This does not rewrite URLs like a reverse proxy but can be useful for viewing a single page.
OSX - install with Homebrew
$ brew install socat
RHEL/CentOS
$ yum install socat
Export the internal host's name or IP address
$ export HOST=internal.localdomain
Using socat you can decrypt the encrypted address.
$ sudo socat TCP4-LISTEN:80,fork,reuseaddr OPENSSL:${HOST}:443,verify=0
In another terminal window/tab run ngrok so you can access the intenal host from a publically accessible address.
$ ngrok http -host-header=${HOST} 127.0.0.1:80