前端 提交加密token 防止有心人刷

<?php
/**
 * Created by PhpStorm.
 * User: andy
 * Date: 2018/4/3
 * Time: 14:17
 */
namespace CommonModelDataModel;
class CheckTokenModel
{
    private $key='sdksjfkdsgshhbdbvdjvbdvvoisjvnvohsvsnj';//密钥
    private $time=300;//token过期秒数

    /**
     * @desc 创建token
    */
    public function creatToken($type) {

        list($usec, $sec) = explode(" ", microtime());
        $time=((float)$usec + (float)$sec);

        $str = md5(session_id().$time*1000000).time();//生成token的原始字符串
        $key = md5($this->key);//密钥

        $code=$this->encrypt($str, 'E', $key);

        session('TOKEN', $code);
        return session('TOKEN');
    }

    /**
     * @desc 校验token
     */
    public function checkToken($token,$type_token='') {
        if(empty($token))
            return FALSE;

        //校验token是否已经过期
        $originalToken=$this->encrypt($token, 'D', md5($this->key));
        $originalTimestamps=substr($originalToken,32);

        if($originalTimestamps+$this->time<time())
            E('110103');
        if ($token == session('TOKEN')) {
            session('TOKEN',null);
            return TRUE;
        } else {
            return FALSE;
        }

    }
    /**
     * @desc 加密/加密 （E/D）
    */
    function encrypt($string,$operation,$key=''){
        $key=md5($key);
        $key_length=strlen($key);
        $string=$operation=='D'?base64_decode($string):substr(md5($string.$key),0,8).$string;
        $string_length=strlen($string);
        $rndkey=$box=array();
        $result='';
        for($i=0;$i<=255;$i++){
            $rndkey[$i]=ord($key[$i%$key_length]);
            $box[$i]=$i;
        }
        for($j=$i=0;$i<256;$i++){
            $j=($j+$box[$i]+$rndkey[$i])%256;
            $tmp=$box[$i];
            $box[$i]=$box[$j];
            $box[$j]=$tmp;
        }
        for($a=$j=$i=0;$i<$string_length;$i++){
            $a=($a+1)%256;
            $j=($j+$box[$a])%256;
            $tmp=$box[$a];
            $box[$a]=$box[$j];
            $box[$j]=$tmp;
            $result.=chr(ord($string[$i])^($box[($box[$a]+$box[$j])%256]));
        }
        if($operation=='D'){
            if(substr($result,0,8)==substr(md5(substr($result,8).$key),0,8)){
                return substr($result,8);
            }else{
                return'';
            }
        }else{
            return str_replace('=','',base64_encode($result));
        }
    }
}