no authentication handler is configured to authenticate for the scheme: "bearer" .net core 2.0

Question

I am new to .net Core, I am trying to upgrade a project from .net Core 1.0 to 2.0, when I am trying to access the API I am getting this error. "no authentication handler is configured to authenticate for the scheme: "bearer" .net core 2.0". As UseJwtBearerAuthentication doesnt work in .net core 2.0 I replacing it with AddAuthentication.

Startup.cs

public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory, IApplicationLifetime appLifetime)
{
        app.UseAuthentication();
        app.UseCors("AllowAll");
        app.UseMvc();

 }

public void ConfigureServices(IServiceCollection services)
{
     var tvp = new TokenValidationParameters
                  {
                      // The signing key must match!
                      ValidateIssuerSigningKey = true,
                      IssuerSigningKey         = _signingKey,

                      // Validate the JWT Issuer (iss) claim
                      ValidateIssuer = true,
                      ValidIssuer    = "ABC",

                      // Validate the JWT Audience (aud) claim
                      ValidateAudience = true,
                      ValidAudience    = "User",

                      // Validate the token expiry
                      ValidateLifetime = true,

                      // If you want to allow a certain amount of clock drift, set that here:
                      ClockSkew = TimeSpan.FromMinutes(5)
                  };

        services.AddSingleton(s => tvp);

        ConfigureAuth(services, tvp);
}

private void ConfigureAuth(IServiceCollection services, TokenValidationParameters tvp)
{
  //TODO: Change events to log something helpful somewhere
        var jwtEvents = new JwtBearerEvents();

        jwtEvents.OnAuthenticationFailed = context =>
                                           {
                                               Debug.WriteLine("JWT Authentication failed.");
                                               return Task.WhenAll();
                                           };

        jwtEvents.OnChallenge = context =>
                                {
                                    Debug.WriteLine("JWT Authentication challenged.");
                                    return Task.WhenAll();
                                };

        jwtEvents.OnMessageReceived = context =>
                                      {
                                          Debug.WriteLine("JWT Message received.");
                                          return Task.WhenAll();
                                      };

        jwtEvents.OnTokenValidated = context =>
                                     {
                                         Debug.WriteLine("JWT Message Token validated.");
                                         return Task.WhenAll();
                                     };

        services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme).AddJwtBearer(o =>
                                                                                        {

         o.TokenValidationParameters = tvp;
         o.Events = jwtEvents;                                                                               });

  }

Under Configure method I have:

 app.UseDefaultFiles();
 app.UseStaticFiles();

 app.UseAuthentication();
 app.UseCors("AllowAll");
 app.UseRequestResponseLogging();
 app.UseNoCacheCacheControl();
 app.UseMvc(); 

AuthController.cs

  [HttpPost]
  [EnableCors("AllowAll")]
  [AllowAnonymous]
  [Authorize(AuthenticationSchemes = 
  JwtBearerDefaults.AuthenticationScheme)]
  public IActionResult Authenticate([FromBody] UserContract model)
  {

  }

AuthenticationMiddleware:

public class AuthenticationMiddleware
{
    private readonly RequestDelegate _next;

    public AuthenticationMiddleware(RequestDelegate next)
    {
        _next = next;
    }

    public async Task Invoke(HttpContext context, IAuthUser authUser)
    {
        if (context.User?.Identity != null)
        {
            if (context.User?.Identity?.IsAuthenticated == true)
            {
                authUser.Username       = context.User.Claims.FirstOrDefault(c => c.Type == ClaimTypes.NameIdentifier)?.Value;
            }

        using (LogContext.PushProperty("Username", authUser.Username))
        {
            await _next.Invoke(context);
        }
    }
}

Answer 1

You can use AddJwtBearer method , please refer to below article for how to use extension :

https://developer.okta.com/blog/2018/03/23/token-authentication-aspnetcore-complete-guide

Code sample below for AddJwtBearer with options and events is for your reference :

services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
.AddJwtBearer("Bearer",options =>
{
    options.TokenValidationParameters = new TokenValidationParameters
    {
        ValidateIssuer = true,
        ValidateAudience = true,
        ValidateLifetime = true,
        ValidateIssuerSigningKey = true,
        ValidIssuer = "Issuer",
        ValidAudience = "Audience",

        IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes("Yourkey"))
    };

    options.Events = new Microsoft.AspNetCore.Authentication.JwtBearer.JwtBearerEvents
    {
        OnAuthenticationFailed = context =>
        {

            if (context.Exception.GetType() == typeof(SecurityTokenExpiredException))
            {
                var loggerFactory = context.HttpContext.RequestServices
                                    .GetRequiredService<ILoggerFactory>();
                var logger = loggerFactory.CreateLogger("Startup");
                logger.LogInformation("Token-Expired");
                context.Response.Headers.Add("Token-Expired", "true");
            }
            return System.Threading.Tasks.Task.CompletedTask;
        },
        OnMessageReceived = (context) =>
        {


            return Task.FromResult(0);
        }
    };
});

And use on controller/action like :

[Authorize(AuthenticationSchemes = JwtBearerDefaults.AuthenticationScheme)]

Don't forget to enable authentication in Configure method :

app.UseAuthentication();