接口中的 sort排序 + md5加密

<?php
/**
 * Created by PhpStorm.
 * User: Shinelon
 * Date: 2019/3/22
 * Time: 21:18
 */

namespace frontend\controllers;


use yii\rest\ActiveController;

class SignController extends ActiveController
{
    public $modelClass='';
    public function actionGetSign(){
        $secret='1609phpB';
        //接值
        $username=\Yii::$app->request->post('username');
        $password=\Yii::$app->request->post('password');
        $rand=rand(11111,99999);
        $time=time();
        //拼到数组里
        $arr=[
            'username'=>$username,
            'password'=>$password,
            'rand'=>$rand,
            'time'=>$time
        ];

        //进行排序
        ksort($arr);

        $str='';

        foreach ($arr as $k=>$v){
            $str .="$k=$v&";
        }
        $last_str=substr($str,0,-1);

        //进行md5加密
        $md_str=md5($last_str);
        $sign=md5($md_str.$secret);
        return $sign;

    }

}