Fix for external logins disappearing after failed login

src/Identity/UI/ref/Microsoft.AspNetCore.Identity.UI.netcoreapp3.0.cs

@@ -168,10 +168,11 @@ public void OnGet() { }
     public abstract partial class RegisterModel : Microsoft.AspNetCore.Mvc.RazorPages.PageModel
     {
         protected RegisterModel() { }
+        public System.Collections.Generic.IList<Microsoft.AspNetCore.Authentication.AuthenticationScheme> ExternalLogins { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
         [Microsoft.AspNetCore.Mvc.BindPropertyAttribute]
         public Microsoft.AspNetCore.Identity.UI.V3.Pages.Account.Internal.RegisterModel.InputModel Input { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
         public string ReturnUrl { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
-        public virtual void OnGet(string returnUrl = null) { }
+        public virtual System.Threading.Tasks.Task OnGetAsync(string returnUrl = null) { throw null; }
         public virtual System.Threading.Tasks.Task<Microsoft.AspNetCore.Mvc.IActionResult> OnPostAsync(string returnUrl = null) { throw null; }
         public partial class InputModel
         {
@@ -580,10 +581,11 @@ public void OnGet() { }
     public abstract partial class RegisterModel : Microsoft.AspNetCore.Mvc.RazorPages.PageModel
     {
         protected RegisterModel() { }
+        public System.Collections.Generic.IList<Microsoft.AspNetCore.Authentication.AuthenticationScheme> ExternalLogins { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
         [Microsoft.AspNetCore.Mvc.BindPropertyAttribute]
         public Microsoft.AspNetCore.Identity.UI.V4.Pages.Account.Internal.RegisterModel.InputModel Input { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
         public string ReturnUrl { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute]set { } }
-        public virtual void OnGet(string returnUrl = null) { }
+        public virtual System.Threading.Tasks.Task OnGetAsync(string returnUrl = null) { throw null; }
         public virtual System.Threading.Tasks.Task<Microsoft.AspNetCore.Mvc.IActionResult> OnPostAsync(string returnUrl = null) { throw null; }
         public partial class InputModel
         {

src/Identity/UI/src/Areas/Identity/Pages/V3/Account/Login.cshtml.cs

@@ -124,6 +124,8 @@ public override async Task<IActionResult> OnPostAsync(string returnUrl = null)
         {
             returnUrl = returnUrl ?? Url.Content("~/");
 
+            ExternalLogins = (await _signInManager.GetExternalAuthenticationSchemesAsync()).ToList();
+
             if (ModelState.IsValid)
             {
                 // This doesn't count login failures towards account lockout

src/Identity/UI/src/Areas/Identity/Pages/V3/Account/Register.cshtml

@@ -8,7 +8,7 @@
 
 <div class="row">
     <div class="col-md-4">
-        <form asp-route-returnUrl="@Model.ReturnUrl" method="post">
+        <form id="registerForm" asp-route-returnUrl="@Model.ReturnUrl" method="post">
             <h4>Create a new account.</h4>
             <hr />
             <div asp-validation-summary="All" class="text-danger"></div>
@@ -27,9 +27,39 @@
                 <input asp-for="Input.ConfirmPassword" class="form-control" />
                 <span asp-validation-for="Input.ConfirmPassword" class="text-danger"></span>
             </div>
-            <button type="submit" class="btn btn-default">Register</button>
+            <button id="registerSubmit" type="submit" class="btn btn-default">Register</button>
         </form>
     </div>
+    <div class="col-md-6 col-md-offset-2">
+        <section>
+            <h4>Use another service to register.</h4>
+            <hr />
+            @{
+                if ((Model.ExternalLogins?.Count ?? 0) == 0)
+                {
+                    <div>
+                        <p>
+                            There are no external authentication services configured. See <a href="https://go.microsoft.com/fwlink/?LinkID=532715">this article</a>
+                            for details on setting up this ASP.NET application to support logging in via external services.
+                        </p>
+                    </div>
+                }
+                else
+                {
+                    <form id="external-account" asp-page="./ExternalLogin" asp-route-returnUrl="@Model.ReturnUrl" method="post" class="form-horizontal">
+                        <div>
+                            <p>
+                                @foreach (var provider in Model.ExternalLogins)
+                                {
+                                    <button type="submit" class="btn btn-default" name="provider" value="@provider.Name" title="Log in using your @provider.DisplayName account">@provider.DisplayName</button>
+                                }
+                            </p>
+                        </div>
+                    </form>
+                }
+            }
+        </section>
+    </div>
 </div>
 
 @section Scripts {

src/Identity/UI/src/Areas/Identity/Pages/V3/Account/Register.cshtml.cs

@@ -2,10 +2,13 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Collections.Generic;
 using System.ComponentModel.DataAnnotations;
+using System.Linq;
 using System.Text.Encodings.Web;
 using System.Threading;
 using System.Threading.Tasks;
+using Microsoft.AspNetCore.Authentication;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Identity.UI.Services;
 using Microsoft.AspNetCore.Mvc;
@@ -36,6 +39,12 @@ public abstract class RegisterModel : PageModel
         /// </summary>
         public string ReturnUrl { get; set; }
 
+        /// <summary>
+        ///     This API supports the ASP.NET Core Identity default UI infrastructure and is not intended to be used
+        ///     directly from your code. This API may change or be removed in future releases.
+        /// </summary>
+        public IList<AuthenticationScheme> ExternalLogins { get; set; }
+
         /// <summary>
         ///     This API supports the ASP.NET Core Identity default UI infrastructure and is not intended to be used
         ///     directly from your code. This API may change or be removed in future releases.
@@ -75,7 +84,7 @@ public class InputModel
         ///     This API supports the ASP.NET Core Identity default UI infrastructure and is not intended to be used
         ///     directly from your code. This API may change or be removed in future releases.
         /// </summary>
-        public virtual void OnGet(string returnUrl = null) => throw new NotImplementedException();
+        public virtual Task OnGetAsync(string returnUrl = null) => throw new NotImplementedException();
 
         /// <summary>
         ///     This API supports the ASP.NET Core Identity default UI infrastructure and is not intended to be used
@@ -108,14 +117,16 @@ public RegisterModel(
             _emailSender = emailSender;
         }
 
-        public override void OnGet(string returnUrl = null)
+        public override async Task OnGetAsync(string returnUrl = null)
         {
             ReturnUrl = returnUrl;
+            ExternalLogins = (await _signInManager.GetExternalAuthenticationSchemesAsync()).ToList();
         }
 
         public override async Task<IActionResult> OnPostAsync(string returnUrl = null)
         {
             returnUrl = returnUrl ?? Url.Content("~/");
+            ExternalLogins = (await _signInManager.GetExternalAuthenticationSchemesAsync()).ToList();
             if (ModelState.IsValid)
             {
                 var user = CreateUser();

src/Identity/UI/src/Areas/Identity/Pages/V4/Account/Login.cshtml.cs

@@ -123,6 +123,8 @@ public override async Task<IActionResult> OnPostAsync(string returnUrl = null)
         {
             returnUrl = returnUrl ?? Url.Content("~/");
 
+            ExternalLogins = (await _signInManager.GetExternalAuthenticationSchemesAsync()).ToList();
+
             if (ModelState.IsValid)
             {
                 // This doesn't count login failures towards account lockout

src/Identity/UI/src/Areas/Identity/Pages/V4/Account/Register.cshtml

@@ -8,7 +8,7 @@
 
 <div class="row">
     <div class="col-md-4">
-        <form asp-route-returnUrl="@Model.ReturnUrl" method="post">
+        <form id="registerForm" asp-route-returnUrl="@Model.ReturnUrl" method="post">
             <h4>Create a new account.</h4>
             <hr />
             <div asp-validation-summary="All" class="text-danger"></div>
@@ -27,9 +27,39 @@
                 <input asp-for="Input.ConfirmPassword" class="form-control" />
                 <span asp-validation-for="Input.ConfirmPassword" class="text-danger"></span>
             </div>
-            <button type="submit" class="btn btn-primary">Register</button>
+            <button id="registerSubmit" type="submit" class="btn btn-primary">Register</button>
         </form>
     </div>
+    <div class="col-md-6 col-md-offset-2">
+        <section>
+            <h4>Use another service to register.</h4>
+            <hr />
+            @{
+                if ((Model.ExternalLogins?.Count ?? 0) == 0)
+                {
+                    <div>
+                        <p>
+                            There are no external authentication services configured. See <a href="https://go.microsoft.com/fwlink/?LinkID=532715">this article</a>
+                            for details on setting up this ASP.NET application to support logging in via external services.
+                        </p>
+                    </div>
+                }
+                else
+                {
+                    <form id="external-account" asp-page="./ExternalLogin" asp-route-returnUrl="@Model.ReturnUrl" method="post" class="form-horizontal">
+                        <div>
+                            <p>
+                                @foreach (var provider in Model.ExternalLogins)
+                                {
+                                    <button type="submit" class="btn btn-primary" name="provider" value="@provider.Name" title="Log in using your @provider.DisplayName account">@provider.DisplayName</button>
+                                }
+                            </p>
+                        </div>
+                    </form>
+                }
+            }
+        </section>
+    </div>
 </div>
 
 @section Scripts {

src/Identity/UI/src/Areas/Identity/Pages/V4/Account/Register.cshtml.cs

@@ -2,10 +2,13 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Collections.Generic;
 using System.ComponentModel.DataAnnotations;
+using System.Linq;
 using System.Text.Encodings.Web;
 using System.Threading;
 using System.Threading.Tasks;
+using Microsoft.AspNetCore.Authentication;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Identity.UI.Services;
 using Microsoft.AspNetCore.Mvc;
@@ -35,6 +38,12 @@ public abstract class RegisterModel : PageModel
         /// </summary>
         public string ReturnUrl { get; set; }
 
+        /// <summary>
+        ///     This API supports the ASP.NET Core Identity default UI infrastructure and is not intended to be used
+        ///     directly from your code. This API may change or be removed in future releases.
+        /// </summary>
+        public IList<AuthenticationScheme> ExternalLogins { get; set; }
+
         /// <summary>
         ///     This API supports the ASP.NET Core Identity default UI infrastructure and is not intended to be used
         ///     directly from your code. This API may change or be removed in future releases.
@@ -74,7 +83,7 @@ public class InputModel
         ///     This API supports the ASP.NET Core Identity default UI infrastructure and is not intended to be used
         ///     directly from your code. This API may change or be removed in future releases.
         /// </summary>
-        public virtual void OnGet(string returnUrl = null) => throw new NotImplementedException();
+        public virtual Task OnGetAsync(string returnUrl = null) => throw new NotImplementedException();
 
         /// <summary>
         ///     This API supports the ASP.NET Core Identity default UI infrastructure and is not intended to be used
@@ -107,14 +116,16 @@ public RegisterModel(
             _emailSender = emailSender;
         }
 
-        public override void OnGet(string returnUrl = null)
+        public override async Task OnGetAsync(string returnUrl = null)
         {
             ReturnUrl = returnUrl;
+            ExternalLogins = (await _signInManager.GetExternalAuthenticationSchemesAsync()).ToList();
         }
 
         public override async Task<IActionResult> OnPostAsync(string returnUrl = null)
         {
             returnUrl = returnUrl ?? Url.Content("~/");
+            ExternalLogins = (await _signInManager.GetExternalAuthenticationSchemesAsync()).ToList();
             if (ModelState.IsValid)
             {
                 var user = CreateUser();

src/Identity/samples/IdentitySample.DefaultUI/Areas/Identity/Pages/Account/Register.cshtml.cs

@@ -2,10 +2,13 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Collections.Generic;
 using System.ComponentModel.DataAnnotations;
+using System.Linq;
 using System.Text.Encodings.Web;
 using System.Threading.Tasks;
 using IdentitySample.DefaultUI.Data;
+using Microsoft.AspNetCore.Authentication;
 using Microsoft.AspNetCore.Identity;
 using Microsoft.AspNetCore.Identity.UI.Services;
 using Microsoft.AspNetCore.Mvc;
@@ -38,6 +41,8 @@ public RegisterModel(
 
         public string ReturnUrl { get; set; }
 
+        public IList<AuthenticationScheme> ExternalLogins { get; set; }
+
         public class InputModel
         {
             [Required]
@@ -67,14 +72,16 @@ public class InputModel
             public int Age { get; set; }
         }
 
-        public void OnGet(string returnUrl = null)
+        public async Task OnGetAsync(string returnUrl = null)
         {
             ReturnUrl = returnUrl;
+            ExternalLogins = (await _signInManager.GetExternalAuthenticationSchemesAsync()).ToList();
         }
 
         public async Task<IActionResult> OnPostAsync(string returnUrl = null)
         {
             returnUrl = returnUrl ?? Url.Content("~/");
+            ExternalLogins = (await _signInManager.GetExternalAuthenticationSchemesAsync()).ToList();
             if (ModelState.IsValid)
             {
                 var user = new ApplicationUser {

src/Identity/test/Identity.FunctionalTests/ManagementTests.cs

@@ -1,4 +1,4 @@
-// Copyright (c) .NET Foundation. All rights reserved.
+// Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;

src/Identity/test/Identity.FunctionalTests/Pages/Account/Register.cs

@@ -1,4 +1,4 @@
-// Copyright (c) .NET Foundation. All rights reserved.
+// Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System.Collections.Generic;
@@ -12,11 +12,29 @@ namespace Microsoft.AspNetCore.Identity.FunctionalTests.Account
     public class Register : DefaultUIPage
     {
         private IHtmlFormElement _registerForm;
+        private IHtmlFormElement _externalLoginForm;
+        private readonly IHtmlElement _contosoButton;
 
         public Register(HttpClient client, IHtmlDocument register, DefaultUIContext context)
             : base(client, register, context)
         {
-            _registerForm = HtmlAssert.HasForm(register);
+            _registerForm = HtmlAssert.HasForm("#registerForm", register);
+            if (context.ContosoLoginEnabled)
+            {
+                _externalLoginForm = HtmlAssert.HasForm("#external-account", register);
+                _contosoButton = HtmlAssert.HasElement("button[value=Contoso]", register);
+            }
+        }
+
+        public async Task<Contoso.Login> ClickLoginWithContosoLinkAsync()
+        {
+            var externalFormResponse = await Client.SendAsync(_externalLoginForm, _contosoButton);
+            var goToContosoLogin = ResponseAssert.IsRedirect(externalFormResponse);
+            var contosoLoginResponse = await Client.GetAsync(goToContosoLogin);
+
+            var contosoLogin = await ResponseAssert.IsHtmlDocumentAsync(contosoLoginResponse);
+
+            return new Contoso.Login(Client, contosoLogin, Context);
         }
 
         public async Task<Index> SubmitRegisterFormForValidUserAsync(string userName, string password)

src/Identity/test/Identity.FunctionalTests/RegistrationTests.cs

@@ -1,4 +1,4 @@
-// Copyright (c) .NET Foundation. All rights reserved.
+// Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
@@ -56,7 +56,7 @@ void ConfigureTestServices(IServiceCollection services) =>
         }
 
         [Fact]
-        public async Task CanRegisterWithASocialLoginProvider()
+        public async Task CanRegisterWithASocialLoginProviderFromLogin()
         {
             // Arrange
             void ConfigureTestServices(IServiceCollection services) =>
@@ -75,6 +75,26 @@ void ConfigureTestServices(IServiceCollection services) =>
             await UserStories.RegisterNewUserWithSocialLoginAsync(client, userName, email);
         }
 
+        [Fact]
+        public async Task CanRegisterWithASocialLoginProviderFromRegister()
+        {
+            // Arrange
+            void ConfigureTestServices(IServiceCollection services) =>
+                services
+                    .SetupTestThirdPartyLogin();
+
+            var client = ServerFactory
+                .WithWebHostBuilder(whb => whb.ConfigureServices(ConfigureTestServices))
+                .CreateClient();
+
+            var guid = Guid.NewGuid();
+            var userName = $"{guid}";
+            var email = $"{guid}@example.com";
+
+            // Act & Assert
+            await UserStories.RegisterNewUserWithSocialLoginAsyncViaRegisterPage(client, userName, email);
+        }
+
         [Fact]
         public async Task CanRegisterWithASocialLoginProvider_WithGlobalAuthorizeFilter()
         {