I'm designing a Web API that will be consumed by external web server.
Only the external web server must be authorized to access the internal API.
The end user will be authenticated against external web server, but the username must be forwarded to Internal API when requesting data, because there is some data filtering based on the username.
What authentication mechanism should in the internal web api server?
I started with X-API-Key header, but then how should I provide username? I would like to avoid passing username in querystrings
I was thinking about basic authentication, where password would be the X-API-Key
bearer token could theoretically work as well, but bearer tokens are usually generated by authorization server, which is not an option in this case.
EDIT:
Note, that the end user does not make any API calls. It simply access a website build using some CMS and the CMS internally fetches the data and generates HTML response.
I am trying to wrap my head around the concept of bearer-only clients in Keycloak.
I understand the concept of public vs confidential and the concept of service accounts and the grant_type=client_credentials stuff. But with bearer-only, I'm stuck.
Googling only reveals fragments of discussions saying:
You cannot obtain a token from keycloak with a bearer-only client.
The docs are unclear as well. All they say is:
Bearer-only access type means that the application only allows bearer token requests.
Ok, if my app only allows bearer token requests, how do I obtain this token if I cannot get it from Keycloak using client id / client secret?
And if you can't obtain a token, what can you at all? Why do these clients exist? Can somebody please provide an example of using this type of client?
Bearer-only access type meaning
Bearer-only access type means that the application only allows bearer
token requests. If this is turned on, this application cannot
participate in browser logins.
So if you select your client as bearer-only then in that case keycloak adapter will not attempt to authenticate users, but only verify bearer tokens. That why keycloak documentation also mentioned bearer-only application will not allow the login from browser.
And if you can't obtain a token, what can you at all? Why do these clients exist?
Your client can't be set as bearer-only on Keycloak Server. You can
still use bearer-only on the adapter configuration though. Keycloak
doesn't allow "bearer only" clients (when setting up your client on
the server) to obtain tokens from the server. Try to change your
client to "confidential" on the server and set bearer-only on your
adapter configuration (keycloak.json).
So if you understand above statement then if you have two microservice which are talking to each other in the case, caller will be confidential and callee will be bearer-only
And Keycloak also mentioned
Bearer only client are web service that never initiate a login .It’s typically used for securing the back-end.
So if you want to use any adapter you can use bearer-only depend on the need
EDIT-
Lets go in more details ..Let see one example i have a web-app and one rest-api for web-app i am using React/Angular/JSF any front end technology and for back-end i am using Java based rest-api OR Nodejs.
Now for above requirement i have to secure both the products(web-app,rest-api) so what will be my work of action? How will I secure both the apps through Keycloak?
So here is details explanation
I have to create two client inside a realm in keycloak
Client A will be use by web-app
Client B will be used by rest-api
So now question will be why two client?
For web-app we want to force user to login via GUI then only generate the token
For rest-api we dont want GUI based api as these api consume by web-app but still secure the access to rest-api.
Now Go to Client A and make its Access Type public client so web-app will ask to login via keycloak GUI or your login page then generate the token
So same token which generated in above step used by rest-api and according to user role and other information data will fetch. So Access Type of Client B will be bearer-only so web-app generated token is passed to rest-api and it is then used to authorize the user .
Hope it will help. Someone want to add more he/she free to add.
Short answer: you can't obtain an access token using a bearer-only client, so authentication flow configuration is irrelevant, but keycloak may still need to know such a bearer only client to manage role / or audience
More details
bearer-only clients usefully represents back-end applications, like web service, called by front application and secured by the authorization server (= keycloak)
Backend / Web service application are not called directly by user, so they can't play in the Oauth2.0 user interactive flow. Setting "bearer-only" document this fact to keycloak server, allowing administrator to configure client without otherwise mandatory values (example redirect uri…) and allowing usefull error messages if someone trying to obtain a token for such a client
However, this doesn't mean you cannot configure specific roles for this client: so it need to appear in keycloak realm.
In addition bearer-only client need to verify the received access token, especially, if this (recommenden) adapter feature "verify-token-audience" is activated, bearer-only client need to verify that the access token has been issued for it: the bearer-only client must be in the audience attribute of the access token:
see https://www.keycloak.org/docs/latest/server_admin/index.html#_audience
for audience managing by keycloak, bearer-only clients needs to be registered in keycloak realm.
In my understanding, it is used when you have some internal service.
Let's say you have ServiceA and ServiceB. A user calls ServiceA which in hand calls ServiceB. ServiceB is never called by the user directly, only by other services. ServiceA will get a token using the user's credentials. And then will use this token to call ServiceB. ServiceB will never initiate a login. It will just use the token to verify permissions.
In this case, ServiceA will be confidential and ServiceB will be bearer-only clients.
An other idea why bearer only clients exist could be that client are misused for role containers sometimes, see the following discussion on the Keycloak User mailing list https://lists.jboss.org/pipermail/keycloak-user/2016-April/005731.html
E. g. the default client "realm-management" is a bearer only client, that contains roles to manage things in a realm. There is no need to invoke a login on a client like this, so public and confidential doesn't make any sense.
Given that I would create an OAUTH2 authentication server.
Given that I would to have separate resource servers, exposing REST APIs.
What are the best communication practies between the authentication server and the API servers?
To explain OAUTH2 server would be a proxy authenticating the user and forwarding requests to different API servers, that are not third party, but under the hood of the OAUTH2 proxy, relying on it to know the agent (user) requesting for the given command\query.
The simplest would be that the authentication server will forward the user id (that is stored with ACL rules also on each API server) under a secure connection, and that access would be restricted to request forwarded from authetication server to resource API servers.
The auth server would in this case forward the user id, but this seems suceptible to mand in the middle attack (altought firewall on API servers would be configured to accept requests only from the authentication server).
Another problem would be compromission of the OAUTH proxy, giving automaticly grant to any request coming from it.
Are there ready solution and patterns to deal with this scenario?
Thanks!
Check the User Account and Authentication Service (UAA) from CloudFoundry. Maybe will help you. It is also available as a stand-alone OAuth2 server.
API Documentation, GitHub
We have a CRM Dynamics 2016 onpremise (IFD configured), we access to the CRM from a Cordova mobile application via SOAP authentication and consume the service "Organization.svc" to get or set Data: everything works fine until now.
After adding a Web Application Proxy, the call to ADFS for the token still working, and returns a valid token. However, the second step of consuming the service "Organization.svc" is blocked : the Web Application Proxy redirects the call to the ADFS login page, which is of course not what I want.
I think the root of the problem is in the fact that the proxy cannot 'read' the SAML token I'm sending in my HTTPRequest.
Did anyone have an idea how to resolve that ?
Could you maybe inspect with Fiddler if the proxy is forwarding the required authentication cookies / headers ? I presume these are ignored by the proxy and ADFS sees the second request as not authenticated.
I saw the word "endpoint" many times in OAuth documents.. However, I still don't know what does this word really mean.. Does anyone have ideas about this?
The OAuth 2.0 Authorization Framework
The authorization process utilizes two authorization server endpoints
(HTTP resources):
Authorization endpoint - used by the client to obtain
authorization from the resource owner via user-agent redirection.
Token endpoint - used by the client to exchange an
authorization
grant for an access token, typically with client authentication.
Its basically the HTTP web address of the authentication server. It could probably be server addresses depending upon how its worked. The first is for requesting access of the user the second could be for granting access to the application. this probably depends upon how the Authentication server is set up.
OAuth endpoints are the URLs you use to make OAuth authentication requests to Server. You need to use the correct OAuth endpoint when issuing authentication requests in your application. The primary OAuth endpoints depend upon the system you are trying to access.
Example Google has two end points:
Request access of user:
https://accounts.google.com/o/oauth2
Exchange tokens
https://accounts.google.com/o/oauth2/token