I am not able to implement a working authentication system in my Blazor .NET8 ServerInteractive application. I am quite new at web dev (I am more of a WinForm/WPF programmer)

I have search internet for now more that a full day but I can’t figure out how to do it properly ans simply.

At the moment, I have kind of a working authentication but not “persistent”. I have implemented a custom AuthenticationStateProvider like this :

public class AuthenticationManager(ILogger<AuthenticationManager> logger) : AuthenticationStateProvider
{
  private ClaimsPrincipal _user = new();

  public override Task<AuthenticationState> GetAuthenticationStateAsync()
  {
    return Task.FromResult(new AuthenticationState(_user));
  }

  public ClaimsPrincipal? LogInUser(string decryptedName, string decryptedPassword)
  {
    try
    {
      // Vérifier si un nom d'utilisateur et un mot de passe ont été fournis
      if (!string.IsNullOrEmpty(decryptedName) && !string.IsNullOrEmpty(decryptedPassword))
      {
        // Recherche d'un utilisateur correspondant dans la base de données
        using DBInterface dbManager = new();
        TUser? dbUser = dbManager.GetAllUsers().FirstOrDefault(u => string.Compare(decryptedName, u.Name, true) == 0);

        // Vérification du mot de passe
        if (dbUser != null && Simple3Des.DecryptString(dbUser.PasswordHash) == decryptedPassword)
        {
          List<Claim> claims =
          [
            new(ClaimTypes.Name, decryptedName),
            new(ClaimTypes.Role, dbUser.AccessLevelEnu.ToString())
          ];
          ClaimsIdentity claimsIdentity = new(claims, CookieAuthenticationDefaults.AuthenticationScheme);

          _user = new(claimsIdentity);

          NotifyAuthenticationStateChanged(GetAuthenticationStateAsync());
          return _user;
        }
      }
    }
    catch (Exception ex)
    {
      logger!.LogError("Erreur dans {methodName} : {exceptionType} : {exceptionMessage}", $"{nameof(AuthenticationManager)}.{nameof(LogInUser)}", ex.GetType().Name, ex.Message);
      throw;
    }
    return null;
}

public void LogOutUser()
  {
    _user = new();
    NotifyAuthenticationStateChanged(GetAuthenticationStateAsync());
  }
}

The login/logout is working, I can even navigate in my website and the user is retained but if I refresh the page (F5) or open a new tab the user is not logged any more. I do understand is normal because of the way my user is stored (private field of AuthenticationManager).

Now, the question is : how to make it work as expected?
I am quite sure it doesn’t require much more but I am stuck…