php代码加密解密

转载自：http://www.javashuo.com/article/p-mmyvwrbc-d.html

<?php  
 
 function RandAbc($length = "") { // 返回随机字符串 
     $str = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";  
     return str_shuffle($str);  
 }   
 
 $filename = 'index.php'; //要加密的文件 
 $T_k1 = RandAbc(); //随机密匙1 
 $T_k2 = RandAbc(); //随机密匙2 
 $vstr = file_get_contents($filename);  
 $v1 = base64_encode($vstr);  
 $c = strtr($v1, $T_k1, $T_k2); //根据密匙替换对应字符。 
 $c = $T_k1.$T_k2.$c;  
 $q1 = "O00O0O";  
 $q2 = "O0O000";  
 $q3 = "O0OO00";  
 $q4 = "OO0O00";  
 $q5 = "OO0000";  
 $q6 = "O00OO0";  
 $s = '$'.$q6.'=urldecode("%6E1%7A%62%2F%6D%615%5C%76%740%6928%2D%70%78%75%71%79%2A6%6C%72%6B%64%679%5F%65%68%63%73%77%6F4%2B%6637%6A");$'.$q1.'=$'.$q6.'{3}.$'.$q6.'{6}.$'.$q6.'{33}.$'.$q6.'{30};$'.$q3.'=$'.$q6.'{33}.$'.$q6.'{10}.$'.$q6.'{24}.$'.$q6.'{10}.$'.$q6.'{24};$'.$q4.'=$'.$q3.'{0}.$'.$q6.'{18}.$'.$q6.'{3}.$'.$q3.'{0}.$'.$q3.'{1}.$'.$q6.'{24};$'.$q5.'=$'.$q6.'{7}.$'.$q6.'{13};$'.$q1.'.=$'.$q6.'{22}.$'.$q6.'{36}.$'.$q6.'{29}.$'.$q6.'{26}.$'.$q6.'{30}.$'.$q6.'{32}.$'.$q6.'{35}.$'.$q6.'{26}.$'.$q6.'{30};eval($'.$q1.'("'.base64_encode('$'.$q2.'="'.$c.'";eval(\'?>\'.$'.$q1.'($'.$q3.'($'.$q4.'($'.$q2.',$'.$q5.'*2),$'.$q4.'($'.$q2.',$'.$q5.',$'.$q5.'),$'.$q4.'($'.$q2.',0,$'.$q5.'))));').'"));';  
 
 $s = '<?php '."\n".$s."\n".' ?>';  
 //echo $s; 
 // 生成 加密后的PHP文件 
 $fpp1 = fopen('temp_'.$filename, 'w');  
 fwrite($fpp1, $s) or die('写文件错误');  
 
 ?>

简单数字加密解密:

function numhash($number)
{
    return (((0x0000FFFF & $number) << 16) + ((0xFFFF0000 & $number) >> 16));
}

https://stackoverflow.com/questions/24350891/how-to-encrypt-decrypt-an-integer-in-php