php 解密小程序获取unionid

小程序代码

php代码

public function login2()
    {
        $post = input();
        if (!empty($post)) {
            $appid = $this->wxappid;
            $secret = $this->wxsecret;
            if(isset($post['code']))                $code        = $post['code'];
            if(isset($post['iv']))                  $iv          = $post['iv'];
            if(isset($post['rawData']))             $rawData     = $post['rawData'];
            if(isset($post['signature']))           $signature   = $post['signature'];
            if(isset($post['encryteData']))       $encryptedData = $post['encryteData'];
            $url = "https://api.weixin.qq.com/sns/jscode2session?appid=" . $appid . "&secret=" . $secret . "&js_code=" . $code . "&grant_type=authorization_code";
            $weixin = file_get_contents($url);
            $jsondecode = json_decode($weixin);
            $res = get_object_vars($jsondecode);
            $sessionKey = $res['session_key'];//取出json里对应的值
　　　　　　　　// 验证签名
            $signature2 = sha1(htmlspecialchars_decode($rawData) . $sessionKey);
            if ($signature2 !== $signature) return json("signNotMatch");

            $data = [];

            $errCode = $this->decryptData($encryptedData, $iv, $sessionKey, $data);

            if ($errCode == 0) {
                return $data;
            } else {
                return json('获取失败');
            }
        }
    }
    public function decryptData( $encryptedData, $iv,$sessionKey, &$data )
    {
        if (strlen($sessionKey) != 24) {
            return json('sessionKey错误');
        }
        $aesKey=base64_decode($sessionKey);

        if (strlen($iv) != 24) {
            return json('iv错误');
        }
        $aesIV=base64_decode($iv);
        $aesCipher=base64_decode($encryptedData);
        $result=openssl_decrypt( $aesCipher, "AES-128-CBC", $aesKey, 1, $aesIV);
        $dataObj=json_decode( $result );
        if( $dataObj  == NULL )
        {
            return json('IllegalBuffer错误');
        }
        if( $dataObj->watermark->appid != $this->wxappid )
        {
            return json('IllegalBuffer错误');
        }
        $data = $result;
        return  $data;
    }