authentication/autorisation web service: Oauth or not? - web-services

We need to implement an authentication/autorisation web service and I am not sure if we should use the Oauth protocol in our situration.
The background of the story:
We have some J2EE web applications in a jboss server. Authentication and authorisation of the applications are implemented by JAAS and deployed in this jboss server.We want to add some new web applications that are implemented in other languages and deployed in other servers. To re-use the authentication/autorisation mechanism in the jboss server, we need to implement authenication/authorisation web services for the new applications.
So here comes some thoughts:
Is it necessary to adapt the OAuth protocol for the authentication/autorisation web service ?
As I know, OAuth2 is use to grant access to functionality, user's data, etc.. without giving the password to the 3rd party app. This is not really our case as we actually own all the applications, although that the newly apps are not in the authentication server.
Another choix is to implement the login webservice et then return the new apps a ticket/token to use later.
In another way, with OAuth protocol, newly apps do not involve in user's login/passwords, which seems to be nice...
Do you have some ideas ?

OAuth works on the concept of "ResourceOwners (Which gets the user credentials and enables the client's access to the server's apis)", "Server (owner of the resources) and the "clients (who want access to the server resources but doesn't have access to the credentials).
OAuth is just one way of providing security to the resources which means it is not necessary to have it for all "authentication/autorisation".
In your case I dont think there is a need of full fledged 3-legged OAuth however you can still go ahead with 0-legged OAuth or some other approach. Also, I don't understand what did you mean by "newly apps do not involve in user's login/passwords" as this is completely composite to what OAuth is meant for. User generally provide the credentials when they login into the app and then that login call ensures that the clients have access to the server resources.
If you just want to "return the new apps a ticket/token to use later" then OAuth is not for you as it is more than just providing the token for later use. Also, token in OAuth is for server's api access.

Related

How to send requests to Cloud Run only from the app?

Subscription based iOS app I'm building uses Cloud Run service invoked via HTTPS request.
How can I make sure that the request can only be invoked by app owners(from the app)?
I've looked at Google Sign-In authentication, but I don't think it is applicable in my case as only those subscribed to the app should have the access, not just those with Gmail account.
I think without a Google Sign-in involved, your question has nothing to do with Cloud Run and can be generalized as:
How to send requests to to a backend app only from its mobile app?
So I'll answer that.
You'll find out that you need some form of "authentication" to prove that you're on a mobile app as a "user". To achieve that, you need some form of sign-in.
You may try to ship a secret (like a token or private key) in the application and use that to authenticate, but this will be susceptible to:
exfiltration of the private they from the application bundle through reverse engineering
applying a man-in-the-middle attack to the HTTPS request (and therefore the token) by trusting a root CA on the device and using e.g. mitmproxy to decrypt the request as plaintext.
In reality, there's no way to fully secure iOS/Android <=> backend communication that. Even the largest apps like Twitter, Instagram etc have their APIs reverse engineered all the time and invoked from non iOS/Android clients as the requests can be spoofed.
If you want to authenticate your existing users, you should figure out how these people login to your app. This could be simple username:password in Authentication: Basic [...] header, or something more complicated like OAuth2 which is what apps like Facebook, Twitter implement under the covers for their mobile apps.
Then you would validate that Authentication header in your Cloud Run application code yourself.
So again, I don't think this is a problem specific to Cloud Run, or any cloud provider.
If your goal is for your API to only be called when your users are authenticated in your app, I would recommend implementing one of the two solutions described on this page:
Using Google Sign-in or Firebase Authentication

End user authentication for RESTful web services

I have an internal-facing RESTful web service. There are various client applications using the service, and the client apps themselves have end users. The web service needs to authorize requests based on the end user identities.
The question: What are the typical options for authenticating the end user here? That is, I want to authenticate the user, not the client application. (I don't mind if authenticating the client application is part of the scheme, but ultimately I need to know that the end user is who I think he or she is.)
One possible scheme, for example, would be to have per-client system accounts, and then have the client simply assert the user's identity (e.g. in an HTTP request header, say). So we authenticate the client application and delegate user authentication to the client. I don't think this is a very strong scheme, though, because it depends too much on keeping the system account credentials secret. I have seen too many examples of people e-mailing system account credentials around to put much faith in this sort of approach.
Another approach might be to have the client app, upon user login, use the user's credentials to get a token from the API, and then use that token for subsequent API requests. That way the authentication is user-specific without requiring the client app to hang onto the username/password credentials.
Anyway I'd like to have a better sense for the range of options I should be considering here.
The problem that you describe with "delegated authentication" is a real one. It means that a "client application" using it's credentials has access to the whole breadth of user data. This access can be used maliciously (for example a "semi-trusted" app harvesting api data) or negligently (for example an app accidentally exposing a Direct Object Reference Vulnerability - https://www.owasp.org/index.php/Top_10_2010-A4-Insecure_Direct_Object_References)
Probably the most prevalent "token based" scheme is OAuth2 (http://oauth.net/2/), and the precursor, OAuth, which many sites choose to continue to use.
OAuth2 has a number of roles:
resource owner (the user in your case)
resource server (your api)
client (the apps you talk about)
authorization server (not clear who or what would fulfil this role in your case)
The basic scheme is that the resource owner authenticates using their credentials directly with the authorization server. They are then asked if they want to grant some information (which may just be a persistent identifier, or a description of the information exposed by your api) to some client. When they accept an 'auth code' is sent to the client and they use that (combined with their own credentials) to receive an 'access token'. This access token can then be used to authenticate against the resource server (which can check it's authenticity back against the authorization server).
Normally the way this is used is that the authorization server and the resource server are owned and managed by the same entity (for example google and facebook would fulfil this role) and then clients are independently managed.
The scheme can also be used internally within an organisation without the "explicit grant" which can still at least confirm that a specific end-user is present before releasing any data from an api.

Authentication for Hospital Management system

I am implementing a Java EE based Hospital Management System that has a web service and two clients are to be connected to it, a Java Swing App and a JSP-based web project. The web service is to be implemented using Stateless EJBs.
Please suggest a way of implementing authentication and login for both clients (Users are taken from database-DB2)
NB: This has to be submitted as a project so server(Websphere) based authentication should be avoided as much as possible. Could not find any resource corresponding to this scenario..
I suppose that users will authenticate to both applications with username (and password). If you don't need user authorization on the service side, you can just create username/password combination for each client and store it in web service configuration file. In that case i would suggest message level security for clients.
http://publib.boulder.ibm.com/infocenter/wasinfo/v7r0/index.jsp?topic=%2Fcom.ibm.websphere.express.doc%2Finfo%2Fexp%2Fae%2Ftwbs_securews.html
In case you need user authorization on service side, you can still rely upon message level security but proceed users credentials instead.
Here are also some examples which might be helpful:
http://www.mkyong.com/webservices/jax-ws/application-authentication-with-jax-ws/
http://www.ibm.com/developerworks/websphere/tutorials/0905_griffith/section7.html

It is possible (and/or a good idea) to reuse OAuth tokens between apps?

I'm working on an iPhone app that uses xAuth to login to Twitter. The app also communicates with my own web service. Rather than maintain a user model inside the web service, I'd like to just allow anyone who's already authenticated via Twitter to make requests.
The high-level use case is this: the user logs into and interacts with Twitter through the app. They can also interact with my web service through the app. The web service itself never interacts with Twitter. Instead of maintaining a separate authentication system on my side, I'd like the server to say "OK, if Twitter says you're #joshfrench then you can have access."
I'm not sure how I should validate requests on the server side, though. How would I pass some proof of authentication from the mobile client to my web service? Can I send along the existing Twitter token and verify it from the server? Or somehow sign the request with my Twitter app's credentials? Is this even a valid use of OAuth?
If you store your twitter app key and secret on both he iphone app and your server, and then somehow transmit the user's oauth token (also called "access token") key/secret from the iphone app to the server, then you can do the same type of api calls from the server.
consumer = OAuth::Consumer.new(app_key, app_secret, …)
access_token = OAuth::AccessToken.new(consumer, user_key, user_secret)
response = access_token.get('/stuff.xml')
So, is it Okay to transmit that info from the app to the server? If you do it securely, and it's within the user's expectation for how the app behaves, then it's a perfectly fine use of oauth.
It's possible that it's not allowed by Twitter's terms of service -- I could imagine there being something that says you can't transfer a user's access secret across the network, or some such thing. (total wild speculation, I don't think it's particularly likely that that's the case)

OAuth recommended for async data transfer in own webapp?

I am making heavy use of async requests by Javascript to the webserver. Since I am building a multitenant application, I want to restrict access to the json services on the user level.
I read a lot about OAuth being recommended for consumer authentification. In my scenario, would the Javascript (client) side be regarded as the consumer and, hence, would you recommend using OAuth for that purpose? If not, what alternatives would you recommend?
OAuth is best at providing a method other than direct sharing of username and password with third party applications or web sites. I would use OAuth or something like it only in the case that you need to provide this type of third-party access to your web application.
If the JS client will be running in a web browser that the user has already logged in to your service, you might just as well use the session cookie that you have already established to authenticate each request.
In fact, such a session cookie will automatically be shared as part of any XHR to your web service.