ASP.NET Core JWT Function part 1/2

TokenController.cs

using Microsoft.Extensions.Configuration;
using Microsoft.IdentityModel.Tokens;
using System.IdentityModel.Tokens.Jwt;
using System.Security.Claims;
using Microsoft.AspNetCore.Authorization;


 public TokenController(IConfiguration config, ApplicationDbContext dbContext)
        {
            _config = config;
            _dbContext = dbContext;
        }

public IActionResult CreateToken([FromBody]LoginCredential login)
{
    IActionResult response = Unauthorized();

    if (login != null)
    {
        var user = Authenticate(login);

        if (user != null)
        {
            var tokenString = BuildToken(user);
            response = Ok(new { Token = tokenString });
        }

    }
    return response;
}

private string BuildToken(Client user)
{
    var key = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(_config["Jwt:Key"]));
    var creds = new SigningCredentials(key, SecurityAlgorithms.HmacSha256);

    var claims = new List<Claim>
    {
        new Claim(ClaimTypes.NameIdentifier, user.Id),
        new Claim(ClaimTypes.Name, user.Name),
        new Claim(ClaimTypes.Version, "1.0")
    };

    var token = new JwtSecurityToken(_config["Jwt:Issuer"],
      _config["Jwt:Issuer"],
      claims,
      notBefore: DateTime.UtcNow,
      expires: DateTime.UtcNow.AddDays(1),
      signingCredentials: creds);

    return new JwtSecurityTokenHandler().WriteToken(token);
}

   private Client Authenticate(LoginCredential login)
        {
            var client = _dbContext.Clients.FirstOrDefault(c => c.Id == login.ClientId && c.Secret == login.ClientSecret);
            return client;
        }

        public class LoginCredential
        {
            public string ClientId { get; set; }
            public string ClientSecret { get; set; }
        }

cool !