在ASP.NET Core 2.0中使用CookieAuthentication

在ASP.NET Core中关于Security有两个容易混淆的概念一个是Authentication（认证），一个是Authorization（授权）。而前者是确定用户是谁的过程，后者是围绕着他们允许做什么，今天的主题就是关于在ASP.NET Core 2.0中如何使用CookieAuthentication认证。

在ASP.NET Core 2.0中使用CookieAuthentication跟在1.0中有些不同，需要在ConfigureServices和Configure中分别设置，前者我们叫注册服务，后者我们叫注册中间件

public void ConfigureServices(IServiceCollection services)
{
    services.AddCookieAuthentication();
    services.AddMvc(options =>
    {
        var policy = new AuthorizationPolicyBuilder()
            .RequireAuthenticatedUser()
            .Build();
　　　　 // 因为是后台系统，必须登陆以后才能操作
        options.Filters.Add(new AuthorizeFilter(policy));
    });
}

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
    if (env.IsDevelopment())
    {
        app.UseDeveloperExceptionPage();
    }
    else
    {
        app.UseExceptionHandler("/Home/Error");
    }
    app.UseStaticFiles();

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

在上面的services.AddCookieAuthentication中没有任何参数，系统会为某些属性指定默认值

public static class CookieAuthenticationDefaults
{
    /// <summary>
    /// The default value used for CookieAuthenticationOptions.AuthenticationScheme
    /// </summary>
    public const string AuthenticationScheme = "Cookies";

    /// <summary>
    /// The prefix used to provide a default CookieAuthenticationOptions.CookieName
    /// </summary>
    public static readonly string CookiePrefix = ".AspNetCore.";

    /// <summary>
    /// The default value used by CookieAuthenticationMiddleware for the
    /// CookieAuthenticationOptions.LoginPath
    /// </summary>
    public static readonly PathString LoginPath = new PathString("/Account/Login");

    /// <summary>
    /// The default value used by CookieAuthenticationMiddleware for the
    /// CookieAuthenticationOptions.LogoutPath
    /// </summary>
    public static readonly PathString LogoutPath = new PathString("/Account/Logout");

    /// <summary>
    /// The default value used by CookieAuthenticationMiddleware for the
    /// CookieAuthenticationOptions.AccessDeniedPath
    /// </summary>
    public static readonly PathString AccessDeniedPath = new PathString("/Account/AccessDenied");

    /// <summary>
    /// The default value of the CookieAuthenticationOptions.ReturnUrlParameter
    /// </summary>
    public static readonly string ReturnUrlParameter = "ReturnUrl";
}

根据微软的命名规范在ConfigureServices统一使用Add***,在Configure统一使用Use***

登陆代码

public async Task<IActionResult> LoginDo()
{
　　var user = new ClaimsPrincipal(new ClaimsIdentity(new[] { new Claim(ClaimTypes.Name, "bob") }, CookieAuthenticationDefaults.AuthenticationScheme));
　　await HttpContext.SignInAsync(CookieAuthenticationDefaults.AuthenticationScheme, user, new AuthenticationProperties
　　{
　　　　IsPersistent = true,
　　　　ExpiresUtc = DateTimeOffset.Now.Add(TimeSpan.FromDays(180))
　　});
　　return Redirect("/");
}

登出代码

public async Task<IActionResult> Logout()
{
    await HttpContext.SignOutAsync(CookieAuthenticationDefaults.AuthenticationScheme);
    return Redirect("/");
}