JWT Authentication in ASP.NET Core Web API in CRUD operation

Question

Aman Gupta · Answer

Hi Firoz To implement JWT authentication in an ASP.NET Core Web API with CRUD operations you need to: Set up JWT in your ASP.NET Core Web API project . Secure your API endpoints with JWT authentication . Create CRUD operations with authentication and authorization . Steps: 1. Install Required Packages In your ASP.NET Core project install the following NuGet packages: Install-Package Microsoft.AspNetCore.Authentication.JwtBearer Install-Package System.IdentityModel.Tokens.Jwt 2. Configure JWT Authentication in Startup.cs (or Program.cs in .NET 6/7) In .NET 6/7  configure JWT authentication in Program.cs as follows: public class Startup { public void ConfigureServices(IServiceCollection services) { // Add JWT Authentication services.AddAuthentication(options => { options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme; options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme; }) .AddJwtBearer(options => { options.TokenValidationParameters = new TokenValidationParameters { ValidateIssuer = true ValidateAudience = true ValidateLifetime = true ValidateIssuerSigningKey = true ValidIssuer = yourIssuer ValidAudience = yourAudience IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(your_secret_key)) // Replace with your key }; }); services.AddControllers(); services.AddAuthorization(); } public void Configure(IApplicationBuilder app IWebHostEnvironment env) { app.UseRouting(); // Enable authentication app.UseAuthentication(); app.UseAuthorization(); app.UseEndpoints(endpoints => { endpoints.MapControllers(); }); } } 3. Generate JWT Token : In your controller create a method to generate the JWT token after a successful login: [HttpPost(login)] public IActionResult Login([FromBody] UserLoginDto login) { if (login.Username == testuser && login.Password == password) // Example credentials { var token = GenerateJwtToken(); return Ok(new { token }); } return Unauthorized(); } private string GenerateJwtToken() { var securityKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(your_secret_key)); var credentials = new SigningCredentials(securityKey SecurityAlgorithms.HmacSha256); var tokenDescriptor = new SecurityTokenDescriptor { Subject = new ClaimsIdentity(new[] { new Claim(ClaimTypes.Name testuser) new Claim(ClaimTypes.Role User) }) Expires = DateTime.Now.AddMinutes(30) Issuer = yourIssuer Audience = yourAudience SigningCredentials = credentials }; var tokenHandler = new JwtSecurityTokenHandler(); var token = tokenHandler.CreateToken(tokenDescriptor); return tokenHandler.WriteToken(token); } 4. Secure CRUD Endpoints with JWT Authentication You can now protect your CRUD API endpoints with [Authorize] to ensure they can only be accessed with a valid JWT token. [Authorize] [ApiController] [Route(api/[controller])] public class ItemsController : ControllerBase { private static List _items = new List (); // GET: api/items [HttpGet] public IActionResult Get() { return Ok(_items); } // GET: api/items/5 [HttpGet({id})] public IActionResult Get(int id) { var item = _items.FirstOrDefault(i => i.Id == id); if (item == null) return NotFound(); return Ok(item); } // POST: api/items [HttpPost] public IActionResult Post([FromBody] Item item) { _items.Add(item); return CreatedAtAction(nameof(Get) new { id = item.Id } item); } // PUT: api/items/5 [HttpPut({id})] public IActionResult Put(int id [FromBody] Item updatedItem) { var item = _items.FirstOrDefault(i => i.Id == id); if (item == null) return NotFound(); item.Name = updatedItem.Name; item.Description = updatedItem.Description; return NoContent(); } // DELETE: api/items/5 [HttpDelete({id})] public IActionResult Delete(int id) { var item = _items.FirstOrDefault(i => i.Id == id); if (item == null) return NotFound(); _items.Remove(item); return NoContent(); } } 5. Test the JWT Authentication with CRUD Login : Send a POST request to /login to get the JWT token. Use JWT in CRUD operations : Include the JWT token in the Authorization header of your API requests: Authorization: Bearer your_jwt_token This setup ensures that all CRUD operations are protected by JWT authentication. Only users with a valid token can access these endpoints.

Ishika Tiwari · Answer

https://jasonwatmore.com/post/2021/07/29/net-5-role-based-authorization-tutorial-with-example-api https://jasonwatmore.com/post/2022/02/18/net-6-role-based-authorization-tutorial-with-example-api

Jignesh Kumar · Answer

Hello Firoz Please refer this article which will help you to undestand step by step https://www.c-sharpcorner.com/article/how-to-implement-jwt-authentication-in-web-api-using-net-6-0-asp-net-core/