如何在asp.net核心中更改IActionFilter中的请求正文

Question

目前我正在向 asp.net 核心控制器发送加密请求。以下是请求体结构：

{
  "body": "pEbXVvl1ue95eGQywK/q80cGHjYk+2VNPYEgnRgU+vI="
}

在此之前，我已经实现了过滤器，IActionFilter所以在OnActionExecuting(ActionExecutingContext context)那里我解密了上面提到的请求正文（正文密钥）

解密后，我得到解密后的请求体，如下所示：

{
  "Urno":"URN123456"
}

解密后，我想将解密的请求（如上所述"Urno":"URN123456"）主体传递给控制器

我曾尝试将字符串转换为字节而不是将其传递给Request.body但没有成功：

public void OnActionExecuting(ActionExecutingContext context)
{
    var request = context.HttpContext.Request;
    request.EnableRewind();
    request.Body.Position = 0;
    using (var reader = new StreamReader(request.Body))
    {                   
        var bodyString = reader.ReadToEnd(); //{ "body": "pEbXVvl1ue95eGQywK/q80cGHjYk+2VNPYEgnRgU+vI="}
        if (bodyString != "")
        {
             var data = JObject.Parse(bodyString);
             var key = data.GetValue("body"); 
             var keybytes = Encoding.UTF8.GetBytes("808080808080808011");
             var iv = Encoding.UTF8.GetBytes("8080808080808080111");
             var encrypted = Convert.FromBase64String(key.ToString());
             var decriptedFromJavascript = DecryptStringFromBytes(encrypted, keybytes, iv); //{ "Urno":"URN123456"}
             byte[] bytes = Encoding.ASCII.GetBytes(decriptedFromJavascript);
             request.Body = new MemoryStream(bytes); // here i am trying to change request body
        }
    }
}
   // controller
[HttpPost("[action]")]
public async Task<string> GetInvestorUrno(Urnoinvestor InfoReq){

}


// class
public class Urnoinvestor 
{
    public string Urno{ get; set; }
}

我想更改请求正文并将解密的请求传递给控制器

Answer 1

对于您的情况，IActionFilter行不通。检查此图像：

在Model binding运行之前ActionFilter该装置无论你改变身体，它不会改变模型。您需要在模型绑定之前尝试过滤器，例如Resource filter.

1. 改成 Resource filter

   public class RequestBodyFilter : IResourceFilter
   {
       public void OnResourceExecuted(ResourceExecutedContext context)
       {
           //throw new NotImplementedException();
       }
   
       public void OnResourceExecuting(ResourceExecutingContext context)
       {
           var request = context.HttpContext.Request;
           request.EnableRewind();
           request.Body.Position = 0;
           using (var reader = new StreamReader(request.Body))
           {
               var decriptedFromJavascript = "{ \"Urno\":\"URN123456\"}"; //{ "Urno":"URN123456"}
               byte[] bytes = Encoding.ASCII.GetBytes(decriptedFromJavascript);
               request.Body = new MemoryStream(bytes); // here i am trying to change request body
           }
       }
   }
   

2. 由于您是从身体绑定的，因此您需要[FromBody]按照@Tony Abrams 的建议指定操作。

   [HttpPost("[action]")]
   [TypeFilter(typeof(RequestBodyFilter))]
   public async Task<string> GetInvestorUrno([FromBody]Urnoinvestor InfoReq)
   {
       return InfoReq.Urno;
   }