JWT on .NET Core 2.0

Question

I\'ve been on quite an adventure to get JWT working on DotNet core 2.0 (now reaching final release today). There is a ton of documentation, but all the sample code

Answer 1

Asp.net Core 2.0 JWT Bearer Token Authentication Implementation with Web Api Demo

Add Package "Microsoft.AspNetCore.Authentication.JwtBearer"

Startup.cs ConfigureServices()

services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
            .AddJwtBearer(cfg =>
            {
                cfg.RequireHttpsMetadata = false;
                cfg.SaveToken = true;

                cfg.TokenValidationParameters = new TokenValidationParameters()
                {
                    ValidIssuer = "me",
                    ValidAudience = "you",
                    IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes("rlyaKithdrYVl6Z80ODU350md")) //Secret
                };

            });

Startup.cs Configure()

// ===== Use Authentication ======
        app.UseAuthentication();

User.cs // It is a model class just for example. It can be anything.

public class User
{
    public Int32 Id { get; set; }
    public string Username { get; set; }
    public string Country { get; set; }
    public string Password { get; set; }
}

UserContext.cs // It is just context class. It can be anything.

public class UserContext : DbContext
{
    public UserContext(DbContextOptions options) : base(options)
    {
        this.Database.EnsureCreated();
    }

    public DbSet Users { get; set; }
}

AccountController.cs

[Route("[controller]")]
public class AccountController : Controller
{

    private readonly UserContext _context;

    public AccountController(UserContext context)
    {
        _context = context;
    }

    [AllowAnonymous]
    [Route("api/token")]
    [HttpPost]
    public async Task Token([FromBody]User user)
    {
        if (!ModelState.IsValid) return BadRequest("Token failed to generate");
        var userIdentified = _context.Users.FirstOrDefault(u => u.Username == user.Username);
            if (userIdentified == null)
            {
                return Unauthorized();
            }
            user = userIdentified;

        //Add Claims
        var claims = new[]
        {
            new Claim(JwtRegisteredClaimNames.UniqueName, "data"),
            new Claim(JwtRegisteredClaimNames.Sub, "data"),
            new Claim(JwtRegisteredClaimNames.Jti, Guid.NewGuid().ToString()),
        };

        var key = new SymmetricSecurityKey(Encoding.UTF8.GetBytes("rlyaKithdrYVl6Z80ODU350md")); //Secret
        var creds = new SigningCredentials(key, SecurityAlgorithms.HmacSha256);

        var token = new JwtSecurityToken("me",
            "you",
            claims,
            expires: DateTime.Now.AddMinutes(30),
            signingCredentials: creds);

        return Ok(new
        {
            access_token = new JwtSecurityTokenHandler().WriteToken(token),
            expires_in = DateTime.Now.AddMinutes(30),
            token_type = "bearer"
        });
    }
}

UserController.cs

[Authorize]
[Route("api/[controller]")]
public class UserController : ControllerBase
{
    private readonly UserContext _context;

    public UserController(UserContext context)
    {
        _context = context;
        if(_context.Users.Count() == 0 )
        {
            _context.Users.Add(new User { Id = 0, Username = "Abdul Hameed Abdul Sattar", Country = "Indian", Password = "123456" });
            _context.SaveChanges();
        }
    }

    [HttpGet("[action]")]
    public IEnumerable GetList()
    {
        return _context.Users.ToList();
    }

    [HttpGet("[action]/{id}", Name = "GetUser")]
    public IActionResult GetById(long id)
    {
        var user = _context.Users.FirstOrDefault(u => u.Id == id);
        if(user == null)
        {
            return NotFound();
        }
        return new ObjectResult(user);
    }


    [HttpPost("[action]")]
    public IActionResult Create([FromBody] User user)
    {
        if(user == null)
        {
            return BadRequest();
        }

        _context.Users.Add(user);
        _context.SaveChanges();

        return CreatedAtRoute("GetUser", new { id = user.Id }, user);

    }

    [HttpPut("[action]/{id}")]
    public IActionResult Update(long id, [FromBody] User user)
    {
        if (user == null)
        {
            return BadRequest();
        }

        var userIdentified = _context.Users.FirstOrDefault(u => u.Id == id);
        if (userIdentified == null)
        {
            return NotFound();
        }

        userIdentified.Country = user.Country;
        userIdentified.Username = user.Username;

        _context.Users.Update(userIdentified);
        _context.SaveChanges();
        return new NoContentResult();
    }


    [HttpDelete("[action]/{id}")]
    public IActionResult Delete(long id)
    {
        var user = _context.Users.FirstOrDefault(u => u.Id == id);
        if (user == null)
        {
            return NotFound();
        }

        _context.Users.Remove(user);
        _context.SaveChanges();

        return new NoContentResult();
    }
}

Test on PostMan:

Pass TokenType and AccessToken in Header in other webservices.

Best of Luck! I am just Beginner. I only spent one week to start learning asp.net core.