Afrisys.JwtAuthentication.AspNetCore 1.0.1

Afrisys.JwtAuthKit

A lightweight JWT authentication and API authorization library for ASP.NET Core.

Designed to simplify secure microservice communication using JWT Audience-based isolation, without complex policy or IdentityServer configuration.

📌 Why This Exists

Modern microservice systems often struggle with:

• Overly complex authentication configuration per service
• Weak service-to-service isolation
• Repeated JWT setup across APIs
• Difficult-to-maintain authorization rules

Afrisys.JwtAuthKit solves this by enforcing a simple principle:

JWT Audience defines API access boundaries

Each API only accepts tokens explicitly intended for it.

✨ Features

• Minimal setup (single-line configuration)
• Automatic JWT Audience validation
• Works with any JWT provider (Duende, Auth0, Keycloak, Azure AD, etc.)
• Lightweight with zero unnecessary dependencies
• Compatible with Controllers and Minimal APIs
• Clean separation of authentication and authorization logic

⚡ Quick Start

1. Install Package

dotnet add package Afrisys.JwtAuthentication.AspNetCore

2. Configure appsettings.json

{
  "Auth": {
    "Authority": "http://your-identity-server.com",
    "Audience": "Your scope here"
  }
}

3. Register in Program.cs

using Afrisys.JwtAuthKit;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddJwtAuthKit(builder.Configuration);

var app = builder.Build();

app.UseAuthentication();
app.UseAuthorization();

app.MapControllers();

app.Run();

4. Secure Your API

[Authorize]
[ApiController]
[Route("api/[controller]")]
public class PlumbingController : ControllerBase
{
    [HttpGet]
    public IActionResult Get()
    {
        return Ok("Secure data accessed successfully.");
    }
}

🔐 How It Works

1. Identity Provider issues a JWT token with an aud (audience) claim
2. Each microservice defines its expected audience
3. The library validates:
   • Token signature
   • Issuer (Authority)
   • Audience match
4. If audience mismatch → request is rejected (401 Unauthorized)

🧭 Audience Mapping Example

🧪 Example Token Request (Client Credentials)

curl --location 'https://your-identity-server.com/connect/token' \
--header 'Content-Type: application/x-www-form-urlencoded' \
--data-urlencode 'client_id=plumbing-api' \
--data-urlencode 'client_secret=your-secret' \
--data-urlencode 'grant_type=client_credentials'

Response

{
  "access_token": "eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9...",
  "token_type": "Bearer",
  "expires_in": 3600
}

🏗️ Architecture Overview

Client / Service
      ↓
Identity Provider (JWT Issuance)
      ↓
Afrisys.JwtAuthKit (Validation Layer)
      ↓
Protected API Resource

⚙️ Requirements

• .NET 8 or later
• ASP.NET Core Web API
• Any JWT-compatible Identity Provider

📄 License

MIT License

❤️ Built For

Developers building secure, scalable, and clean microservice architectures.