C# Modifying Identity or Add a Claim

user_14433974 0
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Application is Blazor Server .NET Core 5.0

I am using .NET Core's Identity system and I am running into a problem. I want to have the person's first name stored with the Identity so I can call on it easily.

Currently I have a class overriding the base identity:

public class ApplicationUser : IdentityUser
{
    public ApplicationUser() : base() { }

    [StringLength(100)]
    public string FirstName { get; set; }
    [StringLength(100)]
    public string LastName { get; set; }
}

My startup.cs has:

        services.AddDefaultIdentity<ApplicationUser>(options => {
            options.SignIn.RequireConfirmedAccount = true;
            }
        )

In my mind that should force the program's intellisense to understand ApplicationUser is the default class when looking for identity.

However, when I try to call:

    var authState = await AuthenticationStateProvider.GetAuthenticationStateAsync();
    var user = authState.User;

It only returns "IdentityUser" data rather than my custom ApplicationUser class.

Is there something I am missing with what AuthenticationStateProvider is returning or a type casting I am missing?

Also, if this is completely incorrect, should I do this with Claims? If so, I cannot find a concrete way to effectively use claims with Blazor Server.

claims-based-identity asp.net-identity blazor c#
1 Answers
public class ApplicationUser : IdentityUser
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
}

Execute in the Package Manager Console:

  1. add-migration CreateAppUser
  2. update-database

Insert values to the FirstName and LastName created in the Users table

Create a class named: ApplicationUserClaimsTransformation

ApplicationUserClaimsTransformation.cs

 using Microsoft.AspNetCore.Authentication;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using WebApplication3.Data;
using WebApplication3.Models;
using System.Security.Claims;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Components.Authorization;

 public class ApplicationUserClaimsTransformation : IClaimsTransformation
    {
        private readonly UserManager<ApplicationUser> _userManager;
        public ApplicationUserClaimsTransformation(UserManager<ApplicationUser> userManager)
        {
            _userManager = userManager;
        }

        
        public async Task<ClaimsPrincipal> TransformAsync(ClaimsPrincipal principal)
        {
            var identity = principal.Identities.FirstOrDefault(c => c.IsAuthenticated);
            if (identity == null) return principal;

            var user = await _userManager.GetUserAsync(principal);
            if (user == null) return principal;

            // Add or replace identity.Claims.

          
             if (!principal.HasClaim(c => c.Type == ClaimTypes.GivenName))
        {
            identity.AddClaim(new Claim(ClaimTypes.GivenName, user.FirstName));
       
        }
        if (!principal.HasClaim(c => c.Type == ClaimTypes.Surname))
        {
          identity.AddClaim(new Claim(ClaimTypes.Surname, user.LastName));
        }

            return new ClaimsPrincipal(identity);
        }
    }

Startup.ConfigureServices

 services.AddScoped<IClaimsTransformation, 
           ApplicationUserClaimsTransformation>();

Index.razor

@page "/"

@inject AuthenticationStateProvider AuthState
@using System.Security
@using System.Security.Claims

@foreach(var c in user.Claims)
{
    <div>@c.Type:  @c.Value</div>
}
@code
    {

    private ClaimsPrincipal user;

 protected override async Task OnInitializedAsync()
    {
        var x = await AuthState.GetAuthenticationStateAsync();
        user =  x.User;
        await base.OnInitializedAsync();
    }
    }

Note: You should alter the IdentityUser name to ApplicationUser in the Startup class, LogOut.cshtml file, _LoginPartial.cshtml file and in the definition of the ApplicationDbContext class:

public class ApplicationDbContext : IdentityDbContext<ApplicationUser>
user_61528910
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