haproxy can do this out of the box. I've been using it for some time to put SSH on port 443 as a backup (not an alternative). frontend mux mode

haproxy can do this out of the box. I've been using it for some time to put SSH on port 443 as a backup (not an alternative). frontend mux mode tcp bind EXTERNAL_IP_HERE:443 acl is_tls req.ssl_ver gt 3 acl is_ssh payload(0,8) -m str SSH-2.0- tcp-request inspect-delay 5s tcp-request content accept if is_ssh tcp-request content accept if is_tls use_backend ssh if is_ssh use_backend https if is_tls where 'ssh' and 'https' are tcp mode backends.