JWT Authentication in ASP.NET Core 6: Claims Principal Not Populated Correctly After Token Validation
Does anyone know how to I'm integrating two systems and I'm building a feature where I'm stuck on something that should probably be simple. I'm relatively new to this, so bear with me. I'm implementing JWT authentication in my ASP.NET Core 6 application, but I've run into a frustrating scenario where the Claims Principal isn't being populated correctly after validating the token. The token is generated properly and includes several claims, but when I inspect the Claims Principal in my controller, it's empty, and I need to seem to access the claims I need. Here's the relevant code for generating the JWT token: ```csharp var claims = new List<Claim> { new Claim(JwtRegisteredClaimNames.Sub, user.Id.ToString()), new Claim("role", user.Role) }; var key = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(configuration["Jwt:Key"])); var creds = new SigningCredentials(key, SecurityAlgorithms.HmacSha256); var token = new JwtSecurityToken( issuer: configuration["Jwt:Issuer"], audience: configuration["Jwt:Audience"], claims: claims, expires: DateTime.Now.AddMinutes(30), signingCredentials: creds ); return new JsonResult(new { token = new JwtSecurityTokenHandler().WriteToken(token) }); ``` In my `Startup.cs`, I set up JWT authentication like this: ```csharp public void ConfigureServices(IServiceCollection services) { services.AddAuthentication(options => { options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme; options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme; }) .AddJwtBearer(options => { options.TokenValidationParameters = new TokenValidationParameters { ValidateIssuer = true, ValidateAudience = true, ValidateLifetime = true, ValidateIssuerSigningKey = true, ValidIssuer = configuration["Jwt:Issuer"], ValidAudience = configuration["Jwt:Audience"], IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(configuration["Jwt:Key"])) }; }); } ``` When I call one of my protected endpoints, I get a 200 OK response, but when I check `User.Claims`, it returns an empty collection. I've tried debugging through the middleware, and it seems the token validation is passing, but the claims aren't being set. I've also checked that the token is being sent correctly in the Authorization header as a Bearer token. Does anyone have insights into what might be causing the Claims Principal to not populate correctly after the token is validated? Are there common pitfalls in configuring JWT authentication in ASP.NET Core 6 that I might have missed? For context: I'm using C# on Windows. I've been using C# for about a year now. I'd love to hear your thoughts on this. This is for a mobile app running on Ubuntu 20.04. This is part of a larger desktop app I'm building. Am I approaching this the right way?