分享一個PHP加密解密的類

 
class ption
{


private static $original = array('=', '+', '/');
private static $later = array('O0O0O', 'o0O0o', 'oo00o');

function __construct()
{

}

private static function md5($skey = '')
{
    $skey = $skey ? $skey : 'ui' ; //uicms::_config('security/authkey');        
    return md5(substr($skey, 0, 16));
}

/**
* @use ption::en($string, $key);
* @param String $string 需要加密的字串
* @param String $skey 密鑰
* @param int $expiry 密文有效期, 加密時候有效， 單位 秒，0 為永久有效
* @return String
*/
static public function en($string = '', $skey = '', $expiry=0)
{       
    if( is_array( $string ) )
    {
        $string = json_encode($string); // uicms::json($string, true, 'en');
    }               
    $string = str_pad($expiry ? $expiry + TIME : 0, 10, 0).$string;     
    $strArr = str_split(base64_encode($string));
    $strCount = count($strArr);     
    $skey = static::md5($skey);     
    foreach (str_split($skey) as $key => $value)
    {
        $key < $strCount && $strArr[$key].=$value;
    }
    return str_replace(self::$original, self::$later, join('', $strArr));
}

/**
* @use ption::de($string, $key);
* @param String $string 需要解密的字串
* @param String $skey 密鑰
* @return String
*/
static public function de($string = '', $skey = '')
{       
    $strArr = str_split(str_replace(self::$later, self::$original, $string), 2);
    $strCount = count($strArr);
    $skey = static::md5($skey);
    foreach (str_split($skey) as $key => $value)
    {
        $key <= $strCount && $strArr[$key][1] === $value && $strArr[$key] = $strArr[$key][0];
    }       
    $result = base64_decode(join('', $strArr));         
    if(substr($result, 0, 10) == 0 || substr($result, 0, 10) - TIME > 0)
    {
        return substr($result, 10);
    }
    else
    {
        return false;
    }       
}   

}
</pre>