AspNetCore.Docs/aspnetcore/security/samesite/sample/Startup.cs

129 lines
4.3 KiB
C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.HttpsPolicy;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
namespace WebSameSite
{
public class Startup
{
public Startup(IConfiguration configuration)
{
Configuration = configuration;
}
public IConfiguration Configuration { get; }
#region snippet5
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
else
{
app.UseExceptionHandler("/Error");
app.UseHsts();
}
app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseRouting();
app.UseCookiePolicy();
app.UseAuthentication();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
endpoints.MapRazorPages();
});
}
#endregion
#region snippet
public void ConfigureServices(IServiceCollection services)
{
services.Configure<CookiePolicyOptions>(options =>
{
options.MinimumSameSitePolicy = (SameSiteMode)(-1);
options.OnAppendCookie = cookieContext =>
CheckSameSite(cookieContext.Context, cookieContext.CookieOptions);
options.OnDeleteCookie = cookieContext =>
CheckSameSite(cookieContext.Context, cookieContext.CookieOptions);
});
services.AddRazorPages();
}
private void CheckSameSite(HttpContext httpContext, CookieOptions options)
{
if (options.SameSite == SameSiteMode.None)
{
var userAgent = httpContext.Request.Headers["User-Agent"].ToString();
if (MyUserAgentDetectionLib.DisallowsSameSiteNone(userAgent))
{
options.SameSite = (SameSiteMode)(-1);
}
}
}
#endregion
public static class MyUserAgentDetectionLib
{
public static bool DisallowsSameSiteNone(string userAgent)
{
// Check if a null or empty string has been passed in, since this
// will cause further interrogation of the useragent to fail.
if (String.IsNullOrWhiteSpace(userAgent))
return false;
// Cover all iOS based browsers here. This includes:
// - Safari on iOS 12 for iPhone, iPod Touch, iPad
// - WkWebview on iOS 12 for iPhone, iPod Touch, iPad
// - Chrome on iOS 12 for iPhone, iPod Touch, iPad
// All of which are broken by SameSite=None, because they use the iOS networking
// stack.
if (userAgent.Contains("CPU iPhone OS 12") ||
userAgent.Contains("iPad; CPU OS 12"))
{
return true;
}
// Cover Mac OS X based browsers that use the Mac OS networking stack. This includes:
// - Safari on Mac OS X.
// This does not include:
// - Chrome on Mac OS X
// Because they do not use the Mac OS networking stack.
if (userAgent.Contains("Macintosh; Intel Mac OS X 10_14") &&
userAgent.Contains("Version/") && userAgent.Contains("Safari"))
{
return true;
}
// Cover Chrome 50-69, because some versions are broken by SameSite=None,
// and none in this range require it.
// Note: this covers some pre-Chromium Edge versions,
// but pre-Chromium Edge does not require SameSite=None.
if (userAgent.Contains("Chrome/5") || userAgent.Contains("Chrome/6"))
{
return true;
}
return false;
}
}
}
}