记得ajax中要带上AntiForgeryToken防止CSRF攻击

经常看到在项目中ajax post数据到服务器不加防伪标记，造成CSRF攻击

在Asp.net Mvc里加入防伪标记很简单在表单中加入Html.AntiForgeryToken()即可。

Html.AntiForgeryToken()会生成一对加密的字符串，分别存放在Cookies 和 input 中。

我们在ajax post中也带上AntiForgeryToken

@model WebApplication1.Controllers.Person
@{
ViewBag.Title = "Index";
}

<h2>Index</h2>
<form id="form1">
<div class="form-horizontal">
<h4>Persen</h4>
<hr />
@Html.ValidationSummary(true, "", new { @class = "text-danger" })
<div class="form-group">
@Html.LabelFor(model => model.Name, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.Name, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.Name, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.Age, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.Age, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.Age, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
<div class="col-md-offset-2 col-md-10">
<input type="button" id="save" value="Create" class="btn btn-default" />
</div>
</div>
</div>

</form>
<script src="~/Scripts/jquery-1.10.2.min.js"></script>
<script src="~/Scripts/jquery.validate.min.js"></script>
<script src="~/Scripts/jquery.validate.unobtrusive.min.js"></script>
<script type="text/javascript">
$(function () {

//var token = $('[name=__RequestVerificationToken]');
//获取防伪标记
var token = $('@Html.AntiForgeryToken()').val();
var headers = {};
//防伪标记放入headers
//也可以将防伪标记放入data
headers["__RequestVerificationToken"] = token;

$("#save").click(function () {
$.ajax({
type: 'POST',
url: '/Home/Index',
cache: false,
headers: headers,
data: { Name: "yangwen", Age: "1" },
success: function (data) {
alert(data)
},
error: function () {
alert("Error")
}
});
})

})
</script>

放在cookies里面的加密字符串

控制器中代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Web;
using System.Web.Helpers;
using System.Web.Mvc;

namespace WebApplication1.Controllers
{
public class HomeController : Controller
{
public ActionResult Index()
{

return View();
}
[HttpPost]
[MyValidateAntiForgeryToken]
public ActionResult Index(Person p)
{
return Json(true, JsonRequestBehavior.AllowGet);
}
}
public class Person
{
public string Name { get; set; }

public int Age { get; set; }
}

public class MyValidateAntiForgeryToken : AuthorizeAttribute
{
public override void OnAuthorization(AuthorizationContext filterContext)
{
var request = filterContext.HttpContext.Request;

if (request.HttpMethod == WebRequestMethods.Http.Post)
{
if (request.IsAjaxRequest())
{
var antiForgeryCookie = request.Cookies[AntiForgeryConfig.CookieName];

var cookieValue = antiForgeryCookie != null
? antiForgeryCookie.Value
: null;
//从cookies 和 Headers 中 验证防伪标记
//这里可以加try-catch
AntiForgery.Validate(cookieValue, request.Headers["__RequestVerificationToken"]);
}
else
{
new ValidateAntiForgeryTokenAttribute()
.OnAuthorization(filterContext);
}
}
}
}

}

这里注释掉ajax中防伪标记在请求

$("#save").click(function () {
$.ajax({
type: 'POST',
url: '/Home/Index',
cache: false,
//      headers: headers,
data: { Name: "yangwen", Age: "1" },
success: function (data) {
alert(data)
},
error: function () {
alert("Error")
}
});
})

默认返回500的状态码。

这里修改ajax中的防伪标记

$(function () {

//var token = $('[name=__RequestVerificationToken]');
//获取防伪标记
var token = $('@Html.AntiForgeryToken()').val();
var headers = {};
//防伪标记放入headers
//也可以将防伪标记放入data
headers["__RequestVerificationToken"] = token+11111111111111111111111111111111111;
$("#save").click(function () {
$.ajax({
type: 'POST',
url: '/Home/Index',
cache: false,
headers: headers,
data: { Name: "yangwen", Age: "1" },
success: function (data) {
alert(data)
},
error: function () {
alert("Error")
}
});
})

})

也是500的状态码。