marechai/Marechai/Areas/Identity/Pages/Account/Manage/ResetAuthenticator.cshtml.cs

using System.Threading.Tasks;
using Marechai.Database.Models;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Microsoft.Extensions.Logging;

namespace Marechai.Areas.Identity.Pages.Account.Manage
{
    public class ResetAuthenticatorModel : PageModel
    {
        readonly ILogger<ResetAuthenticatorModel> _logger;
        readonly SignInManager<ApplicationUser>   _signInManager;
        readonly UserManager<ApplicationUser>     _userManager;

        public ResetAuthenticatorModel(UserManager<ApplicationUser> userManager,
                                       SignInManager<ApplicationUser> signInManager,
                                       ILogger<ResetAuthenticatorModel> logger)
        {
            _userManager   = userManager;
            _signInManager = signInManager;
            _logger        = logger;
        }

        [TempData]
        public string StatusMessage { get; set; }

        public async Task<IActionResult> OnGet()
        {
            ApplicationUser user = await _userManager.GetUserAsync(User);

            if(user == null)
            {
                return NotFound($"Unable to load user with ID '{_userManager.GetUserId(User)}'.");
            }

            return Page();
        }

        public async Task<IActionResult> OnPostAsync()
        {
            ApplicationUser user = await _userManager.GetUserAsync(User);

            if(user == null)
            {
                return NotFound($"Unable to load user with ID '{_userManager.GetUserId(User)}'.");
            }

            await _userManager.SetTwoFactorEnabledAsync(user, false);
            await _userManager.ResetAuthenticatorKeyAsync(user);
            _logger.LogInformation("User with ID '{UserId}' has reset their authentication app key.", user.Id);

            await _signInManager.RefreshSignInAsync(user);

            StatusMessage =
                "Your authenticator app key has been reset, you will need to configure your authenticator app using the new key.";

            return RedirectToPage("./EnableAuthenticator");
        }
    }
}