Hello,

I tried to add google login verification to the umbraco backoffice login page, but the problem of redirection failed.

After I clicked to log in with a google account, an error message from google appeared on the page, error 400. After checking for a long time, I really I don't know what I did wrong, so I came up and asked, I hope you can help, thank you.

The following are the parameters and programs I set. I wrote two programs, GoogleBackofficeAuthenticationExtensions.cs and GoogleBackOfficeExternalLoginProviderOptions.cs.

using Umbraco.Cms.Core.DependencyInjection;
using Umbraco.Extensions;
using Umbraco.Cms.Web.BackOffice.Security;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Configuration;

namespace UmbracoDemo1.OAuth
{
    public static class GoogleBackofficeAuthenticationExtensions
    {
        public static IUmbracoBuilder AddGoogleBackofficeAuthentication(this IUmbracoBuilder builder)
        {
            builder.AddBackOfficeExternalLogins(logins =>
            {
                logins.AddBackOfficeLogin(
                    backOfficeAuthenticationBuilder =>
                    {
                        backOfficeAuthenticationBuilder.AddGoogle(
                            // The scheme must be set with this method to work for the back office
                            backOfficeAuthenticationBuilder.SchemeForBackOffice(GoogleBackOfficeExternalLoginProviderOptions.SchemeName),
                            options =>
                            {
                                ////只有 OAuth 同意畫面中列出的測試使用者具備 OAuth 存取權限，名單如下：
                                ////[email protected]
                                ////  By default this is '/signin-google' but it needs to be changed to this
                                IConfigurationSection googleAuthNSection = builder.Config.GetSection("Authentication:Google");
                                options.CallbackPath = googleAuthNSection["CallbackPath"];
                                options.ClientId = googleAuthNSection["ClientId"];
                                options.ClientSecret = googleAuthNSection["ClientSecret"];
                            });
                    });
            });
            return builder;
            //builder.AddBackOfficeExternalLogins(loginOptions =>
            //    loginOptions.AddBackOfficeLogin(new BackOfficeExternalLoginProviderOptions(
            //        "btn-success",
            //        "fa-google"
            //    ), authOptions => authOptions.AddGoogle("Umbraco.Google","Google", options =>
            //    {
            //        IConfigurationSection googleAuthNSection = builder.Config.GetSection("Authentication:Google");
            //        options.ClientId = googleAuthNSection["ClientId"];
            //        options.ClientSecret = googleAuthNSection["ClientSecret"];
            //    })));
            //return builder;
        }
    }
}

using Microsoft.Extensions.Options;
using Umbraco.Cms.Core;
using Umbraco.Cms.Web.BackOffice.Security;

namespace UmbracoDemo1.OAuth
{
    public class GoogleBackOfficeExternalLoginProviderOptions : IConfigureNamedOptions<BackOfficeExternalLoginProviderOptions>
    {
        public const string SchemeName = "Google";
        public void Configure(string name, BackOfficeExternalLoginProviderOptions options)
        {
            if (name != "Umbraco." + SchemeName)
            {
                return;
            }

            Configure(options);
        }

        public void Configure(BackOfficeExternalLoginProviderOptions options)
        {
            options.ButtonStyle = "btn-danger";
            options.Icon = "fa fa-cloud";
            options.AutoLinkOptions = new ExternalSignInAutoLinkOptions(
                // must be true for auto-linking to be enabled
                autoLinkExternalAccount: true,

                // Optionally specify default user group, else
                // assign in the OnAutoLinking callback
                // (default is editor)
                defaultUserGroups: new[] { Constants.Security.EditorGroupAlias },

                // Optionally specify the default culture to create
                // the user as. If null it will use the default
                // culture defined in the web.config, or it can
                // be dynamically assigned in the OnAutoLinking
                // callback.

                defaultCulture: null,
                // Optionally you can disable the ability to link/unlink
                // manually from within the back office. Set this to false
                // if you don't want the user to unlink from this external
                // provider.
                allowManualLinking: false
            )
            {
                // Optional callback
                OnAutoLinking = (autoLinkUser, loginInfo) =>
                {
                    // You can customize the user before it's linked.
                    // i.e. Modify the user's groups based on the Claims returned
                    // in the externalLogin info
                },
                OnExternalLogin = (user, loginInfo) =>
                {
                    // You can customize the user before it's saved whenever they have
                    // logged in with the external provider.
                    // i.e. Sync the user's name based on the Claims returned
                    // in the externalLogin info

                    return true; //returns a boolean indicating if sign in should continue or not.
                }
            };

            // Optionally you can disable the ability for users
            // to login with a username/password. If this is set
            // to true, it will disable username/password login
            // even if there are other external login providers installed.
            options.DenyLocalLogin = false;

            // Optionally choose to automatically redirect to the
            // external login provider so the user doesn't have
            // to click the login button. This is
            options.AutoRedirectLoginToExternalProvider = false;
        }
    }
}