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 ...
For the past 10+ days I've read an watched ALL the content I could find on understanding OAuth2 and OpenID Connect, only to find that many people disagree on the implementation, which really confuses me.
To my understanding, all the articles and examples I found assume you want access to eg. google calendar, profile info or emails if you eg. login with google, but I do NOT need to access other than my own API's - I only want to use Google, Facebook etc for logging in, and getting an id which I can link to my user in my own database - nothing more than that.
I'll try illustrate my use case and use that as an example.
A note on the diagram: the Authentication service could probably be built into the API Gateway - not that i matters for this example, since this is not about "where to do it", but "how to do it the best way" possible, for an architecture such as mine, where it's used for my own API's / Microservices, and not accessing Google, Facebook etc. external API's
If you can understand what I'm trying to illustrate with this diagram above, please tell me if I've misunderstood this.
The most basic requirements for this architecture you see here are:
Users can login with Google, Facebook, etc.
The same login will be used for all micro-services
OpenId user will have a linked account in the database
User access is defined in my own db, based on groups, roles and permissions
I do not intend to use external API's after the user is authenticated and logged in. No need for ever accessing a users calendar, email etc. so I really just need the authentication part and nothing else (proof of successful login). All user access is defined in my own database.
So a few fundamental questions comes to mind.
First of all, is OpenID Connect even the right tool for the job for authentication only (I'll have no use for authorization, since I will not need read/write access to google / facebook API's other than getting the ID from authenticating)?
People generally do not agree on whether to use the ID or Access token for accessing your own API's. As far as I understand the ID token is for the client (user-agent) only, and the access token is for eg. accessing google calendar, emails etc.... External API's of the OpenID Provider... but since I'll only be accessing my own API's, do I event need the access token or the ID token - what is the correct way to protect your own API's?
If the ID token is really just for the client, so it can show eg. currently logged in user, without going to the DB, I have 0 use for it, since I'll probably query the user from from the db and store it in redux for my react frontend app.
Dilemma: To store user details, groups, roles and permission inside JWT or not for API authorization?
By only storing the user identifier in the token, it means that I always allow authenticated users that has a valid token, to call endpoints BEFORE authorization and first then determine access based on the db query result and the permissions in my own database.
By storing more data about the user inside the JWT, it means that in some cases, I'd be able to do the authorization / access (group, role, permission) check before hitting the API - only possible with user info, groups, roles and permission stored inside a JWT issued upon login. In some cases it would not be possible due to eg. the CMS content access permissions being on a per-node level. But still it would mean a little better performance.
As you can see on the diagram I'm sending all API requests through the gateway, which will (in itself or with an authentication service) translate the opaque access token into some JWT with an identifier, so I can identify the user in the graph database - and then verify if the user has the required groups, roles and permissions - not from an external API, but from my own database like you see on the diagram.
This seems like a lot of work on every request, even if the services can share the JWT in case multiple services should need to cross call each other.
The advantage of always looking up the user, and his permissions in the db, is naturally that the moment the user access levels change, he is denied/granted access immediately and it will always be in sync. If I store the user details, groups, roles and permission inside a JWT and persist that in the client localstorage, I guess it could pose a security issue right, and it would be pretty hard to update the user info, groups, roles and permissions inside that JWT?
One big advantage of storing user access levels and info inside the JWT is of course that in many cases I'd be able to block the user from calling certain API's, instead of having to determine access after a db lookup.
So the whole token translation thing means increased security at the cost of performance, but is is generally recommended and worth it? Or is it safe enough to store user info and groups, roles, permissions inside the JWT?
If yes, do I store all that information from my own DB in the ID Token, Access token or a 3rd token - what token is sent to the API and determines if the user should be granted access to a given resource based on his permissions in the db? Do I really need an access token if I don't need to interact with the ID providers API? Or do I store and append all my groups, roles, permissions inside the ID token (that doesn't seem clean to me) issued by OpenID connect, and call the API and authorize my own API endpoints using that, even if some say you should never use the ID token to access an API? Or do I create a new JWT to store all the info fetched from my database, which is to be used for deciding if the user can access a given resource / API endpoint?
Please do not just link to general specs or general info, since I've already read it all - I just failed to understand how to apply all that info to my actual use case (the diagram above). Try to please be as concrete as possible.
Made another attempt to try and simply the flow:
The following answer does only apply for a OpenID Connect authentication flow with a 3rd party IDP (like Google). It does not apply for an architecture where you host your own IDP.
(There are some API gateways (e.g Tyk or Kong) which support OpenID Connect out of the box.)
You can use JWTs (ID token) to secure your APIs. However, this has one disadvantage. JWTs cannot be revoked easily.
I would not recommend this. Instead you should implement an OAuth2 authorization server which issues access tokens for your API. (In this case, you have two OAuth2 flows. One for authentication and one for authorization. The ID and access token from the IDP are used only for authentication.)
The following picture shows a setup where the API gateway and authentication/authorization server are two separate services. (As mentioned above, the authentication/authorization can also be done by the API gateway.)
The authentication flow (Authorization Code Grant) calls are marked blue. The authorization flow (Implicit Grant) calls are marked green.
1: Your web app is loaded from the app server.
2a: The user clicks on your login button, your web app builds the authorization URL and opens it. (See: Authorization Request)
2b: Because the user hasn't authenticated and has no valid session with your authorization server, the URL he wanted to access is stored and your authorization server responds with a redirect to its login page.
3: The login page is loaded from your authorization server.
4a: The user clicks on "Login with ...".
4b: Your authorization server builds the IDP authorization URL and responds with a redirect to it. (See: Authentication Request)
5a: The IDP authorization URL is opend.
5b: Because the user hasn't authenticated and has no valid session with the IDP, the URL he wanted to access is stored and the IDP responds with a redirect to its login page.
6: The login page is loaded from the IDP.
7a: The user fills in his credentials and clicks on the login button.
7b: The IDP checks the credentials, creates a new session and responds with a redirect to the stored URL.
8a: The IDP authorization URL is opend again.
(The approval steps are ignored here for simplicity.)
8b: The IDP creates an authorization and responds with a redirect to the callback URL of your authorization server. (See: Authentication Response)
9a: The callback URL is opened.
9b: Your authorization server extracts the authorization code from the callback URL.
10a: Your authorization server calls the IDP's token endpoint, gets an ID and access token and validates the data in the ID token. (See: Token Request)
(10b: Your authorization server calls the IDP's user info endpoint if some needed claims aren't available in the ID token.)
11a/b: Your authorization server queries/creates the user in your service/DB, creates a new session and responds with a redirect to the stored URL.
12a: The authorization URL is opend again.
(The approval steps are ignored here for simplicity.)
12b/+13a/b: Your authorization server creates/gets the authorization (creates access token) and responds with a redirect to the callback URL of your web app. (See: Access Token Response)
14a: The callback URL is opened.
14b: Your web app extracts the access token from the callback URL.
15: Your web app makes an API call.
16/17/18: The API gateway checks the access token, exchanges the access token with an JWT (which contains user infos, ...) and forwards the call.
A setup where the authorization server calls the API gateway is also possible. In this case, after the authorization is done, the authorization server passes the access token and JWT to the API gateway. Here, however, everytime the user infos change the authorization server has to "inform" the API gateway.
This is a very long question. But I believe most can be summarised by answering below,
To my understanding, all the articles and examples I found assume you want access to eg. google calendar, profile info or emails if you eg. login with google,
You do not necessarily use Access token (ID token in some occasions) to access the services offered by token issuer.You can consume tokens by your own APIs. What these Identity Providers (synonym to Authorization server, or IDP in shorthand) is to hold identities of end users. For example, typical internet have a Facebook account. With OAuth and OpenID Connect, the same user get the ability to consume your API or any OAuth/OIDC accepted service. This reduce user profile creation for end users.
In corporate domain, OAuth and OIDC serves the same purpose. Having a single Azure AD account lets you to consume MS Word as well as Azure AD's OIDC will issue tokens which can be used to Authorise against an in-house API or an third party ERP product (used in organization) which support OIDC based authentication. Hope it's clear now
A note on the diagram is that the Authentication service could probably be built into the API Gateway - not sure if that would be better?
If you are planning to implement an API gateway, think twice. If things are small scale and if you think you can maintain it, then go ahead. But consider about API managers which could provide most of your required functionalities. I welcome you to read this article about WSO2 API manger and understand its capabilities (No I'm not working for them).
For example, that API manager has built in authentication handling mechanism for OAuth and OIDC. It can handle API authentication with simple set of configurations. With such solution you get rid of the requirement of implement everything.
What if you can't use an API manager and has to do it yourself
OpenID Connect is for authentication. Your application can validate the id token and authenticate end user. To access APIs through API Gateway, I think you should utilise Access token.
To validate the access token, you can use introspection endpoint of the identity provider. And to get user information, you can use user-info endpoint.
Once access token is validated, API gateway could create a session for a limited time (ideally to be less or equal to access token lifetime). Consequent requests should come with this session to accept by API gateway. Alternatively, you can still use validated access token. Since you validated it at the first call, you may cache for a certain time period thus avoiding round trips to validations.
To validate user details, permission and other grants, well you must wither bind user to a session or else associate user to access token from API gateway at token validation. I'm also not super clear about this as I have no idea on how your DB logic works.
First Appreciate your patience in writing a very valuable question in this forum
we too have same situation and problem
I want to go through ,as images are blocked in our company in detail
Was trying to draw paralles to similar one quoted in the book
Advance API In Practise - Prabath Siriwerdena [ page 269]Federating access to API's Chapter. Definitely worth reading of his works
API GW should invoke Token Exchange OAUTH2.0 Profile to IDP [ provided the IDP should support TOken Exchange profile for OAUTH 2.0
The Absence of API Gateway , will result in quite bespoke development
for Access Control for each API Check
you land up in having this check at each of the api or microservice [ either as library which does work for you as a reusable code]
definitely will become a choking point.]
I would like to provide some standarized SSO mechanism in my application (some different clients, growing number of services in the backend). I am wondering if OIDC/OAuth 2 is the right tool for it.
In all examples I have seen, end user is the Resource Owner and it grants permissions (or not) to some external apps by redidericting to a page asking for permissions.
My use case is different, I want to use OAuth inside my system (for apis, web pages etc.): resource owner is i.e. some service with database (plus administrator who have access to it), end user tries to get some resources from the system. User cannot grant anything, he can be granted. I think it's the most classic scenario, which can be named Single-Sign-On. Is there any standard flow for this in OAuth 2 (or preferably OpenId Connect)? Is it achievable? Or am I looking at a wrong tool?
OIDC/OAuth can be used for both consumer as well as enterprise scenario's. The consent steps of OAuth are useful in consumer oriented scenario's. When dealing with enterprise scenario's like yours, there's no point in asking consent since it is implicit, at least for the enterprise's apps. That is certainly covered by OAuth/OIDC: the Authorization Server is not required to ask for consent and can (typically) be configured to skip that step for particular Clients. So: using OpenID Connect without consent would be suitable.
For your usecase you can use combination of OpenID Connect and OAuth Client_Creds flow. For example suppose you have a HRMS application which needs to get the employee data to show to the employee from some DB.
Register HRMS with OPenID Provider
Register HRMS as Client to OAuth Server (OpenID Server and OAuth Server can be same)
When User comes to HRMS application:
a. Check for Id_token cookie, if not present then redirect to IDP
b. IDP authenticates and if successful redirects back to SP with ID token
c. If token is valid then SP sets the token as cookie in the browser using another redirect to itself but to the home page
Now All processing will be server side:
a. HRMS app hits the IDP to get the User Data
b. If successful then it hits the OAuth Server to get the access_token
c. if successful then it uses the access_token to talk to DB Service and
get the data
SP=Service Provider, IDP = Identity Provider
Actual flow can be a little different based on security considerations.
Hope this makes it helps.
At my company we are developing several web applications that uses a REST API server.
First a little introduction.
The app provides the ability to manage users through the REST API and allows the users to login to the app.
Right now the REST API is for internal use only because we plan to develop more apps and communicate to the REST API as the central point of data access. We are handling the REST API authentication with a "Resource Owner Password Credentials Grant" implementation for the internal apps.
What we need is a Single-Sign on service for all the apps, we want a user to login to an app and if he/she access to another of our apps he/she will be already loged in.
We have been experimenting with the CAS protocol, with the CASino library specifically and it works great.
The problem is we don't know how to handle the flow between the apps, the REST API and the SSO service, also I don't know if there is a better choice regarding SSO services.
My questions are...
How we could handle the flow between the apps, the REST API and the
SSO service, because the REST API should be stateless it should not
communicate to the SSO service? or is there a way to communicate the
REST API to the SSO service?
Is there a better choice to implement a Single-Sign on service,
maybe OAth or OpenID and are this options suitable for REST APIs?
Thanks in advance!
Your REST API will have to talk to the SSO server to validate the Access Token, unless all the information it needs is encrypted inside the Access Token. Not sure what you mean by "flow between the apps", you should have all apps talking to a central SSO server.
When a user wants to create an account on WebApp1, the account should be created on the SSO server, either by redirecting them there or if you need a differently styled signup form for each web app, then via an AJAX call to the SSO server's REST API. I would recommend the latter as redirecting is more difficult to debug and it can make a bad user experience.
Make sure the messaging is clear, i.e. not "Sign up for a WebApp1 account", but "Sign up for a MyCompany account to get access to WebApp1".
OAuth 2.0 is very popular and people have more experience with it, so it's easier to get help or integrate with apps created by others.
The doorkeeper gem is a good server library.
OAuth 2.0 is normally used when the SSO server doesn't trust the client apps (e.g. Facebook, Twitter), but it can be implemented in such a way to skip the client authorization step (where the user is asked to approve the client app), and you can use the Resource Owner Password Credentials Grant via a REST API.
CAS is easier than OAuth. It is fairly easy to implement the basic endpoints and that way you can customize it as you wish.
I worked on a CAS-based server with a custom implementation (not sure if it was even really CAS-compliant). The authentication was done with Devise (I don't recommend Devise if you're going to customise it a lot, make your own in this case). The original flow was that the user went to the website, clicked Login/Register and then was redirected to the SSO server and after the user logged in, redirected back with a one-time ticket that the website's backend exchanged to an access token via a REST API call.
Then we added a REST API that was called from each website with AJAX. You send the username/password/captcha/etc and get back an auth token, which the site sends to its own backend. The SSO REST API can also set a cookie on its own domain, so that if the user visit another of our web apps it makes a call on pageload to check if the user is logged in. This way you're automatically logged in on every webapp without the redirect mess.
All tokens issued + the associated user info were sent to a fast Node.js app that would save them to Redis, and the app backends would call this app to validate the access tokens really fast, without putting load to the SSO Rails app.
I am working on a AngularJS web app and I am trying to implement single sign on. I had a nice implementation using Identity server and authorization server with implicit flow and oAuth tokens, however I need a mechanism to sign the user out of all apps they are signed into.
I am currently redirecting the user to authorization server, this then redirects the user to identity server. The user logs on and it shown a consent screen, a Json web token is then sent to the app via the query string and is put into local storage. This token is attached to the Authorization header which the web api (that is on a different domain) receives and either allows or denies the request.
The problem is oAuth has no way of singing a user out of all apps. I have now looked at WS-Federation using Json web tokens but this approach still appears to use cookies which I would like to avoid as the api and client app are on different domains.
Does Thinktecture Identity Server have any way to do this and if so are there any examples I could take a look at.
Thanks
As you already said - OAuth2 is not an authentication protocol and hence does not have the concept of (single) signout.