JwtTokenService 1.0.0

JWT Token Service for ASP.NET Core

A self-contained JWT token service library for ASP.NET Core applications that simplifies token generation, validation, and management.

Features

• Simple JWT token generation with customizable claims
• Token validation and verification
• Token refreshing
• Easy integration with ASP.NET Core dependency injection
• Configurable via appsettings.json or code
• Full support for user roles and custom claims

Installation

Package Manager Console

Install-Package JwtTokenService

.NET CLI

dotnet add package JwtTokenService

Quick Start

Step 1: Configure JWT settings in appsettings.json

{
  "Jwt": {
    "SecretKey": "your-secure-secret-key-with-at-least-32-characters",
    "Issuer": "your-application",
    "Audience": "your-clients",
    "ExpirationInMinutes": 60
  }
}

Step 2: Register the JWT Token Service in Program.cs

// Add JWT token service to the application
builder.Services.AddJwtTokenService(builder.Configuration);

// Or configure JWT options manually
builder.Services.AddJwtTokenService(options => {
    options.SecretKey = "your-secure-secret-key-with-at-least-32-characters";
    options.Issuer = "your-application";
    options.Audience = "your-clients";
    options.ExpirationInMinutes = 60;
});

Step 3: Configure JWT Authentication

var jwtOptions = builder.Configuration.GetSection("Jwt").Get<JwtOptions>() 
    ?? throw new InvalidOperationException("JWT options not configured");

builder.Services.AddAuthentication(options =>
{
    options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
    options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
})
.AddJwtBearer(options =>
{
    options.TokenValidationParameters = new TokenValidationParameters
    {
        ValidateIssuerSigningKey = true,
        IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(jwtOptions.SecretKey)),
        ValidateIssuer = !string.IsNullOrEmpty(jwtOptions.Issuer),
        ValidIssuer = jwtOptions.Issuer,
        ValidateAudience = !string.IsNullOrEmpty(jwtOptions.Audience),
        ValidAudience = jwtOptions.Audience,
        ValidateLifetime = true,
        ClockSkew = TimeSpan.Zero
    };
});

builder.Services.AddAuthorization();

Step 4: Use the JWT Token Service in your controllers

[ApiController]
[Route("api/[controller]")]
public class AuthController : ControllerBase
{
    private readonly IJwtTokenService _jwtTokenService;

    public AuthController(IJwtTokenService jwtTokenService)
    {
        _jwtTokenService = jwtTokenService;
    }

    [HttpPost("login")]
    public IActionResult Login([FromBody] LoginRequest request)
    {
        // Validate user credentials
        if (IsValidUser(request.Username, request.Password))
        {
            var userId = GetUserId(request.Username);
            var roles = GetUserRoles(request.Username);
            
            // Generate the JWT token
            var token = _jwtTokenService.GenerateToken(userId, request.Username, roles);

            return Ok(new { token });
        }

        return Unauthorized();
    }
}

Step 5: Protect your endpoints with the [Authorize] attribute

[Authorize]
[HttpGet("protected")]
public IActionResult Protected()
{
    var userId = User.FindFirst(JwtRegisteredClaimNames.Sub)?.Value;
    var username = User.FindFirst(JwtRegisteredClaimNames.Name)?.Value;
    
    return Ok(new { message = $"Hello, {username}!" });
}

[Authorize(Roles = "Admin")]
[HttpGet("admin-only")]
public IActionResult AdminOnly()
{
    return Ok(new { message = "You are an admin!" });
}

API Reference

JwtOptions

Configuration options for the JWT token service.

• SecretKey - The secret key used to sign the JWT token
• Issuer - The issuer of the JWT token
• Audience - The audience of the JWT token
• ExpirationInMinutes - The expiration time in minutes (default: 60)

IJwtTokenService

• GenerateToken(string userId, string username, IEnumerable<string> roles = null, IDictionary<string, string> additionalClaims = null) - Generates a JWT token for the specified user
• ValidateToken(string token) - Validates a JWT token
• GetClaimsFromToken(string token) - Gets the claims from a JWT token
• RefreshToken(string token) - Refreshes a JWT token

Best Practices

1. Use a strong secret key (at least 32 characters) and keep it secure
2. Store the secret key in a secure location (e.g., Azure Key Vault, User Secrets)
3. Set appropriate expiration times for your tokens
4. Always validate tokens on protected endpoints
5. Use HTTPS to transmit tokens

License

This project is licensed under the MIT License - see the LICENSE file for details.