.net 5 Azure b2c 注销循环

Question

Hello I'm trying to implement azure b2c in an app. Everything works fine logging in. But when I log out it get stuck in an infinite loop. All the examples I can find seem to be .net core 3.1.

Here is my appsettings.

"AzureAdB2C": {
"Instance": "https://xxx.b2clogin.com",
"TenantId": "xxx",
"ClientId": "xxx",
"Domain": "xxx.onmicrosoft.com",
"SignedOutCallbackPath": "/signout/B2C_1_Normal",
"SignUpSignInPolicyId": "B2C_1_Normal",
//"CallbackPath": "/signin/B2C_1_Normal"
}

Here is my startup.

 services.AddAuthentication(OpenIdConnectDefaults.AuthenticationScheme)
 .AddMicrosoftIdentityWebApp(options =>
 {
     Configuration.Bind("AzureAdB2C", options);
 }).EnableTokenAcquisitionToCallDownstreamApi(new string[] { Configuration["ApiScope"] 
 })
 .AddInMemoryTokenCaches
services.AddControllersWithViews(options=>
{
    var policy = new AuthorizationPolicyBuilder()
        .RequireAuthenticatedUser()
        .Build();
    options.Filters.Add(new AuthorizeFilter(policy));
}).AddMicrosoftIdentityUI();

To sign out, I just have a button click.

<a class="nav-link" asp-area="MicrosoftIdentity" asp-controller="Account" asp-action="SignOut">Sign out</a>

It does sign me out, but I'm stuck in a redirect loop back to my app, and then back to the B2C.

Answer 1

I tried to test in my local environment , and it was tested successfully with sign in and sign out from my webapplication using AzureAdB2C credentials.

Here are the steps that i followed:

Created a B2C tenant in Portal and link it to my subscription.

After linked created an App registration with selected as below and authenticate with id and access token .

I have added the userflow and select the following to configure:

Then in visual studio created an Asp.net core web application and provide the domain and policy details which i created in above

Domain name - Azure AD B2C Overview tab Application Id - From app registration overview tab Sign-up or sign-in policy - From user flows Overview

Copied the reply URI and paste in redirect URI section in portal

Here is my appsettings.json file

And it allows me to sign-in and after sign-out it redirect to my home page as well :

For more information please refer the below links:

. How to sign out of Azure ADB2C |MS Q&A .

. Configure session behavior in Azure Active Directory B2C | MS DOC

Answer 2

I had the same issue and it was because of missing support of Razor pages. The default Microsoft.Identity.Web.UI SignOut action uses /Account/SignedOut Razor page as callback url.

var callbackUrl = Url.Page("/Account/SignedOut", pageHandler: null, values: null, protocol: Request.Scheme);

I added Razor support in my Asp.Net core web app and it fixed the issue.

 services.AddRazorPages();

and

app.UseEndpoints(endpoints =>
        {
            endpoints.MapControllerRoute(
                name: "default",
                pattern: "{controller=Home}/{action=Index}/{id?}");
            endpoints.MapRazorPages();
        });

Alternatively you can use your own logout endpoint, which can use any action as signed out callback url.

Thanks.