private ClientAuth whichClientAuthEnum(ChannelHandlerContext ctx) {
        SslHandler sslhandler = ctx.channel().pipeline().get(SslHandler.class);
        if (sslhandler == null) {
            return ClientAuth.NONE;
        }

        ClientAuth clientAuth;
        if (sslhandler.engine().getNeedClientAuth()) {
            clientAuth = ClientAuth.REQUIRE;
        } else if (sslhandler.engine().getWantClientAuth()) {
            clientAuth = ClientAuth.OPTIONAL;
        } else {
            clientAuth = ClientAuth.NONE;
        }
        return clientAuth;
    }
Stores info about the client and server's SSL certificates in the context, after a successful handshake.
<p>
User: michaels@netflix.com Date: 3/29/16 Time: 10:48 AM
zuul-core/src/main/java/com/netflix/zuul/netty/server/ssl/SslHandshakeInfoHandler.java