ASP.NET MVC View 和 Web API 的基本权限验证

环境：Windows 7 Professional SP1 + Microsoft Visual Studio 2013（MVC 5 + Web API 2）

修改Web.config，增加Forms验证模式，在system.web节点中增加以下配置：

<authentication mode="Forms">
  <forms loginUrl="~/login" defaultUrl="~/" protection="All" timeout="20" name="__auth" />
</authentication>

【MVC View Controller 篇】

新建一个PageAuth，继承自AuthorizeAttribute：

using System;
using System.Net;
using System.Web;
using System.Web.Mvc;
using System.Web.Security;

[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, Inherited = true, AllowMultiple = true)]
public class PageAuth : AuthorizeAttribute
{
    protected override bool AuthorizeCore(HttpContextBase httpContext)
    {
        if (httpContext == null)
        {
            return false;
        }

        if (httpContext.User.Identity.IsAuthenticated && base.AuthorizeCore(httpContext))
        {
            return ValidateUser();
        }

        httpContext.Response.StatusCode = (int)HttpStatusCode.Forbidden;
        return false;
    }

    public override void OnAuthorization(AuthorizationContext filterContext)
    {
        base.OnAuthorization(filterContext);

        if (filterContext.HttpContext.Response.StatusCode == (int)HttpStatusCode.Forbidden)
        {
            filterContext.Result = new RedirectToRouteResult("AccessErrorPage", null);
        }
    }

    protected override void HandleUnauthorizedRequest(AuthorizationContext filterContext)
    {
        filterContext.HttpContext.Response.Redirect(FormsAuthentication.LoginUrl);
    }

    private bool ValidateUser()
    {
        //TODO: 权限验证
        return true;
    }
}

建一个Controller的基类PageBase，继承自Controller：

using System.Web.Mvc;

[PageAuth]
public class PageBase : Controller
{
}

所有View的Controller均继承自PageBase，不再继承自Controller。

继承PageBase之后，所有的Controller均需登录，给允许匿名访问的Controller（或Action）增加AllowAnonymous（以AccountController为例）：

using System.Web.Mvc;

public class AccountController : PageBase
{
    [AllowAnonymous]
    public ActionResult Login()  // 可匿名访问
    {
        ViewBag.Title = "用户登录";
        return View();
    }

    public ActionResult Detail(int id)   // 需登录访问
    {
        ViewBag.Title = "用户详情";
        return View();
    }
}

页面Controller的开发，基本结束，接下来就是在登录页面（~/login）使用js提交登录信息，用post方式提交。

提交之后，需要开发Web API的接口了。

【MVC Web API Controller 篇】

同样，新建一个ApiAuth，继承自ActionFilterAttribute：

using System;
using System.Net;
using System.Net.Http;
using System.Web.Http;
using System.Web.Http.Controllers;
using System.Web.Http.Filters;
using System.Web.Security;

[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, Inherited = true, AllowMultiple = true)]
public class ApiAuth : ActionFilterAttribute
{
    public override void OnActionExecuting(HttpActionContext actionContext)
    {
        try
        {
            if (actionContext.ActionDescriptor.GetCustomAttributes<AllowAnonymousAttribute>().Count > 0)   // 允许匿名访问
            {
                base.OnActionExecuting(actionContext);
                return;
            }

            var cookie = actionContext.Request.Headers.GetCookies();
            if (cookie == null || cookie.Count < 1)
            {
                actionContext.Response = new HttpResponseMessage(HttpStatusCode.Forbidden);
                return;
            }

            FormsAuthenticationTicket ticket = null;

            foreach (var perCookie in cookie[0].Cookies)
            {
                if (perCookie.Name == FormsAuthentication.FormsCookieName)
                {
                    ticket = FormsAuthentication.Decrypt(perCookie.Value);
                    break;
                }
            }

            if (ticket == null)
            {
                actionContext.Response = new HttpResponseMessage(HttpStatusCode.Forbidden);
                return;
            }

            // TODO: 添加其它验证方法

            base.OnActionExecuting(actionContext);
        }
        catch
        {
            actionContext.Response = new HttpResponseMessage(HttpStatusCode.Forbidden);
        }
    }
}

新建一个ApiController的基类ApiBase，继承自ApiController：

using System.Web.Http;

[ApiAuth]
public class ApiBase : ApiController
{
}

所有API的Controller均继承自ApiBase，不再继承自ApiController。

继承ApiBase之后，给允许匿名访问的Controller（或Action）增加AllowAnonymous（以LoginController为例）：

using System.Web.Http;
using System.Web.Security;

public class LoginController : ApiBase
{
    [HttpPost]
    [AllowAnonymous]
    public bool Login([FromBody]LoginInfo loginInfo)
    {
        try
        {
            var cookie = FormsAuthentication.GetAuthCookie("Username", false);
            var ticket = FormsAuthentication.Decrypt(cookie.Value);
            var newTicket = new FormsAuthenticationTicket(ticket.Version, ticket.Name, ticket.IssueDate, ticket.Expiration, ticket.IsPersistent, "");
            cookie.Value = FormsAuthentication.Encrypt(newTicket);
            DeyiContext.Response.Cookies.Add(cookie);return true;
        }
        catch
        {
            return false;
        }
    }
}

【写在最后】

网上查了很多方法，还需要时间验证一下各个方法的合理度。

关于Web API的安全性，个人觉得，还是采用SSL的方式更加稳妥一些。

另外，网上很多写的在Web API的权限判断的时候，使用的是actionContext.Request.Headers.Authorization来判断，如下：

if (actionContext.Request.Headers.Authorization == null)
{
    // 判断是否允许匿名访问
}
else
{
    var ticket = FormsAuthentication.Decrypt(actionContext.Request.Headers.Authorization.Parameter);
    // 后续其它验证操作
}

还没有完成测试该方法，慢慢来吧~~~