https://developers.weixin.qq.com/doc/oplatform/Third-party_Platforms/2.0/api/Before_Develop/Technical_Plan.html

msg_encrypt = Base64_Encode( AES_Encrypt[ random(16B) + msg_len(4B) + msg + AESKey] )

存在误导用户

msg_encrypt=Base64_Encode(AES_Encrypt [random(16B)+ msg_len(4B) + msg + ])

直接缺了个参数

实际值为：

msg_encrypt = Base64_Encode( AES_Encrypt[ random(16B) + msg_len(4B) + msg + AppId] )