Rudi.Dev.Azure.Functions.Isolated.Authz 1.1.1

Rudi.Dev.Azure.Functions.Isolated.Authz

Add Authentication / Authorization Middleware to Azure Functions (running Isolated on .NET 7) when using the built in Azure App Service authentication.

This only supports App Roles (not Scopes).

Why

• Azure Functions don't have a built in way to access the ClaimsPrincipal
• Documentation for this has code for In-Process (which this mostly uses)

Can I use this In-Process?

Don't. Accept a ClaimsPrincipal and use a Filter instead.

Usage

Add Rudi.Dev.Azure.Functions.Isolated.Authz from NuGet.

Add the middleware to your Function worker:

.ConfigureFunctionsWorkerDefaults(app =>
    {
        app.AddAuthz(); // <-- Add me
    })

Add a good old [Authorize(..)] attribute to your functions:

[Authorize] // Requires an authenticated user (although don't use this, App Service should be doing this for you)
[Authorize("Required.AppRole")]
[Authorize(new [] { "Required.AppRole", "Another.Required.AppRole" })]

What this actually does

It basically uses the code referenced above from Microsoft to parse the ClientPrincipal, and translate it to a ClaimsPrincipal but with Roles correctly mapped so you can use principal.IsInRole("") in your own code.

The Attribute is just a helper so that you don't have to do that.