.NET 6 Problem: Bearer error="invalid_token"

Question

I am building an API with .NET 6 but I am stuck with this error. I get a token with login then I added that token to header but there is always getting 401: Unauthorized error.

NOTE: I am getting Bearer error="invalid_token" but there is no description.

This is my code;

Program.cs:

using Autofac;
using Autofac.Extensions.DependencyInjection;
using Business.DependencyResolvers.Autofac;
using Core.Utilities.Security.Encryption;
using Core.Utilities.Security.Jwt;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.IdentityModel.Tokens;
using Microsoft.OpenApi.Models;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
// Autofac
builder.Host.UseServiceProviderFactory(new AutofacServiceProviderFactory());
builder.Host.ConfigureContainer<ContainerBuilder>(builder => builder.RegisterModule(new AutofacBusinessModule()));

builder.Services.AddControllers();
// Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen(c =>
{
    c.SwaggerDoc("v1", new OpenApiInfo { Title = "OzkanOner", Version = "v1" });

    c.AddSecurityDefinition("Bearer", new OpenApiSecurityScheme()
    {
        Name = "Authorization",
        Type = SecuritySchemeType.ApiKey,
        Scheme = "Bearer",
        BearerFormat = "JWT",
        In = ParameterLocation.Header,
        Description = "JWT Authorization header using the Bearer scheme."

    });
    c.AddSecurityRequirement(new OpenApiSecurityRequirement{
        {
            new OpenApiSecurityScheme
            {
                Reference = new OpenApiReference
                {
                    Type = ReferenceType.SecurityScheme,
                    Id = "Bearer"
                }
            },
            new string[] {}
        }
    });
});

//CORS
builder.Services.AddCors(options =>
{
    options.AddPolicy("AllowOrigin", builder => builder.WithOrigins("http://localhost:4200"));
});

var tokenOptions = builder.Configuration.GetSection("TokenOptions").Get<TokenOptions>();
builder.Services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme).AddJwtBearer(options =>
{
    options.TokenValidationParameters = new TokenValidationParameters
    {
        ValidateIssuer = true,
        ValidateAudience = true,
        ValidateLifetime = true,
        ValidIssuer = tokenOptions.Issuer,
        ValidAudience = tokenOptions.Audience,
        ValidateIssuerSigningKey = true,
        IssuerSigningKey = SecurityKeyHelper.CreateSecurityKey(tokenOptions.SecurityKey)
    };
});

var app = builder.Build();

// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.UseCors(builder => builder.WithOrigins("http://localhost:4200").AllowAnyHeader());

app.UseHttpsRedirection();

// Authentication & Authorization
app.UseAuthentication();

app.UseAuthorization();

app.MapControllers();

app.Run();

JwtHelper.cs:

using Core.Entities.Concrete;
using Core.Extensions;
using Core.Utilities.Security.Encryption;
using Microsoft.Extensions.Configuration;
using Microsoft.IdentityModel.Tokens;
using System;
using System.Collections.Generic;
using System.IdentityModel.Tokens.Jwt;
using System.Linq;
using System.Security.Claims;
using System.Text;
using System.Threading.Tasks;

namespace Core.Utilities.Security.Jwt
{
    public class JwtHelper : ITokenHelper
    {
        public IConfiguration Configuration { get; }
        private TokenOptions _tokenOptions;
        private DateTime _accessTokenExpiration;
        public JwtHelper(IConfiguration configuration)
        {
            Configuration = configuration;
            _tokenOptions = Configuration.GetSection("TokenOptions").Get<TokenOptions>();

        }
        public AccessToken CreateToken(User user, List<OperationClaim> operationClaims)
        {
            _accessTokenExpiration = DateTime.Now.AddMinutes(_tokenOptions.AccessTokenExpiration);
            var securityKey = SecurityKeyHelper.CreateSecurityKey(_tokenOptions.SecurityKey);
            var signingCredentials = SigningCredentialsHelper.CreateSigningCredentials(securityKey);
            var jwt = CreateJwtSecurityToken(_tokenOptions, user, signingCredentials, operationClaims);
            var jwtSecurityTokenHandler = new JwtSecurityTokenHandler();
            var token = jwtSecurityTokenHandler.WriteToken(jwt);

            return new AccessToken
            {
                Token = token,
                Expiration = _accessTokenExpiration
            };
        }

        public JwtSecurityToken CreateJwtSecurityToken(TokenOptions tokenOptions, User user,
            SigningCredentials signingCredentials, List<OperationClaim> operationClaims)
        {
            var jwt = new JwtSecurityToken(
                issuer: tokenOptions.Issuer,
                audience: tokenOptions.Audience,
                expires: _accessTokenExpiration,
                notBefore: DateTime.Now,
                claims: SetClaims(user, operationClaims),
                signingCredentials: signingCredentials
            );
            return jwt;
        }

        private IEnumerable<Claim> SetClaims(User user, List<OperationClaim> operationClaims)
        {
            var claims = new List<Claim>();
            claims.AddNameIdentifier(user.Id.ToString());
            claims.AddEmail(user.Email);
            claims.AddName($"{user.FirstName} {user.LastName}");
            claims.AddRoles(operationClaims.Select(c => c.Name).ToArray());

            return claims;
        }
    }
}

appsettings.json:

{
  "TokenOptions": {
    "Audience": "https://localhost:7047",
    "Issuer": "https://localhost:7047",
    "AccessTokenExpiration": 60,
    "SecurityKey": "ASD89ays7fhHASDF09ua0sdu6d32ghbjlka"
  },
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft.AspNetCore": "Warning"
    }
  },
  "AllowedHosts": "*"
}

Answer 1

In my case, I was missing System.IdentityModel.Tokens.Jwt nuget package.

Everything compiles and run Ok but throws invalid token while testing the api. Once installed System.IdentityModel.Tokens.Jwt it started working without changing a line of code.

Answer 2

On Program.cs Change:

c.AddSecurityDefinition("Bearer", new OpenApiSecurityScheme()
{
        Name = "Authorization",
        Type = SecuritySchemeType.Http,
        Scheme = "Bearer",
        BearerFormat = "JWT",
        In = ParameterLocation.Header,
        Description = "JWT Authorization header using the Bearer scheme. \r\n\r\n Enter your token in the text input below.\r\n\r\nExample: \"12345abcdef\""

});



builder.Services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme).AddJwtBearer(cfg =>
{
            cfg.RequireHttpsMetadata = false;
            cfg.SaveToken = true;
            options.TokenValidationParameters = new TokenValidationParameters
            {
                ValidIssuer = tokenOptions.Issuer,
                ValidAudience = tokenOptions.Audience,
                IssuerSigningKey = SecurityKeyHelper.CreateSecurityKey(tokenOptions.SecurityKey),
                ClockSkew = TimeSpan.Zero 
            };
});

It works fine using net 6. Download an example at https://drive.google.com/file/d/16VYtX5klxJF1jlnM4nFbz1rFPyCz-TZL/view?usp=sharing , use url: /swagger