How to leverage oauth to implement SSO for micro service apps - ruby-on-rails

We want to establish SSO between microservice apps,
Eg: In a e-commerce site if user logins to main app,user should be automatically allowed to access cart app connected to it, which is a micro service.
I searched Oauth spec but I could find any relevant answer specific to my case.
some of things which differ wrt Oauth are
User need not to authorize resources(cart app) against Identify provider.it should be done seamlessly in backend.
we don't want to use outside Identify provider like facebook,google,Main app(from eg above) should act as identity provider.
Questions
1.Is there a standard way(procedure) defined in oauth to handle these kind of authentication/authorization.?
If not what are the most popular alternatives ?
Other info:
Ours apps are build using Ruby on Rails,if you know any good gems please suggest.
I found couple of questions(1,2) related to this but they much broader. Even google is also not helping,so please don't mark this question as duplicate.

If you do want to use SSO, let all your services accept the same token, returned by Authorization server when user log in. Encrypt it and put to cookies for example - in this case your web frontend will authenticate user by validating that token against Authorization server and return user-specific content.
The same applies to cart service - it can get username by token and return user-specific cart items.
Pros: User can't access other user's data by design, user logout disables every service.
Cons: You will need "superuser" or additional API for background or analytical tasks.

Related

Openid connect/ Oauth2 for Rest APIs

I have different web applications which are registered on IDM (vmware IDM https://github.com/vmware/idm/wiki/Integrating-Webapp-with-OAuth2#authentication-response)
As obvious, all applications are registered with there own client id and client secret. When a user tries to access webapp "A" (webappa.com), it redirects to my IDM login page and after authentication comes back with code that can be exchanged with access and refresh token.
Similar thing happens with webapp "B" etc. This works well. Now I am confused with following 2 use cases?
a. I want to use some API (webappa.com/api/v1/get_user_projects) from webapp "A" for some scripting purpose. So my question is how I can authenticate these APIs against the user? Can I get the tokens for the user from IDM provider by passing his credentials (using some APIs?). If answer to it is NO, then how usually it is handled?
b. Can webapp A and webaap B will have same access/ refresh token at a time against a user?
a.
When a user authenticates it is with certain permissions and for a certain period of time. OAuth is designed so that you can just forward tokens between microservices - but you cannot elevate the permissions or time for a user token. Depending on your use case you may want to consider a different token with different privileges for background tasks.
b.
It is possible but not advisable to follow the Google model via a cookie scoped to a web domain that hosts multiple apps, which is how Google do it (mail.google.com / drive.google.com). So there is a dependency on hosting and domains
The preferred option is for the user to authenticate at App A and then single sign on to App B. The different apps then get separate tokens with different permissions and can more easily evolve separately.
This also depends on how the app is implemented and your technology choices:
An 'old style' web app using a server side technology will expect to issue separate auth cookies per app
An SPA following an intelligent Back End for Front End design could support this model via SameSite cookies if it made sense for a set of related micro-UIs
In the latter case you would need to use a single OAuth client with multiple redirect URIs - eg for mail and drive - since the user could sign in to either of these first.
Apologies for the complicated answer - but it is a very architectural topic with the potential for hidden costs. From a stakeholder viewpoint it is very simple - make it work like Google. Hopefully this answer helps you in your conversations ...

What are you supposed to do after an OAuth2 call succeeds?

At work we have never used 3rd party Auth solutions and I'm trying to inform myself of how they work for my personal projects. Getting the response is easy enough, but feel a bit lost on what to do after I get the response back. Am I supposed to send the auth token to the backend so it can be verified then trigger my app's login process for the given e-mail address/username? Logging them in essentially without a password?
There's two basic use cases for OAuth 2.0 which will determine what you do after the user is authorized. Your use case can also determine which OAuth 2.0 permission scopes you request the user to authorize your app for.
1. Single Sign-on
A simple use case for using a 3rd party OAuth solution is to leverage the 3rd party to perform authentication. Two reasons for this include:
Your users may wish the convenience of logging in with another provider (like Google, Facebook, Twitter, etc.), one where he or she may already have an active session.
You may not wish to implement your own login / authentication / password reset process.
Either way, a common way to implement this is to make an API request using the token to retrieve the user's email address after a successful authentication, which you then map to your own user database to establish an authenticated session for your service. Since you only need to retrieve the user's email address and minimal other information (e.g. name) in this use case, you can ask for a minimal set of scopes.
I do this in my oauth2more library where after receiving a token, I have a generic interface to load a user data which I convert to a SCIM user object. Because I've abstracted the code to retrieve user info in this manner, it's easy to support SSO across mulitple auth providers.
2. Using Service Features
A slightly different use case is that you want the user to authorize your app so you can make commands on behalf of the user via API. In this case, you will use the token to call more general APIs to accomplish your goals. A caveat is that you will need to make sure you ask for the proper permissions when asking the user to authorize your app.
As an example, one thing I've done is ask the user to sign in with Google so I can then make API calls to create and edit Google Sheets and Google Slides using APIs on their behalf.

CAS vs. SAML vs. OAuth2

Before you put me down for asking too basic a question without doing any homework, I'd like to say that I have been doing a lot of reading on these topics, but I'm still confused.
My needs seem simple enough. At my company, we have a bunch of Ruby on Rails applications. I want to build an SSO authentication service which all those applications should use.
Trying to do some research on how to go about doing this, I read about CAS, SAML and OAuth2. (I know that the "Auth" in OAuth stands for authorization, and not authentication, but I read enough articles saying how OAuth can be used for authentication just fine - this is one of them.)
Could someone tell me in simple terms what these 3 are? Are they alternatives (competing)? Is it even right to be comparing them?
And there are so many gems which all seem to be saying very similar stuff:
https://github.com/rubycas/rubycas-server and https://github.com/rubycas/rubycas-client
https://github.com/nbudin/devise_cas_authenticatable
https://github.com/onelogin/ruby-saml
CASino and https://github.com/rbCAS/casino-activerecord_authenticator
And I am sure there are hundreds of OAuth related gems.
I just want a separate Rails application which handles all the authentication for my other Rails apps.
Note: I do not want to allow users to use their Google / Facebook accounts to login. Our users already have accounts on our site. I want them to be able to login using that account once and be able to access all our apps without signing in again. Signing out in any app should sign them out of all apps.
UPDATE
I have come across these two OAuth solutions:
http://dev.mikamai.com/post/110722727899/oauth2-on-rails
http://blog.yorkxin.org/posts/2013/11/05/oauth2-tutorial-grape-api-doorkeeper-en/
They seem to be describing something very similar to what I want. But I haven't found any guide / blog post / tutorial showing how to do this with SAML / CAS.
Suggestions welcome.
UPDATE 2
More details about our use-case.
We do not have any existing SAML architecture in place. Primarily, it is going to be OUR users (registered directly on our website) who are going to be accessing all our applications. In the future, we may have third-party (partner) companies calling our APIs. We may also have users from these third-party (partner) companies (registered on their websites) accessing our apps.
CAS-Server:
A stand-alone central login page where the user enters their credentials (i.e. their username and password).
CAS supports the standardized SAML 1.1 protocol primarily to support
attribute release to clients and single sign-out.
(a table in a SQL database, ActiveDirectory/LDAP, Google accounts, etc.)
Full compatibility with the open, multi-platform CAS protocol (CAS clients are implemented for a wide range of platforms, including PHP, various Java frameworks, .NET, Zope, etc.)
Multi-language localization -- RubyCAS-Server automatically detects the user's preferred language and presents the appropriate interface.
SAML :
Security Assertion Markup Language is an XML-based, open-standard data format for exchanging authentication and authorization data between parties, in particular, between an identity provider and a service provider.
SAML authorization is a two step process and you are expected to implement support for both.
OAuth 2.0:
The OAuth 2.0 authorization framework enables a third-party
application to obtain limited access to an HTTP service, either on
behalf of a resource owner by orchestrating an approval interaction
between the resource owner and the HTTP service, or by allowing the
third-party application to obtain access on its own behalf.
Important Note :
SAML has one feature that OAuth2 lacks: the SAML token contains the user identity information (because of signing). With OAuth2, you don't get that out of the box, and instead, the Resource Server needs to make an additional round trip to validate the token with the Authorization Server.
On the other hand, with OAuth2 you can invalidate an access token on the Authorization Server, and disable it from further access to the Resource Server.
Both approaches have nice features and both will work for SSO. We have proved out both concepts in multiple languages and various kinds of applications. At the end of the day OAuth2 seems to be a better fit for our needs (since there isn't an existing SAML infrastructure in place to utilize).
OAuth2 provides a simpler and more standardized solution which covers
all of our current needs and avoids the use of workarounds for
interoperability with native applications.
When should I use which?
1.If your usecase involves SSO (when at least one actor or participant is an enterprise), then use SAML.
2.If your usecase involves providing access (temporarily or permanent) to resources (such as accounts, pictures, files etc), then use OAuth.
3.If you need to provide access to a partner or customer application to your portal, then use SAML.
4.If your usecase requires a centralized identity source, then use SAML (Identity provider).
5.If your usecase involves mobile devices, then OAuth2 with some form of Bearer Tokens is appropriate.
Reference 1,Reference 2,Reference 3
If you need to authenticate for LDAP or ActiveDirectory then a solution like one of the CAS gems you mentioned above is right for you (RubyCAS, CASino).
If you can afford it, one of the commercial vendors (like Okta) is your best option because they will stay on top of security patches and manage your authentication needs for you. In particular, if you have to support ActiveDirectory, they've already implemented it.
OAuth is most useful for third party authentication, though it can do SSO. So if you wanted to support Google / Facebook logins or be a third party authenticator then it's a great choice. Since you don't want to support Google / Facebook then OAuth is probably not what you want.
If you are only intending to use HTTP POST for your SSO needs then the ruby-saml gem could be the way to go. You would have to implement your own Identity provider and add a service provider component to all your websites (possibly in the form of a gem.) Part of what you would need is a rails api to act as your identity provider. This gem helps support writing API's in rails.
EDIT
You mention the possibility that future third party users might be logging on to your site. This changes your calculus away from rolling your own ruby-saml solution.
The best way to share your authentication API is to implement an OAuth layer. Doorkeeper is a popular solution and is fast becoming the standard for Rails authentication. It's community support, flexibility and ease of use make it the best way to go for a consumable authentication API.
Railscast for implementing doorkeeper
Anjan.
I've used CAS and OAuth in my work. Here are some of my opinions, and hope to help.
Basically
Both CAS and SAML aim to solve SSO situation. And CAS is a service or an authentication system, which can support SAML protocol.
OAuth aims to solve authorization and authentication.
And in practice,
Both CAS and SAML act as an gateway in front of a group of applications which belong to one organization. Just like your case.
OAuth is used to authorize and authenticate between different organizations.
Just my thoughts, and hope to hear more voices.
We have used CAS and SAML in our architecture (Mobile App, Online Portal, and MicroServices) and both are used for different purpose.
Our Online Portal is like online banking that runs in public domain and has to be secure. We don't want to store password and other secure token's in the DB of the online portal, therefore, we use CAS for authentication and authorization. During registration, when user chooses the password, we store the password in CAS and store corresponding token in the DB of Portal
When user login next time, User enters the user name and password in Portal. Portal fetches the token corresponding to user from DB and sends User_name, password, and token to CAS for validation.
But, in case user has already logged in into one application and we redirect user to our another application then we dont want to user to enter username and password again for second application. We use SAML to solve this. First application shares user details with SAML server and gets token in return. First application passes the token to second application. Second application sends token to SAML server to get user details and on success lands user to desired page. Our first application can be Mobile App and second can be Portal in the scenario of App2Web.
Since you have got lot of answers for this question, I would like to suggest you an identity product that can be cater these kind of all protocol in one hand with lot of authentication and user management features. You can just try WSO2 Identity Server version for this.

Implementing a login system for web apps and web API with DotNetOpenAuth

I'm looking for some guidance on what people think are the best set of technologies to use. We are looking to create a web portal to allow customers to register/login with standard credentials or their social accounts (Google, Twitter etc).
Once they are registered and logged in to the portal they can access our different web apps which will know who they are and what permissions they have based on a token. We will also need to secure a set of web APIs using some sort of OAuth mechanism, so the user would possibly create an account on the web app and then create an application which would give them the keys they need to access the API from their own app.
We have a basic portal app using MVC 4 and DotNetOpenAuth which allows a user to create an account and login with either a username and password or their Google, Facebook account etc.
The APIs would be MVC 4 Web APIs
Ideally the whole set up needs to be as simple as possible, I've briefly looked into using Windows Azure Access Control (ACS) as a way to cut out some of the heavy lifting but its hard to tell where exactly it all fits together.
Currently we run an ADFS 2.0 server and WIF to allow web login to our apps but it doesn't seem like it would be an ideal choice when integrating the social login and for securing the web APIs
I guess it could be two quite seperate parts, once they are logged into the portal, how would we go about providing some sort of claims token to the other apps they then access to understand who the user is and what they are allowed to do. And maybe the web API authentication/authorisation is its own entity?
Thanks for your time
We ended up using the built in MVC 4 login system and also added JWT token support, when a user is logged in a JWT token containing their claims is stored as a cookie. This is then automatically passed around our sites on the same domain by the browser, when the web API is called from javascript it checks for the token in the headers sent by the browser and either validates it and returns the correct data or returns an unauthorised response.
It doesn't cover all the bases, we can't give trusted third parties access to our web services yet

Use OAuth 2.0 Tokens to login to Salesforce.com

Currently we are not using OAuth with our apps but we are working on making the shift, we have direct login and capture the user/pass that was entered and store those. We then turn around and use the stored credentials for a feature that allows the user to open a record within Salesforce.com, we pass the user/pass in to the login endpoint along with a starting URL to the specific record, this works great and is a well liked feature as it is a simple SSO from the App to Salesforce.com where the user can see all data that may not be visible within the app.
Moving to OAuth 2.0 and using the standard webflow, we no longer can capture the user/pass, which is actually a good thing as far as security is concerned. We would however like to keep this functionality, is there anyway of SSO'ing into Salesforce.com by passing along one of the OAuth tokens or some kind of sesson id?
After reading more and thinking about what OAuth accomplishes I feel like this probably isn't possible being that the tokens obtained are meant to be used only with the API and not with the front end system. I hope that I am wrong though and there is a way to login to the front end using these tokens.
EDIT
Ok I am editing to hopefully make this more clear. Currently user's authenticate using the login() API method with their user/pass, we store this user/pass locally (not ideal). We then sync a subset of data that the users can access anytime within the app, being that it is a subset, we have a feature to "SSO" to the Salesforce.com front-end. This simply opens Salesforce.com in a web-view (UIWebView) using the URL https://ns8.salesforce.com/?pw=PASSWORD&un=username#example.com&startURL=/recordId. This will log us in to Salesforce.com and open the specified record.
Moving forward we want to use OAuth 2.0 with the web flow so that we aren't handling the user/pass and so that we do not have to deal with Security Tokens or opening specific IP ranges to allow login without a Security Token.
With that said, is there anyway to use the tokens/credentials received from the OAuth authentication to open Salesforce.com, automatically log the user in, and goto a specific record?
I may have mis-used "single sign on" before, but in a sense, this simulates an SSO from our App to Salesforce.com, in that our users can touch a single button within the app and be logged in to the Salesforce.com web interface.
When you request an OAuth token, you can specify what scope it has, options include api only (the original type of tokens), or other options which include the ability to use the token with the UI pages. (see the scope parameter detail in the help). One of the still missing peices is a way to bootstrap the UI with that token when all you can do is tell a browser/webview to goto a URL, but a widely used (but unsupported) way is via frontdoor.jsp, e.g. you'd open https://{instance}/secur/frontdoor.jsp?sid={the_Access_token}&retURL={optional_relative_url_to_open} remember to URLEncode the 2 values.
So I think you are saying your application uses the SFDC username and password to just authenticate to retrieve a record from SFDC to display in your app?
IF this is correct - which I think it is - then you could just use the standard Salesforce Single Sign On system to authenticate. There is a guide here which outlines the process of setting up a SAML SSO system with Pat Patterson writing an interesting feature on how the security system works here. He has also written a great blog post on DeveloperForce here about the nitty details of OAuth in general for Force.com and not just the SAML setup. I have used the OAuth system in an iPad app against SFDC and it works quickly and easily. I can't see why your system should be unable to use the protocol as you desire.
Direct access into Salesforce is a key benefit of SSO and definitely provided. I'm not sure where you read that SSO in Salesforce is API only. From the SSO PDF pbattisson linked for you:
With single sign-on, users only need to memorize a single password to
access both network resources or external applications and Salesforce.
When accessing Salesforce from inside the corporate network, users are
logged in seamlessly, without being prompted to enter a username or
password. When accessing Salesforce from outside the corporate
network, users' corporate network login works to log them in. With
fewer passwords to manage, system administrators receive fewer
requests to reset forgotten passwords.
OAuth 1 & 2 are both supported, though I'm a fan of OAuth 2 since 1 has really finicky additional steps involving the order of parameters and their encoding sequences. I recently wrote an Apex-Twitter integration and quickly realized it wasn't going to be as easy as Facebook, which uses OAuth 2.0.
But in your case it sounds like you just want to provide users with the ability to actually login to Salesforce and go to a specific landing page once authenticated. This is definitely doable.
Good luck!

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