Net Core 2.1 Bearer was not authenticated error in Controller

Question

I am getting an error in net core 2.1:

Bearer was not authenticated.

Failure message: No SecurityTokenValidator available for token: null

The asp net output window is:

info: Microsoft.AspNetCore.Authentication.JwtBearer.JwtBearerHandler[7]
Bearer was not authenticated. Failure message: No SecurityTokenValidator available for token: null
info: Microsoft.AspNetCore.Cors.Infrastructure.CorsService[4]
Policy execution successful.

The accounts controller code is here:

namespace quiz_backend.Controllers
{
    public class Credentials
    {
        public string Email { get; set; }
        public string Password { get; set; }
    }

    [Produces("application/json")]
    [Route("api/Account")]
    public class AccountController : Controller
    {
        readonly UserManager<IdentityUser> userManager;
        readonly SignInManager<IdentityUser> signInManager;

        public AccountController(UserManager<IdentityUser> userManager, SignInManager<IdentityUser> signInManager)
        {
            this.userManager = userManager;
            this.signInManager = signInManager;
        }

        [HttpPost]
        public async Task<IActionResult> Register([FromBody] Credentials credentials)
        {
            var user = new IdentityUser { 
                UserName = credentials.Email, 
                Email = credentials.Email 
            };

            var result = await userManager.CreateAsync(user, credentials.Password);

            if (!result.Succeeded)
                return BadRequest(result.Errors);

            await signInManager.SignInAsync(user, isPersistent: false);
            // create a token
            var signingKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes("this is the secret phrase"));
            var signingCredentials = new SigningCredentials(signingKey, SecurityAlgorithms.HmacSha256);
            var jwt = new JwtSecurityToken(signingCredentials: signingCredentials);
            return Ok(new JwtSecurityTokenHandler().WriteToken(jwt));
        }
    }
}

Here is the startup.cs

namespace quiz_backend
{
    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddCors(options => options.AddPolicy("Cors", builder =>
            {
                builder.AllowAnyOrigin()
                .AllowAnyMethod()
                .AllowAnyHeader();
            }));

            services.AddDbContext<QuizContext>(opt =>opt.UseInMemoryDatabase("quiz"));
            services.AddDbContext<UserDbContext>(opt => opt.UseInMemoryDatabase("user"));

            services.AddIdentity<IdentityUser, IdentityRole>().AddEntityFrameworkStores<UserDbContext>();
            var signingKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes("this is the secret phrase"));
            services.AddAuthentication(options =>{
                options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
                options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
            }).AddJwtBearer(cfg => {
                cfg.RequireHttpsMetadata = false;
                cfg.SaveToken = true;
                cfg.TokenValidationParameters = new TokenValidationParameters()
                {
                    IssuerSigningKey = signingKey,
                    ValidateAudience = false,
                    ValidateLifetime = false,
                    ValidateIssuerSigningKey = true
                };
            });
            services.AddMvc();
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IHostingEnvironment env)
        {
            app.UseAuthentication();
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }

            app.UseCors("Cors");
            
            app.UseMvc();
        }
    }
}

This is the front end auth code to attach the token to the header in ts:

export class AuthInterceptor implements HttpInterceptor {
    constructor() {}
    intercept(req, next) {
        var token = localStorage.getItem('token')
        var authRequest = req.clone({
            headers: req.headers.set('Authorization', `Bearer ${token}`)
        })
        return next.handle(authRequest)
    }
}

Answer 1

Based on your code, it seems that the issue is that the token received is not valid (NULL).

Failure message: No SecurityTokenValidator available for token: null

First of all, you should make sure the token arrives as expected.