<?php 
 function encode_file_contents($filename) { 
     $type=strtolower(substr(strrchr($filename,'.'),1)); 
     if ('php' == $type && is_file($filename) && is_writable($filename)) { // 如果是PHP文件 并且可写 则进行压缩编码 
         $contents = file_get_contents($filename); // 判断文件是否已经被编码处理 
         $contents = php_strip_whitespace($filename);  

         // 去除PHP头部和尾部标识 
         $headerPos = strpos($contents,'<?php'); 
         $footerPos = strrpos($contents,'?>'); 
         $contents = substr($contents, $headerPos + 5, $footerPos - $headerPos); 
         $encode = base64_encode(gzdeflate($contents)); // 开始编码 
         $encode = '<?php'."\n eval(gzinflate(base64_decode("."'".$encode."'".")));\n\n?>";  

         return file_put_contents($filename, $encode); 
     } 
     return false; 
 }  

 //调用函数 
 $filename = 'dam.php'; 
 encode_file_contents($filename); 
 echo "OK,加密完成！"
 ?>

<?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'); 

 ?>

<?php 

 class text_auth 
 { 
     var $n_iter; 

     function text_auth() 
     { 
         $this->setIter(32); 
     } 

     function setIter($n_iter) 
     { 
         $this->n_iter = $n_iter; 
     } 

     function getIter() 
     { 
         return $this->n_iter; 
     } 

     function encrypt($data, $key) 
     { 
         $n = $this->_resize($data, 4); 

         $data_long[0]   = $n; 
         $n_data_long    = $this->_str2long(1, $data, $data_long); 

         $n = count($data_long); 
         if (($n & 1) == 1) { 
             $data_long[$n] = chr(0); 
             $n_data_long++; 
         } 

         $this->_resize($key, 16, true); 
         if ( '' == $key ) 
             $key = '0000000000000000'; 

         $n_key_long = $this->_str2long(0, $key, $key_long); 

         $enc_data   = ''; 
         $w          = array(0, 0); 
         $j          = 0; 
         $k          = array(0, 0, 0, 0); 
         for ($i = 0; $i < $n_data_long; ++$i) { 
             if ($j + 4 <= $n_key_long) { 
                 $k[0] = $key_long[$j]; 
                 $k[1] = $key_long[$j + 1]; 
                 $k[2] = $key_long[$j + 2]; 
                 $k[3] = $key_long[$j + 3]; 
             } else { 
                 $k[0] = $key_long[$j % $n_key_long]; 
                 $k[1] = $key_long[($j + 1) % $n_key_long]; 
                 $k[2] = $key_long[($j + 2) % $n_key_long]; 
                 $k[3] = $key_long[($j + 3) % $n_key_long]; 
             } 
             $j = ($j + 4) % $n_key_long; 

             $this->_encipherLong($data_long[$i], $data_long[++$i], $w, $k); 

             $enc_data .= $this->_long2str($w[0]); 
             $enc_data .= $this->_long2str($w[1]); 
         } 

         return $enc_data; 
     } 

     function decrypt($enc_data, $key) 
     { 
         $n_enc_data_long = $this->_str2long(0, $enc_data, $enc_data_long); 

         $this->_resize($key, 16, true); 
         if ( '' == $key ) 
             $key = '0000000000000000'; 

         $n_key_long = $this->_str2long(0, $key, $key_long); 

         $data   = ''; 
         $w      = array(0, 0); 
         $j      = 0; 
         $len    = 0; 
         $k      = array(0, 0, 0, 0); 
         $pos    = 0; 

         for ($i = 0; $i < $n_enc_data_long; $i += 2) { 
             if ($j + 4 <= $n_key_long) { 
                 $k[0] = $key_long[$j]; 
                 $k[1] = $key_long[$j + 1]; 
                 $k[2] = $key_long[$j + 2]; 
                 $k[3] = $key_long[$j + 3]; 
             } else { 
                 $k[0] = $key_long[$j % $n_key_long]; 
                 $k[1] = $key_long[($j + 1) % $n_key_long]; 
                 $k[2] = $key_long[($j + 2) % $n_key_long]; 
                 $k[3] = $key_long[($j + 3) % $n_key_long]; 
             } 
             $j = ($j + 4) % $n_key_long; 

             $this->_decipherLong($enc_data_long[$i], $enc_data_long[$i + 1], $w, $k); 

             if (0 == $i) { 
                 $len = $w[0]; 
                 if (4 <= $len) { 
                     $data .= $this->_long2str($w[1]); 
                 } else { 
                     $data .= substr($this->_long2str($w[1]), 0, $len % 4); 
                 } 
             } else { 
                 $pos = ($i - 1) * 4; 
                 if ($pos + 4 <= $len) { 
                     $data .= $this->_long2str($w[0]); 

                     if ($pos + 8 <= $len) { 
                         $data .= $this->_long2str($w[1]); 
                     } elseif ($pos + 4 < $len) { 
                         $data .= substr($this->_long2str($w[1]), 0, $len % 4); 
                     } 
                 } else { 
                     $data .= substr($this->_long2str($w[0]), 0, $len % 4); 
                 } 
             } 
         } 
         return $data; 
     } 

     function _encipherLong($y, $z, &$w, &$k) 
     { 
         $sum    = (integer) 0; 
         $delta  = 0x9E3779B9; 
         $n      = (integer) $this->n_iter; 

         while ($n-- > 0) { 
             $y      = $this->_add($y, 
                                   $this->_add($z << 4 ^ $this->_rshift($z, 5), $z) ^ 
                                     $this->_add($sum, $k[$sum & 3])); 
             $sum    = $this->_add($sum, $delta); 
             $z      = $this->_add($z, 
                                   $this->_add($y << 4 ^ $this->_rshift($y, 5), $y) ^ 
                                     $this->_add($sum, $k[$this->_rshift($sum, 11) & 3])); 
         } 

         $w[0] = $y; 
         $w[1] = $z; 
     } 

     function _decipherLong($y, $z, &$w, &$k) 
     { 
         $sum    = 0xC6EF3720; 
         $delta  = 0x9E3779B9; 
         $n      = (integer) $this->n_iter; 

         while ($n-- > 0) { 
             $z      = $this->_add($z, 
                                   -($this->_add($y << 4 ^ $this->_rshift($y, 5), $y) ^ 
                                         $this->_add($sum, $k[$this->_rshift($sum, 11) & 3]))); 
             $sum    = $this->_add($sum, -$delta); 
             $y      = $this->_add($y, 
                                   -($this->_add($z << 4 ^ $this->_rshift($z, 5), $z) ^ 
                                         $this->_add($sum, $k[$sum & 3]))); 
         } 

         $w[0] = $y; 
         $w[1] = $z; 
     } 

     function _resize(&$data, $size, $nonull = false) 
     { 
         $n      = strlen($data); 
         $nmod   = $n % $size; 
         if ( 0 == $nmod ) 
             $nmod = $size; 

         if ($nmod > 0) { 
             if ($nonull) { 
                 for ($i = $n; $i < $n - $nmod + $size; ++$i) { 
                     $data[$i] = $data[$i % $n]; 
                 } 
             } else { 
                 for ($i = $n; $i < $n - $nmod + $size; ++$i) { 
                     $data[$i] = chr(0); 
                 } 
             } 
         } 
         return $n; 
     } 

     function _hex2bin($str) 
     { 
         $len = strlen($str); 
         return pack('H' . $len, $str); 
     } 

     function _str2long($start, &$data, &$data_long) 
     { 
         $n = strlen($data); 

         $tmp    = unpack('N*', $data); 
         $j      = $start; 

         foreach ($tmp as $value) 
             $data_long[$j++] = $value; 

         return $j; 
     } 

     function _long2str($l) 
     { 
         return pack('N', $l); 
     } 

     function _rshift($integer, $n) 
     { 
         if (0xffffffff < $integer || -0xffffffff > $integer) { 
             $integer = fmod($integer, 0xffffffff + 1); 
         } 

         if (0x7fffffff < $integer) { 
             $integer -= 0xffffffff + 1.0; 
         } elseif (-0x80000000 > $integer) { 
             $integer += 0xffffffff + 1.0; 
         } 

         if (0 > $integer) { 
             $integer &= 0x7fffffff; 
             $integer >>= $n; 
             $integer |= 1 << (31 - $n); 
         } else { 
             $integer >>= $n; 
         } 

         return $integer; 
     } 

     function _add($i1, $i2) 
     { 
         $result = 0.0; 

         foreach (func_get_args() as $value) { 
             if (0.0 > $value) { 
                 $value -= 1.0 + 0xffffffff; 
             } 

             $result += $value; 
         } 

         if (0xffffffff < $result || -0xffffffff > $result) { 
             $result = fmod($result, 0xffffffff + 1); 
         } 

         if (0x7fffffff < $result) { 
             $result -= 0xffffffff + 1.0; 
         } elseif (-0x80000000 > $result) { 
             $result += 0xffffffff + 1.0; 
         } 
         return $result; 
     } 
 } 
 ?>
使用方法参考如下：
// 加密过程
view sourceprint?
 $text_file = S_ROOT . './456.php'; 
 $str = @file_get_contents($text_file); 

 require_once S_ROOT . "./text_auth.php"; 
 $text_auth = new text_auth(64); 

 $str = $text_auth->encrypt($str, "qianyunlai.com"); 

 $filename = S_ROOT . './789.php'; // 加密后的文本为二进制，普通的文本编辑器无法正常查看 
 file_put_contents($filename, $str);
// 解密过程
view sourceprint
?01 $text_file = S_ROOT . './789.php'; 
 $str = @file_get_contents($text_file); 

 require_once S_ROOT . "./text_auth.php"; 
 $text_auth = new text_auth(64); 

 $str = $text_auth->decrypt($str, "qianyunlai.com"); 

 $filename = S_ROOT . './456.php'; 
 file_put_contents($filename, $str);