AzureAD and IOS12 SameSite Cookie Infinite Loop

Question

I'm getting the same site cookie problem that I have been seen going around. I am using AzureAD and when I apply the fixes that are out there I still can't stop the infinite loop in IOS12.

I read this page and this one detailing setting SameSiteMode to None. Am I missing something new?

.NET Core 2.1, AzureAD

Here is my startup class:

public class Startup
{
    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
    }

    public IConfiguration Configuration { get; }

    // This method gets called by the runtime. Use this method to add services to the container.
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddAuthentication(AzureADDefaults.AuthenticationScheme)
            .AddAzureAD(options => Configuration.Bind("AzureAd", options))
            .AddCookie(options=>options.Cookie.SameSite = SameSiteMode.None)
            .Services.ConfigureExternalCookie(options =>
            {
                options.Cookie = new Microsoft.AspNetCore.Http.CookieBuilder()
                {
                    SameSite = Microsoft.AspNetCore.Http.SameSiteMode.None
                };
            });

        services.AddMvc(options =>
        {
            var policy = new AuthorizationPolicyBuilder()
                .RequireAuthenticatedUser()
                .Build();
            options.Filters.Add(new AuthorizeFilter(policy));
        })
        .SetCompatibilityVersion(CompatibilityVersion.Version_2_1);

    }



    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {


        app.UseCors(builder =>
        {
            // cannot be set to AllowAnyOrigin, because then the response is not accepted, because the credentials are included
            builder.WithOrigins("https://*.sharepoint.com")
                .SetIsOriginAllowedToAllowWildcardSubdomains()
                .AllowCredentials();
        });

        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }
        else
        {
            app.UseExceptionHandler("/Home/Error");
            app.UseHsts();
        }

        app.UseHttpsRedirection();
        app.UseStaticFiles();
        app.UseCookiePolicy(new CookiePolicyOptions()
        {
            MinimumSameSitePolicy = SameSiteMode.None
        });

        app.UseAuthentication();

        app.UseMvc(routes =>
        {
            routes.MapRoute(
                name: "default",
                template: "{controller=Home}/{action=Index}/{id?}");
        });


    }

EDIT: I have another application deployed to the same box that is not having the same infinite loop issue. I copied the configuration to match that application and it is still not working. Both new .NET Core 2.1 apps.

        services.AddAuthentication(sharedOptions =>
    {
        sharedOptions.DefaultScheme = CookieAuthenticationDefaults.AuthenticationScheme;
        sharedOptions.DefaultChallengeScheme = OpenIdConnectDefaults.AuthenticationScheme;
    })
    .AddAzureAd(options => Configuration.Bind("AzureAd", options))
    .AddCookie();

And:

app.UseAuthentication();

Can anyone help?

Answer 1

This appears to be working with the newest updates from MS and Apple.