Forward Bearer Token IdentityServer Web-API - asp.net-web-api2

I have a Web Application that needs to call a Web API, using a bearer token.
This service will need to call a common service on its own with the user credentials included.
So: Client --> API1 --> API2
Can somebody help me if it is possible to:
- or ask a for a new server to server token for API1 to API2 with the user claims included
- or re-use the received token for the server to server call

If you host both apis, then you can just forward the access token.
It is rather difficult to create a new token with the user credentials from an access token.
The token can be validated on both APIs, and you have the user claims on both APIs.

Old question, but if you are using IdentityServer4, you'll want to create an extension grant, and "refresh" or "delegate" your token on API1 to create a new token for API2.

Related

Oauth + SPA + API backend

I'm setting up a service which needs to authorize against an existing Gitlab as OAuth Provider.
The service is a SPA which gets served by a webpack dev server in dev mode and a nginx server in production mode.
I'm also setting up an external API which should handle the Database and make request to the given gitlab instance (for example pull repos).
My SPA is authorizing against the Gitlab OAuth with the implicit_grant flow and is getting an access token. Currently I pass the access_token after the redirect to my API backend and there I get the Gitlab userid and username via a request to the gitlab instance with the access_token. With these I generate a jwt and send it to the client (SPA) and save it there so I can authorize my API with this JWT.
How would I handle the initial access_token in my backend (cause I need the token to make gitlab calls)?
Currently I'm thinking about writing it to the user in the database and get the user everytime he makes a request (normal passport flow), so I also have the token. But what if the token gets invalid or expires?
Should I use an interceptor in the backend and if the token is invalid (gitlab would give me a 401) redirect the 401 to my client, let him get a new token and pass it back to the backend, generate a new JWT, send this again to the client and let him do the same request as original reuested(via interceptor, too)?
Or should I just redirect the 401 to my client, let him get a new token, let him post this token to for example /renewToken and save the token to the database and use the old JWT?
Hope someone can help me unserstand this flow.
The Credential Management API should be what your looking for on the client. That will retrieve the id and access tokens to that you can compare access tokens with your server/ap and then validate the id token.
Haven't seen a Git example but there are Google and Facebook examples.
You could let the user send the initial access token and your backend API will just act based on the initial access token. Seems to me that it is not necessary to produce another JWT token in this case.

Generate Access Token and validate against IdentityServer4 through Azure API Management

I have an external endpoint which is going to hit the Azure API gateway and that would route it to the backend API which is protected by IdentityServer4 authorization.
I am getting the access token if I hit it through the Postman client with the interactive UI from IdentityServer.
Is there a way I can get the access token required from the Azure API Management to validate against the IdentityServer4 and append it to the header in the request to the backend API?
Yes it is possible to achieve it through custom policy. You can ask your external API-Client/Consumer to paas in credentials in heaser, and then you write a policy inside inbound to can read those user credentials and do a API request (similar to your postman) and get the access token. You can then append the same token and let your request gets forwarded to backend API.
As per your problem statement, this should work. In case not, you might have to explain your scenario with more description/steps.
Here are some of the reference materials for you, I hope it helps.
https://learn.microsoft.com/en-us/azure/api-management/api-management-advanced-policies#SendRequest
https://learn.microsoft.com/en-us/azure/api-management/api-management-sample-send-request
Postman has a luxury of a human user seeing the UI and authorizing API access and IdentityServer4 to issue a token for Postman. There is no such luxury when call is being processed by APIM server, as you could send request for token to IdentityServer4, but who would be presented UI to authorize the action?
The only way is to provision some sort of secret to APIM (header, query, certificate) that would be recognized by IdentityServer4 to allow it issuing tokens for APIM. If such secred is available you could use send-request policy to make a call to IdentityServer4 and obtain required token.
Or make sure that every request to APIM has a token already.

JWT handling with WSO2-AM

we plan to introduce an API management solution and we're currently setting up a proof of concept with WSO2 AM. We want to use the WSO2 API gateway to check whether a certain consumer application is allowed to use an API and to throttle the request rate.
I work on the identity workflow and I wonder how a consuming application can pass a JWT token to the backend service with WSO2-AM in between.
First, this is our current scenario:
Without API gateway
The consuming application gets a JWT token for its carbon user from an identity provider. The JWT contains some claims about the user, e.g. the roles he/she belongs to.
The app calls the service an passes the JWT token in the Authorization HTTP header like: Authorization: Bearer
The service validates the issuer and signature of the JWT and retrieves the claims from it.
So, this is pretty straight forward. Now we put an API gateway in between the application and the service:
With API gateway
The consuming application gets a JWT token for its carbon user from an identity provider.
The consuming application uses OAuth2 to get an access token for the following API calls. We can use the client_credentials grant type and simply pass the the client id and client secret. I haven't yet tried it, but we could possibly use the JWT grant type (see https://docs.wso2.com/display/ISCONNECTORS/Configuring+JWT+Grant+Type) and use the JWT for passing user information to the API gateway.
The API gateway validates the JWT against the public key of the identity provider when using the JWT grant type.
An access token is returned to the app.
The app sends an API request to the gateway and passes the access token in the Authorization HTTP header.
The gateway validates the access token.
The gateway forwards the API request to the service.
And there is my problem: How can the JWT from 1/2. be passed to the service?
There is a documentation for "Passing Enduser Attributes to the Backend Using JWT" (see https://docs.wso2.com/display/AM210/Passing+Enduser+Attributes+to+the+Backend+Using+JWT), but this would introduce a new JWT, issued and signed by WSO2-AM, and I'm not sure, whether this JWT contains all information from the JWT used to create the access token (or even the original JWT).
Another way I could think of is using a custom HTTP header for passing the JWT through the gateway to the service. I cannot use the Authorization header (as we do without the API gateway), because WSO2-AM expects the access token in that header.
Since I'm not happy with either solutions, I want to ask the experts: How would you solve this?
Thanks,
Torsten
The only possibility I can think of is to send the JWT token in a custom Header for the backend service.

Retrieve id_token based on access_token in API

We are current building a collection of back-end ASP.NET Core microservices. These services will not be accessed directly from the front-end application, but rather accessed through an ASP.NET Core API gateway. We are using IdentityServer4 for the OpenID Connect server. I have been able to setup the UseJwtBearerAuthentication middleware to have API gateway validate the JWT bearer token (access_token) against IdentityServer4. I would like to be able to have the API gateway inject the id_token, based on the access_token, into the requests made to the back-end services that may need to know the end-user.
Is there a way to configure the JWT middleware to retrieve the id_token when validation the access_token or do I need to manually call the OpenID Connect server in the API gateway?
You don't use id_tokens at APIs - they are for clients.
If you want to have access to certain identity claims, either include them in the access token (by configuring the ScopeClaims on the resource scope), or use the access token to contact the userinfo endoint which in turn will return the identity claims.
The JWT middleware performs standalone verification, it does not contact the identity server to verify or retrieve anything. You'll have to make an additional call.

How to start with OAuth Client Credentials to protect WebApi using OWIN Oauth?

I am a newbie to OAuth 2.0.
I have fairly read the OAuth 2.0 doc and I saw there are four types of methods for obtaining Authorization.
Types of obtaining authorization:
1.Implicit Grant
2.Resource Owner Password Credentials Grant
3.Client Credentials Grant
4.Authorization Code Grant
In my case, I have Client application, Resource owner, Resource server and Authorization server.
Resource server is a website where Resource owner registers with his/her credentials.
Client application is a third party website who registers into resource server and gets the Client application credentials for accessing it in future.
Authorization server checks the client credentials from client app and grants access token to the client app.
Let us consider, resource server as "www.serversite.com", authorization server as "www.authserver.com" and client application as "www.clientapp.com".
Flow:
Step 1: Also make an assumption that www.serversite.com as a payment gateway site and the client has to integrate "www.serversite.com" into "www.clientapp.com" for creating, executing and refunding payments.
Step 2: So the client "www.clientapp.com" creates an app in server "www.serversite.com" and gets API credentials.
Step 3: Using these API credentials, the client "www.clientapp.com" makes an access token request to the auth server "www.authserver.com".
Step 4: If the API credentials from client app are valid then the auth server grants an access token.
step 5: With this access token, client app request the resource server for further operations like creating payments as well as executing payments.
My questions:
I am using ASP.NET Web API for authorization server and using OWIN.OAuth for generating access token, refresh token, authorization and all the stuffs needed to authorize the client app.
But, in this link (OWIN OAuth 2.0 Authorization Server), I found that, the web api authorize the client app using "Resource Owner Password Credentials Grant" and the sample provided for implementing Owin.OAuth in web api is great, but I have lot of confusions roaming in my mind.
Which way of obtaining authorization is suitable for my process?
(Client Credentials flow or Resource Owner Password Credentials flow)
How to implement Client Credentials Grant type using ASP.NET Web
API(OWIN OAuth)?
Also provide some samples or links that may be helpful for me?
Thanks in advance.
Theres an example of how to get started on the asp.net website, specifically here:
http://www.asp.net/aspnet/overview/owin-and-katana/owin-oauth-20-authorization-server
I quote:
private Task GrantClientCredentails(OAuthGrantClientCredentialsContext context)
{
var identity = new ClaimsIdentity(new GenericIdentity(
context.ClientId, OAuthDefaults.AuthenticationType),
context.Scope.Select(x => new Claim("urn:oauth:scope", x))
);
context.Validated(identity);
return Task.FromResult(0);
}
Obviously you will need to go ahead and verify the actual client id / secret exist perhaps in a local database sometwhere before you go ahead and set the context to validated.
In terms of deciding which flow to use, you need to ask yourself, if the application is requesting access to your APIs on behalf of an actual user, then you need to use Resource Owner, however if the application itself needs access then Client Credentials is the way to go.
Generally speaking though, most implementations use Authorisation Code Flow, so if you can form a security stand point, get the users redirected to a page you host to take their credentials, opposed to sending them over the wire via Resource Owner Flow.