I have a question. I have a desktop computer with Ubuntu 16.4 installed. What I want is that I want to synchronize my appointments /to do list and all my contacts from my android (LineageOS) mobile phone via Davdroid with Thunderbird on my PC. For this I have installed Nextcloud Server 12.0.2 on my PC. Now, my question is whether you would use ssl/tls for this,
I thank you for your answers
SSL is recommended, indeed. If you’re looking at syncing outside of your network you’ll also need to open up firewall ports directly against that PC.
Keep in mind that Davdroid doesn’t like working with self signed certificates, so I’d recommend using a certificate from a Certificate Authority (CA). Let’s Encrypt is a free CA that has multiple options for certificate update clients that’ll work on Ubuntu.
You didn’t mention whether you have a domain or not. CAs can only issue certificates for domains, not IPs. You should definitely use TLS, but you’ll need a domain. Just get a free one if you need to. (I’m using a free .tk domain.)
Also, just as a reminder, you configure TLS in your webserver (Apache/Nginx), it’s not a Nextcloud setting.
Like you, I’m syncing my phone (Cyanogenmod) calendar and contacts with Thunderbird (Lightning and Cardbook). After getting it working unencrypted, I then got it working with self signed certs. Self signed certs are a pain though, and lots of apps refuse to work with them, so I switched to Let’s Encrypt once they went public.
Good luck! I hope you get it all working