PHP source code encryption method

<?php
function RandAbc($length=""){//返回随机字符串
 
 
  $str="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
  return str_shuffle($str);
  
}
 
 
$filename=&#39;index.php&#39;;
 
 
$T_k1=RandAbc();//随机密匙1
 
 
$T_k2=RandAbc();//随机密匙2
 
 
$vstr=file_get_contents($filename);//要加密的文件
 
 
$v1=base64_encode($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";
$s=&#39;$&#39;.$q6.&#39;=urldecode("%6E1%7A%62%2F%6D%615%5C%76%740%6928%2D%70%78%75%71%79%2A6%6C%72%6B%64%679%5F%65%68%63%73%77%6F4%2B%6637%6A");$&#39;.$q1.&#39;=$&#39;.$q6.&#39;{3}.$&#39;.$q6.&#39;{6}.$&#39;.$q6.&#39;{33}.$&#39;.$q6.&#39;{30};$&#39;.$q3.&#39;=$&#39;.$q6.&#39;{33}.$&#39;.$q6.&#39;{10}.$&#39;.$q6.&#39;{24}.$&#39;.$q6.&#39;{10}.$&#39;.$q6.&#39;{24};$&#39;.$q4.&#39;=$&#39;.$q3.&#39;{0}.$&#39;.$q6.&#39;{18}.$&#39;.$q6.&#39;{3}.$&#39;.$q3.&#39;{0}.$&#39;.$q3.&#39;{1}.$&#39;.$q6.&#39;{24};$&#39;.$q5.&#39;=$&#39;.$q6.&#39;{7}.$&#39;.$q6.&#39;{13};$&#39;.$q1.&#39;.=$&#39;.$q6.&#39;{22}.$&#39;.$q6.&#39;{36}.$&#39;.$q6.&#39;{29}.$&#39;.$q6.&#39;{26}.$&#39;.$q6.&#39;{30}.$&#39;.$q6.&#39;{32}.$&#39;.$q6.&#39;{35}.$&#39;.$q6.&#39;{26}.$&#39;.$q6.&#39;{30};eval($&#39;.$q1.&#39;("&#39;.base64_encode(&#39;$&#39;.$q2.&#39;="&#39;.$c.&#39;";eval(\&#39;?>\&#39;.$&#39;.$q1.&#39;($&#39;.$q3.&#39;($&#39;.$q4.&#39;($&#39;.$q2.&#39;,$&#39;.$q5.&#39;*2),$&#39;.$q4.&#39;($&#39;.$q2.&#39;,$&#39;.$q5.&#39;,$&#39;.$q5.&#39;),$&#39;.$q4.&#39;($&#39;.$q2.&#39;,0,$&#39;.$q5.&#39;))));&#39;).&#39;"));&#39;;
 
$s=&#39;<?
&#39;.$s.
&#39;
 ?>&#39;;
 
echo $s;
//生成 加密后的PHP文件
$fpp1 = fopen(&#39;temp&#39;.$filename,&#39;w&#39;);
fwrite($fpp1,$s) or die(&#39;写文件错误&#39;);
 
?>

<? $O00OO0=urldecode("%6E1%7A%62%2F%6D%615%5C%76%740%6928%2D%70%78%75%71%79%2A6%6C%72%6B%64%679%5F%65%68%63%73%77%6F4%2B%6637%6A");$O00O0O=$O00OO0{3}.$O00OO0{6}.$O00OO0{33}.$O00OO0{30};$O0OO00=$O00OO0{33}.$O00OO0{10}.$O00OO0{24}.$O00OO0{10}.$O00OO0{24};$OO0O00=$O0OO00{0}.$O00OO0{18}.$O00OO0{3}.$O0OO00{0}.$O0OO00{1}.$O00OO0{24};$OO0000=$O00OO0{7}.$O00OO0{13};$O00O0O.=$O00OO0{22}.$O00OO0{36}.$O00OO0{29}.$O00OO0{26}.$O00OO0{30}.$O00OO0{32}.$O00OO0{35}.$O00OO0{26}.$O00OO0{30};eval($O00O0O("JE8wTzAwMD0iUWFLRlBtWFdaaGtJeWZUckJFdWxOUlNvSll0QWRwc0hxVm54dkxiT0RjVWp6Q0dpd01lZ25IRE1za0tSeGxoZmlhcWpUekJ5SXV3U2RnR0pBUE90cHZYVUZRTkNtZVlXRWNvYnJaTFZzbThJY2t1eXhreUJ4d0pTZDFUYVlpZU9mTVRUdnpsYVkwdm5udmRUdno5d0RxT0lja3V5eGt5Qnh3SlNkMWRzcTFuWFFjSmJRYjhiRHFPSWNYSXlBTTlQTmtJT0FSdXlLM1RsQW9WU1loOXN2Y0pCWU05cWZjNFhSa3ZCeGNlVlF5VGFZaUpCWWg5c3ZjNVh4S3VhSFI1V050dmh4djlyZ0t1U0RjaFBDcjBEZWt2VUFSeWl4djlGTmtJeWZNZHNxMW5CZDFQeU5rbkZxbzlseG92aVFYVFNlY2U3bW5QaXhLTTFIS2R5SzI5QmcyWVZZaDlzdmM0WHhYdkJnM3VQTjI0RnhYdkJnM3VQTjI0QmVvbHJkRU9JY3lQeU5rdWFxbzlseG92aUNXUE9OMk1objJVbGUzWlNkMVB5Tmt1YVkydkVlMnlGTmJlUENyMERSa3ZCeE05Wk4yTWh4S2Y2Q2tVRmdSdW1Ob01FZWlWWFJrdkJ4TTl6Z2JlUENyMERSa3ZCeE05Wk4yTWh4S2Y2Q2tVRmdSdW1Ob01FZWlWWFJrdkJ4TTltTjI1a0hSQWF3UjVQZGloN2ZKMERkb0lGTmt4UHhpSjlmbzV5QWlUSHhSNWhLMElGTmt4UHgxOWROa2hTZGk0RkhSNVdRMklGTmt4UHhpNVBOa2hYUWNKWHgydkJ4S2RsTmNlUENyMERkb3ViZm0wVlJrdkJ4TTl6Z1dTNnhrTVdBbzlpTHdWaGcyOUJ4a3lYUXE1aGdiMCtnUnVsZXR1eWVicmhnMjlCeGt5WFFxNWhnYjArZzI5QnhreVhRcTUwTjBNaWVrTTVEY2hQQ3IwRFJrdkJ4TTlxeEtJRUhSOUJDV1BFQW9NaUFjVlBDcjBEZkowRGR0SXllM0lQTjI0VnN3VEJ4S2VWUmt2QnhNOXF4S0lFSFI5QkswNWxOUnZFZW9NV3h3Vlhla1VHZWllUENpSlZtblNJY1hkeWVLdlBla3ZhTjI1V3h3VHdxMDlZUWJBUE5rWkZIUk1XZzJ2RWVpNXJIdEpYQ3IwRG4ybHlnMkdQTmtBZGVjVlBDcjBEZWt2VUFSeWl4djlGTmtJeWZNZHNxMW5CZDJseWdSdXllYjVySHRKWENyMERtblBQeGJKU2RNOW5xMUlZUmlBWE4zdUZBS2RPZDEwUExyMERtblNoeDN2aU5tMTFla1VoeFJJRnhvWVNkTTlucTFJWVJpQVhOM3VGQUtkT2QxMFBDcjBEbW5QOXhSVUV4S09JY2J1WEFLZE9zd2VCUTJJRk5vVXlnM3VQTjI0RnFveWJla01pTFlkRk4yR0VRWFRTZWNlN21uUDltblNJY2J1WEFLZE9zd0FoZ1I5U2dSNVhRWFRTZWNlN21uUy9zVjBEc3RJV2VreXJBbTRWQWtNaWZvMUVzcXIvc3d1RXhLSUVIUjlCUXE1RUhSbi9zV3JGZTJJaUhLVDBzYkpJY1dVa2VrTUd4S0l5QWNUaU4zQUVzd2YySWNycGZiSlZ4WGRsTlJ2Yk4zZGh4S2Y5Zmg1c2ZiVGJOM2RoeEtmOWZXSmJmb3hpZ1IxeWUzVGxnMnlCeEUwYlpjZittblNkc294aWdSMXlmdElpZ0UwYmdSdUdIUjVhQW85clFYVFNlY2ZWTms5aXhLSVBMa1k5Zms1RmVrdkVIS1B5ZmJUa2VrTUd4UmRGZWt1eWVXMGJxaDhiZm81bE5SWTlmWHVGZXp4aWdSMXlmYlRFZzNkRk5vVVBOa2U5Zms1RmZiVEdnS2RYSFI1M0hSdTBIbTBiWmNmVk5STWl4MnlCSG92UHgybDBzd2ZyZmJUMGdLZFh4S245ZmsxbEhSNGJmYzgrbW5TVmZjSlZmY0pJY2JKVnNveGlnUjF5ZTJ2MGZvSUZOdFo5Zld6MlpjcjNRY1NiZmNUaU4zQUVzd2Y0SVduT0RiZlZIUm45Zmt4aWdSMXlmVzRJY1ZoOHhYZGxOUllWZTNkV3N3ZE94UngwUVhUU2VjZlZOa01HeHEwYk5vdmtBenhpZ1IxeWZiVEJOM2R5ZTJ5NnhxMGJOazlpeEtJUExrWWJmbzFsZWtBUE5YQVB4dHVTc3dmcmZiVEdnS2RYSFI1U3hSeVhIdG45ZldKYmZveGlnUjF5Z2s5aXhvdmlzd2ZyZmJURWczZEZOb1VQTmtlOWZrNUZmYlQwZ0tkWHhLbjlmazFsSFI0YmZjOCttblNkc294aWdSMXlmdElpZ0UwYmUzQVBBb0lTeFhkbE5SWUJIdHVHTmNmVk5rTUd4cTBiTlJ5aHVYZGxOUlliZmNKVnhYZGxOUnZiTjNkaHhLZjlmV0piZnRJV2VrOU9Ob3lCeEUwYk5rOGJmbzVGZWt2RUhLUHlzd2RCTjNkeWUyeTZ4d2ZWSFJuOWZrMVB4enhpZ1IxeWZiVDBIS3VPeHEwYk5SeWh1WGRsTlJZYmZjOCtmSjBEZmNKVmZjSlZmY0o4eFhkbE5SWVZlM2RXc3dmOHNFMGh4M3ZpTm04K2ZiSlZOazlpeEtJUExrWTlmazVGZWt2RUhLUHlmYlRrZWtNR3hSZEZla3V5ZVcwYnFoOGJmbzVsTlJZOWZrMWxIUjRiZm95aHN3QUdnUnlCZGlURWczZEZOb1VQTmtlOWZrTUJBbzhiZm8xbGVrQVBOWEFQeHR1U3N3ZnJmYlRHZ0tkWEhSNVN4UnlYSHRuOWZXSmJmY1QwZ0tkWHhLbjlmeTlFeFJVa2ZiSkZzVjBEZmNKOHhYZGxOUllWZTNkV3N3ZHZOWHVQQW9VeXh6eGlnUjF5UXFmNWZXNDh4WGRsTlJZVmUzZFdzd2R2Tlh1UEFvVXl4enhpZ1IxeVFxWnJmVzQ4eFhkbE5SWVZlM2RXc3dkdk5YdVBBb1V5eHp4aWdSMXlRcVlic1dyRnhYZGxOUnZFeEtuK21uUzhRMnhpZ1IxeWUydjBzVjBEc281RnhYZGxOUnZFc1dVYk4ydTVzV3pVbW5TOFEyZEZ4dGgrc2M5Qk4yeGlnUjF5ZUU0SWNiSlZmSjBEZkowRG1uU0ljV3JGSHR1R05tNEljVj09IjtldmFsKCc/PicuJE8wME8wTygkTzBPTzAwKCRPTzBPMDAoJE8wTzAwMCwkT08wMDAwKjIpLCRPTzBPMDAoJE8wTzAwMCwkT08wMDAwLCRPTzAwMDApLCRPTzBPMDAoJE8wTzAwMCwwLCRPTzAwMDApKSkpOw==")); ?>