ssl

https://developer.apple.com/documentation/security/secure_transport/using_the_secure_socket_layer_for_network_communication

https://github.com/qinlaoban/Scoket_ssl

https://blog.csdn.net/ws_752958369/article/details/83719253

https://stackoverflow.com/questions/38761837/ios-ssl-connection-in-swift

https://developer.apple.com/library/archive/documentation/Networking/Conceptual/CFNetwork/Introduction/Introduction.html#//apple_ref/doc/uid/TP30001132

https://developer.apple.com/library/archive/documentation/NetworkingInternetWeb/Conceptual/NetworkingOverview/SecureNetworking/SecureNetworking.html