public class Startup
    {
        public IConfigurationRoot Configuration { get; }

        public Startup(IHostingEnvironment env)
        {
            IConfigurationBuilder builder = new ConfigurationBuilder().SetBasePath(env.ContentRootPath)
                                                                      .AddJsonFile("appsettings.json", true, true)
                                                                      .AddJsonFile($"appsettings.{env.EnvironmentName}.json", true)
                                                                      .AddEnvironmentVariables();
            //---
            Configuration = builder.Build();
        }

        public void ConfigureServices(IServiceCollection services)
        {
            services.AddMvc();
        }

        public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
        {
            app.Use(async (context, next) =>
            {
                try
                {
                    await next();
                }
                catch (Exception ex)
                {
                    if (context.Response.HasStarted)
                    {
                        throw;
                    }
                    context.Response.StatusCode = 500;
                    await context.Response.WriteAsync(ex.ToString());
                }
            });
            //---
            app.UseMvc();
            //---
            const string secretKey = "mysupersecret_secretkey!123";
            SymmetricSecurityKey signingKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(secretKey));
            SigningCredentials signingCredentials = new SigningCredentials(signingKey, SecurityAlgorithms.HmacSha256);
            //---
            const string audience = "Audience";
            const string issuer = "Issuer";
            //---
            TokenValidationParameters tokenValidationParameters = new TokenValidationParameters
            {
                ValidateIssuerSigningKey = true,
                IssuerSigningKey = signingKey,

                ValidateIssuer = false,
                ValidIssuer = issuer,

                ValidateAudience = true,
                ValidAudience = audience,

                ValidateLifetime = true,

                ClockSkew = TimeSpan.Zero,
                AuthenticationType = JwtBearerDefaults.AuthenticationScheme
            };
            //---
            app.UseJwtBearerAuthentication(new JwtBearerOptions
            {
                AutomaticAuthenticate = true,
                AutomaticChallenge = true,
                TokenValidationParameters = tokenValidationParameters,
                AuthenticationScheme = JwtBearerDefaults.AuthenticationScheme,
            });
            //---
            app.UseSimpleTokenProvider(new TokenProviderOptions
            {
                Path = "/api/token",
                Audience = audience,
                Issuer = issuer,
                SigningCredentials = signingCredentials,
                Expiration = TimeSpan.FromDays(1),
                IdentityResolver = GetIdentity
            });
        }

        private Task<ClaimsIdentity> GetIdentity(string username, string password)
        {
            if (username == "TEST" && password == "TEST123")
            {
                return Task.FromResult(new ClaimsIdentity(new GenericIdentity(username, "Token"), new Claim[] { }));
            }

            return Task.FromResult<ClaimsIdentity>(null);
        }
    }