NET Core, even in less common scenarios (such as the authentication server not being available). NET Core’s flexible authorization policy makes it easy to have fine-grained control over access to APIs.
Combined with my previous posts on issuing bearer tokens, you should have a good overview of how to use this technology for authentication in ASP.
Authorizing based on roles is available out-of-the-box with ASP. As long as the bearer token used for authentication contains a roles element, ASP. The important thing to know when working with JWT tokens is that in your and then confirm that the claim is valid by checking its value.
NET Core’s JWT bearer authentication middleware will use that data to populate roles for the user. Again, details on custom authorization policies can be found in ASP.
So, a roles-based authorization attribute (like to limit access to managers and admins) can be added to APIs and work immediately. NET Core is done through custom authorization requirements and handlers. NET Core documentation has an excellent write-up on how to use requirements and handlers to customize authorization. NET Core documentation, but here’s a code snippet demonstrating claim validation in an that authorizes users based on the (admittedly strange) requirement that their office number claim be lower than some specified value.
Notice that it’s necessary to parse the office number claim’s value from a string since (as mentioned in my previous post), ASP. Now that we have a simple web API that can authenticate and authorize based on tokens, we can try out JWT bearer token authentication in ASP. The first step is to login with the authentication server we created in my previous post.
Now, shut down the authentication server just to be sure that our web API can authenticate without it being online.
To make the calls work, add an Authorization header with the value “bearer X” where “X” is the JWT bearer token returned from the authentication server.
As long as the token hasn’t expired, its audience and authority match the expected values for this web API, and the user indicated by the token satisfies any custom authorization policies on the action called, a valid response should be served from our web API.
NET Core using libraries like Open Iddict or Identity Server4. Jwt Bearer package that does most of the work for us! No identity or user information is managed by the app directly.
In this post, I’m going to cover the other end of token use on ASP. Instead, it will get all the user information it needs directly from the JWT token that authenticates a caller.