There are a couple of ways to do it.
See the SIP wiki topic about Reverse proxy:
https://github.com/Dan-in-CA/SIP/wiki/Reverse-proxy
You might also look at the web.py docs:
http://webpy.org/cookbook/ssl
See the section under web.py 0.37
SIP will be moving to web.py 0.4 in order to be Python 3 compatible. Then you can use the instructions for that version of web.py.
If you want to access SIP remotely another option is to install PiVPN:
http://www.pivpn.io/
That will give you secure access from anywhere in the world where there is an internet connection.
See the SIP wiki topic about Reverse proxy:
https://github.com/Dan-in-CA/SIP/wiki/Reverse-proxy
You might also look at the web.py docs:
http://webpy.org/cookbook/ssl
See the section under web.py 0.37
SIP will be moving to web.py 0.4 in order to be Python 3 compatible. Then you can use the instructions for that version of web.py.
If you want to access SIP remotely another option is to install PiVPN:
http://www.pivpn.io/
That will give you secure access from anywhere in the world where there is an internet connection.