case with GoogleAuthUtil.
When we had a need to do something similar on a non-google OAuth Server, we kept the tokens in a DB on the website. The app would then use web services to request the token when needed to request data.
The user could do the OAuth registration on either the web or app. They shared the same application token, so they could share the same access token. After the registration we would store the access and refresh tokens in the DB for use from whichever app needed it.