How to debug JWT Bearer Error "invalid_token" - asp.net-web-api

Question

I'm trying to secure an existing AspNet Core 2.0 / angular 4 app using jwt. I'm using angular2-jwt for the client part and it works just fine. However when it comes to my WebApi, my token is always rejected(using AuthHttp from angular2-jwt to launch my requests or even with postman). The only response I get is 401 Bearer error="invalid_token". I've checked it with the jwt.io chrome extension and it seems just fine(signature, audience, issuer). I can't find anything in the IIS logs either as to why it is deemed invalid. So my question is how can I get more information on what is wrong with the token ?
Any help will be much appreciated.
For reference here's my startup.cs
public class Startup
{
public static void Main(string[] args)
{
var host = new WebHostBuilder()
.UseKestrel()
.UseContentRoot(Directory.GetCurrentDirectory())
.UseIISIntegration()
.UseStartup<Startup>()
.Build();
host.Run();
}
public Startup(IHostingEnvironment env)
{
var builder = new ConfigurationBuilder()
.SetBasePath(env.ContentRootPath)
.AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
.AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)
.AddEnvironmentVariables();
Configuration = builder.Build();
}
public IConfigurationRoot Configuration { get; }
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
IConfigurationSection jwtConf = this.Configuration.GetSection("jwt");
services.Configure<Controls.JWTConf>(Configuration.GetSection("jwt"));
services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
.AddJwtBearer(options =>
{
options.TokenValidationParameters =
new TokenValidationParameters
{
ValidateIssuer = true,
ValidateAudience = true,
ValidateLifetime = true,
ValidateIssuerSigningKey = true,
ValidIssuer = jwtConf.GetValue<string>("issuer"),
ValidAudience = jwtConf.GetValue<string>("audience"),
IssuerSigningKey = Security.JwtSecurityKey.Create(jwtConf.GetValue<string>("keyBase"))
};
});
services.AddMvc(
config =>
{
var policy = new AuthorizationPolicyBuilder()
.AddAuthenticationSchemes(JwtBearerDefaults.AuthenticationScheme)
.RequireClaim(ClaimTypes.Name)
.Build();
config.Filters.Add(new AuthorizeFilter(policy));
}
).AddJsonOptions(options => options.SerializerSettings.ContractResolver = new DefaultContractResolver());
services.AddNodeServices();
string conn = this.Configuration.GetConnectionString("optimumDB");
services.AddDbContext<TracDbContext>(options =>
options.UseSqlServer(conn));
// Register the Swagger generator, defining one or more Swagger documents
services.AddSwaggerGen(c =>
{
c.SwaggerDoc("v1", new Info { Title = "Angular 4.0 Universal & ASP.NET Core advanced starter-kit web API", Version = "v1" });
});
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory, TracDbContext context)
{
loggerFactory.AddConsole(Configuration.GetSection("Logging"));
loggerFactory.AddDebug();
app.UseStaticFiles();
app.UseAuthentication();
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
app.UseWebpackDevMiddleware(new WebpackDevMiddlewareOptions
{
HotModuleReplacement = true,
HotModuleReplacementEndpoint = "/dist/__webpack_hmr"
});
app.UseSwagger();
app.UseSwaggerUI(c =>
{
c.SwaggerEndpoint("/swagger/v1/swagger.json", "My API V1");
});
// Enable middleware to serve swagger-ui (HTML, JS, CSS etc.), specifying the Swagger JSON endpoint.
app.MapWhen(x => !x.Request.Path.Value.StartsWith("/swagger", StringComparison.OrdinalIgnoreCase), builder =>
{
builder.UseMvc(routes =>
{
routes.MapSpaFallbackRoute(
name: "spa-fallback",
defaults: new { controller = "Home", action = "Index" });
});
});
}
else
{
app.UseMvc(routes =>
{
routes.MapRoute(
name: "default",
template: "{controller=Home}/{action=Index}/{id?}");
routes.MapRoute(
"Sitemap",
"sitemap.xml",
new { controller = "Home", action = "SitemapXml" });
routes.MapSpaFallbackRoute(
name: "spa-fallback",
defaults: new { controller = "Home", action = "Index" });
});
app.UseExceptionHandler("/Home/Error");
}
}
}
My token generating controller
[Route("api/token")]
[AllowAnonymous]
public class TokenController : Controller
{
private IOptions<JWTConf> jwt;
public TokenController(IOptions<JWTConf> jwtConf)
{
this.jwt = jwtConf;
}
[HttpPost]
public IActionResult Create([FromBody]string userCode)
{
Model.Entities.Utilisateur user = new Model.Entities.Utilisateur { ID_UTILISATEUR = 6 };
JwtToken token = new JwtTokenBuilder()
.AddSecurityKey(JwtSecurityKey.Create(this.jwt.Value.keyBase))
.AddSubject("User")
.AddIssuer(this.jwt.Value.issuer)
.AddAudience(this.jwt.Value.audience)
.AddClaim(ClaimTypes.Name,user.ID_UTILISATEUR.ToString())
.AddExpiry(1440)
.Build();
var tok = new { token = token.Value };
//return Ok(token);
return Ok(JsonConvert.SerializeObject(tok));
}
}
And finally the controller that rejects the token :
[Produces("application/json")]
public class JobsController : BaseController
{
public JobsController(IConfiguration config, TracDbContext db) : base(config, db)
{
}
// GET: api/Jobs
[HttpGet]
[Route("api/Jobs")]
public IEnumerable<Departement> Get()
{
return new GroupedJobs(Db.GetJobs().ToList());
}
[HttpGet]
[Route("api/Jobs/{id}")]
public JOB_CLIENT Get(int id)
{
return Db.GetDetailsJob(id);
}
}

Answer 1

Found the problem ... turns out I was storing my token with quotes around it. So The authorization header that was being sent looked like this
Bearer "TOKEN"
instead of
Bearer TOKEN
Being new to the whole thing I tought the quotes were being added by the AuthHtpp and were part of the protocol.