MQTT双向认证

Android MQTT TLS/SSL 认证：https://blog.csdn.net/emqx_broker/article/details/109801569

implementation 'org.bouncycastle:bcpkix-jdk15on:1.59'

Android中关于The BC provider no longer provides  https://blog.csdn.net/xhlyp3/article/details/109112674

JcaPEMKeyConverter converter = new JcaPEMKeyConverter();//.setProvider("BC");

Unacceptable certificate: CN=Server

android 10以上 自签名证书，SSL报错Unacceptable certificate，android 9 以下正常 问题解决

https://blog.csdn.net/fab357103354/article/details/105867042