参考文章：https://www.t00ls.net/articles-53395.html
作者：redn3ck
通用的表单上传：
POST /upload_file.php HTTP/1.1
Host: xxxxxxxx
Content-Length: 296
Cache-Control: max-age=0
Origin: http://118.24.246.72
Upgrade-Insecure-Requests: 1
Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryHPiofjFbJ4l6hDZW
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8
Referer: http://xxxxxxxxxxxxx/upload.html
Accept-Encoding: gzip, deflate
Accept-Language: zh-CN,zh;q=0.9
Cookie: PHPSESSID=503qgvpca3d7e7pmovl0d1h0q6
Connection: close
------WebKitFormBoundaryHPiofjFbJ4l6hDZW
Content-Disposition: form-data; name="file"; filename="c2.php"
Content-Type: application/octet-stream
123
------WebKitFormBoundaryHPiofjFbJ4l6hDZW
Content-Disposition: form-data; name="submit"
Submit
------WebKitFormBoundaryHPiofjFbJ4l6hDZW--
案例如下：
Content-Type: multipart/form-data; boundary=--------1036030574
----------1036030574
Content-Disposition: form-data; name="Filedata"; filename="pic.jpg"
Content-Type: text/plain
123
----------1036030574--
完整的http报文：
----------1036030574
Content-Disposition: form-data; name="ObjNM";
Content-Type: text/plain
1
----------1036030574
Content-Disposition: form-data; name="FilePath";
Content-Type: text/plain
pic.jpg
----------1036030574
Content-Disposition: form-data; name="UpLoadBtnNM";
Content-Type: text/plain
1
----------1036030574
Content-Disposition: form-data; name="DeleteBtnNM";
Content-Type: text/plain
1
----------1036030574
Content-Disposition: form-data; name="MaxFileSize";
Content-Type: text/plain
1
----------1036030574
Content-Disposition: form-data; name="MaxSize";
Content-Type: text/plain
1
----------1036030574
Content-Disposition: form-data; name="IsCover";
Content-Type: text/plain
1
----------1036030574--
完整的http报文：
