"Message": "Authorization has been denied for this request." OWIN middleware

Question

I added Token based authentication to my OWIN middleware and can generate the token. But while using, the token for an API call with Authorize attribute I always get "Authorization has been denied for this request." It works fine though without Authorize attribute. Here is my startup.cs and controller method. Any thoughts , what is wrong?

startup.cs

    public void Configuration(IAppBuilder app)
            {
                var issuer = ConfigurationManager.AppSettings["issuer"];
                var secret = TextEncodings.Base64Url.Decode(ConfigurationManager.AppSettings["secret"]);
                app.UseOAuthAuthorizationServer(new OAuthAuthorizationServerOptions
                {
                    AuthenticationType = DefaultAuthenticationTypes.ExternalBearer,
                    AllowInsecureHttp = true,
                    TokenEndpointPath = new PathString("/token"),
                    AccessTokenExpireTimeSpan = TimeSpan.FromMinutes(30),
                    Provider = new SimpleAuthProvider(),
                    AccessTokenFormat = new JwtFormat(issuer)
                });
                app.UseJwtBearerAuthentication(new JwtBearerAuthenticationOptions
                {
                    AuthenticationType = DefaultAuthenticationTypes.ExternalBearer,
                    AuthenticationMode = AuthenticationMode.Active,
                    AllowedAudiences = new[] { "*" },
                    IssuerSecurityTokenProviders = new IIssuerSecurityTokenProvider[]
                    {
                        new SymmetricKeyIssuerSecurityTokenProvider(issuer, secret)
                    }
                });
                container = BuildDI();
                var config = new HttpConfiguration();
                config.Formatters.XmlFormatter.UseXmlSerializer = true;
                config.MapHttpAttributeRoutes();
                config.SuppressDefaultHostAuthentication();
                config.Filters.Add(new HostAuthenticationFilter(DefaultAuthenticationTypes.ExternalBearer));
                config.DependencyResolver = new AutofacWebApiDependencyResolver(container);
                app.UseCors(CorsOptions.AllowAll);
                app.UseSerilogRequestContext("RequestId");
                app.UseAutofacMiddleware(container);
                app.UseAutofacWebApi(config);
                app.UseWebApi(config);
                RegisterShutdownCallback(app, container);
            }

 public class SimpleAuthProvider: OAuthAuthorizationServerProvider
        {
            public override Task GrantResourceOwnerCredentials(OAuthGrantResourceOwnerCredentialsContext context)
            {

                if (context.UserName != context.Password)
                {
                    context.SetError("invalid_grant", "The user name or password is incorrect");
                    context.Rejected();
                    return Task.FromResult<object>(null);
                }

                var ticket = new AuthenticationTicket(SetClaimsIdentity(context), new AuthenticationProperties());
                context.Validated(ticket);

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

            public override Task ValidateClientAuthentication(OAuthValidateClientAuthenticationContext context)
            {
                context.Validated();
                return Task.FromResult<object>(null);
            }

            private static ClaimsIdentity SetClaimsIdentity(OAuthGrantResourceOwnerCredentialsContext context)
            {
                var identity = new ClaimsIdentity(DefaultAuthenticationTypes.ExternalBearer);
                identity.AddClaim(new Claim(ClaimTypes.Name, context.UserName));
                return identity;
            }
        }

API Controller Method:

 [HttpGet]
        [Route("sampleroute")]
        [Authorize]
        public async Task<HttpResponseMessage> GetSamples(string search)
        {
            try
            {

                HttpResponseMessage response;
                using (HttpClient client = new HttpClient(Common.CreateHttpClientHandler()))
                {
                     response = await client.GetAsync("test url");
                }
                var result = response.Content.ReadAsStringAsync().Result;
                Samples[] sampleArray = JsonConvert.DeserializeObject<Samples[]>(result);
                var filteredSamples = sampleArray .ToList().Where(y => y.NY_SampleName.ToUpper().Contains(search.ToUpper())).Select(n=>n);
                log.Information("<==========Ended==========>");
                return  Request.CreateResponse(HttpStatusCode.OK,filteredSamples);

            }
            catch (Exception ex)
            {
                log.Error($"Error occured while pulling the Samples:  {ex.ToString()}");
                return Request.CreateErrorResponse(HttpStatusCode.InternalServerError, ex.ToString());
            }
        }

Answer 1

It's probably a problem with the allowed audiences. Here

 app.UseJwtBearerAuthentication(new JwtBearerAuthenticationOptions
 {
     ...     
     AllowedAudiences = new[] { "*" },
     ...
 }

you set the allowed audiences. The tokens audclaim will be checked against the list of AllowedAudiences. But you never add any audience to the token.

In our project I used a CustomJwtFormat based on the code shown in http://bitoftech.net/2014/10/27/json-web-token-asp-net-web-api-2-jwt-owin-authorization-server/

The token will be generated with a call to

var token = new JwtSecurityToken(_issuer, audienceId, data.Identity.Claims, issued.Value.UtcDateTime, expires.Value.UtcDateTime, signingKey);

the second parameter is responsible for the aud claim in the JWT:

From https://msdn.microsoft.com/en-us/library/dn451037(v=vs.114).aspx :

audience Type: System.String

If this value is not null, a { aud, 'audience' } claim will be added.

After setting the aud claim in the token authorization should work fine.

Answer 2

From what I understood, you need to add the header: Authorization: Bearer "token". If you have not modified the default implementation of the authorization request the steps are these:

1. Register user at the endpoint:

   /api/Account/Register
   

2. Post to /token the following items:
   • grant_type: password
   • username: "the username you registered"
   • password: "the password you registered for the user"
3. You will receive a token in the Response

4. Copy that token and create a Request to the method you secured with the [Authorize] filter of type:

    Authorization: Bearer "the_token_you_copied_earlier"
   

   Needless to say, it could be pretty easy for you if you used Postman or Fiddler to make and receive Requests because it shows you how everything works.