Title: SNI-based cert selection in TLS transport socket
Description:
Current Envoy selects cert by selecting filter chain based on SNI, it doesn’t support cert selection based on SNI inside one tls transport socket. But it is possible that we access different services via one filter chain, bumping is such a case since we will attach multiple mimic certs to one tls transport socket. Therefore,we need to implement SNI-based cert selection in transport socket.
cc @ggreenway @mattklein123