APP支付验签错误

参数如下:biz_content=%7B%22product_code%22%3A%22QUICK_MSECURITY_PAY%22%2C%22method%22%3A%22alipay.trade.app.pay%22%2C%22out_trade_no%22%3A%22201910231728481159%22%2C%22total_amount%22%3A%221%22%2C%22subject%22%3A%22%E4%BC%A0%E8%81%94%E6%9C%8D%E5%8A%A1%22%2C%22timeout_express%22%3A%2230m%22%2C%22body%22%3A%22%E4%BC%A0%E8%81%94%E6%9C%8D%E5%8A%A1%22%7D&method=alipay.trade.app.pay&charset=utf-8&version=1.0&notify_url=http://255.255.255.255/api/alipay/notify&app_id=2019081366205325&timestamp=2019-10-23 17:28:48&format=json&sign_type=RSA2&sign=EbzT1g1UNsAblubjSFbfxEgj3cbi+s1jbzofv8IhyL/7KrfYpsA7SKfEN354PO0Gr5pn2ISyg8qLScp+1I8Zy3Oxs7WPefY3XAG1Q0IUI+VBm1Yb27DCNLm8LsjNjj88xa32NGKRYg6bZYQ9n1Zww4Vin7cstgJbY2M6nIF7fv1Mh32p44s1902mu59FMquq+lFSZWhwoW40bRd0PmHyLh4ln0moDXCwESPKuP6RollbUC58/nm36Rt0MTLTQEVTmad7SguD2Qmp6ZxkncuZnYdZcyaj6HJGqMZ8oVT1yczaQ/lNUl0OtcSs8BtDtNX7D7YTMgM/yJxZvN2T0qsClg==

不知道是参数错误还是签名错误，希望有遇到过的大佬解答，谢谢！