Birchsoft.Azure.Function.Identity 1.0.2

Birchsoft.Azure.Function.Identity

Important:

The NuGet package supports only Azure Functions using the isolated worker model and validates JWT issued by Microsoft Entra ID.

The Birchsoft.Azure.Function.Identity package simplifies Azure HTTP Trigger Function Authentication by utilizing JSON Web Tokens (JWT).

Configuration

To set up your function correctly in Azure, follow these steps:

1. Create a JSON configuration file and name it identity.settings.json:

{
    "AzureMEID": {
        "TenantId": "xxxxxxxx-8eba-45ca-a7af-xxxxxxxxxxxx",
        "Audience": "xxxxxxxx-2612-4413-b5b2-xxxxxxxxxxxx",
        "ObjectId": "xxxxxxxx-9f62-4343-aaf6-xxxxxxxxxxxx"
    }
}

The Audience is the Application (client) ID from Azure App Registrations.

You can choose any name for this JSON configuration file, but make sure to specify it as a parameter in the AddAzFunctionIdentityJsonConfig() method.

2. Configure the Program.cs file:

class Program
{
    public static async Task Main(string[] args)
    {
        var host = new HostBuilder()
            .ConfigureAppConfiguration((hostContext, configBuilder) =>
            {
                configBuilder.SetBasePath(hostContext.HostingEnvironment.ContentRootPath)
                        .AddJsonFile("local.settings.json", optional: true, reloadOnChange: true)
                        .AddAzFunctionIdentityJsonConfig(hostContext)
                        .AddEnvironmentVariables();
            })
            .ConfigureFunctionsWebApplication(worker =>
            {
                worker.UseAzFunctionIdentityMiddleware(false);
            })
            .ConfigureServices((hostContext, services) =>
            {
                var configuration = hostContext.Configuration;

                services.AddLogging();
                services.AddAzFunctionIdentityConfig(configuration);
            })
            .Build();

        await host.RunAsync();
    }
}

3. Skip Azure function authorization

You can also bypass Azure Function (endpoint) authorization by adding the attribute [SkipFunctionAuthorization].

[SkipFunctionAuthorization]
[Function("FunctionNotAuth")]
public IActionResult RunNotAuth([HttpTrigger(AuthorizationLevel.Anonymous, "get", "post")] HttpRequest req)
{
    _logger.LogInformation("C# HTTP trigger function processed a request FunctionNotAuth.");
    return new OkObjectResult("Welcome to Azure FunctionNotAuth!");
}

4. Authorization based on roles included in the token.

To authorize functions based on the roles specified in the token, add an attribute, such as [AppRoles("Admin", "User")].

Important:

If the token contains roles and the function does not include the AppRoles attribute with the corresponding role, authentication will fail.

[AppRoles("Admin", "User")]
[Function("FunctionAuthRoles")]
public IActionResult RunAuthRoles([HttpTrigger(AuthorizationLevel.Anonymous, "get", "post")] HttpRequest req)
{
    _logger.LogInformation("C# HTTP trigger function processed a request FunctionAuthRoles.");
    return new OkObjectResult("Welcome to Azure FunctionAuthRoles!");
}