https://developers.weixin.qq.com/doc/oplatform/Third-party_Platforms/Message_Encryption/Message_encryption_and_decryption.html

开发者可以在微信公众平台接口调试工具，在接口类型中选择“消息接口调试”，并选择安全模式的加密调试，进行消息加解密的在线调试。

微信公众平台接口调试工具：https://mp.weixin.qq.com/debug