Teknik/IdentityServer/Services/AccountService.cs

using IdentityModel;
using IdentityServer4.Extensions;
using IdentityServer4.Services;
using IdentityServer4.Stores;
using Microsoft.AspNetCore.Authentication;
using Microsoft.AspNetCore.Http;
using System.Linq;
using System.Threading.Tasks;
using Teknik.IdentityServer.Models;
using Teknik.IdentityServer.Options;
using Teknik.IdentityServer.ViewModels;

namespace Teknik.IdentityServer.Services
{
    public class AccountService
    {
        private readonly IClientStore _clientStore;
        private readonly IIdentityServerInteractionService _interaction;
        private readonly IHttpContextAccessor _httpContextAccessor;
        private readonly IAuthenticationSchemeProvider _schemeProvider;

        public AccountService(
            IIdentityServerInteractionService interaction,
            IHttpContextAccessor httpContextAccessor,
            IAuthenticationSchemeProvider schemeProvider,
            IClientStore clientStore)
        {
            _interaction = interaction;
            _httpContextAccessor = httpContextAccessor;
            _schemeProvider = schemeProvider;
            _clientStore = clientStore;
        }

        public async Task<LoginViewModel> BuildLoginViewModelAsync(string returnUrl)
        {
            var context = await _interaction.GetAuthorizationContextAsync(returnUrl);

            var allowLocal = true;
            if (context?.ClientId != null)
            {
                var client = await _clientStore.FindEnabledClientByIdAsync(context.ClientId);
                if (client != null)
                {
                    allowLocal = client.EnableLocalLogin;
                }
            }

            return new LoginViewModel
            {
                AllowRememberLogin = AccountOptions.AllowRememberLogin,
                EnableLocalLogin = allowLocal && AccountOptions.AllowLocalLogin,
                ReturnUrl = returnUrl,
                Username = context?.LoginHint
            };
        }

        public async Task<LoginViewModel> BuildLoginViewModelAsync(LoginInputModel model)
        {
            var vm = await BuildLoginViewModelAsync(model.ReturnUrl);
            vm.Username = model.Username;
            vm.RememberMe = model.RememberMe;
            return vm;
        }

        public async Task<LogoutViewModel> BuildLogoutViewModelAsync(string logoutId)
        {
            var vm = new LogoutViewModel { LogoutId = logoutId, ShowLogoutPrompt = AccountOptions.ShowLogoutPrompt };

            var user = _httpContextAccessor.HttpContext.User;
            if (user?.Identity.IsAuthenticated != true)
            {
                // if the user is not authenticated, then just show logged out page
                vm.ShowLogoutPrompt = false;
                return vm;
            }

            var context = await _interaction.GetLogoutContextAsync(logoutId);
            if (context?.ShowSignoutPrompt == false)
            {
                // it's safe to automatically sign-out
                vm.ShowLogoutPrompt = false;
                return vm;
            }

            // show the logout prompt. this prevents attacks where the user
            // is automatically signed out by another malicious web page.
            return vm;
        }

        public async Task<LoggedOutViewModel> BuildLoggedOutViewModelAsync(string logoutId)
        {
            // get context information (client name, post logout redirect URI and iframe for federated signout)
            var logout = await _interaction.GetLogoutContextAsync(logoutId);

            var vm = new LoggedOutViewModel
            {
                AutomaticRedirectAfterSignOut = AccountOptions.AutomaticRedirectAfterSignOut,
                PostLogoutRedirectUri = logout?.PostLogoutRedirectUri,
                ClientName = logout?.ClientId,
                SignOutIframeUrl = logout?.SignOutIFrameUrl,
                LogoutId = logoutId
            };

            return vm;
        }
    }
}