So you’re trying to have HTTPS requests going to your backend servers? It should be pretty straightforward:
server s1 192.168.1.1:443
Still, it’s rather unusual, to say the least. Is there a reason for not using your proxy as an SSL termination OR use L4 at the haproxy level and do all the SSL decryption and encryption on the backend servers? I’m asking this because right now, the traffic hits your HAProxy encrypted, it gets decrypted so the proxy can see what’s going on with the request, it get encrypted again, sent to the backend server which decrypts it and does some stuff… You’re basically doing one encrypt / decrypt cycle with no apparent gain and you’re using CPU cycles that could be put to better use.