支付宝异步回调结果包含中文乱码导致验签失败 about pay HOT 10 CLOSED

$alipay = Pay::alipay()->app($config_order);

return show('1', "请求成功", ['sign' => $alipay]);

{
    "status": "1",
    "message": "请求成功",
    "data": {
        "sign": {
            "headers": {}
        }
    }
}

Response {#444
  +headers: ResponseHeaderBag {#445
    #computedCacheControl: array:2 [
      "no-cache" => true
      "private" => true
    ]
    #cookies: []
    #headerNames: array:2 [
      "cache-control" => "Cache-Control"
      "date" => "Date"
    ]
    #headers: array:2 [
      "cache-control" => array:1 [
        0 => "no-cache, private"
      ]
      "date" => array:1 [
        0 => "Thu, 28 Dec 2017 10:22:33 GMT"
      ]
    ]
    #cacheControl: []
  }
  #content: "app_id=2017090608590288&method=alipay.trade.app.pay&format=JSON&charset=utf-8&sign_type=RSA2&version=1.0&return_url=&notify_url=http%3A%2F%2Fwww.mitte.cn%2Fapi%2Falipay%2Fnotify&timestamp=2017-12-28+18%3A22%3A33&sign=A2xEa6%2FiN2o21kD8PU4Ao95NF05%2BkmarT7wJ9b5RbpjSrvZqm0%2BSYR4hAnIzr9PgDBBQtoGIwujr%2F9eIxg%2Fvj4oyHuSxCF%2FkqBXZhqBqY4B0A%2FzEXOpfg%2BflKBrZDFn5bIUAecTf1vYTNgmHNH%2BRMa95Kb61psWuraBTnJLHXrz40wUm23Oc0ZSLTfT6trJ%2BrRyJa9pFDHG53nVYgBLrdXmVPaL4OmSUxMEALOiV%2FNVamfhPDlMXxbezIkXRRyr1JxC6eiFotnwPuXMsCuDg4Hm7%2BXv%2FHfDjEgmHZBbSGUoq31ByDCD0Yo4Xh%2B1FjA6ddni%2FSqXqcfzVx25p0I8Wlg%3D%3D&biz_content=%7B%22out_trade_no%22%3A15134884178798981%2C%22total_amount%22%3A%221199.00%22%2C%22subject%22%3A%22LIEMOCH%5Cu5229%5Cu9a6c%5Cu8d6b+%5Cu7231%5Cu52d2%5Cu7cfb%5Cu5217+%5Cu8de8%5Cu754c%5Cu5b9a%5Cu5236%5Cu62c9%5Cu6746%5Cu7bb1%22%2C%22product_code%22%3A%22CURITY_PAY%22%7D"
  #version: "1.0"
  #statusCode: 200
  #statusText: "OK"
  #charset: null
}