我使用ASP.NET MVC 4 Web应用程序作为某些WCF服务的前端。 所有用户登录/注销和会话控制都在后端完成。 MVC应用程序应该只存储具有会话ID的单个cookie。我的客户端不允许使用表单身份验证，所有内容都必须自定义。
我在web.config中设置了以下内容：
<system.web>
...
<authentication mode="None" />
</system.web>
<system.webServer>
<modules>
...
<remove name="FormsAuthentication" />
...
</modules>
</system.webServer>
我还有一个全局过滤器：
public class FilterConfig
{
public static void RegisterGlobalFilters(GlobalFilterCollection filters)
{
// Force all actions to request auth. Only actions marked with [AllowAnonymous] will be allowed.
filters.Add(new MyAuthorizeAttribute());
}
}
在Global.asax中调用
FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
我已经使用[AllowAnonymous]标记了每个不需要授权的控制器和操作。
现在我必须实现MyAuthorizeAttribute。我尝试了一些教程，但没有一个完全符合我的场景。
基本上，我必须针对每个操作处理以下方案：
据我了解，我需要覆盖AuthorizeCore（检查我的cookie以查看会话是否存在且仍然有效）和HandleUnauthorizedRequest（将用户重定向到Home / Index而不是默认登录页面）。
对于重定向，我试过：
protected override void HandleUnauthorizedRequest(AuthorizationContext filterContext)
{
base.HandleUnauthorizedRequest(filterContext);
filterContext.Result = new RedirectResult("/Home/Index/NeedsLogin");
}
这似乎处理了第二次罚款的情况（我不确定那个基本呼叫，但它是否需要？）。
对于第一种情况，我需要实现AuthorizeCore。我不确定，如何正确地做到这一点。我已经看到AuthorizeAttribute有一些用于处理缓存情况的代码，可能还有更多隐藏的功能，我不想破解它。
对于第三种情况，我不确定MyAuthorizeAttribute是否能够处理它。 AuthorizeAttribute可以捕获Action内部发生的异常，或者我必须在我的全局错误处理程序中处理SecurityFault.SessionExpired情况吗？
答案 0 :(得分：7)
不完全确定我得到了它但是如果您创建一个继承自System.Web.MVC.Authorize属性的自定义授权过滤器。
public class CustomAuthorize : AuthorizeAttribute
{
public override void OnAuthorization(AuthorizationContext filterContext)
{
if (CookieIsValid(filterContext.Request.Cookies["cookieyouwant"])
{
filterContext.Result = new RedirectResult("DestUrl");
}
else
{
filterContext.Result = new RedirectResult("/Home/Index/NeedsLogin");
}
}
}
然后装饰你需要使用这个授权的方法来实现这个技巧吗？
答案 1 :(得分：3)
以下是我现在的表现：
public class MyAuthorizeAttribute : AuthorizeAttribute
{
public override void OnAuthorization(AuthorizationContext filterContext)
{
bool authorized = false;
/// MVC 4 boilerplate code follows
if (filterContext == null)
throw new ArgumentNullException("filterContext");
bool skipAuthorization = filterContext.ActionDescriptor.IsDefined(typeof(AllowAnonymousAttribute), inherit: true)
|| filterContext.ActionDescriptor.ControllerDescriptor.IsDefined(typeof(AllowAnonymousAttribute), inherit: true);
if (skipAuthorization)
{
return;
}
if (OutputCacheAttribute.IsChildActionCacheActive(filterContext))
{
throw new InvalidOperationException(
"MyAuthorizeAttribute cannot be used within a child action caching block."
);
}
// end of MVC code
// custom code
if (!AuthorizeCore(filterContext.HttpContext))
{
// if not authorized from some other Action call, let's try extracting user data from custom encrypted cookie
var identity = MyEncryptedCookieHelper.GetFrontendIdentity(filterContext.HttpContext.Request);
// identity might be null if cookie not received
if (identity == null)
{
filterContext.HttpContext.User = new GenericPrincipal(new GenericIdentity(""), null);
}
else
{
authorized = true;
filterContext.HttpContext.User = new MyFrontendPrincipal(identity);
}
// make sure the Principal's are in sync - there might be situations when they are not!
Thread.CurrentPrincipal = filterContext.HttpContext.User;
}
// MVC 4 boilerplate code follows
if (authorized)
{
// ** IMPORTANT **
// Since we're performing authorization at the action level, the authorization code runs
// after the output caching module. In the worst case this could allow an authorized user
// to cause the page to be cached, then an unauthorized user would later be served the
// cached page. We work around this by telling proxies not to cache the sensitive page,
// then we hook our custom authorization code into the caching mechanism so that we have
// the final say on whether a page should be served from the cache.
HttpCachePolicyBase cachePolicy = filterContext.HttpContext.Response.Cache;
cachePolicy.SetProxyMaxAge(new TimeSpan(0));
cachePolicy.AddValidationCallback(CacheValidateHandler, null /* data */);
}
else
{
HandleUnauthorizedRequest(filterContext);
}
//end of MVC code
}
protected override bool AuthorizeCore(HttpContextBase httpContext)
{
if (httpContext == null)
throw new ArgumentNullException("httpContext");
// check to make sure the user is authenticated as my custom identity
var principal = httpContext.User as MyFrontendPrincipal;
if (principal == null)
return false;
var identity = principal.Identity as MyFrontendIdentity;
if (identity == null)
return false;
return true;
}
protected override void HandleUnauthorizedRequest(AuthorizationContext filterContext)
{
// default MVC result was:
// filterContext.Result = new HttpUnauthorizedResult();
// but I redirect to index login page instead of kicking 401
filterContext.Result = new RedirectResult("/Home/Index/NeedsLogin");
}
// MVC 4 boilerplate code follows
private void CacheValidateHandler(HttpContext context, object data, ref HttpValidationStatus validationStatus)
{
validationStatus = OnCacheAuthorization(new HttpContextWrapper(context));
}
// This method must be thread-safe since it is called by the caching module.
protected virtual HttpValidationStatus OnCacheAuthorization(HttpContextBase httpContext)
{
if (httpContext == null)
throw new ArgumentNullException("httpContext");
bool isAuthorized = AuthorizeCore(httpContext);
return (isAuthorized) ? HttpValidationStatus.Valid : HttpValidationStatus.IgnoreThisRequest;
}
}
但它不处理我的第三种情况，所以我将在全局错误处理程序中实现它。
答案 2 :(得分：3)
关于您的第一个要求：
正如您已经发现的那样，OnAuthorization负责处理多个方面，包括：缓存。
如果您只想自定义验证用户凭据的方式，我建议您改为覆盖AuthorizeCore。 E.g：
public class ClientCookieAuthorizeAttribute : AuthorizeAttribute
{
protected override bool AuthorizeCore(HttpContextBase httpContext)
{
HttpCookie cookie = httpContext.Request.Cookies[_tokenCookieName];
bool isAuthenticated = ValidateUserByCookie(cookie);
return isAuthenticated;
}
private bool ValidateUserByCookie(HttpCookie cookie)
{
var result = false;
// Perform validation
// You could include httpContext as well, to check further information
return result;
}
private static const string _tokenCookieName = "myCookieName";
}
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