这个字符串转换类用处大吗？

转换|字符串

PHP代码:--------------------------------------------------------------------------------
<?
/**
* 字符串转换类
* 著作人：Michael Young
* 日 期：2002-4-21
* E-Mail：windring@yeah.net
* 版权所有
*/
class ExtendString{

var $keyWord="ilovechenyingmm.";

//获取密码
function getPassword(){
if (file_exists("admin.ini")==1){
$file=fopen("admin.ini","r");
fseek($file,31);
$buffer=fgets($file,4096);
fclose($file);
//return $buffer;
return $this->decrypt($buffer); //解密
}else
return "filenoexist";
}

//设置密码
function setPassword($password){
if (file_exists("admin.ini")==1){
$file=fopen("admin.ini","w");
$wStr="[admin password]\nadminPassWord=".$this->encrypt($password);
$wStr.="\n\n#不要随意更改该文件，否则会导致系统无法正常运行";
$result=fwrite($file,$wStr);
fclose($file);
return $result;
}else
return 0;
}

//加密
function encrypt($password){
$keyWord="ilovechenyingmm."; $i=strlen($password);
if ($i<16){
for($j=0;$j<16-i;$j++)
$password=$password." ";
}
$nostr=$password;
for($j=0;$j<strlen($password);$j++){
$c1=substr($password,$j,1);
$c=substr($keyWord,$j,1);
$c2=(ord($c))^(ord($c1));
if (strlen($c2)<=1)
$c2="00".$c2;
if (strlen($c2)==2)
$c2="0".$c2;
$s1.=$c2;
}
return $s1;
}

//解密
function decrypt($password){
$keyWord="ilovechenyingmm.";
$i=strlen($password);
$s1="";
$stemp="";
for ($j=0;$j<$i/3;$j++){
$stemp=substr($password,$j*3,3);
$c=substr($keyWord,$j,1);
$c1=chr((ord($c))^$stemp);
$s1.=$c1;
}
return trim($s1);
}
}
?>