Connect a JWT to the User property in the Controller - authentication

Question

I have a Web API .NET Core 3.0 Service. It gets a header that contains a JWT with claims.
I added the following to ConfigureServices in Startup.cs to map my JWT to the .NET Core Authentication system:
services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
.AddJwtBearer(configureOptions =>
{
configureOptions.Events = new JwtBearerEvents()
{
OnMessageReceived = context =>
{
context.Token = context.HttpContext.Request.Headers["X-JWT-Assertion"];
return Task.CompletedTask;
}
};
});
I also added app.UseAuthentication(); to Configure in Startup.cs.
I then fire up my service and call an HTTP GET operation on it. When I do, I can see that the context.Token is set to my JWT. If I take that JWT over to https://JWT.io it shows that it has many claims.
But a break point in the GET operation shows that User.Claims is empty. What ever is needed to connect the JWT to the User is not happening.
Here are variations that I have tried:
Add [Authorize] above my controller:
Result: 401 Error: Unauthorized
Add [Authorize(JwtBearerDefaults.AuthenticationScheme)] above my controller
Result: The AuthorizationPolicy named: 'Bearer' was not found.
Add services.AddAuthorization() in ConfigureServices and [Authorize] above my controller
Result: 401 Error: Unauthorized
Add [Authorize(JwtBearerDefaults.AuthenticationScheme)] above my controller and code below to ConfigureServices :
services.AddAuthorization(auth =>
{
auth.AddPolicy(JwtBearerDefaults.AuthenticationScheme,
new AuthorizationPolicyBuilder().RequireAuthenticatedUser().Build());
});
Result: 401 Error: Unauthorized
To be clear, I don't want to do any Authorization, but I read that adding it may be needed to map the claims to the user.
What do I need to do to get the User property (that is part of the Controller base class) to be populated with my claims?

Answer 1

I suspect there is something wrong in your configuration. In the ConfigureServices method it should be as follows:
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:Issuer"],
IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(Configuration["Jwt:Key"]))
};
});
Then in the Configure method it should be as follows:
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
...................
app.UseRouting();
app.UseAuthentication();
app.UseAuthorization(); // These two must be before `UseEndpoints` and after `UseRouting`
app.UseEndpoints(endpoints =>
{
endpoints.MapRazorPages();
});
}