Using haproxy for TLS layer

This article explains how to use haproxy to add a TLS layer to any TCP protocol. This includes http or gopher. The following example explains the minimal setup required in order to make it work, haproxy has a lot of options and I won’t use them.

The idea is to let haproxy manage the TLS part and let your http server (or any daemon listening on TCP) replying within the wrapped connection.

You need a simple haproxy.cfg which can looks like that:

defaults
        mode    tcp
        timeout client 50s
        timeout server 50s
        timeout connect 50s
    
frontend haproxy
        bind *:7000 ssl crt /etc/ssl/certificat.pem
        default_backend gopher
    
backend gopher
        server gopher 127.0.0.1:7070 check

The idea is that it waits on port 7000 and will use the file /etc/ssl/certificat.pem as a certificate, and forward requests to the backend on 127.0.0.1:7070. That is ALL. If you want to do https, you need to listen on port 443 and redirect to your port 80.

The PEM file is made from the privkey concatenated with the fullchain certificate. If you use a self signed certificate, you can make it with the following command:

cat secret.key certificate.crt > cert.pem

One can use a folder with PEM certificates files inside instead of using a file. This will allow haproxy to receive connections for ALL the certificates loaded.

For more security, I recommend using the chroot feature and a dh file but it’s out of the current topic.