aes_256_cbc is not secure in TLS Scenes, when will we support GCM/CCM model？

[terryhy520]

AES CBC model is not secure in TLS1.2, and it's unsupported in http2：
TLS 1.2 Cipher Suite Black List
AES GCM/CCM is considered more secure, is there any plan to support AES GCM?
@agentzh